1328 Commits

Author SHA1 Message Date
Linus Torvalds
d6b02199cd - The 7 patch series "powerpc/crash: use generic crashkernel
reservation" from Sourabh Jain changes powerpc's kexec code to use more
   of the generic layers.
 
 - The 2 patch series "get_maintainer: report subsystem status
   separately" from Vlastimil Babka makes some long-requested improvements
   to the get_maintainer output.
 
 - The 4 patch series "ucount: Simplify refcounting with rcuref_t" from
   Sebastian Siewior cleans up and optimizing the refcounting in the ucount
   code.
 
 - The 12 patch series "reboot: support runtime configuration of
   emergency hw_protection action" from Ahmad Fatoum improves the ability
   for a driver to perform an emergency system shutdown or reboot.
 
 - The 16 patch series "Converge on using secs_to_jiffies() part two"
   from Easwar Hariharan performs further migrations from
   msecs_to_jiffies() to secs_to_jiffies().
 
 - The 7 patch series "lib/interval_tree: add some test cases and
   cleanup" from Wei Yang permits more userspace testing of kernel library
   code, adds some more tests and performs some cleanups.
 
 - The 2 patch series "hung_task: Dump the blocking task stacktrace" from
   Masami Hiramatsu arranges for the hung_task detector to dump the stack
   of the blocking task and not just that of the blocked task.
 
 - The 4 patch series "resource: Split and use DEFINE_RES*() macros" from
   Andy Shevchenko provides some cleanups to the resource definition
   macros.
 
 - Plus the usual shower of singleton patches - please see the individual
   changelogs for details.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ+nuqwAKCRDdBJ7gKXxA
 jtNqAQDxqJpjWkzn4yN9CNSs1ivVx3fr6SqazlYCrt3u89WQvwEA1oRrGpETzUGq
 r6khQUIcQImPPcjFqEFpuiSOU0MBZA0=
 =Kii8
 -----END PGP SIGNATURE-----

Merge tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "powerpc/crash: use generic crashkernel reservation" from
   Sourabh Jain changes powerpc's kexec code to use more of the generic
   layers.

 - The series "get_maintainer: report subsystem status separately" from
   Vlastimil Babka makes some long-requested improvements to the
   get_maintainer output.

 - The series "ucount: Simplify refcounting with rcuref_t" from
   Sebastian Siewior cleans up and optimizing the refcounting in the
   ucount code.

 - The series "reboot: support runtime configuration of emergency
   hw_protection action" from Ahmad Fatoum improves the ability for a
   driver to perform an emergency system shutdown or reboot.

 - The series "Converge on using secs_to_jiffies() part two" from Easwar
   Hariharan performs further migrations from msecs_to_jiffies() to
   secs_to_jiffies().

 - The series "lib/interval_tree: add some test cases and cleanup" from
   Wei Yang permits more userspace testing of kernel library code, adds
   some more tests and performs some cleanups.

 - The series "hung_task: Dump the blocking task stacktrace" from Masami
   Hiramatsu arranges for the hung_task detector to dump the stack of
   the blocking task and not just that of the blocked task.

 - The series "resource: Split and use DEFINE_RES*() macros" from Andy
   Shevchenko provides some cleanups to the resource definition macros.

 - Plus the usual shower of singleton patches - please see the
   individual changelogs for details.

* tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  mailmap: consolidate email addresses of Alexander Sverdlin
  fs/procfs: fix the comment above proc_pid_wchan()
  relay: use kasprintf() instead of fixed buffer formatting
  resource: replace open coded variant of DEFINE_RES()
  resource: replace open coded variants of DEFINE_RES_*_NAMED()
  resource: replace open coded variant of DEFINE_RES_NAMED_DESC()
  resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()
  samples: add hung_task detector mutex blocking sample
  hung_task: show the blocker task if the task is hung on mutex
  kexec_core: accept unaccepted kexec segments' destination addresses
  watchdog/perf: optimize bytes copied and remove manual NUL-termination
  lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap()
  lib/interval_tree: skip the check before go to the right subtree
  lib/interval_tree: add test case for span iteration
  lib/interval_tree: add test case for interval_tree_iter_xxx() helpers
  lib/rbtree: add random seed
  lib/rbtree: split tests
  lib/rbtree: enable userland test suite for rbtree related data structure
  checkpatch: describe --min-conf-desc-length
  scripts/gdb/symbols: determine KASLR offset on s390
  ...
2025-04-01 10:06:52 -07:00
Linus Torvalds
eb0ece1602 - The 6 patch series "Enable strict percpu address space checks" from
Uros Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.
 
   This has caused a small amount of fallout - two or three issues were
   reported.  In all cases the calling code was founf to be incorrect.
 
 - The 4 patch series "Some cleanup for memcg" from Chen Ridong
   implements some relatively monir cleanups for the memcontrol code.
 
 - The 17 patch series "mm: fixes for device-exclusive entries (hmm)"
   from David Hildenbrand fixes a boatload of issues which David found then
   using device-exclusive PTE entries when THP is enabled.  More work is
   needed, but this makes thins better - our own HMM selftests now succeed.
 
 - The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry
   Ahmed remove the z3fold and zbud implementations.  They have been
   deprecated for half a year and nobody has complained.
 
 - The 5 patch series "mm: further simplify VMA merge operation" from
   Lorenzo Stoakes implements numerous simplifications in this area.  No
   runtime effects are anticipated.
 
 - The 4 patch series "mm/madvise: remove redundant mmap_lock operations
   from process_madvise()" from SeongJae Park rationalizes the locking in
   the madvise() implementation.  Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.
 
 - The 12 patch series "Tiny cleanup and improvements about SWAP code"
   from Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.
 
 - The 2 patch series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak user-visible
   output.
 
 - The 2 patch series "mm/damon/paddr: fix large folios access and
   schemes handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.
 
 - The 3 patch series "mm/damon/core: fix wrong and/or useless
   damos_walk() behaviors" from SeongJae Park fixes a few issues with the
   accuracy of kdamond's walking of DAMON regions.
 
 - The 3 patch series "expose mapping wrprotect, fix fb_defio use" from
   Lorenzo Stoakes changes the interaction between framebuffer deferred-io
   and core MM.  No functional changes are anticipated - this is
   preparatory work for the future removal of page structure fields.
 
 - The 4 patch series "mm/damon: add support for hugepage_size DAMOS
   filter" from Usama Arif adds a DAMOS filter which permits the filtering
   by huge page sizes.
 
 - The 4 patch series "mm: permit guard regions for file-backed/shmem
   mappings" from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state.  The feature now covers shmem and
   file-backed mappings.
 
 - The 4 patch series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping for
   pte-mapped large folios.
 
 - The 18 patch series "reimplement per-vma lock as a refcount" from
   Suren Baghdasaryan puts the vm_lock back into the vma.  Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy.  This patchset provides small (0-10%) improvements on one
   microbenchmark.
 
 - The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation
   fixes and improves" from SeongJae Park does some maintenance work on the
   DAMON docs.
 
 - The 27 patch series "hugetlb/CMA improvements for large systems" from
   Frank van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped
   pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.
 
 - The 19 patch series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.
 
 - The 12 patch series "selftests/mm: Some cleanups from trying to run
   them" from Brendan Jackman fixes a pile of unrelated issues which
   Brendan encountered while runnimg our selftests.
 
 - The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap"
   from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.
 
 - The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply wasn't
   being effective.
 
 - The 5 patch series "mm: cleanups for device-exclusive entries (hmm)"
   from David Hildenbrand implements a number of unrelated cleanups in this
   code.
 
 - The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman
   Khandual implements a number of preparatoty cleanups to the
   GENERIC_PTDUMP Kconfig logic.
 
 - The 8 patch series "mm/damon: auto-tune aggregation interval" from
   SeongJae Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.
 
 - The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some
   issues in powerpc, sparc and x86 lazy MMU implementations.  Ryan did
   this in preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.
 
 - The 2 patch series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the code
   easier to follow.
 
 - The 3 patch series "page_counter cleanup and size reduction" from
   Shakeel Butt cleans up the page_counter code and fixes a size increase
   which we accidentally added late last year.
 
 - The 3 patch series "Add a command line option that enables control of
   how many threads should be used to allocate huge pages" from Thomas
   Prescher does that.  It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.
 
 - The 3 patch series "Fix calculations in trace_balance_dirty_pages()
   for cgwb" from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.
 
 - The 9 patch series "mm/damon: make allow filters after reject filters
   useful and intuitive" from SeongJae Park improves the handling of allow
   and reject filters.  Behaviour is made more consistent and the
   documention is updated accordingly.
 
 - The 5 patch series "Switch zswap to object read/write APIs" from Yosry
   Ahmed updates zswap to the new object read/write APIs and thus permits
   the removal of some legacy code from zpool and zsmalloc.
 
 - The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang
   does as it claims.
 
 - The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts"
   from Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.
 
 - The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes
   is a preparatoty refactoring and cleanup of the mremap() code.
 
 - The 20 patch series "mm: MM owner tracking for large folios (!hugetlb)
   + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.
 
 - The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS
   filters based on handling layers" from SeongJae Park adds a couple of
   new sysfs directories to ease the management of DAMON/DAMOS filters.
 
 - The 13 patch series "arch, mm: reduce code duplication in mem_init()"
   from Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.
 
 - The 13 patch series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.
 
 - The 3 patch series "mm: page_ext: Introduce new iteration API" from
   Luiz Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.
 
 - The 8 patch series "Buddy allocator like (or non-uniform) folio split"
   from Zi Yan reworks the code to split a folio into smaller folios.  The
   main benefit is lessened memory consumption: fewer post-split folios are
   generated.
 
 - The 2 patch series "Minimize xa_node allocation during xarry split"
   from Zi Yan reduces the number of xarray xa_nodes which are generated
   during an xarray split.
 
 - The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.
 
 - The 3 patch series "Add tracepoints for lowmem reserves, watermarks
   and totalreserve_pages" from Martin Liu adds some more tracepoints to
   the page allocator code.
 
 - The 4 patch series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which SeongJae
   observed during his earlier madvise work.
 
 - The 3 patch series "mm/hwpoison: Fix regressions in memory failure
   handling" from Shuai Xue addresses two quite serious regressions which
   Shuai has observed in the memory-failure implementation.
 
 - The 5 patch series "mm: reliable huge page allocator" from Johannes
   Weiner makes huge page allocations cheaper and more reliable by reducing
   fragmentation.
 
 - The 5 patch series "Minor memcg cleanups & prep for memdescs" from
   Matthew Wilcox is preparatory work for the future implementation of
   memdescs.
 
 - The 4 patch series "track memory used by balloon drivers" from Nico
   Pache introduces a way to track memory used by our various balloon
   drivers.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for active
   pages" from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.
 
 - The 2 patch series "Adding Proactive Memory Reclaim Statistics" from
   Hao Jia separates the proactive reclaim statistics from the direct
   reclaim statistics.
 
 - The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio"
   from Jinjiang Tu fixes our handling of hwpoisoned pages within the
   reclaim code.
 -----BEGIN PGP SIGNATURE-----
 
 iHQEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ+nZaAAKCRDdBJ7gKXxA
 jsOWAPiP4r7CJHMZRK4eyJOkvS1a1r+TsIarrFZtjwvf/GIfAQCEG+JDxVfUaUSF
 Ee93qSSLR1BkNdDw+931Pu0mXfbnBw==
 =Pn2K
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...
2025-04-01 09:29:18 -07:00
Linus Torvalds
7405c0f01a Miscellaneous x86 fixes and updates:
- Fix a large number of x86 Kconfig dependency and help text accuracy
    bugs/problems, by Mateusz Jończyk and David Heideberg.
 
  - Fix a VM_PAT interaction with fork() crash. This also touches
    core kernel code.
 
  - Fix an ORC unwinder bug for interrupt entries
 
  - Fixes and cleanups.
 
  - Fix an AMD microcode loader bug that can promote verification failures
    into success.
 
  - Add early-printk support for MMIO based UARTs on an x86 board that
    had no other serial debugging facility and also experienced early
    boot crashes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmfnFBERHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1iVDxAAmiB4soT3/WbaWJJdeVyxEL7sOmUNOm04
 5kAVHJVK8QGdje0eWa6h7xmuQD3UOxafE2coCrOxHhZi2qpAAY6CPIIy6oIBRwZK
 gLgT5xn1CHojfm4UFC3YUOyecBRPUF2C5jfkajWdZHumyPP/sOObqvGanpQRAYd5
 bfPHEvrBpeEeS7WkATCdyF2j+I5xYflD4g/MDAsMmqasQHOnjBuFX5VBeVxxkysC
 dMsFkFpxqcA95MnnyOnxXzgOtRTY0UystX07D3Bk1pqhG9zor+mp8OynsTRCU87T
 ZPPbUr2qACNmCqEEXl+F1mAkgj5H66xE2gaJdYx0/jBAIbX8Nwih7mMxhJShVU07
 Lhc0tukmVrDoDaVIr2HsxqI8iokuYLszUjDAqEQmQDrgelL6usPYghN1b2bDSJ9r
 0hCO/s79024H/U9oMrC+CF52D5UH/fE98ipigrbKRIO/hOsoxiiniF3DG2NVWZM2
 n5nPnOdbperqjCEteN1nxQfr7XZkvP95Bwmuqqc90XH+tzKJdHruUkbm4ua7NEEz
 WKgsUIYFjeN5ZrHbJaNtHlQueTyvsyGmL1nlaLi/MaJbSXPsM/WfwvHsaKTh3NrE
 BFwEAhMZVLDHEfnFT0Ev7Mm1MGpW8MbHoRBR1+E5FWWNS4X0yGLKXWRp8diw25Tm
 W3ZVsn65E6U=
 =/qKX
 -----END PGP SIGNATURE-----

Merge tag 'x86-urgent-2025-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull misc x86 fixes and updates from Ingo Molnar:

 - Fix a large number of x86 Kconfig dependency and help text accuracy
   bugs/problems, by Mateusz Jończyk and David Heideberg

 - Fix a VM_PAT interaction with fork() crash. This also touches core
   kernel code

 - Fix an ORC unwinder bug for interrupt entries

 - Fixes and cleanups

 - Fix an AMD microcode loader bug that can promote verification
   failures into success

 - Add early-printk support for MMIO based UARTs on an x86 board that
   had no other serial debugging facility and also experienced early
   boot crashes

* tag 'x86-urgent-2025-03-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/microcode/AMD: Fix __apply_microcode_amd()'s return value
  x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()
  x86/fpu: Update the outdated comment above fpstate_init_user()
  x86/early_printk: Add support for MMIO-based UARTs
  x86/dumpstack: Fix inaccurate unwinding from exception stacks due to misplaced assignment
  x86/entry: Fix ORC unwinder for PUSH_REGS with save_ret=1
  x86/Kconfig: Fix lists in X86_EXTENDED_PLATFORM help text
  x86/Kconfig: Correct X86_X2APIC help text
  x86/speculation: Remove the extra #ifdef around CALL_NOSPEC
  x86/Kconfig: Document release year of glibc 2.3.3
  x86/Kconfig: Make CONFIG_PCI_CNB20LE_QUIRK depend on X86_32
  x86/Kconfig: Document CONFIG_PCI_MMCONFIG
  x86/Kconfig: Update lists in X86_EXTENDED_PLATFORM
  x86/Kconfig: Move all X86_EXTENDED_PLATFORM options together
  x86/Kconfig: Always enable ARCH_SPARSEMEM_ENABLE
  x86/Kconfig: Enable X86_X2APIC by default and improve help text
2025-03-30 15:25:15 -07:00
David Hildenbrand
dc84bc2aba x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()
If track_pfn_copy() fails, we already added the dst VMA to the maple
tree. As fork() fails, we'll cleanup the maple tree, and stumble over
the dst VMA for which we neither performed any reservation nor copied
any page tables.

Consequently untrack_pfn() will see VM_PAT and try obtaining the
PAT information from the page table -- which fails because the page
table was not copied.

The easiest fix would be to simply clear the VM_PAT flag of the dst VMA
if track_pfn_copy() fails. However, the whole thing is about "simply"
clearing the VM_PAT flag is shaky as well: if we passed track_pfn_copy()
and performed a reservation, but copying the page tables fails, we'll
simply clear the VM_PAT flag, not properly undoing the reservation ...
which is also wrong.

So let's fix it properly: set the VM_PAT flag only if the reservation
succeeded (leaving it clear initially), and undo the reservation if
anything goes wrong while copying the page tables: clearing the VM_PAT
flag after undoing the reservation.

Note that any copied page table entries will get zapped when the VMA will
get removed later, after copy_page_range() succeeded; as VM_PAT is not set
then, we won't try cleaning VM_PAT up once more and untrack_pfn() will be
happy. Note that leaving these page tables in place without a reservation
is not a problem, as we are aborting fork(); this process will never run.

A reproducer can trigger this usually at the first try:

  https://gitlab.com/davidhildenbrand/scratchspace/-/raw/main/reproducers/pat_fork.c

  WARNING: CPU: 26 PID: 11650 at arch/x86/mm/pat/memtype.c:983 get_pat_info+0xf6/0x110
  Modules linked in: ...
  CPU: 26 UID: 0 PID: 11650 Comm: repro3 Not tainted 6.12.0-rc5+ #92
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014
  RIP: 0010:get_pat_info+0xf6/0x110
  ...
  Call Trace:
   <TASK>
   ...
   untrack_pfn+0x52/0x110
   unmap_single_vma+0xa6/0xe0
   unmap_vmas+0x105/0x1f0
   exit_mmap+0xf6/0x460
   __mmput+0x4b/0x120
   copy_process+0x1bf6/0x2aa0
   kernel_clone+0xab/0x440
   __do_sys_clone+0x66/0x90
   do_syscall_64+0x95/0x180

Likely this case was missed in:

  d155df53f310 ("x86/mm/pat: clear VM_PAT if copy_p4d_range failed")

... and instead of undoing the reservation we simply cleared the VM_PAT flag.

Keep the documentation of these functions in include/linux/pgtable.h,
one place is more than sufficient -- we should clean that up for the other
functions like track_pfn_remap/untrack_pfn separately.

Fixes: d155df53f310 ("x86/mm/pat: clear VM_PAT if copy_p4d_range failed")
Fixes: 2ab640379a0a ("x86: PAT: hooks in generic vm code to help archs to track pfnmap regions - v3")
Reported-by: xingwei lee <xrivendell7@gmail.com>
Reported-by: yuxin wang <wang1315768607@163.com>
Reported-by: Marius Fleischer <fleischermarius@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20250321112323.153741-1-david@redhat.com
Closes: https://lore.kernel.org/lkml/CABOYnLx_dnqzpCW99G81DmOr+2UzdmZMk=T3uxwNxwz+R1RAwg@mail.gmail.com/
Closes: https://lore.kernel.org/lkml/CAJg=8jwijTP5fre8woS4JVJQ8iUA6v+iNcsOgtj9Zfpc3obDOQ@mail.gmail.com/
2025-03-25 22:35:14 +01:00
Linus Torvalds
a50b4fe095 A treewide hrtimer timer cleanup
hrtimers are initialized with hrtimer_init() and a subsequent store to
   the callback pointer. This turned out to be suboptimal for the upcoming
   Rust integration and is obviously a silly implementation to begin with.
 
   This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
   with hrtimer_setup(T, cb);
 
   The conversion was done with Coccinelle and a few manual fixups.
 
   Once the conversion has completely landed in mainline, hrtimer_init()
   will be removed and the hrtimer::function becomes a private member.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmff5jQTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoVvRD/wKtuwmiA66NJFgXC0qVq82A6fO3bY8
 GBdbfysDJIbqGu5PTcULTbJ8qkqv3jeLUv6CcXvS4sZ7y/uJQl2lzf8yrD/0bbwc
 rLI6sHiPSZmK93kNVN4X5H7kvt7cE/DYC9nnEOgK3BY5FgKc4n9887d4aVBhL8Lv
 ODwVXvZ+xi351YCj7qRyPU24zt/p4tkkT1o2k4a0HBluqLI0D+V20fke9IERUL8r
 d1uWKlcn0TqYDesE8HXKIhbst3gx52rMJrXBJDHwFmG6v8Pj1fkTXCVpPo8QcBz8
 OTVkpomN9f/Tx4+GZwhZOF86LhLL3OhxD6pT7JhFCXdmSGv+Ez8uyk1YZysM/XpV
 Juy/1yAcBpDIDkmhMFGdAAn48Nn9Fotty0r4je60zSEp1d/4QMXcFme29qr2JTUE
 iWnQ/HD6DxUjVHqy7CYvvo26Xegg1C7qgyOVt4PYZwAM1VKF5P3kzYTb4SAdxtop
 Tpji1sfW9QV08jqMNo6XntD32DSP9S2HqjO9LwBw700jnx2jjJ35fcJs6iodMOUn
 gckIZLMn3L0OoglPdyA5O7SNTbKE7aFiRKdnT/cJtR3Fa39Qu27CwC5gfiyuie9I
 Q+LG8GLuYSBHXAR+PBK4GWlzJ7Dn8k3eqmbnLeKpRMsU6ZzcttgA64xhaviN2wN0
 iJbvLJeisXr3GA==
 =bYAX
 -----END PGP SIGNATURE-----

Merge tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer cleanups from Thomas Gleixner:
 "A treewide hrtimer timer cleanup

  hrtimers are initialized with hrtimer_init() and a subsequent store to
  the callback pointer. This turned out to be suboptimal for the
  upcoming Rust integration and is obviously a silly implementation to
  begin with.

  This cleanup replaces the hrtimer_init(T); T->function = cb; sequence
  with hrtimer_setup(T, cb);

  The conversion was done with Coccinelle and a few manual fixups.

  Once the conversion has completely landed in mainline, hrtimer_init()
  will be removed and the hrtimer::function becomes a private member"

* tag 'timers-cleanups-2025-03-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits)
  wifi: rt2x00: Switch to use hrtimer_update_function()
  io_uring: Use helper function hrtimer_update_function()
  serial: xilinx_uartps: Use helper function hrtimer_update_function()
  ASoC: fsl: imx-pcm-fiq: Switch to use hrtimer_setup()
  RDMA: Switch to use hrtimer_setup()
  virtio: mem: Switch to use hrtimer_setup()
  drm/vmwgfx: Switch to use hrtimer_setup()
  drm/xe/oa: Switch to use hrtimer_setup()
  drm/vkms: Switch to use hrtimer_setup()
  drm/msm: Switch to use hrtimer_setup()
  drm/i915/request: Switch to use hrtimer_setup()
  drm/i915/uncore: Switch to use hrtimer_setup()
  drm/i915/pmu: Switch to use hrtimer_setup()
  drm/i915/perf: Switch to use hrtimer_setup()
  drm/i915/gvt: Switch to use hrtimer_setup()
  drm/i915/huc: Switch to use hrtimer_setup()
  drm/amdgpu: Switch to use hrtimer_setup()
  stm class: heartbeat: Switch to use hrtimer_setup()
  i2c: Switch to use hrtimer_setup()
  iio: Switch to use hrtimer_setup()
  ...
2025-03-25 10:54:15 -07:00
Uladzislau Rezki (Sony)
b25bcabb6c fork: use __vmalloc_node() for stack allocation
Replace __vmalloc_node_range() by __vmalloc_node().  The last variant
requires less parameters and it uses exactly the same arguments which are
partly now hidden inside __vmalloc_node().

This change does not change any functionality.  It makes the code a bit
simpler.

Link: https://lkml.kernel.org/r/20250317163614.166502-1-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-21 22:03:14 -07:00
Christian Brauner
68db272741
pidfs: ensure that PIDFS_INFO_EXIT is available
When we currently create a pidfd we check that the task hasn't been
reaped right before we create the pidfd. But it is of course possible
that by the time we return the pidfd to userspace the task has already
been reaped since we don't check again after having created a dentry for
it.

This was fine until now because that race was meaningless. But now that
we provide PIDFD_INFO_EXIT it is a problem because it is possible that
the kernel returns a reaped pidfd and it depends on the race whether
PIDFD_INFO_EXIT information is available. This depends on if the task
gets reaped before or after a dentry has been attached to struct pid.

Make this consistent and only returned pidfds for reaped tasks if
PIDFD_INFO_EXIT information is available. This is done by performing
another check whether the task has been reaped right after we attached a
dentry to struct pid.

Since pidfs_exit() is called before struct pid's task linkage is removed
the case where the task got reaped but a dentry was already attached to
struct pid and exit information was recorded and published can be
handled correctly. In that case we do return a pidfd for a reaped task
like we would've before.

Link: https://lore.kernel.org/r/20250316-kabel-fehden-66bdb6a83436@brauner
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-19 14:40:18 +01:00
David Hildenbrand
6af8cb80d3 mm/rmap: basic MM owner tracking for large folios (!hugetlb)
For small folios, we traditionally use the mapcount to decide whether it
was "certainly mapped exclusively" by a single MM (mapcount == 1) or
whether it "maybe mapped shared" by multiple MMs (mapcount > 1).  For
PMD-sized folios that were PMD-mapped, we were able to use a similar
mechanism (single PMD mapping), but for PTE-mapped folios and in the
future folios that span multiple PMDs, this does not work.

So we need a different mechanism to handle large folios.  Let's add a new
mechanism to detect whether a large folio is "certainly mapped
exclusively", or whether it is "maybe mapped shared".

We'll use this information next to optimize CoW reuse for PTE-mapped
anonymous THP, and to convert folio_likely_mapped_shared() to
folio_maybe_mapped_shared(), independent of per-page mapcounts.

For each large folio, we'll have two slots, whereby a slot stores:
 (1) an MM id: unique id assigned to each MM
 (2) a per-MM mapcount

If a slot is unoccupied, it can be taken by the next MM that maps folio
page.

In addition, we'll remember the current state -- "mapped exclusively" vs. 
"maybe mapped shared" -- and use a bit spinlock to sync on updates and to
reduce the total number of atomic accesses on updates.  In the future, it
might be possible to squeeze a proper spinlock into "struct folio".  For
now, keep it simple, as we require the whole thing with THP only, that is
incompatible with RT.

As we have to squeeze this information into the "struct folio" of even
folios of order-1 (2 pages), and we generally want to reduce the required
metadata, we'll assign each MM a unique ID that can fit into an int.  In
total, we can squeeze everything into 4x int (2x long) on 64bit.

32bit support is a bit challenging, because we only have 2x long == 2x int
in order-1 folios.  But we can make it work for now, because we neither
expect many MMs nor very large folios on 32bit.

We will reliably detect folios as "mapped exclusively" vs.  "mapped
shared" as long as only two MMs map pages of a folio at one point in time
-- for example with fork() and short-lived child processes, or with apps
that hand over state from one instance to another.

As soon as three MMs are involved at the same time, we might detect "maybe
mapped shared" although the folio is "mapped exclusively".

Example 1:

(1) App1 faults in a (shmem/file-backed) folio page -> Tracked as MM0
(2) App2 faults in a folio page -> Tracked as MM1
(4) App1 unmaps all folio pages

 -> We will detect "mapped exclusively".

Example 2:

(1) App1 faults in a (shmem/file-backed) folio page -> Tracked as MM0
(2) App2 faults in a folio page -> Tracked as MM1
(3) App3 faults in a folio page -> No slot available, tracked as "unknown"
(4) App1 and App2 unmap all folio pages

 -> We will detect "maybe mapped shared".

Make use of __always_inline to keep possible performance degradation when
(un)mapping large folios to a minimum.

Note: by squeezing the two flags into the "unsigned long" that stores the
MM ids, we can use non-atomic __bit_spin_unlock() and non-atomic
setting/clearing of the "maybe mapped shared" bit, effectively not adding
any new atomics on the hot path when updating the large mapcount + new
metadata, which further helps reduce the runtime overhead in
micro-benchmarks.

Link: https://lkml.kernel.org/r/20250303163014.1128035-13-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:46 -07:00
Andrii Nakryiko
0c555a3c1b mm,procfs: allow read-only remote mm access under CAP_PERFMON
It's very common for various tracing and profiling toolis to need to
access /proc/PID/maps contents for stack symbolization needs to learn
which shared libraries are mapped in memory, at which file offset, etc. 
Currently, access to /proc/PID/maps requires CAP_SYS_PTRACE (unless we are
looking at data for our own process, which is a trivial case not too
relevant for profilers use cases).

Unfortunately, CAP_SYS_PTRACE implies way more than just ability to
discover memory layout of another process: it allows to fully control
arbitrary other processes.  This is problematic from security POV for
applications that only need read-only /proc/PID/maps (and other similar
read-only data) access, and in large production settings CAP_SYS_PTRACE is
frowned upon even for the system-wide profilers.

On the other hand, it's already possible to access similar kind of
information (and more) with just CAP_PERFMON capability.  E.g., setting up
PERF_RECORD_MMAP collection through perf_event_open() would give one
similar information to what /proc/PID/maps provides.

CAP_PERFMON, together with CAP_BPF, is already a very common combination
for system-wide profiling and observability application.  As such, it's
reasonable and convenient to be able to access /proc/PID/maps with
CAP_PERFMON capabilities instead of CAP_SYS_PTRACE.

For procfs, these permissions are checked through common mm_access()
helper, and so we augment that with cap_perfmon() check *only* if
requested mode is PTRACE_MODE_READ.  I.e., PTRACE_MODE_ATTACH wouldn't be
permitted by CAP_PERFMON.  So /proc/PID/mem, which uses
PTRACE_MODE_ATTACH, won't be permitted by CAP_PERFMON, but /proc/PID/maps,
/proc/PID/environ, and a bunch of other read-only contents will be
allowable under CAP_PERFMON.

Besides procfs itself, mm_access() is used by process_madvise() and
process_vm_{readv,writev}() syscalls.  The former one uses
PTRACE_MODE_READ to avoid leaking ASLR metadata, and as such CAP_PERFMON
seems like a meaningful allowable capability as well.

process_vm_{readv,writev} currently assume PTRACE_MODE_ATTACH level of
permissions (though for readv PTRACE_MODE_READ seems more reasonable, but
that's outside the scope of this change), and as such won't be affected by
this patch.

Link: https://lkml.kernel.org/r/20250127222114.1132392-1-andrii@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:30:46 -07:00
Suren Baghdasaryan
3104138517 mm: make vma cache SLAB_TYPESAFE_BY_RCU
To enable SLAB_TYPESAFE_BY_RCU for vma cache we need to ensure that
object reuse before RCU grace period is over will be detected by
lock_vma_under_rcu().

Current checks are sufficient as long as vma is detached before it is
freed.  The only place this is not currently happening is in exit_mmap(). 
Add the missing vma_mark_detached() in exit_mmap().

Another issue which might trick lock_vma_under_rcu() during vma reuse is
vm_area_dup(), which copies the entire content of the vma into a new one,
overriding new vma's vm_refcnt and temporarily making it appear as
attached.  This might trick a racing lock_vma_under_rcu() to operate on a
reused vma if it found the vma before it got reused.  To prevent this
situation, we should ensure that vm_refcnt stays at detached state (0)
when it is copied and advances to attached state only after it is added
into the vma tree.  Introduce vm_area_init_from() which preserves new
vma's vm_refcnt and use it in vm_area_dup().  Since all vmas are in
detached state with no current readers when they are freed,

lock_vma_under_rcu() will not be able to take vm_refcnt after vma got
detached even if vma is reused. vma_mark_attached() in modified to
include a release fence to ensure all stores to the vma happen before
vm_refcnt gets initialized.

Finally, make vm_area_cachep SLAB_TYPESAFE_BY_RCU. This will facilitate
vm_area_struct reuse and will minimize the number of call_rcu() calls.

[surenb@google.com: remove atomic_set_release() usage in tools/]
  Link: https://lkml.kernel.org/r/20250217054351.2973666-1-surenb@google.com
Link: https://lkml.kernel.org/r/20250213224655.1680278-18-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Shivank Garg <shivankg@amd.com>
  Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:21 -07:00
Suren Baghdasaryan
f35ab95ca0 mm: replace vm_lock and detached flag with a reference count
rw_semaphore is a sizable structure of 40 bytes and consumes considerable
space for each vm_area_struct.  However vma_lock has two important
specifics which can be used to replace rw_semaphore with a simpler
structure:

1. Readers never wait.  They try to take the vma_lock and fall back to
   mmap_lock if that fails.

2. Only one writer at a time will ever try to write-lock a vma_lock
   because writers first take mmap_lock in write mode.  Because of these
   requirements, full rw_semaphore functionality is not needed and we can
   replace rw_semaphore and the vma->detached flag with a refcount
   (vm_refcnt).

When vma is in detached state, vm_refcnt is 0 and only a call to
vma_mark_attached() can take it out of this state.  Note that unlike
before, now we enforce both vma_mark_attached() and vma_mark_detached() to
be done only after vma has been write-locked.  vma_mark_attached() changes
vm_refcnt to 1 to indicate that it has been attached to the vma tree. 
When a reader takes read lock, it increments vm_refcnt, unless the top
usable bit of vm_refcnt (0x40000000) is set, indicating presence of a
writer.  When writer takes write lock, it sets the top usable bit to
indicate its presence.  If there are readers, writer will wait using newly
introduced mm->vma_writer_wait.  Since all writers take mmap_lock in write
mode first, there can be only one writer at a time.  The last reader to
release the lock will signal the writer to wake up.  refcount might
overflow if there are many competing readers, in which case read-locking
will fail.  Readers are expected to handle such failures.

In summary:
1. all readers increment the vm_refcnt;
2. writer sets top usable (writer) bit of vm_refcnt;
3. readers cannot increment the vm_refcnt if the writer bit is set;
4. in the presence of readers, writer must wait for the vm_refcnt to drop
to 1 (plus the VMA_LOCK_OFFSET writer bit), indicating an attached vma
with no readers;
5. vm_refcnt overflow is handled by the readers.

While this vm_lock replacement does not yet result in a smaller
vm_area_struct (it stays at 256 bytes due to cacheline alignment), it
allows for further size optimization by structure member regrouping to
bring the size of vm_area_struct below 192 bytes.

[surenb@google.com: fix a crash due to vma_end_read() that should have been removed]
  Link: https://lkml.kernel.org/r/20250220200208.323769-1-surenb@google.com
Link: https://lkml.kernel.org/r/20250213224655.1680278-13-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Tested-by: Shivank Garg <shivankg@amd.com>
  Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:20 -07:00
Suren Baghdasaryan
ce08539660 mm: move mmap_init_lock() out of the header file
mmap_init_lock() is used only from mm_init() in fork.c, therefore it does
not have to reside in the header file.  This move lets us avoid including
additional headers in mmap_lock.h later, when mmap_init_lock() needs to
initialize rcuwait object.

Link: https://lkml.kernel.org/r/20250213224655.1680278-9-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Tested-by: Shivank Garg <shivankg@amd.com>
  Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:19 -07:00
Suren Baghdasaryan
8ef95d8f15 mm: mark vma as detached until it's added into vma tree
Current implementation does not set detached flag when a VMA is first
allocated.  This does not represent the real state of the VMA, which is
detached until it is added into mm's VMA tree.  Fix this by marking new
VMAs as detached and resetting detached flag only after VMA is added into
a tree.

Introduce vma_mark_attached() to make the API more readable and to
simplify possible future cleanup when vma->vm_mm might be used to indicate
detached vma and vma_mark_attached() will need an additional mm parameter.

Link: https://lkml.kernel.org/r/20250213224655.1680278-4-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Shivank Garg <shivankg@amd.com>
  Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:17 -07:00
Suren Baghdasaryan
7b6218ae12 mm: move per-vma lock into vm_area_struct
Back when per-vma locks were introduces, vm_lock was moved out of
vm_area_struct in [1] because of the performance regression caused by
false cacheline sharing.  Recent investigation [2] revealed that the
regressions is limited to a rather old Broadwell microarchitecture and
even there it can be mitigated by disabling adjacent cacheline
prefetching, see [3].

Splitting single logical structure into multiple ones leads to more
complicated management, extra pointer dereferences and overall less
maintainable code.  When that split-away part is a lock, it complicates
things even further.  With no performance benefits, there are no reasons
for this split.  Merging the vm_lock back into vm_area_struct also allows
vm_area_struct to use SLAB_TYPESAFE_BY_RCU later in this patchset.  Move
vm_lock back into vm_area_struct, aligning it at the cacheline boundary
and changing the cache to be cacheline-aligned as well.  With kernel
compiled using defconfig, this causes VMA memory consumption to grow from
160 (vm_area_struct) + 40 (vm_lock) bytes to 256 bytes:

    slabinfo before:
     <name>           ... <objsize> <objperslab> <pagesperslab> : ...
     vma_lock         ...     40  102    1 : ...
     vm_area_struct   ...    160   51    2 : ...

    slabinfo after moving vm_lock:
     <name>           ... <objsize> <objperslab> <pagesperslab> : ...
     vm_area_struct   ...    256   32    2 : ...

Aggregate VMA memory consumption per 1000 VMAs grows from 50 to 64 pages,
which is 5.5MB per 100000 VMAs.  Note that the size of this structure is
dependent on the kernel configuration and typically the original size is
higher than 160 bytes.  Therefore these calculations are close to the
worst case scenario.  A more realistic vm_area_struct usage before this
change is:

     <name>           ... <objsize> <objperslab> <pagesperslab> : ...
     vma_lock         ...     40  102    1 : ...
     vm_area_struct   ...    176   46    2 : ...

Aggregate VMA memory consumption per 1000 VMAs grows from 54 to 64 pages,
which is 3.9MB per 100000 VMAs.  This memory consumption growth can be
addressed later by optimizing the vm_lock.

[1] https://lore.kernel.org/all/20230227173632.3292573-34-surenb@google.com/
[2] https://lore.kernel.org/all/ZsQyI%2F087V34JoIt@xsang-OptiPlex-9020/
[3] https://lore.kernel.org/all/CAJuCfpEisU8Lfe96AYJDZ+OM4NoPmnw9bP53cT_kbfP_pR+-2g@mail.gmail.com/

Link: https://lkml.kernel.org/r/20250213224655.1680278-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Shivank Garg <shivankg@amd.com>
  Link: https://lkml.kernel.org/r/5e19ec93-8307-47c2-bb13-3ddf7150624e@amd.com
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Klara Modin <klarasmodin@gmail.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:17 -07:00
Christian Brauner
3155a19407
pidfs: move setting flags into pidfs_alloc_file()
Instead od adding it into __pidfd_prepare() place it where the actual
file allocation happens and update the outdated comment.

Link: https://lore.kernel.org/r/20250305-work-pidfs-kill_on_last_close-v3-3-c8c3d8361705@kernel.org
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-05 13:26:05 +01:00
Christian Brauner
b573bf6f69
pidfd: rely on automatic cleanup in __pidfd_prepare()
Rely on scope-based cleanup for the allocated file descriptor.

Link: https://lore.kernel.org/r/20250305-work-pidfs-kill_on_last_close-v3-2-c8c3d8361705@kernel.org
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-05 13:25:59 +01:00
Nam Cao
91b7be704d fork: Switch to use hrtimer_setup()
hrtimer_setup() takes the callback function pointer as argument and
initializes the timer completely.

Replace hrtimer_init() and the open coded initialization of
hrtimer::function with the new setup mechanism.

Patch was created by using Coccinelle.

Signed-off-by: Nam Cao <namcao@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/174111145b945391e48936d6debcd43caec3e406.1738746821.git.namcao@linutronix.de
2025-02-18 10:32:32 +01:00
Liam R. Howlett
64c37e134b kernel: be more careful about dup_mmap() failures and uprobe registering
If a memory allocation fails during dup_mmap(), the maple tree can be left
in an unsafe state for other iterators besides the exit path.  All the
locks are dropped before the exit_mmap() call (in mm/mmap.c), but the
incomplete mm_struct can be reached through (at least) the rmap finding
the vmas which have a pointer back to the mm_struct.

Up to this point, there have been no issues with being able to find an
mm_struct that was only partially initialised.  Syzbot was able to make
the incomplete mm_struct fail with recent forking changes, so it has been
proven unsafe to use the mm_struct that hasn't been initialised, as
referenced in the link below.

Although 8ac662f5da19f ("fork: avoid inappropriate uprobe access to
invalid mm") fixed the uprobe access, it does not completely remove the
race.

This patch sets the MMF_OOM_SKIP to avoid the iteration of the vmas on the
oom side (even though this is extremely unlikely to be selected as an oom
victim in the race window), and sets MMF_UNSTABLE to avoid other potential
users from using a partially initialised mm_struct.

When registering vmas for uprobe, skip the vmas in an mm that is marked
unstable.  Modifying a vma in an unstable mm may cause issues if the mm
isn't fully initialised.

Link: https://lore.kernel.org/all/6756d273.050a0220.2477f.003d.GAE@google.com/
Link: https://lkml.kernel.org/r/20250127170221.1761366-1-Liam.Howlett@oracle.com
Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-01 03:53:25 -08:00
Linus Torvalds
c159dfbdd4 Mainly individually changelogged singleton patches. The patch series in
this pull are:
 
 - "lib min_heap: Improve min_heap safety, testing, and documentation"
   from Kuan-Wei Chiu provides various tightenings to the min_heap library
   code.
 
 - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms some
   cleanup and Rust preparation in the xarray library code.
 
 - "Update reference to include/asm-<arch>" from Geert Uytterhoeven fixes
   pathnames in some code comments.
 
 - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses the
   new secs_to_jiffies() in various places where that is appropriate.
 
 - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen
   switches two filesystems to the new mount API.
 
 - "Convert ocfs2 to use folios" from Matthew Wilcox does that.
 
 - "Remove get_task_comm() and print task comm directly" from Yafang Shao
   removes now-unneeded calls to get_task_comm() in various places.
 
 - "squashfs: reduce memory usage and update docs" from Phillip Lougher
   implements some memory savings in squashfs and performs some
   maintainability work.
 
 - "lib: clarify comparison function requirements" from Kuan-Wei Chiu
   tightens the sort code's behaviour and adds some maintenance work.
 
 - "nilfs2: protect busy buffer heads from being force-cleared" from
   Ryusuke Konishi fixes an issues in nlifs when the fs is presented with a
   corrupted image.
 
 - "nilfs2: fix kernel-doc comments for function return values" from
   Ryusuke Konishi fixes some nilfs kerneldoc.
 
 - "nilfs2: fix issues with rename operations" from Ryusuke Konishi
   addresses some nilfs BUG_ONs which syzbot was able to trigger.
 
 - "minmax.h: Cleanups and minor optimisations" from David Laight
   does some maintenance work on the min/max library code.
 
 - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance work
   on the xarray library code.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ5SP5QAKCRDdBJ7gKXxA
 jqN7AQChvwXGG43n4d5SDiA/rH7ddvowQcDqhC9cAMJ1ReR7qwEA8/LIWDE4PdMX
 mJnaZ1/ibpEpearrChCViApQtcyEGQI=
 =ti4E
 -----END PGP SIGNATURE-----

Merge tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Mainly individually changelogged singleton patches. The patch series
  in this pull are:

   - "lib min_heap: Improve min_heap safety, testing, and documentation"
     from Kuan-Wei Chiu provides various tightenings to the min_heap
     library code

   - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms
     some cleanup and Rust preparation in the xarray library code

   - "Update reference to include/asm-<arch>" from Geert Uytterhoeven
     fixes pathnames in some code comments

   - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses
     the new secs_to_jiffies() in various places where that is
     appropriate

   - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen
     switches two filesystems to the new mount API

   - "Convert ocfs2 to use folios" from Matthew Wilcox does that

   - "Remove get_task_comm() and print task comm directly" from Yafang
     Shao removes now-unneeded calls to get_task_comm() in various
     places

   - "squashfs: reduce memory usage and update docs" from Phillip
     Lougher implements some memory savings in squashfs and performs
     some maintainability work

   - "lib: clarify comparison function requirements" from Kuan-Wei Chiu
     tightens the sort code's behaviour and adds some maintenance work

   - "nilfs2: protect busy buffer heads from being force-cleared" from
     Ryusuke Konishi fixes an issues in nlifs when the fs is presented
     with a corrupted image

   - "nilfs2: fix kernel-doc comments for function return values" from
     Ryusuke Konishi fixes some nilfs kerneldoc

   - "nilfs2: fix issues with rename operations" from Ryusuke Konishi
     addresses some nilfs BUG_ONs which syzbot was able to trigger

   - "minmax.h: Cleanups and minor optimisations" from David Laight does
     some maintenance work on the min/max library code

   - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance
     work on the xarray library code"

* tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits)
  ocfs2: use str_yes_no() and str_no_yes() helper functions
  include/linux/lz4.h: add some missing macros
  Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent
  Xarray: remove repeat check in xas_squash_marks()
  Xarray: distinguish large entries correctly in xas_split_alloc()
  Xarray: move forward index correctly in xas_pause()
  Xarray: do not return sibling entries from xas_find_marked()
  ipc/util.c: complete the kernel-doc function descriptions
  gcov: clang: use correct function param names
  latencytop: use correct kernel-doc format for func params
  minmax.h: remove some #defines that are only expanded once
  minmax.h: simplify the variants of clamp()
  minmax.h: move all the clamp() definitions after the min/max() ones
  minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
  minmax.h: reduce the #define expansion of min(), max() and clamp()
  minmax.h: update some comments
  minmax.h: add whitespace around operators and after commas
  nilfs2: do not update mtime of renamed directory that is not moved
  nilfs2: handle errors that nilfs_prepare_chunk() may return
  CREDITS: fix spelling mistake
  ...
2025-01-26 17:50:53 -08:00
Linus Torvalds
8883957b3c \n
-----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEq1nRK9aeMoq1VSgcnJ2qBz9kQNkFAmePs7oACgkQnJ2qBz9k
 QNmHuAf9GkLnY5u1/81xP5V9ukZ4N2yeMW0dydLS5cjWj/St5ELeMAza3jeqtJtD
 j36vbnmy2c5pPaGLAK8BJpMXT/R2TkmmKD004zcfqF2S3SgbGzdgO1zMZzq9KJpM
 woRKZtLuglDajedsDEBBcKotBhlN2+C/sQlFuL1mX4zitk9ajr0qYUB1+JqOeg5f
 qwPsDLT077ADpxd7lVIMcm+OqbduP5KWkBKYHpn7lJcLe1eqVMMzceJroW42zhVG
 Dq8Iln26bbU9Wx6FSPFCUcHEzHRHUfXmu07HN9U0X++0QgWjrmBQQLooGFB/bR4a
 edBrPpVas6xE4/brjgFX3gOKtv8xYg==
 =ewDV
 -----END PGP SIGNATURE-----

Merge tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify pre-content notification support from Jan Kara:
 "This introduces a new fsnotify event (FS_PRE_ACCESS) that gets
  generated before a file contents is accessed.

  The event is synchronous so if there is listener for this event, the
  kernel waits for reply. On success the execution continues as usual,
  on failure we propagate the error to userspace. This allows userspace
  to fill in file content on demand from slow storage. The context in
  which the events are generated has been picked so that we don't hold
  any locks and thus there's no risk of a deadlock for the userspace
  handler.

  The new pre-content event is available only for users with global
  CAP_SYS_ADMIN capability (similarly to other parts of fanotify
  functionality) and it is an administrator responsibility to make sure
  the userspace event handler doesn't do stupid stuff that can DoS the
  system.

  Based on your feedback from the last submission, fsnotify code has
  been improved and now file->f_mode encodes whether pre-content event
  needs to be generated for the file so the fast path when nobody wants
  pre-content event for the file just grows the additional file->f_mode
  check. As a bonus this also removes the checks whether the old
  FS_ACCESS event needs to be generated from the fast path. Also the
  place where the event is generated during page fault has been moved so
  now filemap_fault() generates the event if and only if there is no
  uptodate folio in the page cache.

  Also we have dropped FS_PRE_MODIFY event as current real-world users
  of the pre-content functionality don't really use it so let's start
  with the minimal useful feature set"

* tag 'fsnotify_hsm_for_v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (21 commits)
  fanotify: Fix crash in fanotify_init(2)
  fs: don't block write during exec on pre-content watched files
  fs: enable pre-content events on supported file systems
  ext4: add pre-content fsnotify hook for DAX faults
  btrfs: disable defrag on pre-content watched files
  xfs: add pre-content fsnotify hook for DAX faults
  fsnotify: generate pre-content permission event on page fault
  mm: don't allow huge faults for files with pre content watches
  fanotify: disable readahead if we have pre-content watches
  fanotify: allow to set errno in FAN_DENY permission response
  fanotify: report file range info with pre-content events
  fanotify: introduce FAN_PRE_ACCESS permission event
  fsnotify: generate pre-content permission event on truncate
  fsnotify: pass optional file access range in pre-content event
  fsnotify: introduce pre-content permission events
  fanotify: reserve event bit of deprecated FAN_DIR_MODIFY
  fanotify: rename a misnamed constant
  fanotify: don't skip extra event info if no info_mode is set
  fsnotify: check if file is actually being watched for pre-content events on open
  fsnotify: opt-in for permission events at file open time
  ...
2025-01-23 13:36:06 -08:00
Linus Torvalds
6c4aa896eb Performance events changes for v6.14:
- Seqlock optimizations that arose in a perf context and were
    merged into the perf tree:
 
    - seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
    - mm: Convert mm_lock_seq to a proper seqcount ((Suren Baghdasaryan)
    - mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren Baghdasaryan)
    - mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
 
  - Core perf enhancements:
 
    - Reduce 'struct page' footprint of perf by mapping pages
      in advance (Lorenzo Stoakes)
    - Save raw sample data conditionally based on sample type (Yabin Cui)
    - Reduce sampling overhead by checking sample_type in
      perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin Cui)
    - Export perf_exclude_event() (Namhyung Kim)
 
  - Uprobes scalability enhancements: (Andrii Nakryiko)
 
    - Simplify find_active_uprobe_rcu() VMA checks
    - Add speculative lockless VMA-to-inode-to-uprobe resolution
    - Simplify session consumer tracking
    - Decouple return_instance list traversal and freeing
    - Ensure return_instance is detached from the list before freeing
    - Reuse return_instances between multiple uretprobes within task
    - Guard against kmemdup() failing in dup_return_instance()
 
  - AMD core PMU driver enhancements:
 
    - Relax privilege filter restriction on AMD IBS (Namhyung Kim)
 
  - AMD RAPL energy counters support: (Dhananjay Ugwekar)
 
    - Introduce topology_logical_core_id() (K Prateek Nayak)
 
    - Remove the unused get_rapl_pmu_cpumask() function
    - Remove the cpu_to_rapl_pmu() function
    - Rename rapl_pmu variables
    - Make rapl_model struct global
    - Add arguments to the init and cleanup functions
    - Modify the generic variable names to *_pkg*
    - Remove the global variable rapl_msrs
    - Move the cntr_mask to rapl_pmus struct
    - Add core energy counter support for AMD CPUs
 
  - Intel core PMU driver enhancements:
 
    - Support RDPMC 'metrics clear mode' feature (Kan Liang)
    - Clarify adaptive PEBS processing (Kan Liang)
    - Factor out functions for PEBS records processing (Kan Liang)
    - Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
 
  - Intel uncore driver enhancements: (Kan Liang)
 
    - Convert buggy pmu->func_id use to pmu->registered
    - Support more units on Granite Rapids
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmeOJdQRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1i2yQ/+MXl7yfJOgdbwjBpgGGzH4burEO7ppak+
 ktzz+YjpNgjODe/xMAJGjjblouuYArCnRolc1UPvPm6M7jSY76wi42Y6c4dRtFoB
 2ReSrRqnreLOcrRS9nsTjvWRHfJHqJDVSd9TfHX6ILfzbaizCZOGYk558ZxAKRqu
 Lw7FOvLEe/Y3tg4z8dDg083jsasalKySP9wIPc0BkSqQTOfusd3KXju/Fux/9wkn
 hZcUgF4ds+0bH7xtO1/G9ILqGyeq97X1McIR9bAjln5Mxykclen4hSjRaWWHHo9O
 mzBKmd/blIATisfuuW+QLDQow3M1k3688cz7e9QOeWHHd/dJiMb9RLV90jdND/T/
 uLINC5vNemzyWEfnNiYQ31LjhG3SeuDiKWzRp36MbQcCh6EBdRXWLBgtmxq1L/3o
 ZCaCdtFu5+6epycdyOVZEpWDnjdx4GmLXMZi5WJfZ7fZ/IFjNkjk4OdzI1iRQ+i3
 Sbi75ep59ayTUhm5AB7gCJsP3R7EsZsiPHUenQdA2n9Sj6xE+IuhlS/QDQ9g5mdY
 Ijs0jHeVCGmhYoOD1xWnCZSzlnkEVU3zwfypAK+MC7pgtFMwDy5/Bu1USGxXXDy+
 aKsrJRSgHbtZ1gwoHstqkV+DeCTfElCLYkvigzI5Nmyib5Zp4vkwy2ZLWQjaNjm7
 mqRI7PugUkU=
 =c8XB
 -----END PGP SIGNATURE-----

Merge tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance events updates from Ingo Molnar:
 "Seqlock optimizations that arose in a perf context and were merged
  into the perf tree:

   - seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
   - mm: Convert mm_lock_seq to a proper seqcount (Suren Baghdasaryan)
   - mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren
     Baghdasaryan)
   - mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)

  Core perf enhancements:

   - Reduce 'struct page' footprint of perf by mapping pages in advance
     (Lorenzo Stoakes)
   - Save raw sample data conditionally based on sample type (Yabin Cui)
   - Reduce sampling overhead by checking sample_type in
     perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin
     Cui)
   - Export perf_exclude_event() (Namhyung Kim)

  Uprobes scalability enhancements: (Andrii Nakryiko)

   - Simplify find_active_uprobe_rcu() VMA checks
   - Add speculative lockless VMA-to-inode-to-uprobe resolution
   - Simplify session consumer tracking
   - Decouple return_instance list traversal and freeing
   - Ensure return_instance is detached from the list before freeing
   - Reuse return_instances between multiple uretprobes within task
   - Guard against kmemdup() failing in dup_return_instance()

  AMD core PMU driver enhancements:

   - Relax privilege filter restriction on AMD IBS (Namhyung Kim)

  AMD RAPL energy counters support: (Dhananjay Ugwekar)

   - Introduce topology_logical_core_id() (K Prateek Nayak)
   - Remove the unused get_rapl_pmu_cpumask() function
   - Remove the cpu_to_rapl_pmu() function
   - Rename rapl_pmu variables
   - Make rapl_model struct global
   - Add arguments to the init and cleanup functions
   - Modify the generic variable names to *_pkg*
   - Remove the global variable rapl_msrs
   - Move the cntr_mask to rapl_pmus struct
   - Add core energy counter support for AMD CPUs

  Intel core PMU driver enhancements:

   - Support RDPMC 'metrics clear mode' feature (Kan Liang)
   - Clarify adaptive PEBS processing (Kan Liang)
   - Factor out functions for PEBS records processing (Kan Liang)
   - Simplify the PEBS records processing for adaptive PEBS (Kan Liang)

  Intel uncore driver enhancements: (Kan Liang)

   - Convert buggy pmu->func_id use to pmu->registered
   - Support more units on Granite Rapids"

* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  perf: map pages in advance
  perf/x86/intel/uncore: Support more units on Granite Rapids
  perf/x86/intel/uncore: Clean up func_id
  perf/x86/intel: Support RDPMC metrics clear mode
  uprobes: Guard against kmemdup() failing in dup_return_instance()
  perf/x86: Relax privilege filter restriction on AMD IBS
  perf/core: Export perf_exclude_event()
  uprobes: Reuse return_instances between multiple uretprobes within task
  uprobes: Ensure return_instance is detached from the list before freeing
  uprobes: Decouple return_instance list traversal and freeing
  uprobes: Simplify session consumer tracking
  uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
  uprobes: simplify find_active_uprobe_rcu() VMA checks
  mm: introduce mmap_lock_speculate_{try_begin|retry}
  mm: convert mm_lock_seq to a proper seqcount
  mm/gup: Use raw_seqcount_try_begin()
  seqlock: add raw_seqcount_try_begin
  perf/x86/rapl: Add core energy counter support for AMD CPUs
  perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
  perf/x86/rapl: Remove the global variable rapl_msrs
  ...
2025-01-21 10:52:03 -08:00
Mateusz Guzik
51f8bd6db5 get_task_exe_file: check PF_KTHREAD locklessly
Same thing as 8ac5dc66599c ("get_task_mm: check PF_KTHREAD lockless")

Nowadays PF_KTHREAD is sticky and it was never protected by ->alloc_lock. 
Move the PF_KTHREAD check outside of task_lock() section to make this code
more understandable.

Link: https://lkml.kernel.org/r/20241119143526.704986-1-mjguzik@gmail.com
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-12 20:21:06 -08:00
Lorenzo Stoakes
8ac662f5da fork: avoid inappropriate uprobe access to invalid mm
If dup_mmap() encounters an issue, currently uprobe is able to access the
relevant mm via the reverse mapping (in build_map_info()), and if we are
very unlucky with a race window, observe invalid XA_ZERO_ENTRY state which
we establish as part of the fork error path.

This occurs because uprobe_write_opcode() invokes anon_vma_prepare() which
in turn invokes find_mergeable_anon_vma() that uses a VMA iterator,
invoking vma_iter_load() which uses the advanced maple tree API and thus
is able to observe XA_ZERO_ENTRY entries added to dup_mmap() in commit
d24062914837 ("fork: use __mt_dup() to duplicate maple tree in
dup_mmap()").

This change was made on the assumption that only process tear-down code
would actually observe (and make use of) these values.  However this very
unlikely but still possible edge case with uprobes exists and
unfortunately does make these observable.

The uprobe operation prevents races against the dup_mmap() operation via
the dup_mmap_sem semaphore, which is acquired via uprobe_start_dup_mmap()
and dropped via uprobe_end_dup_mmap(), and held across
register_for_each_vma() prior to invoking build_map_info() which does the
reverse mapping lookup.

Currently these are acquired and dropped within dup_mmap(), which exposes
the race window prior to error handling in the invoking dup_mm() which
tears down the mm.

We can avoid all this by just moving the invocation of
uprobe_start_dup_mmap() and uprobe_end_dup_mmap() up a level to dup_mm()
and only release this lock once the dup_mmap() operation succeeds or clean
up is done.

This means that the uprobe code can never observe an incompletely
constructed mm and resolves the issue in this case.

Link: https://lkml.kernel.org/r/20241210172412.52995-1-lorenzo.stoakes@oracle.com
Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: syzbot+2d788f4f7cb660dac4b7@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/6756d273.050a0220.2477f.003d.GAE@google.com/
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-18 19:04:44 -08:00
Amir Goldstein
0357ef03c9 fs: don't block write during exec on pre-content watched files
Commit 2a010c412853 ("fs: don't block i_writecount during exec") removed
the legacy behavior of getting ETXTBSY on attempt to open and executable
file for write while it is being executed.

This commit was reverted because an application that depends on this
legacy behavior was broken by the change.

We need to allow HSM writing into executable files while executed to
fill their content on-the-fly.

To that end, disable the ETXTBSY legacy behavior for files that are
watched by pre-content events.

This change is not expected to cause regressions with existing systems
which do not have any pre-content event listeners.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20241128142532.465176-1-amir73il@gmail.com
2024-12-11 17:45:18 +01:00
Suren Baghdasaryan
eb449bd969 mm: convert mm_lock_seq to a proper seqcount
Convert mm_lock_seq to be seqcount_t and change all mmap_write_lock
variants to increment it, in-line with the usual seqcount usage pattern.
This lets us check whether the mmap_lock is write-locked by checking
mm_lock_seq.sequence counter (odd=locked, even=unlocked). This will be
used when implementing mmap_lock speculation functions.
As a result vm_lock_seq is also change to be unsigned to match the type
of mm_lock_seq.sequence.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Link: https://lkml.kernel.org/r/20241122174416.1367052-2-surenb@google.com
2024-12-02 12:01:38 +01:00
Christian Brauner
3b83203538
Revert "fs: don't block i_writecount during exec"
This reverts commit 2a010c41285345da60cece35575b4e0af7e7bf44.

Rui Ueyama <rui314@gmail.com> writes:

> I'm the creator and the maintainer of the mold linker
> (https://github.com/rui314/mold). Recently, we discovered that mold
> started causing process crashes in certain situations due to a change
> in the Linux kernel. Here are the details:
>
> - In general, overwriting an existing file is much faster than
> creating an empty file and writing to it on Linux, so mold attempts to
> reuse an existing executable file if it exists.
>
> - If a program is running, opening the executable file for writing
> previously failed with ETXTBSY. If that happens, mold falls back to
> creating a new file.
>
> - However, the Linux kernel recently changed the behavior so that
> writing to an executable file is now always permitted
> (https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2a010c412853).
>
> That caused mold to write to an executable file even if there's a
> process running that file. Since changes to mmap'ed files are
> immediately visible to other processes, any processes running that
> file would almost certainly crash in a very mysterious way.
> Identifying the cause of these random crashes took us a few days.
>
> Rejecting writes to an executable file that is currently running is a
> well-known behavior, and Linux had operated that way for a very long
> time. So, I don’t believe relying on this behavior was our mistake;
> rather, I see this as a regression in the Linux kernel.

Quoting myself from commit 2a010c412853 ("fs: don't block i_writecount during exec")

> Yes, someone in userspace could potentially be relying on this. It's not
> completely out of the realm of possibility but let's find out if that's
> actually the case and not guess.

It seems we found out that someone is relying on this obscure behavior.
So revert the change.

Link: https://github.com/rui314/mold/issues/1361
Link: https://lore.kernel.org/r/4a2bc207-76be-4715-8e12-7fc45a76a125@leemhuis.info
Cc: <stable@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-11-27 12:51:30 +01:00
Linus Torvalds
5c00ff742b - The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection algorithm.
   This leads to improved memory savings.
 
 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
 
 	- "refine mas_mab_cp()"
 	- "Reduce the space to be cleared for maple_big_node"
 	- "maple_tree: simplify mas_push_node()"
 	- "Following cleanup after introduce mas_wr_store_type()"
 	- "refine storing null"
 
 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.
 
 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping code.
 
 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of shadow
   entries.
 
 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.
 
 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in the
   hugetlb code.
 
 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page into
   small pages.  Instead we replace the whole thing with a THP.  More
   consistent cleaner and potentiall saves a large number of pagefaults.
 
 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.
 
 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to do.
 
 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio size
   rather than as individual pages.  A 20% speedup was observed.
 
 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
 
 - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
   removes the long-deprecated memcgv2 charge moving feature.
 
 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.
 
 - The series "x86/module: use large ROX pages for text allocations" from
   Mike Rapoport teaches x86 to use large pages for read-only-execute
   module text.
 
 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.
 
 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/.  A slow march towards shrinking
   struct page.
 
 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.
 
 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression.  It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.
 
 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
   over to the KUnit framework.
 
 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a single
   VMA, rather than requiring that multiple VMAs be created for this.
   Improved efficiencies for userspace memory allocators are expected.
 
 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.
 
 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.
 
 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP from
   the kernel boot command line.
 
 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.
 
 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep is
   enabled.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZzwFqgAKCRDdBJ7gKXxA
 jkeuAQCkl+BmeYHE6uG0hi3pRxkupseR6DEOAYIiTv0/l8/GggD/Z3jmEeqnZaNq
 xyyenpibWgUoShU2wZ/Ha8FE5WDINwg=
 =JfWR
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "zram: optimal post-processing target selection" from
   Sergey Senozhatsky improves zram's post-processing selection
   algorithm. This leads to improved memory savings.

 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
	- "refine mas_mab_cp()"
	- "Reduce the space to be cleared for maple_big_node"
	- "maple_tree: simplify mas_push_node()"
	- "Following cleanup after introduce mas_wr_store_type()"
	- "refine storing null"

 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.

 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping
   code.

 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of
   shadow entries.

 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.

 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in
   the hugetlb code.

 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page
   into small pages. Instead we replace the whole thing with a THP. More
   consistent cleaner and potentiall saves a large number of pagefaults.

 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.

 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to
   do.

 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio
   size rather than as individual pages. A 20% speedup was observed.

 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON
   splitting.

 - The series "memcg-v1: fully deprecate charge moving" from Shakeel
   Butt removes the long-deprecated memcgv2 charge moving feature.

 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.

 - The series "x86/module: use large ROX pages for text allocations"
   from Mike Rapoport teaches x86 to use large pages for
   read-only-execute module text.

 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.

 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/. A slow march towards shrinking
   struct page.

 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.

 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression. It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.

 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in
   tests over to the KUnit framework.

 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a
   single VMA, rather than requiring that multiple VMAs be created for
   this. Improved efficiencies for userspace memory allocators are
   expected.

 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.

 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.

 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP
   from the kernel boot command line.

 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.

 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep
   is enabled.

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Linus Torvalds
bf9aa14fc5 A rather large update for timekeeping and timers:
- The final step to get rid of auto-rearming posix-timers
 
     posix-timers are currently auto-rearmed by the kernel when the signal
     of the timer is ignored so that the timer signal can be delivered once
     the corresponding signal is unignored.
 
     This requires to throttle the timer to prevent a DoS by small intervals
     and keeps the system pointlessly out of low power states for no value.
     This is a long standing non-trivial problem due to the lock order of
     posix-timer lock and the sighand lock along with life time issues as
     the timer and the sigqueue have different life time rules.
 
     Cure this by:
 
      * Embedding the sigqueue into the timer struct to have the same life
        time rules. Aside of that this also avoids the lookup of the timer
        in the signal delivery and rearm path as it's just a always valid
        container_of() now.
 
      * Queuing ignored timer signals onto a seperate ignored list.
 
      * Moving queued timer signals onto the ignored list when the signal is
        switched to SIG_IGN before it could be delivered.
 
      * Walking the ignored list when SIG_IGN is lifted and requeue the
        signals to the actual signal lists. This allows the signal delivery
        code to rearm the timer.
 
     This also required to consolidate the signal delivery rules so they are
     consistent across all situations. With that all self test scenarios
     finally succeed.
 
   - Core infrastructure for VFS multigrain timestamping
 
     This is required to allow the kernel to use coarse grained time stamps
     by default and switch to fine grained time stamps when inode attributes
     are actively observed via getattr().
 
     These changes have been provided to the VFS tree as well, so that the
     VFS specific infrastructure could be built on top.
 
   - Cleanup and consolidation of the sleep() infrastructure
 
     * Move all sleep and timeout functions into one file
 
     * Rework udelay() and ndelay() into proper documented inline functions
       and replace the hardcoded magic numbers by proper defines.
 
     * Rework the fsleep() implementation to take the reality of the timer
       wheel granularity on different HZ values into account. Right now the
       boundaries are hard coded time ranges which fail to provide the
       requested accuracy on different HZ settings.
 
     * Update documentation for all sleep/timeout related functions and fix
       up stale documentation links all over the place
 
     * Fixup a few usage sites
 
   - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP clocks
 
     A system can have multiple PTP clocks which are participating in
     seperate and independent PTP clock domains. So far the kernel only
     considers the PTP clock which is based on CLOCK TAI relevant as that's
     the clock which drives the timekeeping adjustments via the various user
     space daemons through adjtimex(2).
 
     The non TAI based clock domains are accessible via the file descriptor
     based posix clocks, but their usability is very limited. They can't be
     accessed fast as they always go all the way out to the hardware and
     they cannot be utilized in the kernel itself.
 
     As Time Sensitive Networking (TSN) gains traction it is required to
     provide fast user and kernel space access to these clocks.
 
     The approach taken is to utilize the timekeeping and adjtimex(2)
     infrastructure to provide this access in a similar way how the kernel
     provides access to clock MONOTONIC, REALTIME etc.
 
     Instead of creating a duplicated infrastructure this rework converts
     timekeeping and adjtimex(2) into generic functionality which operates
     on pointers to data structures instead of using static variables.
 
     This allows to provide time accessors and adjtimex(2) functionality for
     the independent PTP clocks in a subsequent step.
 
   - Consolidate hrtimer initialization
 
     hrtimers are set up by initializing the data structure and then
     seperately setting the callback function for historical reasons.
 
     That's an extra unnecessary step and makes Rust support less straight
     forward than it should be.
 
     Provide a new set of hrtimer_setup*() functions and convert the core
     code and a few usage sites of the less frequently used interfaces over.
 
     The bulk of the htimer_init() to hrtimer_setup() conversion is already
     prepared and scheduled for the next merge window.
 
   - Drivers:
 
     * Ensure that the global timekeeping clocksource is utilizing the
       cluster 0 timer on MIPS multi-cluster systems.
 
       Otherwise CPUs on different clusters use their cluster specific
       clocksource which is not guaranteed to be synchronized with other
       clusters.
 
     * Mostly boring cleanups, fixes, improvements and code movement
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmc7kPITHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoZKkD/9OUL6fOJrDUmOYBa4QVeMyfTef4EaL
 tvwIMM/29XQFeiq3xxCIn+EMnHjXn2lvIhYGQ7GKsbKYwvJ7ZBDpQb+UMhZ2nKI9
 6D6BP6WomZohKeH2fZbJQAdqOi3KRYdvQdIsVZUexkqiaVPphRvOH9wOr45gHtZM
 EyMRSotPlQTDqcrbUejDMEO94GyjDCYXRsyATLxjmTzL/N4xD4NRIiotjM2vL/a9
 8MuCgIhrKUEyYlFoOxxeokBsF3kk3/ez2jlG9b/N8VLH3SYIc2zgL58FBgWxlmgG
 bY71nVG3nUgEjxBd2dcXAVVqvb+5widk8p6O7xxOAQKTLMcJ4H0tQDkMnzBtUzvB
 DGAJDHAmAr0g+ja9O35Pkhunkh4HYFIbq0Il4d1HMKObhJV0JumcKuQVxrXycdm3
 UZfq3seqHsZJQbPgCAhlFU0/2WWScocbee9bNebGT33KVwSp5FoVv89C/6Vjb+vV
 Gusc3thqrQuMAZW5zV8g4UcBAA/xH4PB0I+vHib+9XPZ4UQ7/6xKl2jE0kd5hX7n
 AAUeZvFNFqIsY+B6vz+Jx/yzyM7u5cuXq87pof5EHVFzv56lyTp4ToGcOGYRgKH5
 JXeYV1OxGziSDrd5vbf9CzdWMzqMvTefXrHbWrjkjhNOe8E1A8O88RZ5uRKZhmSw
 hZZ4hdM9+3T7cg==
 =2VC6
 -----END PGP SIGNATURE-----

Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "A rather large update for timekeeping and timers:

   - The final step to get rid of auto-rearming posix-timers

     posix-timers are currently auto-rearmed by the kernel when the
     signal of the timer is ignored so that the timer signal can be
     delivered once the corresponding signal is unignored.

     This requires to throttle the timer to prevent a DoS by small
     intervals and keeps the system pointlessly out of low power states
     for no value. This is a long standing non-trivial problem due to
     the lock order of posix-timer lock and the sighand lock along with
     life time issues as the timer and the sigqueue have different life
     time rules.

     Cure this by:

       - Embedding the sigqueue into the timer struct to have the same
         life time rules. Aside of that this also avoids the lookup of
         the timer in the signal delivery and rearm path as it's just a
         always valid container_of() now.

       - Queuing ignored timer signals onto a seperate ignored list.

       - Moving queued timer signals onto the ignored list when the
         signal is switched to SIG_IGN before it could be delivered.

       - Walking the ignored list when SIG_IGN is lifted and requeue the
         signals to the actual signal lists. This allows the signal
         delivery code to rearm the timer.

     This also required to consolidate the signal delivery rules so they
     are consistent across all situations. With that all self test
     scenarios finally succeed.

   - Core infrastructure for VFS multigrain timestamping

     This is required to allow the kernel to use coarse grained time
     stamps by default and switch to fine grained time stamps when inode
     attributes are actively observed via getattr().

     These changes have been provided to the VFS tree as well, so that
     the VFS specific infrastructure could be built on top.

   - Cleanup and consolidation of the sleep() infrastructure

       - Move all sleep and timeout functions into one file

       - Rework udelay() and ndelay() into proper documented inline
         functions and replace the hardcoded magic numbers by proper
         defines.

       - Rework the fsleep() implementation to take the reality of the
         timer wheel granularity on different HZ values into account.
         Right now the boundaries are hard coded time ranges which fail
         to provide the requested accuracy on different HZ settings.

       - Update documentation for all sleep/timeout related functions
         and fix up stale documentation links all over the place

       - Fixup a few usage sites

   - Rework of timekeeping and adjtimex(2) to prepare for multiple PTP
     clocks

     A system can have multiple PTP clocks which are participating in
     seperate and independent PTP clock domains. So far the kernel only
     considers the PTP clock which is based on CLOCK TAI relevant as
     that's the clock which drives the timekeeping adjustments via the
     various user space daemons through adjtimex(2).

     The non TAI based clock domains are accessible via the file
     descriptor based posix clocks, but their usability is very limited.
     They can't be accessed fast as they always go all the way out to
     the hardware and they cannot be utilized in the kernel itself.

     As Time Sensitive Networking (TSN) gains traction it is required to
     provide fast user and kernel space access to these clocks.

     The approach taken is to utilize the timekeeping and adjtimex(2)
     infrastructure to provide this access in a similar way how the
     kernel provides access to clock MONOTONIC, REALTIME etc.

     Instead of creating a duplicated infrastructure this rework
     converts timekeeping and adjtimex(2) into generic functionality
     which operates on pointers to data structures instead of using
     static variables.

     This allows to provide time accessors and adjtimex(2) functionality
     for the independent PTP clocks in a subsequent step.

   - Consolidate hrtimer initialization

     hrtimers are set up by initializing the data structure and then
     seperately setting the callback function for historical reasons.

     That's an extra unnecessary step and makes Rust support less
     straight forward than it should be.

     Provide a new set of hrtimer_setup*() functions and convert the
     core code and a few usage sites of the less frequently used
     interfaces over.

     The bulk of the htimer_init() to hrtimer_setup() conversion is
     already prepared and scheduled for the next merge window.

   - Drivers:

       - Ensure that the global timekeeping clocksource is utilizing the
         cluster 0 timer on MIPS multi-cluster systems.

         Otherwise CPUs on different clusters use their cluster specific
         clocksource which is not guaranteed to be synchronized with
         other clusters.

       - Mostly boring cleanups, fixes, improvements and code movement"

* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
  posix-timers: Fix spurious warning on double enqueue versus do_exit()
  clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
  clocksource/drivers/gpx: Remove redundant casts
  clocksource/drivers/timer-ti-dm: Fix child node refcount handling
  dt-bindings: timer: actions,owl-timer: convert to YAML
  clocksource/drivers/ralink: Add Ralink System Tick Counter driver
  clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
  clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
  clocksource/drivers:sp804: Make user selectable
  clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
  hrtimers: Delete hrtimer_init_on_stack()
  alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
  io_uring: Switch to use hrtimer_setup_on_stack()
  sched/idle: Switch to use hrtimer_setup_on_stack()
  hrtimers: Delete hrtimer_init_sleeper_on_stack()
  wait: Switch to use hrtimer_setup_sleeper_on_stack()
  timers: Switch to use hrtimer_setup_sleeper_on_stack()
  net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
  futex: Switch to use hrtimer_setup_sleeper_on_stack()
  fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
  ...
2024-11-19 16:35:06 -08:00
Linus Torvalds
0892d74213 x86/splitlock changes for v6.13:
- Move Split and Bus lock code to a dedicated file (Ravi Bangoria)
  - Add split/bus lock support for AMD (Ravi Bangoria)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmc7gMERHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1hEaQ//YRk2Dc3VkiwC+ZE44Bi4ZlztACzjvkL/
 sFjOqX4dSWJLMFDPfISGGEN4e20IFA46uYXwoZQOZEz5RY4tPaJYw+o1aBP5YYEN
 EEv4iRc20FIIYckkyCShP00dKoZlmb6FbxyUysRRwZW0XJuMVLyJnGNmZs0peVvt
 5c8+7erl0CPN9RaR66lULT4YenyvUZ7DChfeB3a1LbazC5+IrEumiIysLJUKj6zN
 075+FeQ084156sFR+LUSjblxLKzY/OqT/727osST2WlMo/HWLIJImCXodHMHG+LC
 dRI0NFFU9zn2G6rGcoltLNsU/TSJfaWoGS8pm6c96kItEZly/BFz5MF1IQIbCfDx
 YFJpil1zJQQeV3FUXldhKGoSio0fv0KWcqC0TLjj/DhqprjdktJGuGIX6ChmkytA
 TDLZPWZxInZdVnWVMBuaJ6defMRBLART02u9DRIoXYEX6aDLjJ1JFTRe5hU9vVab
 cq+GR3ZSeDM9gSGjfW6dGG5746KXX+Wwxv4stxSoygSxmrLPH38CrZ5m66edtKzq
 P+V2/utvhdHZSKawsIpM4Xz5u7fweySkVFQjJyEEeMWyXnfC+alP9OUsVTKS8mFa
 zKbX7mEgnBDcEE9w6O5itL4nIgB3Kooci5uEWDRTAYUee82Hqk09Ycyb5XQkJ7bs
 Cl65CoY+XAA=
 =QpKp
 -----END PGP SIGNATURE-----

Merge tag 'x86-splitlock-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 splitlock updates from Ingo Molnar:

 - Move Split and Bus lock code to a dedicated file (Ravi Bangoria)

 - Add split/bus lock support for AMD (Ravi Bangoria)

* tag 'x86-splitlock-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/bus_lock: Add support for AMD
  x86/split_lock: Move Split and Bus lock code to a dedicated file
2024-11-19 14:34:02 -08:00
Linus Torvalds
3f020399e4 Scheduler changes for v6.13:
- Core facilities:
 
     - Add the "Lazy preemption" model (CONFIG_PREEMPT_LAZY=y), which optimizes
       fair-class preemption by delaying preemption requests to the
       tick boundary, while working as full preemption for RR/FIFO/DEADLINE
       classes. (Peter Zijlstra)
 
         - x86: Enable Lazy preemption (Peter Zijlstra)
         - riscv: Enable Lazy preemption (Jisheng Zhang)
 
     - Initialize idle tasks only once (Thomas Gleixner)
 
     - sched/ext: Remove sched_fork() hack (Thomas Gleixner)
 
  - Fair scheduler:
     - Optimize the PLACE_LAG when se->vlag is zero (Huang Shijie)
 
  - Idle loop:
       Optimize the generic idle loop by removing unnecessary
       memory barrier (Zhongqiu Han)
 
  - RSEQ:
     - Improve cache locality of RSEQ concurrency IDs for
       intermittent workloads (Mathieu Desnoyers)
 
  - Waitqueues:
     - Make wake_up_{bit,var} less fragile (Neil Brown)
 
  - PSI:
     - Pass enqueue/dequeue flags to psi callbacks directly (Johannes Weiner)
 
  - Preparatory patches for proxy execution:
     - core: Add move_queued_task_locked helper (Connor O'Brien)
     - core: Consolidate pick_*_task to task_is_pushable helper (Connor O'Brien)
     - core: Split out __schedule() deactivate task logic into a helper (John Stultz)
     - core: Split scheduler and execution contexts (Peter Zijlstra)
     - locking/mutex: Make mutex::wait_lock irq safe (Juri Lelli)
     - locking/mutex: Expose __mutex_owner() (Juri Lelli)
     - locking/mutex: Remove wakeups from under mutex::wait_lock (Peter Zijlstra)
 
  - Misc fixes and cleanups:
     - core: Remove unused __HAVE_THREAD_FUNCTIONS hook support (David Disseldorp)
     - core: Update the comment for TIF_NEED_RESCHED_LAZY (Sebastian Andrzej Siewior)
     - wait: Remove unused bit_wait_io_timeout (Dr. David Alan Gilbert)
     - fair: remove the DOUBLE_TICK feature (Huang Shijie)
     - fair: fix the comment for PREEMPT_SHORT (Huang Shijie)
     - uclamp: Fix unnused variable warning (Christian Loehle)
     - rt: No PREEMPT_RT=y for all{yes,mod}config
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmc7fnQRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1hZTBAAozVdWA2m51aNa67HvAZta/olmrIagVbW
 inwbTgqa8b+UfeWEuKOfrZr5khjEh6pLgR3dBTib1uH6xxYj/Okds+qbPWSBPVLh
 yzavlm/zJZM1U1XtxE3eyVfqWik4GrY7DoIMDQQr+YH7rNXonJeJkll38OI2E5MC
 q3Q01qyMo8RJJX8qkf3f8ObOoP/51NsVniTw0Zb2fzEhXz8FjezLlxk6cMfgSkJG
 lg9gfIwUZ7Xg5neRo4kJcc3Ht31KYOhWSiupBJzRD1hss/N/AybvMcTX/Cm8d07w
 HIAdDDAn84o46miFo/a0V/hsJZ72idWbqxVJUCtaezrpOUiFkG+uInRvG/ynr0lF
 5dEI9f+6PUw8Nc7L72IyHkobjPqS2IefSaxYYCBKmxMX2qrenfTor/pKiWzzhBIl
 rX3MZSuUJ8NjV4rNGD/qXRM1IsMJrsDwxDyv+sRec3XdH33x286ds6aAUEPDQ6N7
 96VS0sOKcNUJN8776ErNjlIxRl8HTlpkaO3nZlQIfXgTlXUpRvOuKbEWqP+606lo
 oANgJTKgUhgJPWZnvmdRxDjSiOp93QcImjus9i1tN81FGiEDleONsJUxu2Di1E5+
 s1nCiytjq+cdvzCqFyiOZUh+g6kSZ4yXxNgLg2UvbXzX1zOeUQT3WtyKUhMPXhU8
 esh1TgbUbpE=
 =Zcqj
 -----END PGP SIGNATURE-----

Merge tag 'sched-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Core facilities:

   - Add the "Lazy preemption" model (CONFIG_PREEMPT_LAZY=y), which
     optimizes fair-class preemption by delaying preemption requests to
     the tick boundary, while working as full preemption for
     RR/FIFO/DEADLINE classes. (Peter Zijlstra)
        - x86: Enable Lazy preemption (Peter Zijlstra)
        - riscv: Enable Lazy preemption (Jisheng Zhang)

   - Initialize idle tasks only once (Thomas Gleixner)

   - sched/ext: Remove sched_fork() hack (Thomas Gleixner)

  Fair scheduler:

   - Optimize the PLACE_LAG when se->vlag is zero (Huang Shijie)

  Idle loop:

   - Optimize the generic idle loop by removing unnecessary memory
     barrier (Zhongqiu Han)

  RSEQ:

   - Improve cache locality of RSEQ concurrency IDs for intermittent
     workloads (Mathieu Desnoyers)

  Waitqueues:

   - Make wake_up_{bit,var} less fragile (Neil Brown)

  PSI:

   - Pass enqueue/dequeue flags to psi callbacks directly (Johannes
     Weiner)

  Preparatory patches for proxy execution:

   - Add move_queued_task_locked helper (Connor O'Brien)

   - Consolidate pick_*_task to task_is_pushable helper (Connor O'Brien)

   - Split out __schedule() deactivate task logic into a helper (John
     Stultz)

   - Split scheduler and execution contexts (Peter Zijlstra)

   - Make mutex::wait_lock irq safe (Juri Lelli)

   - Expose __mutex_owner() (Juri Lelli)

   - Remove wakeups from under mutex::wait_lock (Peter Zijlstra)

  Misc fixes and cleanups:

   - Remove unused __HAVE_THREAD_FUNCTIONS hook support (David
     Disseldorp)

   - Update the comment for TIF_NEED_RESCHED_LAZY (Sebastian Andrzej
     Siewior)

   - Remove unused bit_wait_io_timeout (Dr. David Alan Gilbert)

   - remove the DOUBLE_TICK feature (Huang Shijie)

   - fix the comment for PREEMPT_SHORT (Huang Shijie)

   - Fix unnused variable warning (Christian Loehle)

   - No PREEMPT_RT=y for all{yes,mod}config"

* tag 'sched-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  sched, x86: Update the comment for TIF_NEED_RESCHED_LAZY.
  sched: No PREEMPT_RT=y for all{yes,mod}config
  riscv: add PREEMPT_LAZY support
  sched, x86: Enable Lazy preemption
  sched: Enable PREEMPT_DYNAMIC for PREEMPT_RT
  sched: Add Lazy preemption model
  sched: Add TIF_NEED_RESCHED_LAZY infrastructure
  sched/ext: Remove sched_fork() hack
  sched: Initialize idle tasks only once
  sched: psi: pass enqueue/dequeue flags to psi callbacks directly
  sched/uclamp: Fix unnused variable warning
  sched: Split scheduler and execution contexts
  sched: Split out __schedule() deactivate task logic into a helper
  sched: Consolidate pick_*_task to task_is_pushable helper
  sched: Add move_queued_task_locked helper
  locking/mutex: Expose __mutex_owner()
  locking/mutex: Make mutex::wait_lock irq safe
  locking/mutex: Remove wakeups from under mutex::wait_lock
  sched: Improve cache locality of RSEQ concurrency IDs for intermittent workloads
  sched: idle: Optimize the generic idle loop by removing needless memory barrier
  ...
2024-11-19 14:16:06 -08:00
Thomas Gleixner
69f032c92c signal: Provide ignored_posix_timers list
To prepare for handling posix timer signals on sigaction(SIG_IGN) properly,
add a list to task::signal.

This list will be used to queue posix timers so their signal can be
requeued when SIG_IGN is lifted later.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/20241105064213.920101900@linutronix.de
2024-11-07 02:14:45 +01:00
Nanyong Sun
f2f484085e mm: move mm flags to mm_types.h
The types of mm flags are now far beyond the core dump related features. 
This patch moves mm flags from linux/sched/coredump.h to linux/mm_types.h.
The linux/sched/coredump.h has include the mm_types.h, so the C files
related to coredump does not need to change head file inclusion.  In
addition, the inclusion of sched/coredump.h now can be deleted from the C
files that irrelevant to core dump.

Link: https://lkml.kernel.org/r/20240926074922.2721274-1-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:56:26 -08:00
Lorenzo Stoakes
cd3f8467af mm: refactor mm_access() to not return NULL
mm_access() can return NULL if the mm is not found, but this is handled
the same as an error in all callers, with some translating this into an
-ESRCH error.

Only proc_mem_open() returns NULL if no mm is found, however in this case
it is clearer and makes more sense to explicitly handle the error. 
Additionally we take the opportunity to refactor the function to eliminate
unnecessary nesting.

Simplify things by simply returning -ESRCH if no mm is found - this both
eliminates confusing use of the IS_ERR_OR_NULL() macro, and simplifies
callers which would return -ESRCH by returning this error directly.

[lorenzo.stoakes@oracle.com: prefer neater pointer error comparison]
  Link: https://lkml.kernel.org/r/2fae1834-749a-45e1-8594-5e5979cf7103@lucifer.local
Link: https://lkml.kernel.org/r/20240924201023.193135-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:56:23 -08:00
Linus Torvalds
b019b4a670 A single fix for posix CPU timers
When a thread is cloned, the posix CPU timers are not inherited.
 
   If the parent has a CPU timer armed the corresponding tick dependency in
   the tasks tick_dep_mask is set and copied to the new thread, which means
   the new thread and all decendants will prevent the system to go into full
   NOHZ operation.
 
   Clear the tick dependency mask in copy_process() to fix this.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmcnT/oTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoZw5D/0bqjjMYiE0ws8nuuXN1gL2T1wt6P2C
 2zzEKnk6nsxnGbMfFs7XifDkqSOHNVro7F6kCkz6cH4U/VSK6R2nNONbufz4mNWk
 6uDvdlZps30ekmxN+C3fB6S/4MNVOhXFFXjsQhT/PxX/CfibVP5fATLtcRLq9Lfx
 mV3nnxKTHPjDGz2/2QRyYpA3G1fzOj/l2QeJsVAIC8GxCo7drLVe0yn5Yt+13zhU
 JMjgt9ox4PKFsjaXrqvt1yKNTtb+evjYSIVXxIg60oxUkfva6XFLXJv3rjbARUNj
 aqBHfkZ1/d2Hwc0WexDZfvhNWeCqnfUA+db7ALSYICbNd37EVxWVZA2TwfkkWKSt
 RDq3xX6NJSd71h0lxDvzv7Ph3NUq23rq3LycAkjqfhiFjPQmE6axtnioXcR5mtVp
 q9tilB/3I4zj4BIYPfd9KowkdclRSK+B3Oo0DTyuVhKLggF0UD3poDxT4HxnBCFB
 uKDV8GDsoD8Ksjsl0/X/D4oorqLYAT0tG9gxMw1Kii16gijhhu5qeqTWY+qs9ieg
 2J+Ku83QLQgljvy2s7y0AnMZMxaeKN5YMs6zNV+yGAoTFyft3CnBMKalPHfOCI0A
 fdKHi2aKm+lLrp/UIG2Yw9N1xfcrGWA2moH+9dw6zTyAei+TInP+WYndI7VR5EDf
 3KvW3OoRf0sywA==
 =83r/
 -----END PGP SIGNATURE-----

Merge tag 'timers-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Thomas Gleixner:
 "A single fix for posix CPU timers.

  When a thread is cloned, the posix CPU timers are not inherited.

  If the parent has a CPU timer armed the corresponding tick dependency
  in the tasks tick_dep_mask is set and copied to the new thread, which
  means the new thread and all decendants will prevent the system to go
  into full NOHZ operation.

  Clear the tick dependency mask in copy_process() to fix this"

* tag 'timers-urgent-2024-11-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  posix-cpu-timers: Clear TICK_DEP_BIT_POSIX_TIMER on clone
2024-11-03 08:22:21 -10:00
Lorenzo Stoakes
985da552a9 fork: only invoke khugepaged, ksm hooks if no error
There is no reason to invoke these hooks early against an mm that is in an
incomplete state.

The change in commit d24062914837 ("fork: use __mt_dup() to duplicate
maple tree in dup_mmap()") makes this more pertinent as we may be in a
state where entries in the maple tree are not yet consistent.

Their placement early in dup_mmap() only appears to have been meaningful
for early error checking, and since functionally it'd require a very small
allocation to fail (in practice 'too small to fail') that'd only occur in
the most dire circumstances, meaning the fork would fail or be OOM'd in
any case.

Since both khugepaged and KSM tracking are there to provide optimisations
to memory performance rather than critical functionality, it doesn't
really matter all that much if, under such dire memory pressure, we fail
to register an mm with these.

As a result, we follow the example of commit d2081b2bf819 ("mm:
khugepaged: make khugepaged_enter() void function") and make ksm_fork() a
void function also.

We only expose the mm to these functions once we are done with them and
only if no error occurred in the fork operation.

Link: https://lkml.kernel.org/r/e0cb8b840c9d1d5a6e84d4f8eff5f3f2022aa10c.1729014377.git.lorenzo.stoakes@oracle.com
Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28 21:40:39 -07:00
Lorenzo Stoakes
f64e67e5d3 fork: do not invoke uffd on fork if error occurs
Patch series "fork: do not expose incomplete mm on fork".

During fork we may place the virtual memory address space into an
inconsistent state before the fork operation is complete.

In addition, we may encounter an error during the fork operation that
indicates that the virtual memory address space is invalidated.

As a result, we should not be exposing it in any way to external machinery
that might interact with the mm or VMAs, machinery that is not designed to
deal with incomplete state.

We specifically update the fork logic to defer khugepaged and ksm to the
end of the operation and only to be invoked if no error arose, and
disallow uffd from observing fork events should an error have occurred.


This patch (of 2):

Currently on fork we expose the virtual address space of a process to
userland unconditionally if uffd is registered in VMAs, regardless of
whether an error arose in the fork.

This is performed in dup_userfaultfd_complete() which is invoked
unconditionally, and performs two duties - invoking registered handlers
for the UFFD_EVENT_FORK event via dup_fctx(), and clearing down
userfaultfd_fork_ctx objects established in dup_userfaultfd().

This is problematic, because the virtual address space may not yet be
correctly initialised if an error arose.

The change in commit d24062914837 ("fork: use __mt_dup() to duplicate
maple tree in dup_mmap()") makes this more pertinent as we may be in a
state where entries in the maple tree are not yet consistent.

We address this by, on fork error, ensuring that we roll back state that
we would otherwise expect to clean up through the event being handled by
userland and perform the memory freeing duty otherwise performed by
dup_userfaultfd_complete().

We do this by implementing a new function, dup_userfaultfd_fail(), which
performs the same loop, only decrementing reference counts.

Note that we perform mmgrab() on the parent and child mm's, however
userfaultfd_ctx_put() will mmdrop() this once the reference count drops to
zero, so we will avoid memory leaks correctly here.

Link: https://lkml.kernel.org/r/cover.1729014377.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/d3691d58bb58712b6fb3df2be441d175bd3cdf07.1729014377.git.lorenzo.stoakes@oracle.com
Fixes: d24062914837 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-28 21:40:38 -07:00
Benjamin Segall
b5413156ba posix-cpu-timers: Clear TICK_DEP_BIT_POSIX_TIMER on clone
When cloning a new thread, its posix_cputimers are not inherited, and
are cleared by posix_cputimers_init(). However, this does not clear the
tick dependency it creates in tsk->tick_dep_mask, and the handler does
not reach the code to clear the dependency if there were no timers to
begin with.

Thus if a thread has a cputimer running before clone/fork, all
descendants will prevent nohz_full unless they create a cputimer of
their own.

Fix this by entirely clearing the tick_dep_mask in copy_process().
(There is currently no inherited state that needs a tick dependency)

Process-wide timers do not have this problem because fork does not copy
signal_struct as a baseline, it creates one from scratch.

Fixes: b78783000d5c ("posix-cpu-timers: Migrate to use new tick dependency mask model")
Signed-off-by: Ben Segall <bsegall@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/xm26o737bq8o.fsf@google.com
2024-10-27 10:36:04 +01:00
Mathieu Desnoyers
7e019dcc47 sched: Improve cache locality of RSEQ concurrency IDs for intermittent workloads
commit 223baf9d17f25 ("sched: Fix performance regression introduced by mm_cid")
introduced a per-mm/cpu current concurrency id (mm_cid), which keeps
a reference to the concurrency id allocated for each CPU. This reference
expires shortly after a 100ms delay.

These per-CPU references keep the per-mm-cid data cache-local in
situations where threads are running at least once on each CPU within
each 100ms window, thus keeping the per-cpu reference alive.

However, intermittent workloads behaving in bursts spaced by more than
100ms on each CPU exhibit bad cache locality and degraded performance
compared to purely per-cpu data indexing, because concurrency IDs are
allocated over various CPUs and cores, therefore losing cache locality
of the associated data.

Introduce the following changes to improve per-mm-cid cache locality:

- Add a "recent_cid" field to the per-mm/cpu mm_cid structure to keep
  track of which mm_cid value was last used, and use it as a hint to
  attempt re-allocating the same concurrency ID the next time this
  mm/cpu needs to allocate a concurrency ID,

- Add a per-mm CPUs allowed mask, which keeps track of the union of
  CPUs allowed for all threads belonging to this mm. This cpumask is
  only set during the lifetime of the mm, never cleared, so it
  represents the union of all the CPUs allowed since the beginning of
  the mm lifetime (note that the mm_cpumask() is really arch-specific
  and tailored to the TLB flush needs, and is thus _not_ a viable
  approach for this),

- Add a per-mm nr_cpus_allowed to keep track of the weight of the
  per-mm CPUs allowed mask (for fast access),

- Add a per-mm max_nr_cid to keep track of the highest number of
  concurrency IDs allocated for the mm. This is used for expanding the
  concurrency ID allocation within the upper bound defined by:

    min(mm->nr_cpus_allowed, mm->mm_users)

  When the next unused CID value reaches this threshold, stop trying
  to expand the cid allocation and use the first available cid value
  instead.

  Spreading allocation to use all the cid values within the range

    [ 0, min(mm->nr_cpus_allowed, mm->mm_users) - 1 ]

  improves cache locality while preserving mm_cid compactness within the
  expected user limits,

- In __mm_cid_try_get, only return cid values within the range
  [ 0, mm->nr_cpus_allowed ] rather than [ 0, nr_cpu_ids ]. This
  prevents allocating cids above the number of allowed cpus in
  rare scenarios where cid allocation races with a concurrent
  remote-clear of the per-mm/cpu cid. This improvement is made
  possible by the addition of the per-mm CPUs allowed mask,

- In sched_mm_cid_migrate_to, use mm->nr_cpus_allowed rather than
  t->nr_cpus_allowed. This criterion was really meant to compare
  the number of mm->mm_users to the number of CPUs allowed for the
  entire mm. Therefore, the prior comparison worked fine when all
  threads shared the same CPUs allowed mask, but not so much in
  scenarios where those threads have different masks (e.g. each
  thread pinned to a single CPU). This improvement is made
  possible by the addition of the per-mm CPUs allowed mask.

* Benchmarks

Each thread increments 16kB worth of 8-bit integers in bursts, with
a configurable delay between each thread's execution. Each thread run
one after the other (no threads run concurrently). The order of
thread execution in the sequence is random. The thread execution
sequence begins again after all threads have executed. The 16kB areas
are allocated with rseq_mempool and indexed by either cpu_id, mm_cid
(not cache-local), or cache-local mm_cid. Each thread is pinned to its
own core.

Testing configurations:

8-core/1-L3:        Use 8 cores within a single L3
24-core/24-L3:      Use 24 cores, 1 core per L3
192-core/24-L3:     Use 192 cores (all cores in the system)
384-thread/24-L3:   Use 384 HW threads (all HW threads in the system)

Intermittent workload delays between threads: 200ms, 10ms.

Hardware:

CPU(s):                   384
  On-line CPU(s) list:    0-383
Vendor ID:                AuthenticAMD
  Model name:             AMD EPYC 9654 96-Core Processor
    Thread(s) per core:   2
    Core(s) per socket:   96
    Socket(s):            2
Caches (sum of all):
  L1d:                    6 MiB (192 instances)
  L1i:                    6 MiB (192 instances)
  L2:                     192 MiB (192 instances)
  L3:                     768 MiB (24 instances)

Each result is an average of 5 test runs. The cache-local speedup
is calculated as: (cache-local mm_cid) / (mm_cid).

Intermittent workload delay: 200ms

                     per-cpu     mm_cid    cache-local mm_cid    cache-local speedup
                         (ns)      (ns)                  (ns)
8-core/1-L3             1374      19289                  1336            14.4x
24-core/24-L3           2423      26721                  1594            16.7x
192-core/24-L3          2291      15826                  2153             7.3x
384-thread/24-L3        1874      13234                  1907             6.9x

Intermittent workload delay: 10ms

                     per-cpu     mm_cid    cache-local mm_cid    cache-local speedup
                         (ns)      (ns)                  (ns)
8-core/1-L3               662       756                   686             1.1x
24-core/24-L3            1378      3648                  1035             3.5x
192-core/24-L3           1439     10833                  1482             7.3x
384-thread/24-L3         1503     10570                  1556             6.8x

[ This deprecates the prior "sched: NUMA-aware per-memory-map concurrency IDs"
  patch series with a simpler and more general approach. ]

[ This patch applies on top of v6.12-rc1. ]

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/lkml/20240823185946.418340-1-mathieu.desnoyers@efficios.com/
2024-10-14 12:52:40 +02:00
Al Viro
678379e1d4 close_range(): fix the logics in descriptor table trimming
Cloning a descriptor table picks the size that would cover all currently
opened files.  That's fine for clone() and unshare(), but for close_range()
there's an additional twist - we clone before we close, and it would be
a shame to have
	close_range(3, ~0U, CLOSE_RANGE_UNSHARE)
leave us with a huge descriptor table when we are not going to keep
anything past stderr, just because some large file descriptor used to
be open before our call has taken it out.

Unfortunately, it had been dealt with in an inherently racy way -
sane_fdtable_size() gets a "don't copy anything past that" argument
(passed via unshare_fd() and dup_fd()), close_range() decides how much
should be trimmed and passes that to unshare_fd().

The problem is, a range that used to extend to the end of descriptor
table back when close_range() had looked at it might very well have stuff
grown after it by the time dup_fd() has allocated a new files_struct
and started to figure out the capacity of fdtable to be attached to that.

That leads to interesting pathological cases; at the very least it's a
QoI issue, since unshare(CLONE_FILES) is atomic in a sense that it takes
a snapshot of descriptor table one might have observed at some point.
Since CLOSE_RANGE_UNSHARE close_range() is supposed to be a combination
of unshare(CLONE_FILES) with plain close_range(), ending up with a
weird state that would never occur with unshare(2) is confusing, to put
it mildly.

It's not hard to get rid of - all it takes is passing both ends of the
range down to sane_fdtable_size().  There we are under ->files_lock,
so the race is trivially avoided.

So we do the following:
	* switch close_files() from calling unshare_fd() to calling
dup_fd().
	* undo the calling convention change done to unshare_fd() in
60997c3d45d9 "close_range: add CLOSE_RANGE_UNSHARE"
	* introduce struct fd_range, pass a pointer to that to dup_fd()
and sane_fdtable_size() instead of "trim everything past that point"
they are currently getting.  NULL means "we are not going to be punching
any holes"; NR_OPEN_MAX is gone.
	* make sane_fdtable_size() use find_last_bit() instead of
open-coding it; it's easier to follow that way.
	* while we are at it, have dup_fd() report errors by returning
ERR_PTR(), no need to use a separate int *errorp argument.

Fixes: 60997c3d45d9 "close_range: add CLOSE_RANGE_UNSHARE"
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2024-09-29 21:52:29 -04:00
Linus Torvalds
aa486552a1 memblock: updates for 6.12-rc1
* new memblock_estimated_nr_free_pages() helper to replace totalram_pages()
   which is less accurate when CONFIG_DEFERRED_STRUCT_PAGE_INIT is set
 * fixes for memblock tests
 -----BEGIN PGP SIGNATURE-----
 
 iQFEBAABCgAuFiEEeOVYVaWZL5900a/pOQOGJssO/ZEFAmbejv0QHHJwcHRAa2Vy
 bmVsLm9yZwAKCRA5A4Ymyw79kVVlB/4yOoCDvJyUocEY0/Zv5bdRGXlAI0Igp3VV
 E0rEpvIjTBWwp/KZziQ8zMFk5zL/Aqb081vRsCko0lh2wjD5tFgNWWJG/sryQ/tX
 vc88p83KEXxNy4QC1qCh8dvHGIZVuLQ8oWQ7QFuH2ResdOaLdcfnobcu6/W/pBE0
 60/0bNdNgFPgnCpFIcWvGFOqZ10akhw4xYrwRsCKAQEeqeKyQE/DBFUvNrqkOuNG
 +4k71X/9mcuEDBKGRCf5XzCf7nwk4k8pzOc4xMeEhAaaV2uZdENfQuu1Av7nqRah
 zhYveo0Wd0cnGWORBT/ddzPDeBjdP2ZM9qR70yoSj2mQ7a3ixLfd
 =wtsK
 -----END PGP SIGNATURE-----

Merge tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock updates from Mike Rapoport:

 - new memblock_estimated_nr_free_pages() helper to replace
   totalram_pages() which is less accurate when
   CONFIG_DEFERRED_STRUCT_PAGE_INIT is set

 - fixes for memblock tests

* tag 'memblock-v6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  s390/mm: get estimated free pages by memblock api
  kernel/fork.c: get estimated free pages by memblock api
  mm/memblock: introduce a new helper memblock_estimated_nr_free_pages()
  memblock test: fix implicit declaration of function 'strscpy'
  memblock test: fix implicit declaration of function 'isspace'
  memblock test: fix implicit declaration of function 'memparse'
  memblock test: add the definition of __setup()
  memblock test: fix implicit declaration of function 'virt_to_phys'
  tools/testing: abstract two init.h into common include directory
  memblock tests: include export.h in linkage.h as kernel dose
  memblock tests: include memory_hotplug.h in mmzone.h as kernel dose
2024-09-25 11:35:19 -07:00
Linus Torvalds
88264981f2 sched_ext: Initial pull request for v6.12
This is the initial pull request of sched_ext. The v7 patchset
 (https://lkml.kernel.org/r/20240618212056.2833381-1-tj@kernel.org) is
 applied on top of tip/sched/core + bpf/master as of Jun 18th.
 
   tip/sched/core 793a62823d1c ("sched/core: Drop spinlocks on contention iff kernel is preempti
 ble")
   bpf/master f6afdaf72af7 ("Merge branch 'bpf-support-resilient-split-btf'")
 
 Since then, the following pulls were made:
 
 - v6.11-rc1 is pulled to keep up with the mainline.
 
 - tip/sched/core was pulled several times:
 
   - 7b9f6c864a34, 0df340ceae2e, 5ac998574f93, 0b1777f0fa04: To resolve
     conflicts. See each commit for details on conflicts and their
     resolutions.
 
   - d7b01aef9dbd: To receive fd03c5b85855 ("sched: Rework pick_next_task()")
     and related commits. @prev in added to sched_class->put_prev_task() and
     put_prev_task() is reordered after ->pick_task(), which makes
     sched_class->switch_class() unnecessary. The follow-up commits update
     sched_ext accordingly and drop sched_class->switch_class().
 
 - bpf/master was pulled to receive baebe9aaba1e ("bpf: allow passing struct
   bpf_iter_<type> as kfunc arguments") and related changes in preparation
   for the DSQ iterator patchset
 
 To obtain the net sched_ext changes, diff against:
 
   git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext.git for-6.12-base
 
 which is the merge of:
 
   tip/sched/core bc9057da1a22 ("sched/cpufreq: Use NSEC_PER_MSEC for deadline task")
   bpf/master 2ad6d23f465 ("selftests/bpf: Do not update vmlinux.h unnecessarily")
 
 Since the v7 patchset, the following changes were made:
 
 - cpuperf support which was a part of the v6 patchset was posted separately
   and then applied after reviews.
 
 - cgroup support which was a part of the v6 patchset was posted seprately,
   iterated and then applied.
 
 - Improve integration with sched core.
 
 - Double locking usage in migration paths dropped. Depend on
   TASK_ON_RQ_MIGRATING synchronization instead.
 
 - The BPF scheduler couldn't directly dispatch to the local DSQ of another
   CPU using a SCX_DSQ_LOCAL_ON verdict. This caused difficulties around
   handling non-wakeup enqueues. Updated so that SCX_DSQ_LOCAL_ON can be used
   in the enqueue path too.
 
 - DSQ iterator which was a part of the v6 patchset was posted separately.
   The iterator itself was applied after a couple revisions. The associated
   selective consumption kfunc can use further improvements and is still
   being worked on.
 
 - scx_bpf_dispatch[_vtime]_from_dsq() added to increase flexibility. A task
   can now be transferred between two DSQs from almost any context. This
   involved significant refactoring of migration code.
 
 - Various fixes and improvements.
 
 As the branch is based on top of tip/sched/core + bpf/master, please merge
 after both are applied.
 -----BEGIN PGP SIGNATURE-----
 
 iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZuOSuA4cdGpAa2VybmVs
 Lm9yZwAKCRCxYfJx3gVYGVZyAQDBU3WPkYKB8gl6a6YQ+/PzBXorOK7mioS9A2iJ
 vBR3FgEAg1vtcss1S+2juWmVq7ItiFNWCqtXzUr/bVmL9CqqDwA=
 =bOOC
 -----END PGP SIGNATURE-----

Merge tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext support from Tejun Heo:
 "This implements a new scheduler class called ‘ext_sched_class’, or
  sched_ext, which allows scheduling policies to be implemented as BPF
  programs.

  The goals of this are:

   - Ease of experimentation and exploration: Enabling rapid iteration
     of new scheduling policies.

   - Customization: Building application-specific schedulers which
     implement policies that are not applicable to general-purpose
     schedulers.

   - Rapid scheduler deployments: Non-disruptive swap outs of scheduling
     policies in production environments"

See individual commits for more documentation, but also the cover letter
for the latest series:

Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/

* tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits)
  sched: Move update_other_load_avgs() to kernel/sched/pelt.c
  sched_ext: Don't trigger ops.quiescent/runnable() on migrations
  sched_ext: Synchronize bypass state changes with rq lock
  scx_qmap: Implement highpri boosting
  sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()
  sched_ext: Compact struct bpf_iter_scx_dsq_kern
  sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq()
  sched_ext: Move consume_local_task() upward
  sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq()
  sched_ext: Reorder args for consume_local/remote_task()
  sched_ext: Restructure dispatch_to_local_dsq()
  sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling
  sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON
  sched_ext: Refactor consume_remote_task()
  sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate
  sched_ext: Add missing static to scx_dump_data
  sched_ext: Add missing static to scx_has_op[]
  sched_ext: Temporarily work around pick_task_scx() being called without balance_scx()
  sched_ext: Add a cgroup scheduler which uses flattened hierarchy
  sched_ext: Add cgroup support
  ...
2024-09-21 09:44:57 -07:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZu1BBwAKCRDdBJ7gKXxA
 jlWNAQDYlqQLun7bgsAN4sSvi27VUuWv1q70jlMXTfmjJAvQqwD/fBFVR6IOOiw7
 AkDbKWP2k0hWPiNJBGwoqxdHHx09Xgo=
 =s0T+
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Linus Torvalds
78567e2bc7 cgroup: Changes for v6.12
- cpuset isolation improvements.
 
 - cpuset cgroup1 support is split into its own file behind the new config
   option CONFIG_CPUSET_V1. This makes it the second controller which makes
   cgroup1 support optional after memcg.
 
 - Handling of unavailable v1 controller handling improved during cgroup1
   mount operations.
 
 - union_find applied to cpuset. It makes code simpler and more efficient.
 
 - Reduce spurious events in pids.events.
 
 - Cleanups and other misc changes.
 
 - Contains a merge of cgroup/for-6.11-fixes to receive cpuset fixes that
   further changes build upon.
 -----BEGIN PGP SIGNATURE-----
 
 iIQEABYKACwWIQTfIjM1kS57o3GsC/uxYfJx3gVYGQUCZuNU3Q4cdGpAa2VybmVs
 Lm9yZwAKCRCxYfJx3gVYGdMsAP9yqPxu//LiJ3lPWhKcVVKtdwrA3AYDLE81VSJO
 5VZJhAD+Ic+Ly/jZjDtjjQpZ1U3JsBpBRcVBqzeH0gD7eXaJgwk=
 =h/+c
 -----END PGP SIGNATURE-----

Merge tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - cpuset isolation improvements

 - cpuset cgroup1 support is split into its own file behind the new
   config option CONFIG_CPUSET_V1. This makes it the second controller
   which makes cgroup1 support optional after memcg

 - Handling of unavailable v1 controller handling improved during
   cgroup1 mount operations

 - union_find applied to cpuset. It makes code simpler and more
   efficient

 - Reduce spurious events in pids.events

 - Cleanups and other misc changes

 - Contains a merge of cgroup/for-6.11-fixes to receive cpuset fixes
   that further changes build upon

* tag 'cgroup-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (34 commits)
  cgroup: Do not report unavailable v1 controllers in /proc/cgroups
  cgroup: Disallow mounting v1 hierarchies without controller implementation
  cgroup/cpuset: Expose cpuset filesystem with cpuset v1 only
  cgroup/cpuset: Move cpu.h include to cpuset-internal.h
  cgroup/cpuset: add sefltest for cpuset v1
  cgroup/cpuset: guard cpuset-v1 code under CONFIG_CPUSETS_V1
  cgroup/cpuset: rename functions shared between v1 and v2
  cgroup/cpuset: move v1 interfaces to cpuset-v1.c
  cgroup/cpuset: move validate_change_legacy to cpuset-v1.c
  cgroup/cpuset: move legacy hotplug update to cpuset-v1.c
  cgroup/cpuset: add callback_lock helper
  cgroup/cpuset: move memory_spread to cpuset-v1.c
  cgroup/cpuset: move relax_domain_level to cpuset-v1.c
  cgroup/cpuset: move memory_pressure to cpuset-v1.c
  cgroup/cpuset: move common code to cpuset-internal.h
  cgroup/cpuset: introduce cpuset-v1.c
  selftest/cgroup: Make test_cpuset_prs.sh deal with pre-isolated CPUs
  cgroup/cpuset: Account for boot time isolated CPUs
  cgroup/cpuset: remove use_parent_ecpus of cpuset
  cgroup/cpuset: remove fetch_xcpus
  ...
2024-09-18 06:39:03 +02:00
Oleg Nesterov
ed8d5b0ce1 Revert "uprobes: use vm_special_mapping close() functionality"
This reverts commit 08e28de1160a712724268fd33d77b32f1bc84d1c.

A malicious application can munmap() its "[uprobes]" vma and in this case
xol_mapping.close == uprobe_clear_state() will free the memory which can
be used by another thread, or the same thread when it hits the uprobe bp
afterwards.

Link: https://lkml.kernel.org/r/20240911131320.GA3448@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 01:07:01 -07:00
Sven Schnelle
08e28de116 uprobes: use vm_special_mapping close() functionality
The following KASAN splat was shown:

[   44.505448] ==================================================================                                                                      20:37:27 [3421/145075]
[   44.505455] BUG: KASAN: slab-use-after-free in special_mapping_close+0x9c/0xc8
[   44.505471] Read of size 8 at addr 00000000868dac48 by task sh/1384
[   44.505479]
[   44.505486] CPU: 51 UID: 0 PID: 1384 Comm: sh Not tainted 6.11.0-rc6-next-20240902-dirty #1496
[   44.505503] Hardware name: IBM 3931 A01 704 (z/VM 7.3.0)
[   44.505508] Call Trace:
[   44.505511]  [<000b0324d2f78080>] dump_stack_lvl+0xd0/0x108
[   44.505521]  [<000b0324d2f5435c>] print_address_description.constprop.0+0x34/0x2e0
[   44.505529]  [<000b0324d2f5464c>] print_report+0x44/0x138
[   44.505536]  [<000b0324d1383192>] kasan_report+0xc2/0x140
[   44.505543]  [<000b0324d2f52904>] special_mapping_close+0x9c/0xc8
[   44.505550]  [<000b0324d12c7978>] remove_vma+0x78/0x120
[   44.505557]  [<000b0324d128a2c6>] exit_mmap+0x326/0x750
[   44.505563]  [<000b0324d0ba655a>] __mmput+0x9a/0x370
[   44.505570]  [<000b0324d0bbfbe0>] exit_mm+0x240/0x340
[   44.505575]  [<000b0324d0bc0228>] do_exit+0x548/0xd70
[   44.505580]  [<000b0324d0bc1102>] do_group_exit+0x132/0x390
[   44.505586]  [<000b0324d0bc13b6>] __s390x_sys_exit_group+0x56/0x60
[   44.505592]  [<000b0324d0adcbd6>] do_syscall+0x2f6/0x430
[   44.505599]  [<000b0324d2f78434>] __do_syscall+0xa4/0x170
[   44.505606]  [<000b0324d2f9454c>] system_call+0x74/0x98
[   44.505614]
[   44.505616] Allocated by task 1384:
[   44.505621]  kasan_save_stack+0x40/0x70
[   44.505630]  kasan_save_track+0x28/0x40
[   44.505636]  __kasan_kmalloc+0xa0/0xc0
[   44.505642]  __create_xol_area+0xfa/0x410
[   44.505648]  get_xol_area+0xb0/0xf0
[   44.505652]  uprobe_notify_resume+0x27a/0x470
[   44.505657]  irqentry_exit_to_user_mode+0x15e/0x1d0
[   44.505664]  pgm_check_handler+0x122/0x170
[   44.505670]
[   44.505672] Freed by task 1384:
[   44.505676]  kasan_save_stack+0x40/0x70
[   44.505682]  kasan_save_track+0x28/0x40
[   44.505687]  kasan_save_free_info+0x4a/0x70
[   44.505693]  __kasan_slab_free+0x5a/0x70
[   44.505698]  kfree+0xe8/0x3f0
[   44.505704]  __mmput+0x20/0x370
[   44.505709]  exit_mm+0x240/0x340
[   44.505713]  do_exit+0x548/0xd70
[   44.505718]  do_group_exit+0x132/0x390
[   44.505722]  __s390x_sys_exit_group+0x56/0x60
[   44.505727]  do_syscall+0x2f6/0x430
[   44.505732]  __do_syscall+0xa4/0x170
[   44.505738]  system_call+0x74/0x98

The problem is that uprobe_clear_state() kfree's struct xol_area, which
contains struct vm_special_mapping *xol_mapping. This one is passed to
_install_special_mapping() in xol_add_vma().
__mput reads:

static inline void __mmput(struct mm_struct *mm)
{
        VM_BUG_ON(atomic_read(&mm->mm_users));

        uprobe_clear_state(mm);
        exit_aio(mm);
        ksm_exit(mm);
        khugepaged_exit(mm); /* must run before exit_mmap */
        exit_mmap(mm);
        ...
}

So uprobe_clear_state() in the beginning free's the memory area
containing the vm_special_mapping data, but exit_mmap() uses this
address later via vma->vm_private_data (which was set in
_install_special_mapping().

Fix this by moving uprobe_clear_state() to uprobes.c and use it as
close() callback.

[usama.anjum@collabora.com: remove unneeded condition]
  Link: https://lkml.kernel.org/r/20240906101825.177490-1-usama.anjum@collabora.com
Link: https://lkml.kernel.org/r/20240903073629.2442754-1-svens@linux.ibm.com
Fixes: 223febc6e557 ("mm: add optional close() to struct vm_special_mapping")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:39:14 -07:00
Tejun Heo
649e980dad Merge branch 'bpf/master' into for-6.12
Pull bpf/master to receive baebe9aaba1e ("bpf: allow passing struct
bpf_iter_<type> as kfunc arguments") and related changes in preparation for
the DSQ iterator patchset.

Signed-off-by: Tejun Heo <tj@kernel.org>
2024-09-04 11:41:32 -10:00
David Hildenbrand
394290cba9 mm: turn USE_SPLIT_PTE_PTLOCKS / USE_SPLIT_PTE_PTLOCKS into Kconfig options
Patch series "mm: split PTE/PMD PT table Kconfig cleanups+clarifications".

This series is a follow up to the fixes:
	"[PATCH v1 0/2] mm/hugetlb: fix hugetlb vs. core-mm PT locking"

When working on the fixes, I wondered why 8xx is fine (-> never uses split
PT locks) and how PT locking even works properly with PMD page table
sharing (-> always requires split PMD PT locks).

Let's improve the split PT lock detection, make hugetlb properly depend on
it and make 8xx bail out if it would ever get enabled by accident.

As an alternative to patch #3 we could extend the Kconfig
SPLIT_PTE_PTLOCKS option from patch #2 -- but enforcing it closer to the
code that actually implements it feels a bit nicer for documentation
purposes, and there is no need to actually disable it because it should
always be disabled (!SMP).

Did a bunch of cross-compilations to make sure that split PTE/PMD PT locks
are still getting used where we would expect them.

[1] https://lkml.kernel.org/r/20240725183955.2268884-1-david@redhat.com


This patch (of 3):

Let's clean that up a bit and prepare for depending on
CONFIG_SPLIT_PMD_PTLOCKS in other Kconfig options.

More cleanups would be reasonable (like the arch-specific "depends on" for
CONFIG_SPLIT_PTE_PTLOCKS), but we'll leave that for another day.

Link: https://lkml.kernel.org/r/20240726150728.3159964-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240726150728.3159964-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:25:51 -07:00
Christian Brauner
232590ea7f
Revert "pidfd: prevent creation of pidfds for kthreads"
This reverts commit 3b5bbe798b2451820e74243b738268f51901e7d0.

Eric reported that systemd-shutdown gets broken by blocking the creating
of pidfds for kthreads as older versions seems to rely on being able to
create a pidfd for any process in /proc.

Reported-by: Eric Biggers <ebiggers@kernel.org>
Link: https://lore.kernel.org/r/20240818035818.GA1929@sol.localdomain
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-21 22:32:58 +02:00
Christian Brauner
3b5bbe798b
pidfd: prevent creation of pidfds for kthreads
It's currently possible to create pidfds for kthreads but it is unclear
what that is supposed to mean. Until we have use-cases for it and we
figured out what behavior we want block the creation of pidfds for
kthreads.

Link: https://lore.kernel.org/r/20240731-gleis-mehreinnahmen-6bbadd128383@brauner
Fixes: 32fcb426ec00 ("pid: add pidfd_open()")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-08-12 22:03:26 +02:00
Wei Yang
0910bf0ef8 kernel/fork.c: get estimated free pages by memblock api
Instead of getting estimated free pages from memblock directly, we have
introduced an API, memblock_estimated_nr_free_pages(), which is more
friendly for users.

Just replace it with new API, no functional change.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
CC: Mike Rapoport <rppt@kernel.org>
CC: David Hildenbrand <david@redhat.com>
CC: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240808001415.6298-2-richard.weiyang@gmail.com
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2024-08-11 19:19:00 +03:00