<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/fs/proc/base.c, branch for-next</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2024-11-23T17:58:07+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-23T17:58:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5c00ff742bf5caf85f60e1c73999f99376fb865d'/>
<id>5c00ff742bf5caf85f60e1c73999f99376fb865d</id>
<content type='text'>
Pull MM updates from Andrew Morton:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MM updates from Andrew Morton:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-11-20T00:35:06+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-11-20T00:35:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bf9aa14fc523d2763fc9a10672a709224e8fcaf4'/>
<id>bf9aa14fc523d2763fc9a10672a709224e8fcaf4</id>
<content type='text'>
Pull timer updates from Thomas Gleixner:
 "A rather large update for timekeeping and timers:

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

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

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

     Cure this by:

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

       - Queuing ignored timer signals onto a seperate ignored list.

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

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

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

   - Core infrastructure for VFS multigrain timestamping

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

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

   - Cleanup and consolidation of the sleep() infrastructure

       - Move all sleep and timeout functions into one file

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

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

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

       - Fixup a few usage sites

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

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

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

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

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

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

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

   - Consolidate hrtimer initialization

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

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

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

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

   - Drivers:

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

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

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

* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
  posix-timers: Fix spurious warning on double enqueue versus do_exit()
  clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
  clocksource/drivers/gpx: Remove redundant casts
  clocksource/drivers/timer-ti-dm: Fix child node refcount handling
  dt-bindings: timer: actions,owl-timer: convert to YAML
  clocksource/drivers/ralink: Add Ralink System Tick Counter driver
  clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
  clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
  clocksource/drivers:sp804: Make user selectable
  clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
  hrtimers: Delete hrtimer_init_on_stack()
  alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
  io_uring: Switch to use hrtimer_setup_on_stack()
  sched/idle: Switch to use hrtimer_setup_on_stack()
  hrtimers: Delete hrtimer_init_sleeper_on_stack()
  wait: Switch to use hrtimer_setup_sleeper_on_stack()
  timers: Switch to use hrtimer_setup_sleeper_on_stack()
  net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
  futex: Switch to use hrtimer_setup_sleeper_on_stack()
  fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull timer updates from Thomas Gleixner:
 "A rather large update for timekeeping and timers:

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

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

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

     Cure this by:

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

       - Queuing ignored timer signals onto a seperate ignored list.

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

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

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

   - Core infrastructure for VFS multigrain timestamping

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

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

   - Cleanup and consolidation of the sleep() infrastructure

       - Move all sleep and timeout functions into one file

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

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

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

       - Fixup a few usage sites

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

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

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

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

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

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

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

   - Consolidate hrtimer initialization

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

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

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

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

   - Drivers:

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

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

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

* tag 'timers-core-2024-11-18' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (140 commits)
  posix-timers: Fix spurious warning on double enqueue versus do_exit()
  clocksource/drivers/arm_arch_timer: Use of_property_present() for non-boolean properties
  clocksource/drivers/gpx: Remove redundant casts
  clocksource/drivers/timer-ti-dm: Fix child node refcount handling
  dt-bindings: timer: actions,owl-timer: convert to YAML
  clocksource/drivers/ralink: Add Ralink System Tick Counter driver
  clocksource/drivers/mips-gic-timer: Always use cluster 0 counter as clocksource
  clocksource/drivers/timer-ti-dm: Don't fail probe if int not found
  clocksource/drivers:sp804: Make user selectable
  clocksource/drivers/dw_apb: Remove unused dw_apb_clockevent functions
  hrtimers: Delete hrtimer_init_on_stack()
  alarmtimer: Switch to use hrtimer_setup() and hrtimer_setup_on_stack()
  io_uring: Switch to use hrtimer_setup_on_stack()
  sched/idle: Switch to use hrtimer_setup_on_stack()
  hrtimers: Delete hrtimer_init_sleeper_on_stack()
  wait: Switch to use hrtimer_setup_sleeper_on_stack()
  timers: Switch to use hrtimer_setup_sleeper_on_stack()
  net: pktgen: Switch to use hrtimer_setup_sleeper_on_stack()
  futex: Switch to use hrtimer_setup_sleeper_on_stack()
  fs/aio: Switch to use hrtimer_setup_sleeper_on_stack()
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>posix-timers: Embed sigqueue in struct k_itimer</title>
<updated>2024-11-07T01:14:44+00:00</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2024-11-05T08:14:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6017a158beb13b412e55a451379798aae5876514'/>
<id>6017a158beb13b412e55a451379798aae5876514</id>
<content type='text'>
To cure the SIG_IGN handling for posix interval timers, the preallocated
sigqueue needs to be embedded into struct k_itimer to prevent life time
races of all sorts.

Now that the prerequisites are in place, embed the sigqueue into struct
k_itimer and fixup the relevant usage sites.

Aside of preparing for proper SIG_IGN handling, this spares an extra
allocation.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/all/20241105064213.719695194@linutronix.de

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To cure the SIG_IGN handling for posix interval timers, the preallocated
sigqueue needs to be embedded into struct k_itimer to prevent life time
races of all sorts.

Now that the prerequisites are in place, embed the sigqueue into struct
k_itimer and fixup the relevant usage sites.

Aside of preparing for proper SIG_IGN handling, this spares an extra
allocation.

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Frederic Weisbecker &lt;frederic@kernel.org&gt;
Acked-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/all/20241105064213.719695194@linutronix.de

</pre>
</div>
</content>
</entry>
<entry>
<title>mm: refactor mm_access() to not return NULL</title>
<updated>2024-11-06T00:56:23+00:00</updated>
<author>
<name>Lorenzo Stoakes</name>
<email>lorenzo.stoakes@oracle.com</email>
</author>
<published>2024-09-24T20:10:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cd3f8467afd470ccab0de2fbc7c76664af4a0bac'/>
<id>cd3f8467afd470ccab0de2fbc7c76664af4a0bac</id>
<content type='text'>
mm_access() can return NULL if the mm is not found, but this is handled
the same as an error in all callers, with some translating this into an
-ESRCH error.

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

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

[lorenzo.stoakes@oracle.com: prefer neater pointer error comparison]
  Link: https://lkml.kernel.org/r/2fae1834-749a-45e1-8594-5e5979cf7103@lucifer.local
Link: https://lkml.kernel.org/r/20240924201023.193135-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes &lt;lorenzo.stoakes@oracle.com&gt;
Suggested-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
mm_access() can return NULL if the mm is not found, but this is handled
the same as an error in all callers, with some translating this into an
-ESRCH error.

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

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

[lorenzo.stoakes@oracle.com: prefer neater pointer error comparison]
  Link: https://lkml.kernel.org/r/2fae1834-749a-45e1-8594-5e5979cf7103@lucifer.local
Link: https://lkml.kernel.org/r/20240924201023.193135-1-lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes &lt;lorenzo.stoakes@oracle.com&gt;
Suggested-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>remove pointless includes of &lt;linux/fdtable.h&gt;</title>
<updated>2024-10-07T17:34:41+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@zeniv.linux.org.uk</email>
</author>
<published>2024-06-03T03:58:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=be5498cac2ddb112c5bd7433d5e834a1a2493427'/>
<id>be5498cac2ddb112c5bd7433d5e834a1a2493427</id>
<content type='text'>
some of those used to be needed, some had been cargo-culted for
no reason...

Reviewed-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
some of those used to be needed, some had been cargo-culted for
no reason...

Reviewed-by: Christian Brauner &lt;brauner@kernel.org&gt;
Signed-off-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-09-19T13:55:58+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-19T13:55:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2004cef11ea072838f99bd95cefa5c8e45df0847'/>
<id>2004cef11ea072838f99bd95cefa5c8e45df0847</id>
<content type='text'>
Pull scheduler updates from Ingo Molnar:

 - Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
   de Oliveira's last major contribution to the kernel:

     "SCHED_DEADLINE servers can help fixing starvation issues of low
      priority tasks (e.g., SCHED_OTHER) when higher priority tasks
      monopolize CPU cycles. Today we have RT Throttling; DEADLINE
      servers should be able to replace and improve that."

   (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
   Esmat, Huang Shijie)

 - Preparatory changes for sched_ext integration:
     - Use set_next_task(.first) where required
     - Fix up set_next_task() implementations
     - Clean up DL server vs. core sched
     - Split up put_prev_task_balance()
     - Rework pick_next_task()
     - Combine the last put_prev_task() and the first set_next_task()
     - Rework dl_server
     - Add put_prev_task(.next)

   (Peter Zijlstra, with a fix by Tejun Heo)

 - Complete the EEVDF transition and refine EEVDF scheduling:
     - Implement delayed dequeue
     - Allow shorter slices to wakeup-preempt
     - Use sched_attr::sched_runtime to set request/slice suggestion
     - Document the new feature flags
     - Remove unused and duplicate-functionality fields
     - Simplify &amp; unify pick_next_task_fair()
     - Misc debuggability enhancements

   (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
   Schneider and Chuyi Zhou)

 - Initialize the vruntime of a new task when it is first enqueued,
   resulting in significant decrease in latency of newly woken tasks
   (Zhang Qiao)

 - Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
   (K Prateek Nayak, Peter Zijlstra)

 - Clean up and clarify the usage of Clean up usage of rt_task()
   (Qais Yousef)

 - Preempt SCHED_IDLE entities in strict cgroup hierarchies
   (Tianchen Ding)

 - Clarify the documentation of time units for deadline scheduler
   parameters (Christian Loehle)

 - Remove the HZ_BW chicken-bit feature flag introduced a year ago,
   the original change seems to be working fine (Phil Auld)

 - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
   Peilin He, Qais Yousefm and Vincent Guittot)

* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  sched/cpufreq: Use NSEC_PER_MSEC for deadline task
  cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
  sched/deadline: Clarify nanoseconds in uapi
  sched/deadline: Convert schedtool example to chrt
  sched/debug: Fix the runnable tasks output
  sched: Fix sched_delayed vs sched_core
  kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
  kthread: Fix task state in kthread worker if being frozen
  sched/pelt: Use rq_clock_task() for hw_pressure
  sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
  sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
  sched: Add put_prev_task(.next)
  sched: Rework dl_server
  sched: Combine the last put_prev_task() and the first set_next_task()
  sched: Rework pick_next_task()
  sched: Split up put_prev_task_balance()
  sched: Clean up DL server vs core sched
  sched: Fixup set_next_task() implementations
  sched: Use set_next_task(.first) where required
  sched/fair: Properly deactivate sched_delayed task upon class change
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull scheduler updates from Ingo Molnar:

 - Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
   de Oliveira's last major contribution to the kernel:

     "SCHED_DEADLINE servers can help fixing starvation issues of low
      priority tasks (e.g., SCHED_OTHER) when higher priority tasks
      monopolize CPU cycles. Today we have RT Throttling; DEADLINE
      servers should be able to replace and improve that."

   (Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
   Esmat, Huang Shijie)

 - Preparatory changes for sched_ext integration:
     - Use set_next_task(.first) where required
     - Fix up set_next_task() implementations
     - Clean up DL server vs. core sched
     - Split up put_prev_task_balance()
     - Rework pick_next_task()
     - Combine the last put_prev_task() and the first set_next_task()
     - Rework dl_server
     - Add put_prev_task(.next)

   (Peter Zijlstra, with a fix by Tejun Heo)

 - Complete the EEVDF transition and refine EEVDF scheduling:
     - Implement delayed dequeue
     - Allow shorter slices to wakeup-preempt
     - Use sched_attr::sched_runtime to set request/slice suggestion
     - Document the new feature flags
     - Remove unused and duplicate-functionality fields
     - Simplify &amp; unify pick_next_task_fair()
     - Misc debuggability enhancements

   (Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
   Schneider and Chuyi Zhou)

 - Initialize the vruntime of a new task when it is first enqueued,
   resulting in significant decrease in latency of newly woken tasks
   (Zhang Qiao)

 - Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
   (K Prateek Nayak, Peter Zijlstra)

 - Clean up and clarify the usage of Clean up usage of rt_task()
   (Qais Yousef)

 - Preempt SCHED_IDLE entities in strict cgroup hierarchies
   (Tianchen Ding)

 - Clarify the documentation of time units for deadline scheduler
   parameters (Christian Loehle)

 - Remove the HZ_BW chicken-bit feature flag introduced a year ago,
   the original change seems to be working fine (Phil Auld)

 - Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
   Peilin He, Qais Yousefm and Vincent Guittot)

* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  sched/cpufreq: Use NSEC_PER_MSEC for deadline task
  cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
  sched/deadline: Clarify nanoseconds in uapi
  sched/deadline: Convert schedtool example to chrt
  sched/debug: Fix the runnable tasks output
  sched: Fix sched_delayed vs sched_core
  kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
  kthread: Fix task state in kthread worker if being frozen
  sched/pelt: Use rq_clock_task() for hw_pressure
  sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
  sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
  sched: Add put_prev_task(.next)
  sched: Rework dl_server
  sched: Combine the last put_prev_task() and the first set_next_task()
  sched: Rework pick_next_task()
  sched: Split up put_prev_task_balance()
  sched: Clean up DL server vs core sched
  sched: Fixup set_next_task() implementations
  sched: Use set_next_task(.first) where required
  sched/fair: Properly deactivate sched_delayed task upon class change
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2024-09-17T05:25:37+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-17T05:25:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9ea925c806dbb8fee6797f59148daaf7f648832e'/>
<id>9ea925c806dbb8fee6797f59148daaf7f648832e</id>
<content type='text'>
Pull timer updates from Thomas Gleixner:
 "Core:

   - Overhaul of posix-timers in preparation of removing the workaround
     for periodic timers which have signal delivery ignored.

   - Remove the historical extra jiffie in msleep()

     msleep() adds an extra jiffie to the timeout value to ensure
     minimal sleep time. The timer wheel ensures minimal sleep time
     since the large rewrite to a non-cascading wheel, but the extra
     jiffie in msleep() remained unnoticed. Remove it.

   - Make the timer slack handling correct for realtime tasks.

     The procfs interface is inconsistent and does neither reflect
     reality nor conforms to the man page. Show the correct 0 slack for
     real time tasks and enforce it at the core level instead of having
     inconsistent individual checks in various timer setup functions.

   - The usual set of updates and enhancements all over the place.

  Drivers:

   - Allow the ACPI PM timer to be turned off during suspend

   - No new drivers

   - The usual updates and enhancements in various drivers"

* tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  ntp: Make sure RTC is synchronized when time goes backwards
  treewide: Fix wrong singular form of jiffies in comments
  cpu: Use already existing usleep_range()
  timers: Rename next_expiry_recalc() to be unique
  platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function
  clocksource/drivers/jcore: Use request_percpu_irq()
  clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
  clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
  clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
  clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
  platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended
  clocksource: acpi_pm: Add external callback for suspend/resume
  clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
  dt-bindings: timer: rockchip: Add rk3576 compatible
  timers: Annotate possible non critical data race of next_expiry
  timers: Remove historical extra jiffie for timeout in msleep()
  hrtimer: Use and report correct timerslack values for realtime tasks
  hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse.
  timers: Add sparse annotation for timer_sync_wait_running().
  signal: Replace BUG_ON()s
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull timer updates from Thomas Gleixner:
 "Core:

   - Overhaul of posix-timers in preparation of removing the workaround
     for periodic timers which have signal delivery ignored.

   - Remove the historical extra jiffie in msleep()

     msleep() adds an extra jiffie to the timeout value to ensure
     minimal sleep time. The timer wheel ensures minimal sleep time
     since the large rewrite to a non-cascading wheel, but the extra
     jiffie in msleep() remained unnoticed. Remove it.

   - Make the timer slack handling correct for realtime tasks.

     The procfs interface is inconsistent and does neither reflect
     reality nor conforms to the man page. Show the correct 0 slack for
     real time tasks and enforce it at the core level instead of having
     inconsistent individual checks in various timer setup functions.

   - The usual set of updates and enhancements all over the place.

  Drivers:

   - Allow the ACPI PM timer to be turned off during suspend

   - No new drivers

   - The usual updates and enhancements in various drivers"

* tag 'timers-core-2024-09-16' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  ntp: Make sure RTC is synchronized when time goes backwards
  treewide: Fix wrong singular form of jiffies in comments
  cpu: Use already existing usleep_range()
  timers: Rename next_expiry_recalc() to be unique
  platform/x86:intel/pmc: Fix comment for the pmc_core_acpi_pm_timer_suspend_resume function
  clocksource/drivers/jcore: Use request_percpu_irq()
  clocksource/drivers/cadence-ttc: Add missing clk_disable_unprepare in ttc_setup_clockevent
  clocksource/drivers/asm9260: Add missing clk_disable_unprepare in asm9260_timer_init
  clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()
  clocksource/drivers/ingenic: Use devm_clk_get_enabled() helpers
  platform/x86:intel/pmc: Enable the ACPI PM Timer to be turned off when suspended
  clocksource: acpi_pm: Add external callback for suspend/resume
  clocksource/drivers/arm_arch_timer: Using for_each_available_child_of_node_scoped()
  dt-bindings: timer: rockchip: Add rk3576 compatible
  timers: Annotate possible non critical data race of next_expiry
  timers: Remove historical extra jiffie for timeout in msleep()
  hrtimer: Use and report correct timerslack values for realtime tasks
  hrtimer: Annotate hrtimer_cpu_base_.*_expiry() for sparse.
  timers: Add sparse annotation for timer_sync_wait_running().
  signal: Replace BUG_ON()s
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'vfs-6.12.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2024-09-16T07:36:59+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-16T07:36:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e8fc317dfca9021f0ea9ed77061d8df677e47a9f'/>
<id>e8fc317dfca9021f0ea9ed77061d8df677e47a9f</id>
<content type='text'>
Pull procfs updates from Christian Brauner:
 "This contains the following changes for procfs:

   - Add config options and parameters to block forcing memory writes.

     This adds a Kconfig option and boot param to allow removing the
     FOLL_FORCE flag from /proc/&lt;pid&gt;/mem write calls as this can be
     used in various attacks.

     The traditional forcing behavior is kept as default because it can
     break GDB and some other use cases.

     This is the simpler version that you had requested.

   - Restrict overmounting of ephemeral entities.

     It is currently possible to mount on top of various ephemeral
     entities in procfs. This specifically includes magic links. To
     recap, magic links are links of the form /proc/&lt;pid&gt;/fd/&lt;nr&gt;. They
     serve as references to a target file and during path lookup they
     cause a jump to the target path. Such magic links disappear if the
     corresponding file descriptor is closed.

     Currently it is possible to overmount such magic links. This is
     mostly interesting for an attacker that wants to somehow trick a
     process into e.g., reopening something that it didn't intend to
     reopen or to hide a malicious file descriptor.

     But also it risks leaking mounts for long-running processes. When
     overmounting a magic link like above, the mount will not be
     detached when the file descriptor is closed. Only the target
     mountpoint will disappear. Which has the consequence of making it
     impossible to unmount that mount afterwards. So the mount will
     stick around until the process exits and the /proc/&lt;pid&gt;/ directory
     is cleaned up during proc_flush_pid() when the dentries are pruned
     and invalidated.

     That in turn means it's possible for a program to accidentally leak
     mounts and it's also possible to make a task leak mounts without
     it's knowledge if the attacker just keeps overmounting things under
     /proc/&lt;pid&gt;/fd/&lt;nr&gt;.

     Disallow overmounting of such ephemeral entities.

   - Cleanup the readdir method naming in some procfs file operations.

   - Replace kmalloc() and strcpy() with a simple kmemdup() call"

* tag 'vfs-6.12.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  proc: fold kmalloc() + strcpy() into kmemdup()
  proc: block mounting on top of /proc/&lt;pid&gt;/fdinfo/*
  proc: block mounting on top of /proc/&lt;pid&gt;/fd/*
  proc: block mounting on top of /proc/&lt;pid&gt;/map_files/*
  proc: add proc_splice_unmountable()
  proc: proc_readfdinfo() -&gt; proc_fdinfo_iterate()
  proc: proc_readfd() -&gt; proc_fd_iterate()
  proc: add config &amp; param to block forcing mem writes
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull procfs updates from Christian Brauner:
 "This contains the following changes for procfs:

   - Add config options and parameters to block forcing memory writes.

     This adds a Kconfig option and boot param to allow removing the
     FOLL_FORCE flag from /proc/&lt;pid&gt;/mem write calls as this can be
     used in various attacks.

     The traditional forcing behavior is kept as default because it can
     break GDB and some other use cases.

     This is the simpler version that you had requested.

   - Restrict overmounting of ephemeral entities.

     It is currently possible to mount on top of various ephemeral
     entities in procfs. This specifically includes magic links. To
     recap, magic links are links of the form /proc/&lt;pid&gt;/fd/&lt;nr&gt;. They
     serve as references to a target file and during path lookup they
     cause a jump to the target path. Such magic links disappear if the
     corresponding file descriptor is closed.

     Currently it is possible to overmount such magic links. This is
     mostly interesting for an attacker that wants to somehow trick a
     process into e.g., reopening something that it didn't intend to
     reopen or to hide a malicious file descriptor.

     But also it risks leaking mounts for long-running processes. When
     overmounting a magic link like above, the mount will not be
     detached when the file descriptor is closed. Only the target
     mountpoint will disappear. Which has the consequence of making it
     impossible to unmount that mount afterwards. So the mount will
     stick around until the process exits and the /proc/&lt;pid&gt;/ directory
     is cleaned up during proc_flush_pid() when the dentries are pruned
     and invalidated.

     That in turn means it's possible for a program to accidentally leak
     mounts and it's also possible to make a task leak mounts without
     it's knowledge if the attacker just keeps overmounting things under
     /proc/&lt;pid&gt;/fd/&lt;nr&gt;.

     Disallow overmounting of such ephemeral entities.

   - Cleanup the readdir method naming in some procfs file operations.

   - Replace kmalloc() and strcpy() with a simple kmemdup() call"

* tag 'vfs-6.12.procfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  proc: fold kmalloc() + strcpy() into kmemdup()
  proc: block mounting on top of /proc/&lt;pid&gt;/fdinfo/*
  proc: block mounting on top of /proc/&lt;pid&gt;/fd/*
  proc: block mounting on top of /proc/&lt;pid&gt;/map_files/*
  proc: add proc_splice_unmountable()
  proc: proc_readfdinfo() -&gt; proc_fdinfo_iterate()
  proc: proc_readfd() -&gt; proc_fd_iterate()
  proc: add config &amp; param to block forcing mem writes
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs</title>
<updated>2024-09-16T07:14:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-09-16T07:14:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3352633ce6b221d64bf40644d412d9670e7d56e3'/>
<id>3352633ce6b221d64bf40644d412d9670e7d56e3</id>
<content type='text'>
Pull vfs file updates from Christian Brauner:
 "This is the work to cleanup and shrink struct file significantly.

  Right now, (focusing on x86) struct file is 232 bytes. After this
  series struct file will be 184 bytes aka 3 cacheline and a spare 8
  bytes for future extensions at the end of the struct.

  With struct file being as ubiquitous as it is this should make a
  difference for file heavy workloads and allow further optimizations in
  the future.

   - struct fown_struct was embedded into struct file letting it take up
     32 bytes in total when really it shouldn't even be embedded in
     struct file in the first place. Instead, actual users of struct
     fown_struct now allocate the struct on demand. This frees up 24
     bytes.

   - Move struct file_ra_state into the union containg the cleanup hooks
     and move f_iocb_flags out of the union. This closes a 4 byte hole
     we created earlier and brings struct file to 192 bytes. Which means
     struct file is 3 cachelines and we managed to shrink it by 40
     bytes.

   - Reorder struct file so that nothing crosses a cacheline.

     I suspect that in the future we will end up reordering some members
     to mitigate false sharing issues or just because someone does
     actually provide really good perf data.

   - Shrinking struct file to 192 bytes is only part of the work.

     Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
     is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
     located outside of the object because the cache doesn't know what
     part of the memory can safely be overwritten as it may be needed to
     prevent object recycling.

     That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
     adding a new cacheline.

     So this also contains work to add a new kmem_cache_create_rcu()
     function that allows the caller to specify an offset where the
     freelist pointer is supposed to be placed. Thus avoiding the
     implicit addition of a fourth cacheline.

   - And finally this removes the f_version member in struct file.

     The f_version member isn't particularly well-defined. It is mainly
     used as a cookie to detect concurrent seeks when iterating
     directories. But it is also abused by some subsystems for
     completely unrelated things.

     It is mostly a directory and filesystem specific thing that doesn't
     really need to live in struct file and with its wonky semantics it
     really lacks a specific function.

     For pipes, f_version is (ab)used to defer poll notifications until
     a write has happened. And struct pipe_inode_info is used by
     multiple struct files in their -&gt;private_data so there's no chance
     of pushing that down into file-&gt;private_data without introducing
     another pointer indirection.

     But pipes don't rely on f_pos_lock so this adds a union into struct
     file encompassing f_pos_lock and a pipe specific f_pipe member that
     pipes can use. This union of course can be extended to other file
     types and is similar to what we do in struct inode already"

* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  fs: remove f_version
  pipe: use f_pipe
  fs: add f_pipe
  ubifs: store cookie in private data
  ufs: store cookie in private data
  udf: store cookie in private data
  proc: store cookie in private data
  ocfs2: store cookie in private data
  input: remove f_version abuse
  ext4: store cookie in private data
  ext2: store cookie in private data
  affs: store cookie in private data
  fs: add generic_llseek_cookie()
  fs: use must_set_pos()
  fs: add must_set_pos()
  fs: add vfs_setpos_cookie()
  s390: remove unused f_version
  ceph: remove unused f_version
  adi: remove unused f_version
  mm: Removed @freeptr_offset to prevent doc warning
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull vfs file updates from Christian Brauner:
 "This is the work to cleanup and shrink struct file significantly.

  Right now, (focusing on x86) struct file is 232 bytes. After this
  series struct file will be 184 bytes aka 3 cacheline and a spare 8
  bytes for future extensions at the end of the struct.

  With struct file being as ubiquitous as it is this should make a
  difference for file heavy workloads and allow further optimizations in
  the future.

   - struct fown_struct was embedded into struct file letting it take up
     32 bytes in total when really it shouldn't even be embedded in
     struct file in the first place. Instead, actual users of struct
     fown_struct now allocate the struct on demand. This frees up 24
     bytes.

   - Move struct file_ra_state into the union containg the cleanup hooks
     and move f_iocb_flags out of the union. This closes a 4 byte hole
     we created earlier and brings struct file to 192 bytes. Which means
     struct file is 3 cachelines and we managed to shrink it by 40
     bytes.

   - Reorder struct file so that nothing crosses a cacheline.

     I suspect that in the future we will end up reordering some members
     to mitigate false sharing issues or just because someone does
     actually provide really good perf data.

   - Shrinking struct file to 192 bytes is only part of the work.

     Files use a slab that is SLAB_TYPESAFE_BY_RCU and when a kmem cache
     is created with SLAB_TYPESAFE_BY_RCU the free pointer must be
     located outside of the object because the cache doesn't know what
     part of the memory can safely be overwritten as it may be needed to
     prevent object recycling.

     That has the consequence that SLAB_TYPESAFE_BY_RCU may end up
     adding a new cacheline.

     So this also contains work to add a new kmem_cache_create_rcu()
     function that allows the caller to specify an offset where the
     freelist pointer is supposed to be placed. Thus avoiding the
     implicit addition of a fourth cacheline.

   - And finally this removes the f_version member in struct file.

     The f_version member isn't particularly well-defined. It is mainly
     used as a cookie to detect concurrent seeks when iterating
     directories. But it is also abused by some subsystems for
     completely unrelated things.

     It is mostly a directory and filesystem specific thing that doesn't
     really need to live in struct file and with its wonky semantics it
     really lacks a specific function.

     For pipes, f_version is (ab)used to defer poll notifications until
     a write has happened. And struct pipe_inode_info is used by
     multiple struct files in their -&gt;private_data so there's no chance
     of pushing that down into file-&gt;private_data without introducing
     another pointer indirection.

     But pipes don't rely on f_pos_lock so this adds a union into struct
     file encompassing f_pos_lock and a pipe specific f_pipe member that
     pipes can use. This union of course can be extended to other file
     types and is similar to what we do in struct inode already"

* tag 'vfs-6.12.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (26 commits)
  fs: remove f_version
  pipe: use f_pipe
  fs: add f_pipe
  ubifs: store cookie in private data
  ufs: store cookie in private data
  udf: store cookie in private data
  proc: store cookie in private data
  ocfs2: store cookie in private data
  input: remove f_version abuse
  ext4: store cookie in private data
  ext2: store cookie in private data
  affs: store cookie in private data
  fs: add generic_llseek_cookie()
  fs: use must_set_pos()
  fs: add must_set_pos()
  fs: add vfs_setpos_cookie()
  s390: remove unused f_version
  ceph: remove unused f_version
  adi: remove unused f_version
  mm: Removed @freeptr_offset to prevent doc warning
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>proc: store cookie in private data</title>
<updated>2024-09-12T09:58:44+00:00</updated>
<author>
<name>Christian Brauner</name>
<email>brauner@kernel.org</email>
</author>
<published>2024-08-30T13:04:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b4dba2efa8106002076b070fdff24ed6bf1ea87b'/>
<id>b4dba2efa8106002076b070fdff24ed6bf1ea87b</id>
<content type='text'>
Store the cookie to detect concurrent seeks on directories in
file-&gt;private_data.

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-14-6d3e4816aa7b@kernel.org
Reviewed-by: Jeff Layton &lt;jlayton@kernel.org&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Store the cookie to detect concurrent seeks on directories in
file-&gt;private_data.

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-14-6d3e4816aa7b@kernel.org
Reviewed-by: Jeff Layton &lt;jlayton@kernel.org&gt;
Signed-off-by: Christian Brauner &lt;brauner@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
