Commit Graph

1166 Commits

Author SHA1 Message Date
Shakeel Butt
f689054aac percpu_counter: add percpu_counter_sum_all interface
The percpu_counter is used for scenarios where performance is more
important than the accuracy.  For percpu_counter users, who want more
accurate information in their slowpath, percpu_counter_sum is provided
which traverses all the online CPUs to accumulate the data.  The reason it
only needs to traverse online CPUs is because percpu_counter does
implement CPU offline callback which syncs the local data of the offlined
CPU.

However there is a small race window between the online CPUs traversal of
percpu_counter_sum and the CPU offline callback.  The offline callback has
to traverse all the percpu_counters on the system to flush the CPU local
data which can be a lot.  During that time, the CPU which is going offline
has already been published as offline to all the readers.  So, as the
offline callback is running, percpu_counter_sum can be called for one
counter which has some state on the CPU going offline.  Since
percpu_counter_sum only traverses online CPUs, it will skip that specific
CPU and the offline callback might not have flushed the state for that
specific percpu_counter on that offlined CPU.

Normally this is not an issue because percpu_counter users can deal with
some inaccuracy for small time window.  However a new user i.e.  mm_struct
on the cleanup path wants to check the exact state of the percpu_counter
through check_mm().  For such users, this patch introduces
percpu_counter_sum_all() which traverses all possible CPUs and it is used
in fork.c:check_mm() to avoid the potential race.

This issue is exposed by the later patch "mm: convert mm's rss stats into
percpu_counter".

Link: https://lkml.kernel.org/r/20221109012011.881058-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:40 -08:00
Shakeel Butt
f1a7941243 mm: convert mm's rss stats into percpu_counter
Currently mm_struct maintains rss_stats which are updated on page fault
and the unmapping codepaths.  For page fault codepath the updates are
cached per thread with the batch of TASK_RSS_EVENTS_THRESH which is 64. 
The reason for caching is performance for multithreaded applications
otherwise the rss_stats updates may become hotspot for such applications.

However this optimization comes with the cost of error margin in the rss
stats.  The rss_stats for applications with large number of threads can be
very skewed.  At worst the error margin is (nr_threads * 64) and we have a
lot of applications with 100s of threads, so the error margin can be very
high.  Internally we had to reduce TASK_RSS_EVENTS_THRESH to 32.

Recently we started seeing the unbounded errors for rss_stats for specific
applications which use TCP rx0cp.  It seems like vm_insert_pages()
codepath does not sync rss_stats at all.

This patch converts the rss_stats into percpu_counter to convert the error
margin from (nr_threads * 64) to approximately (nr_cpus ^ 2).  However
this conversion enable us to get the accurate stats for situations where
accuracy is more important than the cpu cost.

This patch does not make such tradeoffs - we can just use
percpu_counter_add_local() for the updates and percpu_counter_sum() (or
percpu_counter_sync() + percpu_counter_read) for the readers.  At the
moment the readers are either procfs interface, oom_killer and memory
reclaim which I think are not performance critical and should be ok with
slow read.  However I think we can make that change in a separate patch.

Link: https://lkml.kernel.org/r/20221024052841.3291983-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-30 15:58:40 -08:00
Linus Torvalds
676cb49573 - hfs and hfsplus kmap API modernization from Fabio Francesco
- Valentin Schneider makes crash-kexec work properly when invoked from
   an NMI-time panic.
 
 - ntfs bugfixes from Hawkins Jiawei
 
 - Jiebin Sun improves IPC msg scalability by replacing atomic_t's with
   percpu counters.
 
 - nilfs2 cleanups from Minghao Chi
 
 - lots of other single patches all over the tree!
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0Yf0gAKCRDdBJ7gKXxA
 joapAQDT1d1zu7T8yf9cQXkYnZVuBKCjxKE/IsYvqaq1a42MjQD/SeWZg0wV05B8
 DhJPj9nkEp6R3Rj3Mssip+3vNuceAQM=
 =lUQY
 -----END PGP SIGNATURE-----

Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...
2022-10-12 11:00:22 -07:00
Xu Panda
ef79361b26 fork: remove duplicate included header files
linux/sched/mm.h is included more than once.

Link: https://lkml.kernel.org/r/20220912071556.16811-1-xu.panda@zte.com.cn
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner (Microsoft) <brauner@kernel.org>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-11 18:51:10 -07:00
Linus Torvalds
27bc50fc90 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
linux-next for a couple of months without, to my knowledge, any negative
   reports (or any positive ones, come to that).
 
 - Also the Maple Tree from Liam R.  Howlett.  An overlapping range-based
   tree for vmas.  It it apparently slight more efficient in its own right,
   but is mainly targeted at enabling work to reduce mmap_lock contention.
 
   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.
 
   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   (https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com).
   This has yet to be addressed due to Liam's unfortunately timed
   vacation.  He is now back and we'll get this fixed up.
 
 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer.  It uses
   clang-generated instrumentation to detect used-unintialized bugs down to
   the single bit level.
 
   KMSAN keeps finding bugs.  New ones, as well as the legacy ones.
 
 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.
 
 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support
   file/shmem-backed pages.
 
 - userfaultfd updates from Axel Rasmussen
 
 - zsmalloc cleanups from Alexey Romanov
 
 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure
 
 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.
 
 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.
 
 - memcg cleanups from Kairui Song.
 
 - memcg fixes and cleanups from Johannes Weiner.
 
 - Vishal Moola provides more folio conversions
 
 - Zhang Yi removed ll_rw_block() :(
 
 - migration enhancements from Peter Xu
 
 - migration error-path bugfixes from Huang Ying
 
 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths.  For optimizations by PMEM drivers, DRM
   drivers, etc.
 
 - vma merging improvements from Jakub Matěn.
 
 - NUMA hinting cleanups from David Hildenbrand.
 
 - xu xin added aditional userspace visibility into KSM merging activity.
 
 - THP & KSM code consolidation from Qi Zheng.
 
 - more folio work from Matthew Wilcox.
 
 - KASAN updates from Andrey Konovalov.
 
 - DAMON cleanups from Kaixu Xia.
 
 - DAMON work from SeongJae Park: fixes, cleanups.
 
 - hugetlb sysfs cleanups from Muchun Song.
 
 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCY0HaPgAKCRDdBJ7gKXxA
 joPjAQDZ5LlRCMWZ1oxLP2NOTp6nm63q9PWcGnmY50FjD/dNlwEAnx7OejCLWGWf
 bbTuk6U2+TKgJa4X7+pbbejeoqnt5QU=
 =xfWx
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in
   linux-next for a couple of months without, to my knowledge, any
   negative reports (or any positive ones, come to that).

 - Also the Maple Tree from Liam Howlett. An overlapping range-based
   tree for vmas. It it apparently slightly more efficient in its own
   right, but is mainly targeted at enabling work to reduce mmap_lock
   contention.

   Liam has identified a number of other tree users in the kernel which
   could be beneficially onverted to mapletrees.

   Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat
   at [1]. This has yet to be addressed due to Liam's unfortunately
   timed vacation. He is now back and we'll get this fixed up.

 - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses
   clang-generated instrumentation to detect used-unintialized bugs down
   to the single bit level.

   KMSAN keeps finding bugs. New ones, as well as the legacy ones.

 - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of
   memory into THPs.

 - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to
   support file/shmem-backed pages.

 - userfaultfd updates from Axel Rasmussen

 - zsmalloc cleanups from Alexey Romanov

 - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and
   memory-failure

 - Huang Ying adds enhancements to NUMA balancing memory tiering mode's
   page promotion, with a new way of detecting hot pages.

 - memcg updates from Shakeel Butt: charging optimizations and reduced
   memory consumption.

 - memcg cleanups from Kairui Song.

 - memcg fixes and cleanups from Johannes Weiner.

 - Vishal Moola provides more folio conversions

 - Zhang Yi removed ll_rw_block() :(

 - migration enhancements from Peter Xu

 - migration error-path bugfixes from Huang Ying

 - Aneesh Kumar added ability for a device driver to alter the memory
   tiering promotion paths. For optimizations by PMEM drivers, DRM
   drivers, etc.

 - vma merging improvements from Jakub Matěn.

 - NUMA hinting cleanups from David Hildenbrand.

 - xu xin added aditional userspace visibility into KSM merging
   activity.

 - THP & KSM code consolidation from Qi Zheng.

 - more folio work from Matthew Wilcox.

 - KASAN updates from Andrey Konovalov.

 - DAMON cleanups from Kaixu Xia.

 - DAMON work from SeongJae Park: fixes, cleanups.

 - hugetlb sysfs cleanups from Muchun Song.

 - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core.

Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1]

* tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits)
  hugetlb: allocate vma lock for all sharable vmas
  hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer
  hugetlb: fix vma lock handling during split vma and range unmapping
  mglru: mm/vmscan.c: fix imprecise comments
  mm/mglru: don't sync disk for each aging cycle
  mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol
  mm: memcontrol: use do_memsw_account() in a few more places
  mm: memcontrol: deprecate swapaccounting=0 mode
  mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled
  mm/secretmem: remove reduntant return value
  mm/hugetlb: add available_huge_pages() func
  mm: remove unused inline functions from include/linux/mm_inline.h
  selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory
  selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd
  selftests/vm: add thp collapse shmem testing
  selftests/vm: add thp collapse file and tmpfs testing
  selftests/vm: modularize thp collapse memory operations
  selftests/vm: dedup THP helpers
  mm/khugepaged: add tracepoint to hpage_collapse_scan_file()
  mm/madvise: add file and shmem support to MADV_COLLAPSE
  ...
2022-10-10 17:53:04 -07:00
Linus Torvalds
30c999937f Scheduler changes for v6.1:
- Debuggability:
 
      - Change most occurances of BUG_ON() to WARN_ON_ONCE()
 
      - Reorganize & fix TASK_ state comparisons, turn it into a bitmap
 
      - Update/fix misc scheduler debugging facilities
 
  - Load-balancing & regular scheduling:
 
      - Improve the behavior of the scheduler in presence of lot of
        SCHED_IDLE tasks - in particular they should not impact other
        scheduling classes.
 
      - Optimize task load tracking, cleanups & fixes
 
      - Clean up & simplify misc load-balancing code
 
  - Freezer:
 
      - Rewrite the core freezer to behave better wrt thawing and be simpler
        in general, by replacing PF_FROZEN with TASK_FROZEN & fixing/adjusting
        all the fallout.
 
  - Deadline scheduler:
 
      - Fix the DL capacity-aware code
 
      - Factor out dl_task_is_earliest_deadline() & replenish_dl_new_period()
 
      - Relax/optimize locking in task_non_contending()
 
  - Cleanups:
 
      - Factor out the update_current_exec_runtime() helper
 
      - Various cleanups, simplifications
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmM/01cRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1geZA/+PB4KC1T9aVxzaTHI36R03YgJYZmIdtxw
 wTf02MixePmz+gQCbepJbempGOh5ST28aOcI0xhdYOql5B63MaUBBMlB0HvGUyDG
 IU3zETqLMRtAbnSTdQFv8m++ECUtZYp8/x1FCel4WO7ya4ETkRu1NRfCoUepEhpZ
 aVAlae9LH3NBaF9t7s0PT2lTjf3pIzMFRkddJ0ywJhbFR3VnWat05fAK+J6fGY8+
 LS54coefNlJD4oDh5TY8uniL1j5SmWmmwbk9Cdj7bLU5P3dFSS0/+5FJNHJPVGDE
 srGT7wstRUcDrN0CnZo48VIUBiApJCCDqTfJYi9wNYd0NAHvwY6MIJJgEIY8mKsI
 L/qH26H81Wt+ezSZ/5JIlGlZ/LIeNaa6OO/fbWEYABBQogvvx3nxsRNUYKSQzumH
 CnSBasBjLnjWyLlK4qARM9cI7NFSEK6NUigrEx/7h8JFu/8T4DlSy6LsF1HUyKgq
 4+FJLAqG6cL0tcwB/fHYd0oRESN8dStnQhGxSojgufwLc7dlFULvCYF5JM/dX+/V
 IKwbOfIOeOn6ViMtSOXAEGdII+IQ2/ZFPwr+8Z5JC7NzvTVL6xlu/3JXkLZR3L7o
 yaXTSaz06h1vil7Z+GRf7RHc+wUeGkEpXh5vnarGZKXivhFdWsBdROIJANK+xR0i
 TeSLCxQxXlU=
 =KjMD
 -----END PGP SIGNATURE-----

Merge tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Debuggability:

   - Change most occurances of BUG_ON() to WARN_ON_ONCE()

   - Reorganize & fix TASK_ state comparisons, turn it into a bitmap

   - Update/fix misc scheduler debugging facilities

  Load-balancing & regular scheduling:

   - Improve the behavior of the scheduler in presence of lot of
     SCHED_IDLE tasks - in particular they should not impact other
     scheduling classes.

   - Optimize task load tracking, cleanups & fixes

   - Clean up & simplify misc load-balancing code

  Freezer:

   - Rewrite the core freezer to behave better wrt thawing and be
     simpler in general, by replacing PF_FROZEN with TASK_FROZEN &
     fixing/adjusting all the fallout.

  Deadline scheduler:

   - Fix the DL capacity-aware code

   - Factor out dl_task_is_earliest_deadline() &
     replenish_dl_new_period()

   - Relax/optimize locking in task_non_contending()

  Cleanups:

   - Factor out the update_current_exec_runtime() helper

   - Various cleanups, simplifications"

* tag 'sched-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  sched: Fix more TASK_state comparisons
  sched: Fix TASK_state comparisons
  sched/fair: Move call to list_last_entry() in detach_tasks
  sched/fair: Cleanup loop_max and loop_break
  sched/fair: Make sure to try to detach at least one movable task
  sched: Show PF_flag holes
  freezer,sched: Rewrite core freezer logic
  sched: Widen TAKS_state literals
  sched/wait: Add wait_event_state()
  sched/completion: Add wait_for_completion_state()
  sched: Add TASK_ANY for wait_task_inactive()
  sched: Change wait_task_inactive()s match_state
  freezer,umh: Clean up freezer/initrd interaction
  freezer: Have {,un}lock_system_sleep() save/restore flags
  sched: Rename task_running() to task_on_cpu()
  sched/fair: Cleanup for SIS_PROP
  sched/fair: Default to false in test_idle_cores()
  sched/fair: Remove useless check in select_idle_core()
  sched/fair: Avoid double search on same cpu
  sched/fair: Remove redundant check in select_idle_smt()
  ...
2022-10-10 09:10:28 -07:00
Linus Torvalds
493ffd6605 ucounts: Split rlimit and ucount values and max values
After the ucount rlimit code was merged a bunch of small but
 siginificant bugs were found and fixed.  At the time it was realized
 that part of the problem was that while the ucount rlimits were very
 similar to the oridinary ucounts (in being nested counts with limits)
 the semantics were slightly different and the code would be less error
 prone if there was less sharing.  This is the long awaited cleanup
 that should hopefully keep things more comprehensible and less error
 prone for whoever needs to touch that code next.
 
 Alexey Gladkov (1):
       ucounts: Split rlimit and ucount values and max values
 
  fs/exec.c                      |  2 +-
  fs/proc/array.c                |  2 +-
  include/linux/user_namespace.h | 35 ++++++++++++++++++++++-------------
  kernel/fork.c                  | 12 ++++++------
  kernel/sys.c                   |  2 +-
  kernel/ucount.c                | 34 +++++++++++++++-------------------
  kernel/user_namespace.c        | 10 +++++-----
  7 files changed, 51 insertions(+), 46 deletions(-)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgjlraLDcwBA2B+6cC/v6Eiajj0AFAmM7U4cACgkQC/v6Eiaj
 j0AbRA//RVrGJ9n5iYyHM7WgeoTlFbaupEyLTq5dEpkOMD9CEB4OpMymGA/VXbeX
 cjgF5dqykfrdpYBwJdosl1fgq15ZFe9ChKhPGQkI5CGlwyRYTl2kq+FrZLC790s8
 c4TN3fKO1DyQPn5+UNzlBgLP8ofiUqeScZJDGa+LeMlUIv1OFS3m05jHuG/uzl6b
 bbbdcn61tFKOFCapbE72hWusEQssPOAN+dSY1/lwKO05WOKR0N2CR0EHyZhW2Owd
 GIQ27Zh5ed/9xRNlxa8VIa+JDfuATbPeoWcvRmiWSEoAxKtPBUf8lwcltlHBUcKK
 72MH+KU9AaIZ1prq9ng4xEaM+vXiSSNspYB8siwph7au1gWx1Yu2yYVavEPeFB9o
 C0JaD7kTh6Mhk6xdPhnmFUHFOLLGC5LdnBcIwwoMb1jlwP4QJRVucbjpqaOptoiE
 SeWhRRKUBwpcQdztQZCR+X0h1paHRJJXplHFmeEGcMviGWntgKUaxXJQ4BJrnRTO
 pagn7h181KVF7u9Toh0IWzrd322mXNqmcgwhzE/S9pa5EJMQHt7qYkDzQCgEwoap
 JmIld9tKkv/0fYMOHordjMb1OY37feI7FyDAuZuLP1ZWYgKhOq0LrD5x8PzKmoyM
 6oKAOfXZUVT/Pnw21nEzAtHsazV3mLRpW+gLLiLSiWoSaYT4x14=
 =kjVh
 -----END PGP SIGNATURE-----

Merge tag 'ucount-rlimits-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ucounts update from Eric Biederman:
 "Split rlimit and ucount values and max values

  After the ucount rlimit code was merged a bunch of small but
  siginificant bugs were found and fixed. At the time it was realized
  that part of the problem was that while the ucount rlimits were very
  similar to the oridinary ucounts (in being nested counts with limits)
  the semantics were slightly different and the code would be less error
  prone if there was less sharing.

  This is the long awaited cleanup that should hopefully keep things
  more comprehensible and less error prone for whoever needs to touch
  that code next"

* tag 'ucount-rlimits-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucounts: Split rlimit and ucount values and max values
2022-10-09 16:24:05 -07:00
Linus Torvalds
e572410e47 ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT
Recently I had a conversation where it was pointed out to me that
 SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite
 difficult for a tracer to handle.
 
 Keeping SIGKILL working after the process has been killed is pain
 from an implementation point of view.
 
 So since the debuggers don't want this behavior let's see if we can
 remove this wart for the userspace API
 
 If a regression is detected it should only need to be the last change
 that is the reverted.  The other two are just general cleanups that
 make the last patch simpler.
 
 Eric W. Biederman (3):
       signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
       signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
       signal: Drop signals received after a fatal signal has been processed
 
  fs/coredump.c                |  2 +-
  include/linux/sched/signal.h |  1 +
  kernel/exit.c                | 20 +++++++++++++++++++-
  kernel/fork.c                |  2 ++
  kernel/signal.c              |  3 ++-
  5 files changed, 25 insertions(+), 3 deletions(-)
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgjlraLDcwBA2B+6cC/v6Eiajj0AFAmM7U40ACgkQC/v6Eiaj
 j0B7eRAAst6EW4nkxiDBN/PRo43Kz7tkYCZGLAq73vZAaKkyTFSwghT85cZwTsuc
 px/iDPWZpSGdIeHhdt1giJeuFG0FuoMR9prQVx3z/fM6KLXEJb86OtW1c1uW00Bh
 TkhVPQiF/9bc+Eb/nRKF61NA4sP0OXwO1+t/zBL4clekO9vFLP1DpRBE9OrNlHq2
 NlDqoPqq6SsKYG8f+J2LJKKzRWLICvHCtz4uUt6O11Wt/PH2TZYdYnXf/2vvZyzS
 SOs8kQjw4QPSptcNH/LIZz0WNHagn1uU/2/T106LOgPgcr515T4MhqOK+Wp95BjA
 0RrhsfdMD+7HArqLmt9VKgKO9Gs+T/M6jQZgpUyzlw3qPorKUGu4s9UnUgS7l4uz
 oNV9no1Ei2fQ+YR6RBR74579a45FWkqRBsaia59KFCzZxRsQz8VB1cqcIgl9dFUA
 f81qt9FiX8duVYZIcoT79BvV1bQ3LGwyygrH+X3sDTQSdN/aeZ24JdGP2MNtYO/c
 jWN/mMVHc1xOsYmACVGETWhZf0Y7lGGBYSIJ92jT2HxIuEiqmFE4kngRjKcYgL/G
 1/o9z8VntMq5t+ZcQY5WfK/WpSeSPXa6TsP80PEm/hvdMwZLEO4IzCR+gPJB6oJS
 KPQ3EZfRCB2Jb1qBmcpbleA/RBA0iJUZtBvtIPI7QmMTR+VRdhc=
 =gX4y
 -----END PGP SIGNATURE-----

Merge tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull ptrace update from Eric Biederman:
 "ptrace: Stop supporting SIGKILL for PTRACE_EVENT_EXIT

  Recently I had a conversation where it was pointed out to me that
  SIGKILL sent to a tracee stropped in PTRACE_EVENT_EXIT is quite
  difficult for a tracer to handle.

  Keeping SIGKILL working after the process has been killed is pain from
  an implementation point of view.

  So since the debuggers don't want this behavior let's see if we can
  remove this wart for the userspace API

  If a regression is detected it should only need to be the last change
  that is the reverted. The other two are just general cleanups that
  make the last patch simpler"

* tag 'signal-for-v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  signal: Drop signals received after a fatal signal has been processed
  signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
  signal: Ensure SIGNAL_GROUP_EXIT gets set in do_group_exit
2022-10-09 16:14:15 -07:00
Alexander Potapenko
50b5e49ca6 kmsan: handle task creation and exiting
Tell KMSAN that a new task is created, so the tool creates a backing
metadata structure for that task.

Link: https://lkml.kernel.org/r/20220915150417.722975-17-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:20 -07:00
Mike Kravetz
8d9bfb2608 hugetlb: add vma based lock for pmd sharing
Allocate a new hugetlb_vma_lock structure and hang off vm_private_data for
synchronization use by vmas that could be involved in pmd sharing.  This
data structure contains a rw semaphore that is the primary tool used for
synchronization.

This new structure is ref counted, so that it can exist when NOT attached
to a vma.  This is only helpful in resolving lock ordering issues where
code may need to obtain the vma_lock while there are no guarantees the vma
may go away.  By obtaining a ref on the structure, it can be guaranteed
that at least the rw semaphore will not go away.

Only add infrastructure for the new lock here.  Actual use will be added
in subsequent patches.

[mike.kravetz@oracle.com: fix build issue for missing hugetlb_vma_lock_release]
  Link: https://lkml.kernel.org/r/YyNUtA1vRASOE4+M@monkey
Link: https://lkml.kernel.org/r/20220914221810.95771-7-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Prakash Sangappa <prakash.sangappa@oracle.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-03 14:03:17 -07:00
Liam R. Howlett
763ecb0350 mm: remove the vma linked list
Replace any vm_next use with vma_find().

Update free_pgtables(), unmap_vmas(), and zap_page_range() to use the
maple tree.

Use the new free_pgtables() and unmap_vmas() in do_mas_align_munmap().  At
the same time, alter the loop to be more compact.

Now that free_pgtables() and unmap_vmas() take a maple tree as an
argument, rearrange do_mas_align_munmap() to use the new tree to hold the
vmas to remove.

Remove __vma_link_list() and __vma_unlink_list() as they are exclusively
used to update the linked list.

Drop linked list update from __insert_vm_struct().

Rework validation of tree as it was depending on the linked list.

[yang.lee@linux.alibaba.com: fix one kernel-doc comment]
  Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=1949
  Link: https://lkml.kernel.org/r/20220824021918.94116-1-yang.lee@linux.alibaba.comLink: https://lkml.kernel.org/r/20220906194824.2110408-69-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:26 -07:00
Matthew Wilcox (Oracle)
fa5e587679 fork: use VMA iterator
The VMA iterator is faster than the linked list and removing the linked
list will shrink the vm_area_struct.

Link: https://lkml.kernel.org/r/20220906194824.2110408-50-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:22 -07:00
Liam R. Howlett
7964cf8caa mm: remove vmacache
By using the maple tree and the maple tree state, the vmacache is no
longer beneficial and is complicating the VMA code.  Remove the vmacache
to reduce the work in keeping it up to date and code complexity.

Link: https://lkml.kernel.org/r/20220906194824.2110408-26-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:18 -07:00
Liam R. Howlett
524e00b36e mm: remove rb tree.
Remove the RB tree and start using the maple tree for vm_area_struct
tracking.

Drop validate_mm() calls in expand_upwards() and expand_downwards() as the
lock is not held.

Link: https://lkml.kernel.org/r/20220906194824.2110408-18-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:16 -07:00
Liam R. Howlett
c9dbe82cb9 kernel/fork: use maple tree for dup_mmap() during forking
The maple tree was already tracking VMAs in this function by an earlier
commit, but the rbtree iterator was being used to iterate the list.
Change the iterator to use a maple tree native iterator and switch to the
maple tree advanced API to avoid multiple walks of the tree during insert
operations.  Unexport the now-unused vma_store() function.

For performance reasons we bulk allocate the maple tree nodes.  The node
calculations are done internally to the tree and use the VMA count and
assume the worst-case node requirements.  The VM_DONT_COPY flag does not
allow for the most efficient copy method of the tree and so a bulk loading
algorithm is used.

Link: https://lkml.kernel.org/r/20220906194824.2110408-15-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:16 -07:00
Liam R. Howlett
d4af56c5c7 mm: start tracking VMAs with maple tree
Start tracking the VMAs with the new maple tree structure in parallel with
the rb_tree.  Add debug and trace events for maple tree operations and
duplicate the rb_tree that is created on forks into the maple tree.

The maple tree is added to the mm_struct including the mm_init struct,
added support in required mm/mmap functions, added tracking in kernel/fork
for process forking, and used to find the unmapped_area and checked
against what the rbtree finds.

This also moves the mmap_lock() in exit_mmap() since the oom reaper call
does walk the VMAs.  Otherwise lockdep will be unhappy if oom happens.

When splitting a vma fails due to allocations of the maple tree nodes,
the error path in __split_vma() calls new->vm_ops->close(new).  The page
accounting for hugetlb is actually in the close() operation,  so it
accounts for the removal of 1/2 of the VMA which was not adjusted.  This
results in a negative exit value.  To avoid the negative charge, set
vm_start = vm_end and vm_pgoff = 0.

There is also a potential accounting issue in special mappings from
insert_vm_struct() failing to allocate, so reverse the charge there in
the failure scenario.

Link: https://lkml.kernel.org/r/20220906194824.2110408-9-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:14 -07:00
Yu Zhao
bd74fdaea1 mm: multi-gen LRU: support page table walks
To further exploit spatial locality, the aging prefers to walk page tables
to search for young PTEs and promote hot pages.  A kill switch will be
added in the next patch to disable this behavior.  When disabled, the
aging relies on the rmap only.

NB: this behavior has nothing similar with the page table scanning in the
2.4 kernel [1], which searches page tables for old PTEs, adds cold pages
to swapcache and unmaps them.

To avoid confusion, the term "iteration" specifically means the traversal
of an entire mm_struct list; the term "walk" will be applied to page
tables and the rmap, as usual.

An mm_struct list is maintained for each memcg, and an mm_struct follows
its owner task to the new memcg when this task is migrated.  Given an
lruvec, the aging iterates lruvec_memcg()->mm_list and calls
walk_page_range() with each mm_struct on this list to promote hot pages
before it increments max_seq.

When multiple page table walkers iterate the same list, each of them gets
a unique mm_struct; therefore they can run concurrently.  Page table
walkers ignore any misplaced pages, e.g., if an mm_struct was migrated,
pages it left in the previous memcg will not be promoted when its current
memcg is under reclaim.  Similarly, page table walkers will not promote
pages from nodes other than the one under reclaim.

This patch uses the following optimizations when walking page tables:
1. It tracks the usage of mm_struct's between context switches so that
   page table walkers can skip processes that have been sleeping since
   the last iteration.
2. It uses generational Bloom filters to record populated branches so
   that page table walkers can reduce their search space based on the
   query results, e.g., to skip page tables containing mostly holes or
   misplaced pages.
3. It takes advantage of the accessed bit in non-leaf PMD entries when
   CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG=y.
4. It does not zigzag between a PGD table and the same PMD table
   spanning multiple VMAs. IOW, it finishes all the VMAs within the
   range of the same PMD table before it returns to a PGD table. This
   improves the cache performance for workloads that have large
   numbers of tiny VMAs [2], especially when CONFIG_PGTABLE_LEVELS=5.

Server benchmark results:
  Single workload:
    fio (buffered I/O): no change

  Single workload:
    memcached (anon): +[8, 10]%
                Ops/sec      KB/sec
      patch1-7: 1147696.57   44640.29
      patch1-8: 1245274.91   48435.66

  Configurations:
    no change

Client benchmark results:
  kswapd profiles:
    patch1-7
      48.16%  lzo1x_1_do_compress (real work)
       8.20%  page_vma_mapped_walk (overhead)
       7.06%  _raw_spin_unlock_irq
       2.92%  ptep_clear_flush
       2.53%  __zram_bvec_write
       2.11%  do_raw_spin_lock
       2.02%  memmove
       1.93%  lru_gen_look_around
       1.56%  free_unref_page_list
       1.40%  memset

    patch1-8
      49.44%  lzo1x_1_do_compress (real work)
       6.19%  page_vma_mapped_walk (overhead)
       5.97%  _raw_spin_unlock_irq
       3.13%  get_pfn_folio
       2.85%  ptep_clear_flush
       2.42%  __zram_bvec_write
       2.08%  do_raw_spin_lock
       1.92%  memmove
       1.44%  alloc_zspage
       1.36%  memset

  Configurations:
    no change

Thanks to the following developers for their efforts [3].
  kernel test robot <lkp@intel.com>

[1] https://lwn.net/Articles/23732/
[2] https://llvm.org/docs/ScudoHardenedAllocator.html
[3] https://lore.kernel.org/r/202204160827.ekEARWQo-lkp@intel.com/

Link: https://lkml.kernel.org/r/20220918080010.2920238-9-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Acked-by: Brian Geffon <bgeffon@google.com>
Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org>
Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Steven Barrett <steven@liquorix.net>
Acked-by: Suleiman Souhlal <suleiman@google.com>
Tested-by: Daniel Byrne <djbyrne@mtu.edu>
Tested-by: Donald Carr <d@chaos-reins.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru>
Tested-by: Shuang Zhai <szhai2@cs.rochester.edu>
Tested-by: Sofia Trinh <sofia.trinh@edi.works>
Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michael Larabel <Michael@MichaelLarabel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-26 19:46:09 -07:00
Linus Torvalds
f489921dba execve reverts for v6.0-rc7
- Remove the recent "unshare time namespace on vfork+exec" feature (Andrei Vagin)
 -----BEGIN PGP SIGNATURE-----
 
 iQJKBAABCgA0FiEEpcP2jyKd1g9yPm4TiXL039xtwCYFAmMoxpIWHGtlZXNjb29r
 QGNocm9taXVtLm9yZwAKCRCJcvTf3G3AJpd/D/9V7iLUZoquMvXFonv//sRH21P+
 u7vH03q0X4lSov73jdjizq8znZl9RVO14IYi+6lQE8VHyOjzjBoTALRPnirNCyGa
 Ia8P+LPaOHDTDQmGqt+9xmPKp3z0qwrpWWyTrFHLo7GRzWtI0QjQsSlgUTIz7jCw
 dSwLRWN6n7d3hzNzFWt9VUOOlzpip8NTcnAbC9YA5dPFLO85+wZ4ZpMYYfFJMcQj
 N/Zm63lrqAU0wy7EhonkKJQDjgRP/zYUs6VJMejHqYl951SrZJ+DgXEGaAwR14Sz
 IZAUhSM5Fl8alhkrcmlkiy9A5P014iVRR6AaSyeT2616fac97wY1EWHxvBMqzNsB
 AJJqjPHoN+mc8cqt9lMyIhbmS8WkTuyTHziEcFyyTVsNYGYN6x9hVVZalqPrl8o3
 Y3zC6MfRK33JNVB2GZVUzsf5EZC3mjz9VJKKmLwYmG4X7/JOvIVCiW123b060T7z
 b49PzI+0rTG8SHTk1I/T8NpWuvLRTCglzZK06q971uyT80xPoGD/HmSpmm+86dHs
 k3WV2qBoz31Eaoewa3NJqn6pBxQLy9WAZP6rJb3aQSFwDRCuvKO4CUpHAXILt5U+
 SoarR5445zVzY3NYHaf/3BRsEnCQS06U67ma0lAmMWk4J3ehFOY0DrRqtLJ02iwd
 sKJD/KnKC+IEcLjrAA==
 =yFGx
 -----END PGP SIGNATURE-----

Merge tag 'execve-v6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve reverts from Kees Cook:
 "The recent work to support time namespace unsharing turns out to have
  some undesirable corner cases, so rather than allowing the API to stay
  exposed for another release, it'd be best to remove it ASAP, with the
  replacement getting another cycle of testing. Nothing is known to use
  this yet, so no userspace breakage is expected.

  For more details, see:

    https://lore.kernel.org/lkml/ed418e43ad28b8688cfea2b7c90fce1c@ispras.ru

  Summary:

   - Remove the recent 'unshare time namespace on vfork+exec' feature
     (Andrei Vagin)"

* tag 'execve-v6.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  Revert "fs/exec: allow to unshare a time namespace on vfork+exec"
  Revert "selftests/timens: add a test for vfork+exit"
2022-09-20 08:38:55 -07:00
Andrei Vagin
33a2d6bc34 Revert "fs/exec: allow to unshare a time namespace on vfork+exec"
This reverts commit 133e2d3e81.

Alexey pointed out a few undesirable side effects of the reverted change.
First, it doesn't take into account that CLONE_VFORK can be used with
CLONE_THREAD. Second, a child process doesn't enter a target time name-space,
if its parent dies before the child calls exec. It happens because the parent
clears vfork_done.

Eric W. Biederman suggests installing a time namespace as a task gets a new mm.
It includes all new processes cloned without CLONE_VM and all tasks that call
exec(). This is an user API change, but we think there aren't users that depend
on the old behavior.

It is too late to make such changes in this release, so let's roll back
this patch and introduce the right one in the next release.

Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220913102551.1121611-3-avagin@google.com
2022-09-13 10:38:43 -07:00
Peter Zijlstra
f5d39b0208 freezer,sched: Rewrite core freezer logic
Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

	freezer_do_not_count();
	schedule();
	freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

	TASK_FREEZABLE	-> TASK_FROZEN
	__TASK_STOPPED	-> TASK_FROZEN
	__TASK_TRACED	-> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org
2022-09-07 21:53:50 +02:00
Yishai Hadas
85eaeb5058 IB/core: Fix a nested dead lock as part of ODP flow
Fix a nested dead lock as part of ODP flow by using mmput_async().

From the below call trace [1] can see that calling mmput() once we have
the umem_odp->umem_mutex locked as required by
ib_umem_odp_map_dma_and_lock() might trigger in the same task the
exit_mmap()->__mmu_notifier_release()->mlx5_ib_invalidate_range() which
may dead lock when trying to lock the same mutex.

Moving to use mmput_async() will solve the problem as the above
exit_mmap() flow will be called in other task and will be executed once
the lock will be available.

[1]
[64843.077665] task:kworker/u133:2  state:D stack:    0 pid:80906 ppid:
2 flags:0x00004000
[64843.077672] Workqueue: mlx5_ib_page_fault mlx5_ib_eqe_pf_action [mlx5_ib]
[64843.077719] Call Trace:
[64843.077722]  <TASK>
[64843.077724]  __schedule+0x23d/0x590
[64843.077729]  schedule+0x4e/0xb0
[64843.077735]  schedule_preempt_disabled+0xe/0x10
[64843.077740]  __mutex_lock.constprop.0+0x263/0x490
[64843.077747]  __mutex_lock_slowpath+0x13/0x20
[64843.077752]  mutex_lock+0x34/0x40
[64843.077758]  mlx5_ib_invalidate_range+0x48/0x270 [mlx5_ib]
[64843.077808]  __mmu_notifier_release+0x1a4/0x200
[64843.077816]  exit_mmap+0x1bc/0x200
[64843.077822]  ? walk_page_range+0x9c/0x120
[64843.077828]  ? __cond_resched+0x1a/0x50
[64843.077833]  ? mutex_lock+0x13/0x40
[64843.077839]  ? uprobe_clear_state+0xac/0x120
[64843.077860]  mmput+0x5f/0x140
[64843.077867]  ib_umem_odp_map_dma_and_lock+0x21b/0x580 [ib_core]
[64843.077931]  pagefault_real_mr+0x9a/0x140 [mlx5_ib]
[64843.077962]  pagefault_mr+0xb4/0x550 [mlx5_ib]
[64843.077992]  pagefault_single_data_segment.constprop.0+0x2ac/0x560
[mlx5_ib]
[64843.078022]  mlx5_ib_eqe_pf_action+0x528/0x780 [mlx5_ib]
[64843.078051]  process_one_work+0x22b/0x3d0
[64843.078059]  worker_thread+0x53/0x410
[64843.078065]  ? process_one_work+0x3d0/0x3d0
[64843.078073]  kthread+0x12a/0x150
[64843.078079]  ? set_kthread_struct+0x50/0x50
[64843.078085]  ret_from_fork+0x22/0x30
[64843.078093]  </TASK>

Fixes: 36f30e486d ("IB/core: Improve ODP to use hmm_range_fault()")
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/74d93541ea533ef7daec6f126deb1072500aeb16.1661251841.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
2022-09-05 14:47:40 +03:00
Linus Torvalds
965a9d75e3 Tracing updates for 5.20 / 6.0
- Runtime verification infrastructure
   This is the biggest change for this pull request. It introduces the
   runtime verification that is necessary for running Linux on safety
   critical systems. It allows for deterministic automata models to be
   inserted into the kernel that will attach to tracepoints, where the
   information on these tracepoints will move the model from state to state.
   If a state is encountered that does not belong to the model, it will then
   activate a given reactor, that could just inform the user or even panic
   the kernel (for which safety critical systems will detect and can recover
   from).
 
 - Two monitor models are also added: Wakeup In Preemptive (WIP - not to be
   confused with "work in progress"), and Wakeup While Not Running (WWNR).
 
 - Added __vstring() helper to the TRACE_EVENT() macro to replace several
   vsnprintf() usages that were all doing it wrong.
 
 - eprobes now can have their event autogenerated when the event name is left
   off.
 
 - The rest is various cleanups and fixes.
 -----BEGIN PGP SIGNATURE-----
 
 iIoEABYIADIWIQRRSw7ePDh/lE+zeZMp5XQQmuv6qgUCYu0yzRQccm9zdGVkdEBn
 b29kbWlzLm9yZwAKCRAp5XQQmuv6qj4HAP4tQtV55rjj4DQ5XIXmtI3/64PmyRSJ
 +y4DEXi1UvEUCQD/QAuQfWoT/7gh35ltkfeS4t3ockzy14rrkP5drZigiQA=
 =kEtM
 -----END PGP SIGNATURE-----

Merge tag 'trace-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:

 - Runtime verification infrastructure

   This is the biggest change here. It introduces the runtime
   verification that is necessary for running Linux on safety critical
   systems.

   It allows for deterministic automata models to be inserted into the
   kernel that will attach to tracepoints, where the information on
   these tracepoints will move the model from state to state.

   If a state is encountered that does not belong to the model, it will
   then activate a given reactor, that could just inform the user or
   even panic the kernel (for which safety critical systems will detect
   and can recover from).

 - Two monitor models are also added: Wakeup In Preemptive (WIP - not to
   be confused with "work in progress"), and Wakeup While Not Running
   (WWNR).

 - Added __vstring() helper to the TRACE_EVENT() macro to replace
   several vsnprintf() usages that were all doing it wrong.

 - eprobes now can have their event autogenerated when the event name is
   left off.

 - The rest is various cleanups and fixes.

* tag 'trace-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (50 commits)
  rv: Unlock on error path in rv_unregister_reactor()
  tracing: Use alignof__(struct {type b;}) instead of offsetof()
  tracing/eprobe: Show syntax error logs in error_log file
  scripts/tracing: Fix typo 'the the' in comment
  tracepoints: It is CONFIG_TRACEPOINTS not CONFIG_TRACEPOINT
  tracing: Use free_trace_buffer() in allocate_trace_buffers()
  tracing: Use a struct alignof to determine trace event field alignment
  rv/reactor: Add the panic reactor
  rv/reactor: Add the printk reactor
  rv/monitor: Add the wwnr monitor
  rv/monitor: Add the wip monitor
  rv/monitor: Add the wip monitor skeleton created by dot2k
  Documentation/rv: Add deterministic automata instrumentation documentation
  Documentation/rv: Add deterministic automata monitor synthesis documentation
  tools/rv: Add dot2k
  Documentation/rv: Add deterministic automaton documentation
  tools/rv: Add dot2c
  Documentation/rv: Add a basic documentation
  rv/include: Add instrumentation helper functions
  rv/include: Add deterministic automata monitor definition via C macros
  ...
2022-08-05 09:41:12 -07:00
Linus Torvalds
7d9d077c78 RCU pull request for v5.20 (or whatever)
This pull request contains the following branches:
 
 doc.2022.06.21a: Documentation updates.
 
 fixes.2022.07.19a: Miscellaneous fixes.
 
 nocb.2022.07.19a: Callback-offload updates, perhaps most notably a new
 	RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to
 	be offloaded at boot time, regardless of kernel boot parameters.
 	This is useful to battery-powered systems such as ChromeOS
 	and Android.  In addition, a new RCU_NOCB_CPU_CB_BOOST kernel
 	boot parameter prevents offloaded callbacks from interfering
 	with real-time workloads and with energy-efficiency mechanisms.
 
 poll.2022.07.21a: Polled grace-period updates, perhaps most notably
 	making these APIs account for both normal and expedited grace
 	periods.
 
 rcu-tasks.2022.06.21a: Tasks RCU updates, perhaps most notably reducing
 	the CPU overhead of RCU tasks trace grace periods by more than
 	a factor of two on a system with 15,000 tasks.	The reduction
 	is expected to increase with the number of tasks, so it seems
 	reasonable to hypothesize that a system with 150,000 tasks might
 	see a 20-fold reduction in CPU overhead.
 
 torture.2022.06.21a: Torture-test updates.
 
 ctxt.2022.07.05a: Updates that merge RCU's dyntick-idle tracking into
 	context tracking, thus reducing the overhead of transitioning to
 	kernel mode from either idle or nohz_full userspace execution
 	for kernels that track context independently of RCU.  This is
 	expected to be helpful primarily for kernels built with
 	CONFIG_NO_HZ_FULL=y.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEbK7UrM+RBIrCoViJnr8S83LZ+4wFAmLgMcgTHHBhdWxtY2tA
 a2VybmVsLm9yZwAKCRCevxLzctn7jArXD/0fjbCwqpRjHVTzjMY8jN4zDkqZZD6m
 g8Fx27hZ4ToNFwRptyHwNezrNj14skjAJEXfdjaVw32W62ivXvf0HINvSzsTLCSq
 k2kWyBdXLc9CwY5p5W4smnpn5VoAScjg5PoPL59INoZ/Zziji323C7Zepl/1DYJt
 0T6bPCQjo1ZQoDUCyVpSjDmAqxnderWG0MeJVt74GkLqmnYLANg0GH8c7mH4+9LL
 kVGlLp5nlPgNJ4FEoFdMwNU8T/ETmaVld/m2dkiawjkXjJzB2XKtBigU91DDmXz5
 7DIdV4ABrxiy4kGNqtIe/jFgnKyVD7xiDpyfjd6KTeDr/rDS8u2ZH7+1iHsyz3g0
 Np/tS3vcd0KR+gI/d0eXxPbgm5sKlCmKw/nU2eArpW/+4LmVXBUfHTG9Jg+LJmBc
 JrUh6aEdIZJZHgv/nOQBNig7GJW43IG50rjuJxAuzcxiZNEG5lUSS23ysaA9CPCL
 PxRWKSxIEfK3kdmvVO5IIbKTQmIBGWlcWMTcYictFSVfBgcCXpPAksGvqA5JiUkc
 egW+xLFo/7K+E158vSKsVqlWZcEeUbsNJ88QOlpqnRgH++I2Yv/LhK41XfJfpH+Y
 ALxVaDd+mAq6v+qSHNVq9wT3ozXIPy/zK1hDlMIqx40h2YvaEsH4je+521oSoN9r
 vX60+QNxvUBLwA==
 =vUNm
 -----END PGP SIGNATURE-----

Merge tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

 - Documentation updates

 - Miscellaneous fixes

 - Callback-offload updates, perhaps most notably a new
   RCU_NOCB_CPU_DEFAULT_ALL Kconfig option that causes all CPUs to be
   offloaded at boot time, regardless of kernel boot parameters.

   This is useful to battery-powered systems such as ChromeOS and
   Android. In addition, a new RCU_NOCB_CPU_CB_BOOST kernel boot
   parameter prevents offloaded callbacks from interfering with
   real-time workloads and with energy-efficiency mechanisms

 - Polled grace-period updates, perhaps most notably making these APIs
   account for both normal and expedited grace periods

 - Tasks RCU updates, perhaps most notably reducing the CPU overhead of
   RCU tasks trace grace periods by more than a factor of two on a
   system with 15,000 tasks.

   The reduction is expected to increase with the number of tasks, so it
   seems reasonable to hypothesize that a system with 150,000 tasks
   might see a 20-fold reduction in CPU overhead

 - Torture-test updates

 - Updates that merge RCU's dyntick-idle tracking into context tracking,
   thus reducing the overhead of transitioning to kernel mode from
   either idle or nohz_full userspace execution for kernels that track
   context independently of RCU.

   This is expected to be helpful primarily for kernels built with
   CONFIG_NO_HZ_FULL=y

* tag 'rcu.2022.07.26a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (98 commits)
  rcu: Add irqs-disabled indicator to expedited RCU CPU stall warnings
  rcu: Diagnose extended sync_rcu_do_polled_gp() loops
  rcu: Put panic_on_rcu_stall() after expedited RCU CPU stall warnings
  rcutorture: Test polled expedited grace-period primitives
  rcu: Add polled expedited grace-period primitives
  rcutorture: Verify that polled GP API sees synchronous grace periods
  rcu: Make Tiny RCU grace periods visible to polled APIs
  rcu: Make polled grace-period API account for expedited grace periods
  rcu: Switch polled grace-period APIs to ->gp_seq_polled
  rcu/nocb: Avoid polling when my_rdp->nocb_head_rdp list is empty
  rcu/nocb: Add option to opt rcuo kthreads out of RT priority
  rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread()
  rcu/nocb: Add an option to offload all CPUs on boot
  rcu/nocb: Fix NOCB kthreads spawn failure with rcu_nocb_rdp_deoffload() direct call
  rcu/nocb: Invert rcu_state.barrier_mutex VS hotplug lock locking order
  rcu/nocb: Add/del rdp to iterate from rcuog itself
  rcu/tree: Add comment to describe GP-done condition in fqs loop
  rcu: Initialize first_gp_fqs at declaration in rcu_gp_fqs()
  rcu/kvfree: Remove useless monitor_todo flag
  rcu: Cleanup RCU urgency state for offline CPU
  ...
2022-08-02 19:12:45 -07:00
Daniel Bristot de Oliveira
792575348f rv/include: Add deterministic automata monitor definition via C macros
In Linux terms, the runtime verification monitors are encapsulated
inside the "RV monitor" abstraction. The "RV monitor" includes a set
of instances of the monitor (per-cpu monitor, per-task monitor, and
so on), the helper functions that glue the monitor to the system
reference model, and the trace output as a reaction for event parsing
and exceptions, as depicted below:

Linux  +----- RV Monitor ----------------------------------+ Formal
 Realm |                                                   |  Realm
 +-------------------+     +----------------+     +-----------------+
 |   Linux kernel    |     |     Monitor    |     |     Reference   |
 |     Tracing       |  -> |   Instance(s)  | <-  |       Model     |
 | (instrumentation) |     | (verification) |     | (specification) |
 +-------------------+     +----------------+     +-----------------+
        |                          |                       |
        |                          V                       |
        |                     +----------+                 |
        |                     | Reaction |                 |
        |                     +--+--+--+-+                 |
        |                        |  |  |                   |
        |                        |  |  +-> trace output ?  |
        +------------------------|--|----------------------+
                                 |  +----> panic ?
                                 +-------> <user-specified>

Add the rv/da_monitor.h, enabling automatic code generation for the
*Monitor Instance(s)* using C macros, and code to support it.

The benefits of the usage of macro for monitor synthesis are 3-fold as it:

- Reduces the code duplication;
- Facilitates the bug fix/improvement;
- Avoids the case of developers changing the core of the monitor code
  to manipulate the model in a (let's say) non-standard way.

This initial implementation presents three different types of monitor
instances:

- DECLARE_DA_MON_GLOBAL(name, type)
- DECLARE_DA_MON_PER_CPU(name, type)
- DECLARE_DA_MON_PER_TASK(name, type)

The first declares the functions for a global deterministic automata monitor,
the second for monitors with per-cpu instances, and the third with per-task
instances.

Link: https://lkml.kernel.org/r/51b0bf425a281e226dfeba7401d2115d6091f84e.1659052063.git.bristot@kernel.org

Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2022-07-30 14:01:28 -04:00
Eric W. Biederman
d80f7d7b2c signal: Guarantee that SIGNAL_GROUP_EXIT is set on process exit
Track how many threads have not started exiting and when the last
thread starts exiting set SIGNAL_GROUP_EXIT.

This guarantees that SIGNAL_GROUP_EXIT will get set when a process
exits.  In practice this achieves nothing as glibc's implementation of
_exit calls sys_group_exit then sys_exit.  While glibc's implemenation
of pthread_exit calls exit (which cleansup and calls _exit) if it is
the last thread and sys_exit if it is the last thread.

This means the only way the kernel might observe a process that does
not set call exit_group is if the language runtime does not use glibc.

With more cleanups I hope to move the decrement of quick_threads
earlier.

Link: https://lkml.kernel.org/r/87bkukd4tc.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-07-20 10:23:51 -05:00
Paul E. McKenney
434c9eefb9 rcu-tasks: Add data structures for lightweight grace periods
This commit adds fields to task_struct and to rcu_tasks_percpu that will
be used to avoid the task-list scan for RCU Tasks Trace grace periods,
and also initializes these fields.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: KP Singh <kpsingh@kernel.org>
2022-06-20 09:22:28 -07:00
Andrei Vagin
133e2d3e81 fs/exec: allow to unshare a time namespace on vfork+exec
Right now, a new process can't be forked in another time namespace
if it shares mm with its parent. It is prohibited, because each time
namespace has its own vvar page that is mapped into a process address
space.

When a process calls exec, it gets a new mm and so it could be "legal"
to switch time namespace in that case. This was not implemented and
now if we want to do this, we need to add another clone flag to not
break backward compatibility.

We don't have any user requests to switch times on exec except the
vfork+exec combination, so there is no reason to add a new clone flag.
As for vfork+exec, this should be safe to allow switching timens with
the current clone flag. Right now, vfork (CLONE_VFORK | CLONE_VM) fails
if a child is forked into another time namespace. With this change,
vfork creates a new process in parent's timens, and the following exec
does the actual switch to the target time namespace.

Suggested-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220613060723.197407-1-avagin@gmail.com
2022-06-15 07:58:04 -07:00
Linus Torvalds
1ec6574a3c This set of changes updates init and user mode helper tasks to be
ordinary user mode tasks.
 
 In commit 40966e316f ("kthread: Ensure struct kthread is present for
 all kthreads") caused init and the user mode helper threads that call
 kernel_execve to have struct kthread allocated for them.  This struct
 kthread going away during execve in turned made a use after free of
 struct kthread possible.
 
 The commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
 init and umh") is enough to fix the use after free and is simple enough
 to be backportable.
 
 The rest of the changes pass struct kernel_clone_args to clean things
 up and cause the code to make sense.
 
 In making init and the user mode helpers tasks purely user mode tasks
 I ran into two complications.  The function task_tick_numa was
 detecting tasks without an mm by testing for the presence of
 PF_KTHREAD.  The initramfs code in populate_initrd_image was using
 flush_delayed_fput to ensuere the closing of all it's file descriptors
 was complete, and flush_delayed_fput does not work in a userspace thread.
 
 I have looked and looked and more complications and in my code review
 I have not found any, and neither has anyone else with the code sitting
 in linux-next.
 
 Link: https://lkml.kernel.org/r/87mtfu4up3.fsf@email.froward.int.ebiederm.org
 
 Eric W. Biederman (8):
       kthread: Don't allocate kthread_struct for init and umh
       fork: Pass struct kernel_clone_args into copy_thread
       fork: Explicity test for idle tasks in copy_thread
       fork: Generalize PF_IO_WORKER handling
       init: Deal with the init process being a user mode process
       fork: Explicitly set PF_KTHREAD
       fork: Stop allowing kthreads to call execve
       sched: Update task_tick_numa to ignore tasks without an mm
 
  arch/alpha/kernel/process.c      | 13 ++++++------
  arch/arc/kernel/process.c        | 13 ++++++------
  arch/arm/kernel/process.c        | 12 ++++++-----
  arch/arm64/kernel/process.c      | 12 ++++++-----
  arch/csky/kernel/process.c       | 15 ++++++-------
  arch/h8300/kernel/process.c      | 10 ++++-----
  arch/hexagon/kernel/process.c    | 12 ++++++-----
  arch/ia64/kernel/process.c       | 15 +++++++------
  arch/m68k/kernel/process.c       | 12 ++++++-----
  arch/microblaze/kernel/process.c | 12 ++++++-----
  arch/mips/kernel/process.c       | 13 ++++++------
  arch/nios2/kernel/process.c      | 12 ++++++-----
  arch/openrisc/kernel/process.c   | 12 ++++++-----
  arch/parisc/kernel/process.c     | 18 +++++++++-------
  arch/powerpc/kernel/process.c    | 15 +++++++------
  arch/riscv/kernel/process.c      | 12 ++++++-----
  arch/s390/kernel/process.c       | 12 ++++++-----
  arch/sh/kernel/process_32.c      | 12 ++++++-----
  arch/sparc/kernel/process_32.c   | 12 ++++++-----
  arch/sparc/kernel/process_64.c   | 12 ++++++-----
  arch/um/kernel/process.c         | 15 +++++++------
  arch/x86/include/asm/fpu/sched.h |  2 +-
  arch/x86/include/asm/switch_to.h |  8 +++----
  arch/x86/kernel/fpu/core.c       |  4 ++--
  arch/x86/kernel/process.c        | 18 +++++++++-------
  arch/xtensa/kernel/process.c     | 17 ++++++++-------
  fs/exec.c                        |  8 ++++---
  include/linux/sched/task.h       |  8 +++++--
  init/initramfs.c                 |  2 ++
  init/main.c                      |  2 +-
  kernel/fork.c                    | 46 +++++++++++++++++++++++++++++++++-------
  kernel/sched/fair.c              |  2 +-
  kernel/umh.c                     |  6 +++---
  33 files changed, 234 insertions(+), 160 deletions(-)
 
 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEgjlraLDcwBA2B+6cC/v6Eiajj0AFAmKaR/MACgkQC/v6Eiaj
 j0Aayg/7Bx66872d9c6igkJ+MPCTuh+v9QKCGwiYEmiU4Q5sVAFB0HPJO27qC14u
 630X0RFNZTkPzNNEJNIW4kw6Dj8s8YRKf+FgQAVt4SzdRwT7eIPDjk1nGraopPJ3
 O04pjvuTmUyidyViRyFcf2ptx/pnkrwP8jUSc+bGTgfASAKAgAokqKE5ecjewbBc
 Y/EAkQ6QW7KxPjeSmpAHwI+t3BpBev9WEC4PbhRhsBCQFO2+PJiklvqdhVNBnIjv
 qUezll/1xv9UYgniB15Q4Nb722SmnWSU3r8as1eFPugzTHizKhufrrpyP+KMK1A0
 tdtEJNs5t2DZF7ZbGTFSPqJWmyTYLrghZdO+lOmnaSjHxK4Nda1d4NzbefJ0u+FE
 tutewowvHtBX6AFIbx+H3O+DOJM2IgNMf+ReQDU/TyNyVf3wBrTbsr9cLxypIJIp
 zze8npoLMlB7B4yxVo5ES5e63EXfi3iHl0L3/1EhoGwriRz1kWgVLUX/VZOUpscL
 RkJHsW6bT8sqxPWAA5kyWjEN+wNR2PxbXi8OE4arT0uJrEBMUgDCzydzOv5tJB00
 mSQdytxH9LVdsmxBKAOBp5X6WOLGA4yb1cZ6E/mEhlqXMpBDF1DaMfwbWqxSYi4q
 sp5zU3SBAW0qceiZSsWZXInfbjrcQXNV/DkDRDO9OmzEZP4m1j0=
 =x6fy
 -----END PGP SIGNATURE-----

Merge tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

Pull kthread updates from Eric Biederman:
 "This updates init and user mode helper tasks to be ordinary user mode
  tasks.

  Commit 40966e316f ("kthread: Ensure struct kthread is present for
  all kthreads") caused init and the user mode helper threads that call
  kernel_execve to have struct kthread allocated for them. This struct
  kthread going away during execve in turned made a use after free of
  struct kthread possible.

  Here, commit 343f4c49f2 ("kthread: Don't allocate kthread_struct for
  init and umh") is enough to fix the use after free and is simple
  enough to be backportable.

  The rest of the changes pass struct kernel_clone_args to clean things
  up and cause the code to make sense.

  In making init and the user mode helpers tasks purely user mode tasks
  I ran into two complications. The function task_tick_numa was
  detecting tasks without an mm by testing for the presence of
  PF_KTHREAD. The initramfs code in populate_initrd_image was using
  flush_delayed_fput to ensuere the closing of all it's file descriptors
  was complete, and flush_delayed_fput does not work in a userspace
  thread.

  I have looked and looked and more complications and in my code review
  I have not found any, and neither has anyone else with the code
  sitting in linux-next"

* tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  sched: Update task_tick_numa to ignore tasks without an mm
  fork: Stop allowing kthreads to call execve
  fork: Explicitly set PF_KTHREAD
  init: Deal with the init process being a user mode process
  fork: Generalize PF_IO_WORKER handling
  fork: Explicity test for idle tasks in copy_thread
  fork: Pass struct kernel_clone_args into copy_thread
  kthread: Don't allocate kthread_struct for init and umh
2022-06-03 16:03:05 -07:00
Linus Torvalds
98931dd95f Yang Shi has improved the behaviour of khugepaged collapsing of readonly
file-backed transparent hugepages.
 
 Johannes Weiner has arranged for zswap memory use to be tracked and
 managed on a per-cgroup basis.
 
 Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime
 enablement of the recent huge page vmemmap optimization feature.
 
 Baolin Wang contributes a series to fix some issues around hugetlb
 pagetable invalidation.
 
 Zhenwei Pi has fixed some interactions between hwpoisoned pages and
 virtualization.
 
 Tong Tiangen has enabled the use of the presently x86-only
 page_table_check debugging feature on arm64 and riscv.
 
 David Vernet has done some fixup work on the memcg selftests.
 
 Peter Xu has taught userfaultfd to handle write protection faults against
 shmem- and hugetlbfs-backed files.
 
 More DAMON development from SeongJae Park - adding online tuning of the
 feature and support for monitoring of fixed virtual address ranges.  Also
 easier discovery of which monitoring operations are available.
 
 Nadav Amit has done some optimization of TLB flushing during mprotect().
 
 Neil Brown continues to labor away at improving our swap-over-NFS support.
 
 David Hildenbrand has some fixes to anon page COWing versus
 get_user_pages().
 
 Peng Liu fixed some errors in the core hugetlb code.
 
 Joao Martins has reduced the amount of memory consumed by device-dax's
 compound devmaps.
 
 Some cleanups of the arch-specific pagemap code from Anshuman Khandual.
 
 Muchun Song has found and fixed some errors in the TLB flushing of
 transparent hugepages.
 
 Roman Gushchin has done more work on the memcg selftests.
 
 And, of course, many smaller fixes and cleanups.  Notably, the customary
 million cleanup serieses from Miaohe Lin.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCYo52xQAKCRDdBJ7gKXxA
 jtJFAQD238KoeI9z5SkPMaeBRYSRQmNll85mxs25KapcEgWgGQD9FAb7DJkqsIVk
 PzE+d9hEfirUGdL6cujatwJ6ejYR8Q8=
 =nFe6
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Almost all of MM here. A few things are still getting finished off,
  reviewed, etc.

   - Yang Shi has improved the behaviour of khugepaged collapsing of
     readonly file-backed transparent hugepages.

   - Johannes Weiner has arranged for zswap memory use to be tracked and
     managed on a per-cgroup basis.

   - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for
     runtime enablement of the recent huge page vmemmap optimization
     feature.

   - Baolin Wang contributes a series to fix some issues around hugetlb
     pagetable invalidation.

   - Zhenwei Pi has fixed some interactions between hwpoisoned pages and
     virtualization.

   - Tong Tiangen has enabled the use of the presently x86-only
     page_table_check debugging feature on arm64 and riscv.

   - David Vernet has done some fixup work on the memcg selftests.

   - Peter Xu has taught userfaultfd to handle write protection faults
     against shmem- and hugetlbfs-backed files.

   - More DAMON development from SeongJae Park - adding online tuning of
     the feature and support for monitoring of fixed virtual address
     ranges. Also easier discovery of which monitoring operations are
     available.

   - Nadav Amit has done some optimization of TLB flushing during
     mprotect().

   - Neil Brown continues to labor away at improving our swap-over-NFS
     support.

   - David Hildenbrand has some fixes to anon page COWing versus
     get_user_pages().

   - Peng Liu fixed some errors in the core hugetlb code.

   - Joao Martins has reduced the amount of memory consumed by
     device-dax's compound devmaps.

   - Some cleanups of the arch-specific pagemap code from Anshuman
     Khandual.

   - Muchun Song has found and fixed some errors in the TLB flushing of
     transparent hugepages.

   - Roman Gushchin has done more work on the memcg selftests.

  ... and, of course, many smaller fixes and cleanups. Notably, the
  customary million cleanup serieses from Miaohe Lin"

* tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits)
  mm: kfence: use PAGE_ALIGNED helper
  selftests: vm: add the "settings" file with timeout variable
  selftests: vm: add "test_hmm.sh" to TEST_FILES
  selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests
  selftests: vm: add migration to the .gitignore
  selftests/vm/pkeys: fix typo in comment
  ksm: fix typo in comment
  selftests: vm: add process_mrelease tests
  Revert "mm/vmscan: never demote for memcg reclaim"
  mm/kfence: print disabling or re-enabling message
  include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace"
  include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion"
  mm: fix a potential infinite loop in start_isolate_page_range()
  MAINTAINERS: add Muchun as co-maintainer for HugeTLB
  zram: fix Kconfig dependency warning
  mm/shmem: fix shmem folio swapoff hang
  cgroup: fix an error handling path in alloc_pagecache_max_30M()
  mm: damon: use HPAGE_PMD_SIZE
  tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate
  nodemask.h: fix compilation error with GCC12
  ...
2022-05-26 12:32:41 -07:00
Linus Torvalds
3e2cbc016b - Add Raptor Lake to the set of CPU models which support splitlock
- Make life miserable for apps using split locks by slowing them down
 considerably while the rest of the system remains responsive. The hope
 is it will hurt more and people will really fix their misaligned locks
 apps. As a result, free a TIF bit.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEzv7L6UO9uDPlPSfHEsHwGGHeVUoFAmKL5PQACgkQEsHwGGHe
 VUrz1Q//QjAKyKsAwCzGSPergtnZp9drimSuNsZAz6/xL8wFnn2nfWJTxugNF5jg
 n0Hal2oUGC8lg13mliB7NuDNu4RUWpkFzTzcIbPT8K9h7CUBdQPzqS7E3/p4s/eG
 ZCHp8psBGNp8+/+/LFfu9yhzYsAH9ji5KWmOzTVx9UdP3ovgR8BuCI7FCVJSfRz7
 cY690XgvcuKoXKckVNaCcoQXPJxykfk4Y1yt1TpITqivFbs2I0vLgzEhoRcTAhPA
 nX3pR3uy6oaA6rZAapRt8lbLWOwIEWoI0Tt1v+r5p28+nFiCRfm1XdPYK6CDBlox
 UuMBK4WyvSKjKHLu3wEdLCvYbs1kw2l9pXvS3hrqsKhbdeXKrxrNZ3zshwFMAYap
 MY/nSTsKSWUUgMgUbWI084csapGFB+hxwY8OVr6JXbxE8YYD/yCbPGOe1cLI7MMt
 /H3F6vNqSzdp1N3mAaaKVxiiT21lHIn6oJuSZcDE5sOvBwvpXsOp/w3FxhJCOX49
 PXrZLZmSHkDQSbh1XnvT/a+rq3XX1TFXFz71HYZf1yDk+xTijECglNtGnGSdj2Za
 iOw6M8VduV5Wy3ED9ubonruuHEJn6njpx/MH1B9+mAZsuLBpmuYFBxOn6AHOkXSb
 MVJD4flHXj0ugYm4Q5Y3yi24iWLsRI9utTOU079VL6i6DmFXeZc=
 =svvI
 -----END PGP SIGNATURE-----

Merge tag 'x86_splitlock_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 splitlock updates from Borislav Petkov:

 - Add Raptor Lake to the set of CPU models which support splitlock

 - Make life miserable for apps using split locks by slowing them down
   considerably while the rest of the system remains responsive. The
   hope is it will hurt more and people will really fix their misaligned
   locks apps. As a result, free a TIF bit.

* tag 'x86_splitlock_for_v5.19_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/split_lock: Enable the split lock feature on Raptor Lake
  x86/split-lock: Remove unused TIF_SLD bit
  x86/split_lock: Make life miserable for split lockers
2022-05-23 19:24:47 -07:00
Yang Shi
d2081b2bf8 mm: khugepaged: make khugepaged_enter() void function
The most callers of khugepaged_enter() don't care about the return value. 
Only dup_mmap(), anonymous THP page fault and MADV_HUGEPAGE handle the
error by returning -ENOMEM.  Actually it is not harmful for them to ignore
the error case either.  It also sounds overkilling to fail fork() and page
fault early due to khugepaged_enter() error, and MADV_HUGEPAGE does set
VM_HUGEPAGE flag regardless of the error.

Link: https://lkml.kernel.org/r/20220510203222.24246-6-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Vlastmil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-19 14:08:49 -07:00
Alexey Gladkov
de399236e2 ucounts: Split rlimit and ucount values and max values
Since the semantics of maximum rlimit values are different, it would be
better not to mix ucount and rlimit values. This will prevent the error
of using inc_count/dec_ucount for rlimit parameters.

This patch also renames the functions to emphasize the lack of
connection between rlimit and ucount.

v3:
- Fix BUG:KASAN:use-after-free_in_dec_ucount.

v2:
- Fix the array-index-out-of-bounds that was found by the lkp project.

Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Link: https://lkml.kernel.org/r/20220518171730.l65lmnnjtnxnftpq@example.org
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2022-05-18 18:24:57 -05:00
Eric W. Biederman
753550eb0c fork: Explicitly set PF_KTHREAD
Instead of implicitly inheriting PF_KTHREAD from the parent process
examine arguments in kernel_clone_args to see if PF_KTHREAD should be
set.  This makes knowledge of which new threads are kernel threads
explicit.

This also makes it so that init and the user mode helper processes
no longer have PF_KTHREAD set.

Link: https://lkml.kernel.org/r/20220506141512.516114-6-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-07 09:01:59 -05:00
Eric W. Biederman
5bd2e97c86 fork: Generalize PF_IO_WORKER handling
Add fn and fn_arg members into struct kernel_clone_args and test for
them in copy_thread (instead of testing for PF_KTHREAD | PF_IO_WORKER).
This allows any task that wants to be a user space task that only runs
in kernel mode to use this functionality.

The code on x86 is an exception and still retains a PF_KTHREAD test
because x86 unlikely everything else handles kthreads slightly
differently than user space tasks that start with a function.

The functions that created tasks that start with a function
have been updated to set ".fn" and ".fn_arg" instead of
".stack" and ".stack_size".  These functions are fork_idle(),
create_io_thread(), kernel_thread(), and user_mode_thread().

Link: https://lkml.kernel.org/r/20220506141512.516114-4-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-07 09:01:59 -05:00
Eric W. Biederman
36cb0e1cda fork: Explicity test for idle tasks in copy_thread
The architectures ia64 and parisc have special handling for the idle
thread in copy_process.  Add a flag named idle to kernel_clone_args
and use it to explicity test if an idle process is being created.

Fullfill the expectations of the rest of the copy_thread
implemetations and pass a function pointer in .stack from fork_idle().
This makes what is happening in copy_thread better defined, and is
useful to make idle threads less special.

Link: https://lkml.kernel.org/r/20220506141512.516114-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-07 09:01:59 -05:00
Eric W. Biederman
c5febea095 fork: Pass struct kernel_clone_args into copy_thread
With io_uring we have started supporting tasks that are for most
purposes user space tasks that exclusively run code in kernel mode.

The kernel task that exec's init and tasks that exec user mode
helpers are also user mode tasks that just run kernel code
until they call kernel execve.

Pass kernel_clone_args into copy_thread so these oddball
tasks can be supported more cleanly and easily.

v2: Fix spelling of kenrel_clone_args on h8300
Link: https://lkml.kernel.org/r/20220506141512.516114-2-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-07 09:01:48 -05:00
Eric W. Biederman
343f4c49f2 kthread: Don't allocate kthread_struct for init and umh
If kthread_is_per_cpu runs concurrently with free_kthread_struct the
kthread_struct that was just freed may be read from.

This bug was introduced by commit 40966e316f ("kthread: Ensure
struct kthread is present for all kthreads").  When kthread_struct
started to be allocated for all tasks that have PF_KTHREAD set.  This
in turn required the kthread_struct to be freed in kernel_execve and
violated the assumption that kthread_struct will have the same
lifetime as the task.

Looking a bit deeper this only applies to callers of kernel_execve
which is just the init process and the user mode helper processes.
These processes really don't want to be kernel threads but are for
historical reasons.  Mostly that copy_thread does not know how to take
a kernel mode function to the process with for processes without
PF_KTHREAD or PF_IO_WORKER set.

Solve this by not allocating kthread_struct for the init process and
the user mode helper processes.

This is done by adding a kthread member to struct kernel_clone_args.
Setting kthread in fork_idle and kernel_thread.  Adding
user_mode_thread that works like kernel_thread except it does not set
kthread.  In fork only allocating the kthread_struct if .kthread is set.

I have looked at kernel/kthread.c and since commit 40966e316f
("kthread: Ensure struct kthread is present for all kthreads") there
have been no assumptions added that to_kthread or __to_kthread will
not return NULL.

There are a few callers of to_kthread or __to_kthread that assume a
non-NULL struct kthread pointer will be returned.  These functions are
kthread_data(), kthread_parmme(), kthread_exit(), kthread(),
kthread_park(), kthread_unpark(), kthread_stop().  All of those functions
can reasonably expected to be called when it is know that a task is a
kthread so that assumption seems reasonable.

Cc: stable@vger.kernel.org
Fixes: 40966e316f ("kthread: Ensure struct kthread is present for all kthreads")
Reported-by: Максим Кутявин <maximkabox13@gmail.com>
Link: https://lkml.kernel.org/r/20220506141512.516114-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2022-05-06 14:49:44 -05:00
Fenghua Yu
2667ed10d9 mm: Fix PASID use-after-free issue
The PASID is being freed too early.  It needs to stay around until after
device drivers that might be using it have had a chance to clear it out
of the hardware.

The relevant refcounts are:

  mmget() /mmput()  refcount the mm's address space
  mmgrab()/mmdrop() refcount the mm itself

The PASID is currently tied to the life of the mm's address space and freed
in __mmput().  This makes logical sense because the PASID can't be used
once the address space is gone.

But, this misses an important point: even after the address space is gone,
the PASID will still be programmed into a device.  Device drivers might,
for instance, still need to flush operations that are outstanding and need
to use that PASID.  They do this at file->release() time.

Device drivers call the IOMMU driver to hold a reference on the mm itself
and drop it at file->release() time.  But, the IOMMU driver holds a
reference on the mm itself, not the address space.  The address space (and
the PASID) is long gone by the time the driver tries to clean up.  This is
effectively a use-after-free bug on the PASID.

To fix this, move the PASID free operation from __mmput() to __mmdrop().
This ensures that the IOMMU driver's existing mmgrab() keeps the PASID
allocated until it drops its mm reference.

Fixes: 701fac4038 ("iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit")
Reported-by: Zhangfei Gao <zhangfei.gao@foxmail.com>
Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Suggested-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Zhangfei Gao <zhangfei.gao@foxmail.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20220428180041.806809-1-fenghua.yu@intel.com
2022-05-01 10:17:17 +02:00
Tony Luck
b041b525da x86/split_lock: Make life miserable for split lockers
In https://lore.kernel.org/all/87y22uujkm.ffs@tglx/ Thomas
said:

  Its's simply wishful thinking that stuff gets fixed because of a
  WARN_ONCE(). This has never worked. The only thing which works is to
  make stuff fail hard or slow it down in a way which makes it annoying
  enough to users to complain.

He was talking about WBINVD. But it made me think about how we use the
split lock detection feature in Linux.

Existing code has three options for applications:

 1) Don't enable split lock detection (allow arbitrary split locks)
 2) Warn once when a process uses split lock, but let the process
    keep running with split lock detection disabled
 3) Kill process that use split locks

Option 2 falls into the "wishful thinking" territory that Thomas warns does
nothing. But option 3 might not be viable in a situation with legacy
applications that need to run.

Hence make option 2 much stricter to "slow it down in a way which makes
it annoying".

Primary reason for this change is to provide better quality of service to
the rest of the applications running on the system. Internal testing shows
that even with many processes splitting locks, performance for the rest of
the system is much more responsive.

The new "warn" mode operates like this.  When an application tries to
execute a bus lock the #AC handler.

 1) Delays (interruptibly) 10 ms before moving to next step.

 2) Blocks (interruptibly) until it can get the semaphore
	If interrupted, just return. Assume the signal will either
	kill the task, or direct execution away from the instruction
	that is trying to get the bus lock.
 3) Disables split lock detection for the current core
 4) Schedules a work queue to re-enable split lock detect in 2 jiffies
 5) Returns

The work queue that re-enables split lock detection also releases the
semaphore.

There is a corner case where a CPU may be taken offline while split lock
detection is disabled. A CPU hotplug handler handles this case.

Old behaviour was to only print the split lock warning on the first
occurrence of a split lock from a task. Preserve that by adding a flag to
the task structure that suppresses subsequent split lock messages from that
task.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220310204854.31752-2-tony.luck@intel.com
2022-04-27 15:43:38 +02:00
Andrey Konovalov
51fb34de2a kasan, arm64: reset pointer tags of vmapped stacks
Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.

Reset the tag of kernel stack pointers after allocation in
arch_alloc_vmap_stack().

For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.

For HW_TAGS KASAN, there's no instrumentation-related issues.  However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.

Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.

[andreyknvl@google.com: fix case when a stack is retrieved from cached_stacks]
  Link: https://lkml.kernel.org/r/f50c5f96ef896d7936192c888b0c0a7674e33184.1644943792.git.andreyknvl@google.com
[dan.carpenter@oracle.com: remove unnecessary check in alloc_thread_stack_node()]
  Link: https://lkml.kernel.org/r/20220301080706.GB17208@kili

Link: https://lkml.kernel.org/r/698c5ab21743c796d46c15d075b9481825973e34.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-24 19:06:47 -07:00
Andrey Konovalov
c08e6a1206 kasan, fork: reset pointer tags of vmapped stacks
Once tag-based KASAN modes start tagging vmalloc() allocations, kernel
stacks start getting tagged if CONFIG_VMAP_STACK is enabled.

Reset the tag of kernel stack pointers after allocation in
alloc_thread_stack_node().

For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation
can't handle the SP register being tagged.

For HW_TAGS KASAN, there's no instrumentation-related issues.  However,
the impact of having a tagged SP register needs to be properly evaluated,
so keep it non-tagged for now.

Note, that the memory for the stack allocation still gets tagged to catch
vmalloc-into-stack out-of-bounds accesses.

Link: https://lkml.kernel.org/r/c6c96f012371ecd80e1936509ebcd3b07a5956f7.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-24 19:06:47 -07:00
Linus Torvalds
169e77764a Networking changes for 5.18.
Core
 ----
 
  - Introduce XDP multi-buffer support, allowing the use of XDP with
    jumbo frame MTUs and combination with Rx coalescing offloads (LRO).
 
  - Speed up netns dismantling (5x) and lower the memory cost a little.
    Remove unnecessary per-netns sockets. Scope some lists to a netns.
    Cut down RCU syncing. Use batch methods. Allow netdev registration
    to complete out of order.
 
  - Support distinguishing timestamp types (ingress vs egress) and
    maintaining them across packet scrubbing points (e.g. redirect).
 
  - Continue the work of annotating packet drop reasons throughout
    the stack.
 
  - Switch netdev error counters from an atomic to dynamically
    allocated per-CPU counters.
 
  - Rework a few preempt_disable(), local_irq_save() and busy waiting
    sections problematic on PREEMPT_RT.
 
  - Extend the ref_tracker to allow catching use-after-free bugs.
 
 BPF
 ---
 
  - Introduce "packing allocator" for BPF JIT images. JITed code is
    marked read only, and used to be allocated at page granularity.
    Custom allocator allows for more efficient memory use, lower
    iTLB pressure and prevents identity mapping huge pages from
    getting split.
 
  - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
    the correct probe read access method, add appropriate helpers.
 
  - Convert the BPF preload to use light skeleton and drop
    the user-mode-driver dependency.
 
  - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
    its use as a packet generator.
 
  - Allow local storage memory to be allocated with GFP_KERNEL if called
    from a hook allowed to sleep.
 
  - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
    bits to come later).
 
  - Add unstable conntrack lookup helpers for BPF by using the BPF
    kfunc infra.
 
  - Allow cgroup BPF progs to return custom errors to user space.
 
  - Add support for AF_UNIX iterator batching.
 
  - Allow iterator programs to use sleepable helpers.
 
  - Support JIT of add, and, or, xor and xchg atomic ops on arm64.
 
  - Add BTFGen support to bpftool which allows to use CO-RE in kernels
    without BTF info.
 
  - Large number of libbpf API improvements, cleanups and deprecations.
 
 Protocols
 ---------
 
  - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.
 
  - Adjust TSO packet sizes based on min_rtt, allowing very low latency
    links (data centers) to always send full-sized TSO super-frames.
 
  - Make IPv6 flow label changes (AKA hash rethink) more configurable,
    via sysctl and setsockopt. Distinguish between server and client
    behavior.
 
  - VxLAN support to "collect metadata" devices to terminate only
    configured VNIs. This is similar to VLAN filtering in the bridge.
 
  - Support inserting IPv6 IOAM information to a fraction of frames.
 
  - Add protocol attribute to IP addresses to allow identifying where
    given address comes from (kernel-generated, DHCP etc.)
 
  - Support setting socket and IPv6 options via cmsg on ping6 sockets.
 
  - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
    Define dscp_t and stop taking ECN bits into account in fib-rules.
 
  - Add support for locked bridge ports (for 802.1X).
 
  - tun: support NAPI for packets received from batched XDP buffs,
    doubling the performance in some scenarios.
 
  - IPv6 extension header handling in Open vSwitch.
 
  - Support IPv6 control message load balancing in bonding, prevent
    neighbor solicitation and advertisement from using the wrong port.
    Support NS/NA monitor selection similar to existing ARP monitor.
 
  - SMC
    - improve performance with TCP_CORK and sendfile()
    - support auto-corking
    - support TCP_NODELAY
 
  - MCTP (Management Component Transport Protocol)
    - add user space tag control interface
    - I2C binding driver (as specified by DMTF DSP0237)
 
  - Multi-BSSID beacon handling in AP mode for WiFi.
 
  - Bluetooth:
    - handle MSFT Monitor Device Event
    - add MGMT Adv Monitor Device Found/Lost events
 
  - Multi-Path TCP:
    - add support for the SO_SNDTIMEO socket option
    - lots of selftest cleanups and improvements
 
  - Increase the max PDU size in CAN ISOTP to 64 kB.
 
 Driver API
 ----------
 
  - Add HW counters for SW netdevs, a mechanism for devices which
    offload packet forwarding to report packet statistics back to
    software interfaces such as tunnels.
 
  - Select the default NIC queue count as a fraction of number of
    physical CPU cores, instead of hard-coding to 8.
 
  - Expose devlink instance locks to drivers. Allow device layer of
    drivers to use that lock directly instead of creating their own
    which always runs into ordering issues in devlink callbacks.
 
  - Add header/data split indication to guide user space enabling
    of TCP zero-copy Rx.
 
  - Allow configuring completion queue event size.
 
  - Refactor page_pool to enable fragmenting after allocation.
 
  - Add allocation and page reuse statistics to page_pool.
 
  - Improve Multiple Spanning Trees support in the bridge to allow
    reuse of topologies across VLANs, saving HW resources in switches.
 
  - DSA (Distributed Switch Architecture):
    - replay and offload of host VLAN entries
    - offload of static and local FDB entries on LAG interfaces
    - FDB isolation and unicast filtering
 
 New hardware / drivers
 ----------------------
 
  - Ethernet:
    - LAN937x T1 PHYs
    - Davicom DM9051 SPI NIC driver
    - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
    - Microchip ksz8563 switches
    - Netronome NFP3800 SmartNICs
    - Fungible SmartNICs
    - MediaTek MT8195 switches
 
  - WiFi:
    - mt76: MediaTek mt7916
    - mt76: MediaTek mt7921u USB adapters
    - brcmfmac: Broadcom BCM43454/6
 
  - Mobile:
    - iosm: Intel M.2 7360 WWAN card
 
 Drivers
 -------
 
  - Convert many drivers to the new phylink API built for split PCS
    designs but also simplifying other cases.
 
  - Intel Ethernet NICs:
    - add TTY for GNSS module for E810T device
    - improve AF_XDP performance
    - GTP-C and GTP-U filter offload
    - QinQ VLAN support
 
  - Mellanox Ethernet NICs (mlx5):
    - support xdp->data_meta
    - multi-buffer XDP
    - offload tc push_eth and pop_eth actions
 
  - Netronome Ethernet NICs (nfp):
    - flow-independent tc action hardware offload (police / meter)
    - AF_XDP
 
  - Other Ethernet NICs:
    - at803x: fiber and SFP support
    - xgmac: mdio: preamble suppression and custom MDC frequencies
    - r8169: enable ASPM L1.2 if system vendor flags it as safe
    - macb/gem: ZynqMP SGMII
    - hns3: add TX push mode
    - dpaa2-eth: software TSO
    - lan743x: multi-queue, mdio, SGMII, PTP
    - axienet: NAPI and GRO support
 
  - Mellanox Ethernet switches (mlxsw):
    - source and dest IP address rewrites
    - RJ45 ports
 
  - Marvell Ethernet switches (prestera):
    - basic routing offload
    - multi-chain TC ACL offload
 
  - NXP embedded Ethernet switches (ocelot & felix):
    - PTP over UDP with the ocelot-8021q DSA tagging protocol
    - basic QoS classification on Felix DSA switch using dcbnl
    - port mirroring for ocelot switches
 
  - Microchip high-speed industrial Ethernet (sparx5):
    - offloading of bridge port flooding flags
    - PTP Hardware Clock
 
  - Other embedded switches:
    - lan966x: PTP Hardward Clock
    - qca8k: mdio read/write operations via crafted Ethernet packets
 
  - Qualcomm 802.11ax WiFi (ath11k):
    - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
    - enable RX PPDU stats in monitor co-exist mode
 
  - Intel WiFi (iwlwifi):
    - UHB TAS enablement via BIOS
    - band disablement via BIOS
    - channel switch offload
    - 32 Rx AMPDU sessions in newer devices
 
  - MediaTek WiFi (mt76):
    - background radar detection
    - thermal management improvements on mt7915
    - SAR support for more mt76 platforms
    - MBSSID and 6 GHz band on mt7915
 
  - RealTek WiFi:
    - rtw89: AP mode
    - rtw89: 160 MHz channels and 6 GHz band
    - rtw89: hardware scan
 
  - Bluetooth:
    - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)
 
  - Microchip CAN (mcp251xfd):
    - multiple RX-FIFOs and runtime configurable RX/TX rings
    - internal PLL, runtime PM handling simplification
    - improve chip detection and error handling after wakeup
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE6jPA+I1ugmIBA4hXMUZtbf5SIrsFAmI7YBcACgkQMUZtbf5S
 IrveSBAAmSNJlUK6vPsnNzs7IhsZnfI/AUjm2TCLZnlhKttbpI4A/4Pohk33V7RS
 FGX7f8kjEfhUwrIiLDgeCnztNHRECrCmk6aZc/jLEvecmTauJ+f6kjShkDY/wix+
 AkPHmrZnQeLPAEVuljDdV+sL6ik08+zQL7PazIYHsaSKKC0MGQptRwcri8PLRAKE
 KPBAhVhleq2rAZ/ntprSN52F4Af6rpFTrPIWuN8Bqdbc9dy5094LT0mpOOWYvgr3
 /DLvvAPuLemwyIQkjWknVKBRUAQcmNPC+BY3J8K3LRaiNhekGqOFan46BfqP+k2J
 6DWu0Qrp2yWt4BMOeEToZR5rA6v5suUAMIBu8PRZIDkINXQMlIxHfGjZyNm0rVfw
 7edNri966yus9OdzwPa32MIG3oC6PnVAwYCJAjjBMNS8sSIkp7wgHLkgWN4UFe2H
 K/e6z8TLF4UQ+zFM0aGI5WZ+9QqWkTWEDF3R3OhdFpGrznna0gxmkOeV2YvtsgxY
 cbS0vV9Zj73o+bYzgBKJsw/dAjyLdXoHUGvus26VLQ78S/VGunVKtItwoxBAYmZo
 krW964qcC89YofzSi8RSKLHuEWtNWZbVm8YXr75u6jpr5GhMBu0CYefLs+BuZcxy
 dw8c69cGneVbGZmY2J3rBhDkchbuICl8vdUPatGrOJAoaFdYKuw=
 =ELpe
 -----END PGP SIGNATURE-----

Merge tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Jakub Kicinski:
 "The sprinkling of SPI drivers is because we added a new one and Mark
  sent us a SPI driver interface conversion pull request.

  Core
  ----

   - Introduce XDP multi-buffer support, allowing the use of XDP with
     jumbo frame MTUs and combination with Rx coalescing offloads (LRO).

   - Speed up netns dismantling (5x) and lower the memory cost a little.
     Remove unnecessary per-netns sockets. Scope some lists to a netns.
     Cut down RCU syncing. Use batch methods. Allow netdev registration
     to complete out of order.

   - Support distinguishing timestamp types (ingress vs egress) and
     maintaining them across packet scrubbing points (e.g. redirect).

   - Continue the work of annotating packet drop reasons throughout the
     stack.

   - Switch netdev error counters from an atomic to dynamically
     allocated per-CPU counters.

   - Rework a few preempt_disable(), local_irq_save() and busy waiting
     sections problematic on PREEMPT_RT.

   - Extend the ref_tracker to allow catching use-after-free bugs.

  BPF
  ---

   - Introduce "packing allocator" for BPF JIT images. JITed code is
     marked read only, and used to be allocated at page granularity.
     Custom allocator allows for more efficient memory use, lower iTLB
     pressure and prevents identity mapping huge pages from getting
     split.

   - Make use of BTF type annotations (e.g. __user, __percpu) to enforce
     the correct probe read access method, add appropriate helpers.

   - Convert the BPF preload to use light skeleton and drop the
     user-mode-driver dependency.

   - Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
     its use as a packet generator.

   - Allow local storage memory to be allocated with GFP_KERNEL if
     called from a hook allowed to sleep.

   - Introduce fprobe (multi kprobe) to speed up mass attachment (arch
     bits to come later).

   - Add unstable conntrack lookup helpers for BPF by using the BPF
     kfunc infra.

   - Allow cgroup BPF progs to return custom errors to user space.

   - Add support for AF_UNIX iterator batching.

   - Allow iterator programs to use sleepable helpers.

   - Support JIT of add, and, or, xor and xchg atomic ops on arm64.

   - Add BTFGen support to bpftool which allows to use CO-RE in kernels
     without BTF info.

   - Large number of libbpf API improvements, cleanups and deprecations.

  Protocols
  ---------

   - Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.

   - Adjust TSO packet sizes based on min_rtt, allowing very low latency
     links (data centers) to always send full-sized TSO super-frames.

   - Make IPv6 flow label changes (AKA hash rethink) more configurable,
     via sysctl and setsockopt. Distinguish between server and client
     behavior.

   - VxLAN support to "collect metadata" devices to terminate only
     configured VNIs. This is similar to VLAN filtering in the bridge.

   - Support inserting IPv6 IOAM information to a fraction of frames.

   - Add protocol attribute to IP addresses to allow identifying where
     given address comes from (kernel-generated, DHCP etc.)

   - Support setting socket and IPv6 options via cmsg on ping6 sockets.

   - Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
     Define dscp_t and stop taking ECN bits into account in fib-rules.

   - Add support for locked bridge ports (for 802.1X).

   - tun: support NAPI for packets received from batched XDP buffs,
     doubling the performance in some scenarios.

   - IPv6 extension header handling in Open vSwitch.

   - Support IPv6 control message load balancing in bonding, prevent
     neighbor solicitation and advertisement from using the wrong port.
     Support NS/NA monitor selection similar to existing ARP monitor.

   - SMC
      - improve performance with TCP_CORK and sendfile()
      - support auto-corking
      - support TCP_NODELAY

   - MCTP (Management Component Transport Protocol)
      - add user space tag control interface
      - I2C binding driver (as specified by DMTF DSP0237)

   - Multi-BSSID beacon handling in AP mode for WiFi.

   - Bluetooth:
      - handle MSFT Monitor Device Event
      - add MGMT Adv Monitor Device Found/Lost events

   - Multi-Path TCP:
      - add support for the SO_SNDTIMEO socket option
      - lots of selftest cleanups and improvements

   - Increase the max PDU size in CAN ISOTP to 64 kB.

  Driver API
  ----------

   - Add HW counters for SW netdevs, a mechanism for devices which
     offload packet forwarding to report packet statistics back to
     software interfaces such as tunnels.

   - Select the default NIC queue count as a fraction of number of
     physical CPU cores, instead of hard-coding to 8.

   - Expose devlink instance locks to drivers. Allow device layer of
     drivers to use that lock directly instead of creating their own
     which always runs into ordering issues in devlink callbacks.

   - Add header/data split indication to guide user space enabling of
     TCP zero-copy Rx.

   - Allow configuring completion queue event size.

   - Refactor page_pool to enable fragmenting after allocation.

   - Add allocation and page reuse statistics to page_pool.

   - Improve Multiple Spanning Trees support in the bridge to allow
     reuse of topologies across VLANs, saving HW resources in switches.

   - DSA (Distributed Switch Architecture):
      - replay and offload of host VLAN entries
      - offload of static and local FDB entries on LAG interfaces
      - FDB isolation and unicast filtering

  New hardware / drivers
  ----------------------

   - Ethernet:
      - LAN937x T1 PHYs
      - Davicom DM9051 SPI NIC driver
      - Realtek RTL8367S, RTL8367RB-VB switch and MDIO
      - Microchip ksz8563 switches
      - Netronome NFP3800 SmartNICs
      - Fungible SmartNICs
      - MediaTek MT8195 switches

   - WiFi:
      - mt76: MediaTek mt7916
      - mt76: MediaTek mt7921u USB adapters
      - brcmfmac: Broadcom BCM43454/6

   - Mobile:
      - iosm: Intel M.2 7360 WWAN card

  Drivers
  -------

   - Convert many drivers to the new phylink API built for split PCS
     designs but also simplifying other cases.

   - Intel Ethernet NICs:
      - add TTY for GNSS module for E810T device
      - improve AF_XDP performance
      - GTP-C and GTP-U filter offload
      - QinQ VLAN support

   - Mellanox Ethernet NICs (mlx5):
      - support xdp->data_meta
      - multi-buffer XDP
      - offload tc push_eth and pop_eth actions

   - Netronome Ethernet NICs (nfp):
      - flow-independent tc action hardware offload (police / meter)
      - AF_XDP

   - Other Ethernet NICs:
      - at803x: fiber and SFP support
      - xgmac: mdio: preamble suppression and custom MDC frequencies
      - r8169: enable ASPM L1.2 if system vendor flags it as safe
      - macb/gem: ZynqMP SGMII
      - hns3: add TX push mode
      - dpaa2-eth: software TSO
      - lan743x: multi-queue, mdio, SGMII, PTP
      - axienet: NAPI and GRO support

   - Mellanox Ethernet switches (mlxsw):
      - source and dest IP address rewrites
      - RJ45 ports

   - Marvell Ethernet switches (prestera):
      - basic routing offload
      - multi-chain TC ACL offload

   - NXP embedded Ethernet switches (ocelot & felix):
      - PTP over UDP with the ocelot-8021q DSA tagging protocol
      - basic QoS classification on Felix DSA switch using dcbnl
      - port mirroring for ocelot switches

   - Microchip high-speed industrial Ethernet (sparx5):
      - offloading of bridge port flooding flags
      - PTP Hardware Clock

   - Other embedded switches:
      - lan966x: PTP Hardward Clock
      - qca8k: mdio read/write operations via crafted Ethernet packets

   - Qualcomm 802.11ax WiFi (ath11k):
      - add LDPC FEC type and 802.11ax High Efficiency data in radiotap
      - enable RX PPDU stats in monitor co-exist mode

   - Intel WiFi (iwlwifi):
      - UHB TAS enablement via BIOS
      - band disablement via BIOS
      - channel switch offload
      - 32 Rx AMPDU sessions in newer devices

   - MediaTek WiFi (mt76):
      - background radar detection
      - thermal management improvements on mt7915
      - SAR support for more mt76 platforms
      - MBSSID and 6 GHz band on mt7915

   - RealTek WiFi:
      - rtw89: AP mode
      - rtw89: 160 MHz channels and 6 GHz band
      - rtw89: hardware scan

   - Bluetooth:
      - mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)

   - Microchip CAN (mcp251xfd):
      - multiple RX-FIFOs and runtime configurable RX/TX rings
      - internal PLL, runtime PM handling simplification
      - improve chip detection and error handling after wakeup"

* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
  llc: fix netdevice reference leaks in llc_ui_bind()
  drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
  ice: don't allow to run ice_send_event_to_aux() in atomic ctx
  ice: fix 'scheduling while atomic' on aux critical err interrupt
  net/sched: fix incorrect vlan_push_eth dest field
  net: bridge: mst: Restrict info size queries to bridge ports
  net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
  drivers: net: xgene: Fix regression in CRC stripping
  net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
  net: dsa: fix missing host-filtered multicast addresses
  net/mlx5e: Fix build warning, detected write beyond size of field
  iwlwifi: mvm: Don't fail if PPAG isn't supported
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  netdevice: add missing dm_private kdoc
  net: bridge: mst: prevent NULL deref in br_mst_info_size()
  selftests: forwarding: Use same VRF for port and VLAN upper
  ...
2022-03-24 13:13:26 -07:00
Jakub Kicinski
0db8640df5 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2022-03-21 v2

We've added 137 non-merge commits during the last 17 day(s) which contain
a total of 143 files changed, 7123 insertions(+), 1092 deletions(-).

The main changes are:

1) Custom SEC() handling in libbpf, from Andrii.

2) subskeleton support, from Delyan.

3) Use btf_tag to recognize __percpu pointers in the verifier, from Hao.

4) Fix net.core.bpf_jit_harden race, from Hou.

5) Fix bpf_sk_lookup remote_port on big-endian, from Jakub.

6) Introduce fprobe (multi kprobe) _without_ arch bits, from Masami.
The arch specific bits will come later.

7) Introduce multi_kprobe bpf programs on top of fprobe, from Jiri.

8) Enable non-atomic allocations in local storage, from Joanne.

9) Various var_off ptr_to_btf_id fixed, from Kumar.

10) bpf_ima_file_hash helper, from Roberto.

11) Add "live packet" mode for XDP in BPF_PROG_RUN, from Toke.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (137 commits)
  selftests/bpf: Fix kprobe_multi test.
  Revert "rethook: x86: Add rethook x86 implementation"
  Revert "arm64: rethook: Add arm64 rethook implementation"
  Revert "powerpc: Add rethook support"
  Revert "ARM: rethook: Add rethook arm implementation"
  bpftool: Fix a bug in subskeleton code generation
  bpf: Fix bpf_prog_pack when PMU_SIZE is not defined
  bpf: Fix bpf_prog_pack for multi-node setup
  bpf: Fix warning for cast from restricted gfp_t in verifier
  bpf, arm: Fix various typos in comments
  libbpf: Close fd in bpf_object__reuse_map
  bpftool: Fix print error when show bpf map
  bpf: Fix kprobe_multi return probe backtrace
  Revert "bpf: Add support to inline bpf_get_func_ip helper on x86"
  bpf: Simplify check in btf_parse_hdr()
  selftests/bpf/test_lirc_mode2.sh: Exit with proper code
  bpf: Check for NULL return from bpf_get_btf_vmlinux
  selftests/bpf: Test skipping stacktrace
  bpf: Adjust BPF stack helper functions to accommodate skip > 0
  bpf: Select proper size for bpf_prog_pack
  ...
====================

Link: https://lore.kernel.org/r/20220322050159.5507-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-03-22 11:18:49 -07:00
Linus Torvalds
bba90e0964 Core code updates:
- Reduce the amount of work to release a task stack in context
     switch. There is no real reason to do cgroup accounting and memory
     freeing in this performance sensitive context. Aside of this the
     invoked functions cannot be called from this preemption disabled
     context on PREEMPT_RT enabled kernels. Solve this by moving the
     accounting into do_exit() and delaying the freeing of the stack unless
     the vmap stack can be cached.
 
   - Provide a mechanism to delay raising signals from atomic context on
     PREEMPT_RT enabled kernels as sighand::lock cannot be acquired.  Store
     the information in the task struct and raise it in the exit path.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmI4U6gTHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoSpkEACwgaaQUbqVrpw5yb6LbwzUPnjEdFNN
 uUQCv0XZD8LWbfhcQQVSPWGho7S/w2Mkpdhi0DkVb2K0dkB7EvITSNEC4KoS/yez
 8iQBpv6Lm00quHdNLjkQySSZ4NYB8M1GasBI7zSBjROK/+sRqioTPQsM0oDemGmD
 uMvw0dgDJRlB8X4LZv0xuJbYLdSzu2VOlWd5aJG9BUgHkd7PfUWMlHsa29FP0hkP
 A5yziOnr9kMsmCAsgmiyDW/GmefrEealby5M/jgnxTruF/OLnDsP+PYMlws47fPx
 g6xpHkT5H0zQJ/nMJtK2JAlxpnbIl4cLuUnpn7wX316yjBpP2s3Pw04AVdzPPoBa
 ufAoOLFtnrKN6enIqLWaJHGAsBHEULw6d3/7HoAEQOVWChnQSuWOob8z0QDbvM14
 kKtz+LTrO+P5a15fd4g5+9lFBXJUTnF74SYQNwxIm2cV9hxrf15NhAr8yg+RtUvF
 /ilNNAFtXkASLqs9moEi7U+GyBYwemG+gduVZ3Dw8FBxK/vHmDrhlItcZdKom+UJ
 k4VFDVhzd2GYRHMrcaLfkCYew6ou+LD/rjdPhIU9OQHgILIMLY5aLqxDuyPtHqDz
 TEyF5qsL4wYLIUdsWlqyHISqQQ6LfnpIyko5kb2Zt56sYtrcZr8swDy+yimiEOdL
 G4BzQu0nVbCLhw==
 =uGTc
 -----END PGP SIGNATURE-----

Merge tag 'core-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core process handling RT latency updates from Thomas Gleixner:

 - Reduce the amount of work to release a task stack in context switch.
   There is no real reason to do cgroup accounting and memory freeing in
   this performance sensitive context.

   Aside of this the invoked functions cannot be called from this
   preemption disabled context on PREEMPT_RT enabled kernels. Solve this
   by moving the accounting into do_exit() and delaying the freeing of
   the stack unless the vmap stack can be cached.

 - Provide a mechanism to delay raising signals from atomic context on
   PREEMPT_RT enabled kernels as sighand::lock cannot be acquired. Store
   the information in the task struct and raise it in the exit path.

* tag 'core-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  signal, x86: Delay calling signals in atomic on RT enabled kernels
  fork: Use IS_ENABLED() in account_kernel_stack()
  fork: Only cache the VMAP stack in finish_task_switch()
  fork: Move task stack accounting to do_exit()
  fork: Move memcg_charge_kernel_stack() into CONFIG_VMAP_STACK
  fork: Don't assign the stack pointer in dup_task_struct()
  fork, IA64: Provide alloc_thread_stack_node() for IA64
  fork: Duplicate task_struct before stack allocation
  fork: Redo ifdefs around task stack handling
2022-03-21 12:37:33 -07:00
Linus Torvalds
3fd33273a4 Reenable ENQCMD/PASID support:
- Simplify the PASID handling to allocate the PASID once, associate it to
    the mm of a process and free it on mm_exit(). The previous attempt of
    refcounted PASIDs and dynamic alloc()/free() turned out to be error
    prone and too complex. The PASID space is 20bits, so the case of
    resource exhaustion is a pure academic concern.
 
  - Populate the PASID MSR on demand via #GP to avoid racy updates via IPIs.
 
  - Reenable ENQCMD and let objtool check for the forbidden usage of ENQCMD
    in the kernel.
 
  - Update the documentation for Shared Virtual Addressing accordingly.
 -----BEGIN PGP SIGNATURE-----
 
 iQJHBAABCgAxFiEEQp8+kY+LLUocC4bMphj1TA10mKEFAmI4WpETHHRnbHhAbGlu
 dXRyb25peC5kZQAKCRCmGPVMDXSYoUfnD/0bY94rgEX4Uuy/mFQ1W8X8XlcyKrha
 0/cRATb+4QV/pwJgGr2nClKhGlFMYPdJLvKMC1TCUPCVrLD1RNmluIZoFzeqXwhm
 jDdCcFOuGZ2D4ujDPWwOOpKBT1ytovnQa7+lH6QJyKkEqdcC2ncOvGJQoiRxRQIG
 8wTVs/OUvQJ5ZhSZQMKQN4uMWMyHEjhbroYS30/uNi/598jTPgzlEoa14XocQ9Os
 nS6ALvjuc9MsJ34F61etMaJU1ZMI3Wx75u9QjEvX6hmJs87YdvgwE7lzJUKFDEuh
 gewM0wp2fTa8/azzP0eMiHTin56PqFdmllzRqXmilbZMEPOeI29dZVArCdpKcAn0
 r9p1kJUT3Xl2G3Oir/OdCaaQHcznD1Y5ZFOyh12wgEucZ/rdeSr7nq7n5HoOL5Bw
 Q2o6YvTkE9DOL0nTN1lSXGiPspou7fzX0uUcRBrbJUS3sBv4zGIlaJXUaTVnSdAt
 VZj4LeOK7v2BjyeiOY0iaaIQd3xjmLUF0UjozXS5M13SoVcToZRbyWqhDzPvNuKA
 imQb/dnFpXhABgmuqAiJLeqM0VtGMFNc780OURkcsBSPng+iSEdV4DzuhK0jpU8x
 Uk1RuGMd/vgmrlDFBrw+orQQiiKR1ixpI0LiHfcOBycfJhqTwcnrNZvAN5/do28Z
 E23+QzlUbZF0cw==
 =Dy8V
 -----END PGP SIGNATURE-----

Merge tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 PASID support from Thomas Gleixner:
 "Reenable ENQCMD/PASID support:

   - Simplify the PASID handling to allocate the PASID once, associate
     it to the mm of a process and free it on mm_exit().

     The previous attempt of refcounted PASIDs and dynamic
     alloc()/free() turned out to be error prone and too complex. The
     PASID space is 20bits, so the case of resource exhaustion is a pure
     academic concern.

   - Populate the PASID MSR on demand via #GP to avoid racy updates via
     IPIs.

   - Reenable ENQCMD and let objtool check for the forbidden usage of
     ENQCMD in the kernel.

   - Update the documentation for Shared Virtual Addressing accordingly"

* tag 'x86-pasid-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation/x86: Update documentation for SVA (Shared Virtual Addressing)
  tools/objtool: Check for use of the ENQCMD instruction in the kernel
  x86/cpufeatures: Re-enable ENQCMD
  x86/traps: Demand-populate PASID MSR via #GP
  sched: Define and initialize a flag to identify valid PASID in the task
  x86/fpu: Clear PASID when copying fpstate
  iommu/sva: Assign a PASID to mm on PASID allocation and free it on mm exit
  kernel/fork: Initialize mm's PASID
  iommu/ioasid: Introduce a helper to check for valid PASIDs
  mm: Change CONFIG option for mm->pasid field
  iommu/sva: Rename CONFIG_IOMMU_SVA_LIB to CONFIG_IOMMU_SVA
2022-03-21 12:28:13 -07:00
Masami Hiramatsu
54ecbe6f1e rethook: Add a generic return hook
Add a return hook framework which hooks the function return. Most of the
logic came from the kretprobe, but this is independent from kretprobe.

Note that this is expected to be used with other function entry hooking
feature, like ftrace, fprobe, adn kprobes. Eventually this will replace
the kretprobe (e.g. kprobe + rethook = kretprobe), but at this moment,
this is just an additional hook.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735285066.1084943.9259661137330166643.stgit@devnote2
2022-03-17 20:16:29 -07:00
Suren Baghdasaryan
5c26f6ac94 mm: refactor vm_area_struct::anon_vma_name usage code
Avoid mixing strings and their anon_vma_name referenced pointers by
using struct anon_vma_name whenever possible.  This simplifies the code
and allows easier sharing of anon_vma_name structures when they
represent the same name.

[surenb@google.com: fix comment]

Link: https://lkml.kernel.org/r/20220223153613.835563-1-surenb@google.com
Link: https://lkml.kernel.org/r/20220224231834.1481408-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Colin Cross <ccross@google.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Alexey Gladkov <legion@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Chris Hyser <chris.hyser@oracle.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Xiaofeng Cao <caoxiaofeng@yulong.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-03-05 11:08:32 -08:00
Sebastian Andrzej Siewior
0ce055f853 fork: Use IS_ENABLED() in account_kernel_stack()
Not strickly needed but checking CONFIG_VMAP_STACK instead of
task_stack_vm_area()' result allows the compiler the remove the else
path in the CONFIG_VMAP_STACK case where the pointer can't be NULL.

Check for CONFIG_VMAP_STACK in order to use the proper path.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-9-bigeasy@linutronix.de
2022-02-22 22:25:02 +01:00
Sebastian Andrzej Siewior
e540bf3162 fork: Only cache the VMAP stack in finish_task_switch()
The task stack could be deallocated later, but for fork()/exec() kind of
workloads (say a shell script executing several commands) it is important
that the stack is released in finish_task_switch() so that in VMAP_STACK
case it can be cached and reused in the new task.

For PREEMPT_RT it would be good if the wake-up in vfree_atomic() could
be avoided in the scheduling path. Far worse are the other
free_thread_stack() implementations which invoke __free_pages()/
kmem_cache_free() with disabled preemption.

Cache the stack in free_thread_stack() in the VMAP_STACK case and
RCU-delay the free path otherwise. Free the stack in the RCU callback.
In the VMAP_STACK case this is another opportunity to fill the cache.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-8-bigeasy@linutronix.de
2022-02-22 22:25:02 +01:00
Sebastian Andrzej Siewior
1a03d3f13f fork: Move task stack accounting to do_exit()
There is no need to perform the stack accounting of the outgoing task in
its final schedule() invocation which happens with preemption disabled.
The task is leaving, the resources will be freed and the accounting can
happen in do_exit() before the actual schedule invocation which
frees the stack memory.

Move the accounting of the stack memory from release_task_stack() to
exit_task_stack_account() which then can be invoked from do_exit().

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20220217102406.3697941-7-bigeasy@linutronix.de
2022-02-22 22:25:02 +01:00