Commit Graph

352 Commits

Author SHA1 Message Date
Linus Torvalds
e991acf1bc Significant patch series in this pull request:
- The 2 patch series "squashfs: Remove page->mapping references" from
   Matthew Wilcox gets us closer to being able to remove page->mapping.
 
 - The 5 patch series "relayfs: misc changes" from Jason Xing does some
   maintenance and minor feature addition work in relayfs.
 
 - The 5 patch series "kdump: crashkernel reservation from CMA" from Jiri
   Bohac switches us from static preallocation of the kdump crashkernel's
   working memory over to dynamic allocation.  So the difficulty of
   a-priori estimation of the second kernel's needs is removed and the
   first kernel obtains extra memory.
 
 - The 5 patch series "generalize panic_print's dump function to be used
   by other kernel parts" from Feng Tang implements some consolidation and
   rationalizatio of the various ways in which a faiing kernel splats
   information at the operator.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaI+82gAKCRDdBJ7gKXxA
 jj4JAP9xb+w9DrBY6sa+7KTPIb+aTqQ7Zw3o9O2m+riKQJv6jAEA6aEwRnDA0451
 fDT5IqVlCWGvnVikdZHSnvhdD7TGsQ0=
 =rT71
 -----END PGP SIGNATURE-----

Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page->mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -> "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...
2025-08-03 16:23:09 -07:00
Jiri Olsa
aa644c4052 uprobes: revert ref_ctr_offset in uprobe_unregister error path
There's error path that could lead to inactive uprobe:

  1) uprobe_register succeeds - updates instruction to int3 and
     changes ref_ctr from 0 to 1
  2) uprobe_unregister fails  - int3 stays in place, but ref_ctr
     is changed to 0 (it's not restored to 1 in the fail path)
     uprobe is leaked
  3) another uprobe_register comes and re-uses the leaked uprobe
     and succeds - but int3 is already in place, so ref_ctr update
     is skipped and it stays 0 - uprobe CAN NOT be triggered now
  4) uprobe_unregister fails because ref_ctr value is unexpected

Fix this by reverting the updated ref_ctr value back to 1 in step 2),
which is the case when uprobe_unregister fails (int3 stays in place), but
we have already updated refctr.

The new scenario will go as follows:

  1) uprobe_register succeeds - updates instruction to int3 and
     changes ref_ctr from 0 to 1
  2) uprobe_unregister fails  - int3 stays in place and ref_ctr
     is reverted to 1..  uprobe is leaked
  3) another uprobe_register comes and re-uses the leaked uprobe
     and succeds - but int3 is already in place, so ref_ctr update
     is skipped and it stays 1 - uprobe CAN be triggered now
  4) uprobe_unregister succeeds

Link: https://lkml.kernel.org/r/20250514101809.2010193-1-jolsa@kernel.org
Fixes: 1cc33161a8 ("uprobes: Support SDT markers having reference count (semaphore)")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:57:53 -07:00
Alistair Popple
6b4a80e424 mm: filter zone device pages returned from folio_walk_start()
Previously dax pages were skipped by the pagewalk code as pud_special() or
vm_normal_page{_pmd}() would be false for DAX pages.  Now that dax pages
are refcounted normally that is no longer the case, so the pagewalk code
will start returning them.

Most callers already explicitly filter for DAX or zone device pages so
don't need updating.  However some don't, so add checks to those callers.

Link: https://lkml.kernel.org/r/4ecb7b357fc5b435588024770b88bbb695c30090.1750323463.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Björn Töpel <bjorn@kernel.org>
Cc: Björn Töpel <bjorn@rivosinc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Inki Dae <m.szyprowski@samsung.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Groves <john@groves.net>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:16 -07:00
Shivank Garg
a984f16fba mm: use folio_expected_ref_count() helper for reference counting
Replace open-coded folio reference count calculations with the
folio_expected_ref_count().

No functional changes intended.

Link: https://lkml.kernel.org/r/20250611052706.515408-2-shivankg@amd.com
Signed-off-by: Shivank Garg <shivankg@amd.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-09 22:42:08 -07:00
David Hildenbrand
6e3092d788 kernel/events/uprobes: uprobe_write_opcode() rewrite
uprobe_write_opcode() does some pretty low-level things that really, it
shouldn't be doing: for example, manually breaking COW by allocating
anonymous folios and replacing mapped pages.

Further, it does seem to do some shaky things: for example, writing to
possible COW-shared anonymous pages or zapping anonymous pages that might
be pinned.  We're also not taking care of uffd, uffd-wp, softdirty ... 
although rather corner cases here.  Let's just get it right like ordinary
ptrace writes would.

Let's rewrite the code, leaving COW-breaking to core-MM, triggered by
FOLL_FORCE|FOLL_WRITE (note that the code was already using FOLL_FORCE).

We'll use GUP to lookup/faultin the page and break COW if required.  Then,
we'll walk the page tables using a folio_walk to perform our page
modification atomically by temporarily unmap the PTE + flushing the TLB.

Likely, we could avoid the temporary unmap in case we can just atomically
write the instruction, but that will be a separate project.

Unfortunately, we still have to implement the zapping logic manually,
because we only want to zap in specific circumstances (e.g., page content
identical).

Note that we can now handle large folios (compound pages) and the shared
zeropage just fine, so drop these checks.

Link: https://lkml.kernel.org/r/20250321113713.204682-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: tongtiangen <tongtiangen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11 17:48:18 -07:00
David Hildenbrand
8a5577428e kernel/events/uprobes: pass VMA to set_swbp(), set_orig_insn() and uprobe_write_opcode()
We already have the VMA, no need to look it up using
get_user_page_vma_remote().  We can now switch to get_user_pages_remote().

Link: https://lkml.kernel.org/r/20250321113713.204682-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: tongtiangen <tongtiangen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11 17:48:18 -07:00
David Hildenbrand
b56e644665 kernel/events/uprobes: pass VMA instead of MM to remove_breakpoint()
Patch series "kernel/events/uprobes: uprobe_write_opcode() rewrite", v3.

Currently, uprobe_write_opcode() implements COW-breaking manually, which
is really far from ideal.  Further, there is interest in supporting
uprobes on hugetlb pages [1], and leaving at least the COW-breaking to the
core will make this much easier.

Also, I think the current code doesn't really handle some things properly
(see patch #3) when replacing/zapping pages.

Let's rewrite it, to leave COW-breaking to the fault handler, and handle
registration/unregistration by temporarily unmapping the anonymous page,
modifying it, and mapping it again.  We still have to implement zapping of
anonymous pages ourselves, unfortunately.

We could look into not performing the temporary unmapping if we can
perform the write atomically, which would likely also make adding hugetlb
support a lot easier.  But, limited (e.g., only PMD/PUD) hugetlb support
could be added on top of this with some tweaking.

Note that we now won't have to allocate another anonymous folio when
unregistering (which will be beneficial for hugetlb as well), we can
simply modify the already-mapped one from the registration (if any).  When
registering a uprobe, we'll first trigger a ptrace-like write fault to
break COW, to then modify the already-mapped page.

Briefly sanity tested with perf probes and with the bpf uprobes selftest.


This patch (of 3):

Pass VMA instead of MM to remove_breakpoint() and remove the "MM" argument
from install_breakpoint(), because it can easily be derived from the VMA.

Link: https://lkml.kernel.org/r/20250321113713.204682-1-david@redhat.com
Link: https://lkml.kernel.org/r/20250321113713.204682-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Namhyung kim <namhyung@kernel.org>
Cc: Russel King <linux@armlinux.org.uk>
Cc: tongtiangen <tongtiangen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-11 17:48:17 -07:00
Andrii Nakryiko
0cd575cab1 uprobes: Avoid false-positive lockdep splat on CONFIG_PREEMPT_RT=y in the ri_timer() uprobe timer callback, use raw_write_seqcount_*()
Avoid a false-positive lockdep warning in the CONFIG_PREEMPT_RT=y
configuration when using write_seqcount_begin() in the uprobe timer
callback by using raw_write_* APIs.

Uprobe's use of timer callback is guaranteed to not race with itself
for a given uprobe_task, and as such seqcount's insistence on having
preemption disabled on the writer side is irrelevant. So switch to
raw_ variants of seqcount API instead of disabling preemption unnecessarily.

Also, point out in the comments more explicitly why we use seqcount
despite our reader side being rather simple and never retrying. We favor
well-maintained kernel primitive in favor of open-coding our own memory
barriers.

Fixes: 8622e45b5d ("uprobes: Reuse return_instances between multiple uretprobes within task")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20250404194848.2109539-1-andrii@kernel.org
2025-04-07 20:15:16 +02:00
Jeff Xu
3d38922abf mseal sysmap: uprobe mapping
Provide support to mseal the uprobe mapping.

Unlike other system mappings, the uprobe mapping is not established during
program startup.  However, its lifetime is the same as the process's
lifetime.  It could be sealed from creation.

Test was done with perf tool, and observe the uprobe mapping is sealed.

Link: https://lkml.kernel.org/r/20250305021711.3867874-6-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Cc: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Cc: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Anna-Maria Behnsen <anna-maria@linutronix.de>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Benjamin Berg <benjamin@sipsolutions.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Elliot Hughes <enh@google.com>
Cc: Florian Faineli <f.fainelli@gmail.com>
Cc: Greg Ungerer <gerg@kernel.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Jason A. Donenfeld <jason@zx2c4.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Linus Waleij <linus.walleij@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport <mike.rapoport@gmail.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephen Röttger <sroettger@google.com>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-04-01 15:17:16 -07:00
Linus Torvalds
eb0ece1602 - The 6 patch series "Enable strict percpu address space checks" from
Uros Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.
 
   This has caused a small amount of fallout - two or three issues were
   reported.  In all cases the calling code was founf to be incorrect.
 
 - The 4 patch series "Some cleanup for memcg" from Chen Ridong
   implements some relatively monir cleanups for the memcontrol code.
 
 - The 17 patch series "mm: fixes for device-exclusive entries (hmm)"
   from David Hildenbrand fixes a boatload of issues which David found then
   using device-exclusive PTE entries when THP is enabled.  More work is
   needed, but this makes thins better - our own HMM selftests now succeed.
 
 - The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry
   Ahmed remove the z3fold and zbud implementations.  They have been
   deprecated for half a year and nobody has complained.
 
 - The 5 patch series "mm: further simplify VMA merge operation" from
   Lorenzo Stoakes implements numerous simplifications in this area.  No
   runtime effects are anticipated.
 
 - The 4 patch series "mm/madvise: remove redundant mmap_lock operations
   from process_madvise()" from SeongJae Park rationalizes the locking in
   the madvise() implementation.  Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.
 
 - The 12 patch series "Tiny cleanup and improvements about SWAP code"
   from Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.
 
 - The 2 patch series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak user-visible
   output.
 
 - The 2 patch series "mm/damon/paddr: fix large folios access and
   schemes handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.
 
 - The 3 patch series "mm/damon/core: fix wrong and/or useless
   damos_walk() behaviors" from SeongJae Park fixes a few issues with the
   accuracy of kdamond's walking of DAMON regions.
 
 - The 3 patch series "expose mapping wrprotect, fix fb_defio use" from
   Lorenzo Stoakes changes the interaction between framebuffer deferred-io
   and core MM.  No functional changes are anticipated - this is
   preparatory work for the future removal of page structure fields.
 
 - The 4 patch series "mm/damon: add support for hugepage_size DAMOS
   filter" from Usama Arif adds a DAMOS filter which permits the filtering
   by huge page sizes.
 
 - The 4 patch series "mm: permit guard regions for file-backed/shmem
   mappings" from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state.  The feature now covers shmem and
   file-backed mappings.
 
 - The 4 patch series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping for
   pte-mapped large folios.
 
 - The 18 patch series "reimplement per-vma lock as a refcount" from
   Suren Baghdasaryan puts the vm_lock back into the vma.  Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy.  This patchset provides small (0-10%) improvements on one
   microbenchmark.
 
 - The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation
   fixes and improves" from SeongJae Park does some maintenance work on the
   DAMON docs.
 
 - The 27 patch series "hugetlb/CMA improvements for large systems" from
   Frank van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped
   pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.
 
 - The 19 patch series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.
 
 - The 12 patch series "selftests/mm: Some cleanups from trying to run
   them" from Brendan Jackman fixes a pile of unrelated issues which
   Brendan encountered while runnimg our selftests.
 
 - The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap"
   from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.
 
 - The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply wasn't
   being effective.
 
 - The 5 patch series "mm: cleanups for device-exclusive entries (hmm)"
   from David Hildenbrand implements a number of unrelated cleanups in this
   code.
 
 - The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman
   Khandual implements a number of preparatoty cleanups to the
   GENERIC_PTDUMP Kconfig logic.
 
 - The 8 patch series "mm/damon: auto-tune aggregation interval" from
   SeongJae Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.
 
 - The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some
   issues in powerpc, sparc and x86 lazy MMU implementations.  Ryan did
   this in preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.
 
 - The 2 patch series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the code
   easier to follow.
 
 - The 3 patch series "page_counter cleanup and size reduction" from
   Shakeel Butt cleans up the page_counter code and fixes a size increase
   which we accidentally added late last year.
 
 - The 3 patch series "Add a command line option that enables control of
   how many threads should be used to allocate huge pages" from Thomas
   Prescher does that.  It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.
 
 - The 3 patch series "Fix calculations in trace_balance_dirty_pages()
   for cgwb" from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.
 
 - The 9 patch series "mm/damon: make allow filters after reject filters
   useful and intuitive" from SeongJae Park improves the handling of allow
   and reject filters.  Behaviour is made more consistent and the
   documention is updated accordingly.
 
 - The 5 patch series "Switch zswap to object read/write APIs" from Yosry
   Ahmed updates zswap to the new object read/write APIs and thus permits
   the removal of some legacy code from zpool and zsmalloc.
 
 - The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang
   does as it claims.
 
 - The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts"
   from Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.
 
 - The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes
   is a preparatoty refactoring and cleanup of the mremap() code.
 
 - The 20 patch series "mm: MM owner tracking for large folios (!hugetlb)
   + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.
 
 - The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS
   filters based on handling layers" from SeongJae Park adds a couple of
   new sysfs directories to ease the management of DAMON/DAMOS filters.
 
 - The 13 patch series "arch, mm: reduce code duplication in mem_init()"
   from Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.
 
 - The 13 patch series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.
 
 - The 3 patch series "mm: page_ext: Introduce new iteration API" from
   Luiz Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.
 
 - The 8 patch series "Buddy allocator like (or non-uniform) folio split"
   from Zi Yan reworks the code to split a folio into smaller folios.  The
   main benefit is lessened memory consumption: fewer post-split folios are
   generated.
 
 - The 2 patch series "Minimize xa_node allocation during xarry split"
   from Zi Yan reduces the number of xarray xa_nodes which are generated
   during an xarray split.
 
 - The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.
 
 - The 3 patch series "Add tracepoints for lowmem reserves, watermarks
   and totalreserve_pages" from Martin Liu adds some more tracepoints to
   the page allocator code.
 
 - The 4 patch series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which SeongJae
   observed during his earlier madvise work.
 
 - The 3 patch series "mm/hwpoison: Fix regressions in memory failure
   handling" from Shuai Xue addresses two quite serious regressions which
   Shuai has observed in the memory-failure implementation.
 
 - The 5 patch series "mm: reliable huge page allocator" from Johannes
   Weiner makes huge page allocations cheaper and more reliable by reducing
   fragmentation.
 
 - The 5 patch series "Minor memcg cleanups & prep for memdescs" from
   Matthew Wilcox is preparatory work for the future implementation of
   memdescs.
 
 - The 4 patch series "track memory used by balloon drivers" from Nico
   Pache introduces a way to track memory used by our various balloon
   drivers.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for active
   pages" from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.
 
 - The 2 patch series "Adding Proactive Memory Reclaim Statistics" from
   Hao Jia separates the proactive reclaim statistics from the direct
   reclaim statistics.
 
 - The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio"
   from Jinjiang Tu fixes our handling of hwpoisoned pages within the
   reclaim code.
 -----BEGIN PGP SIGNATURE-----
 
 iHQEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ+nZaAAKCRDdBJ7gKXxA
 jsOWAPiP4r7CJHMZRK4eyJOkvS1a1r+TsIarrFZtjwvf/GIfAQCEG+JDxVfUaUSF
 Ee93qSSLR1BkNdDw+931Pu0mXfbnBw==
 =Pn2K
 -----END PGP SIGNATURE-----

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

Pull MM updates from Andrew Morton:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...
2025-04-01 09:29:18 -07:00
David Hildenbrand
096cbb80ab kernel/events/uprobes: handle device-exclusive entries correctly in __replace_page()
Ever since commit b756a3b5e7 ("mm: device exclusive memory access") we
can return with a device-exclusive entry from page_vma_mapped_walk().

__replace_page() is not prepared for that, so teach it about these PFN
swap PTEs.  Note that device-private entries are so far not applicable on
that path, because GUP would never have returned such folios (conversion
to device-private happens by page migration, not in-place conversion of
the PTE).

There is a race between GUP and us locking the folio to look it up using
page_vma_mapped_walk(), so this is likely a fix (unless something else
could prevent that race, but it doesn't look like).  pte_pfn() on
something that is not a present pte could give use garbage, and we'd
wrongly mess up the mapcount because it was already adjusted by calling
folio_remove_rmap_pte() when making the entry device-exclusive.

Link: https://lkml.kernel.org/r/20250210193801.781278-9-david@redhat.com
Fixes: b756a3b5e7 ("mm: device exclusive memory access")
Signed-off-by: David Hildenbrand <david@redhat.com>
Tested-by: Alistair Popple <apopple@nvidia.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Karol Herbst <kherbst@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lyude <lyude@redhat.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Simona Vetter <simona.vetter@ffwll.ch>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yanteng Si <si.yanteng@linux.dev>
Cc: Barry Song <v-songbaohua@oppo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:05:58 -07:00
Jiri Olsa
fa6192adc3 uprobes/x86: Harden uretprobe syscall trampoline check
Jann reported a possible issue when trampoline_check_ip returns
address near the bottom of the address space that is allowed to
call into the syscall if uretprobes are not set up:

   https://lore.kernel.org/bpf/202502081235.5A6F352985@keescook/T/#m9d416df341b8fbc11737dacbcd29f0054413cbbf

Though the mmap minimum address restrictions will typically prevent
creating mappings there, let's make sure uretprobe syscall checks
for that.

Fixes: ff474a78ce ("uprobe: Add uretprobe syscall to speed up return probe")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250212220433.3624297-1-jolsa@kernel.org
2025-03-06 12:22:45 +01:00
Ingo Molnar
ef2f798600 Merge branch 'perf/urgent' into perf/core, to pick up dependent patches and fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-03-01 19:41:14 +01:00
Andrii Nakryiko
f8c857238a uprobes: Remove too strict lockdep_assert() condition in hprobe_expire()
hprobe_expire() is used to atomically switch pending uretprobe instance
(struct return_instance) from being SRCU protected to be refcounted.
This can be done from background timer thread, or synchronously within
current thread when task is forked.

In the former case, return_instance has to be protected through RCU read
lock, and that's what hprobe_expire() used to check with
lockdep_assert(rcu_read_lock_held()).

But in the latter case (hprobe_expire() called from dup_utask()) there
is no RCU lock being held, and it's both unnecessary and incovenient.
Inconvenient due to the intervening memory allocations inside
dup_return_instance()'s loop. Unnecessary because dup_utask() is called
synchronously in current thread, and no uretprobe can run at that point,
so return_instance can't be freed either.

So drop rcu_read_lock_held() condition, and expand corresponding comment
to explain necessary lifetime guarantees. lockdep_assert()-detected
issue is a false positive.

Fixes: dd1a756778 ("uprobes: SRCU-protect uretprobe lifetime (with timeout)")
Reported-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20250225223214.2970740-1-andrii@kernel.org
2025-02-25 23:36:19 +01:00
Tong Tiangen
bddf10d26e uprobes: Reject the shared zeropage in uprobe_write_opcode()
We triggered the following crash in syzkaller tests:

  BUG: Bad page state in process syz.7.38  pfn:1eff3
  page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eff3
  flags: 0x3fffff00004004(referenced|reserved|node=0|zone=1|lastcpupid=0x1fffff)
  raw: 003fffff00004004 ffffe6c6c07bfcc8 ffffe6c6c07bfcc8 0000000000000000
  raw: 0000000000000000 0000000000000000 00000000fffffffe 0000000000000000
  page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  Call Trace:
   <TASK>
   dump_stack_lvl+0x32/0x50
   bad_page+0x69/0xf0
   free_unref_page_prepare+0x401/0x500
   free_unref_page+0x6d/0x1b0
   uprobe_write_opcode+0x460/0x8e0
   install_breakpoint.part.0+0x51/0x80
   register_for_each_vma+0x1d9/0x2b0
   __uprobe_register+0x245/0x300
   bpf_uprobe_multi_link_attach+0x29b/0x4f0
   link_create+0x1e2/0x280
   __sys_bpf+0x75f/0xac0
   __x64_sys_bpf+0x1a/0x30
   do_syscall_64+0x56/0x100
   entry_SYSCALL_64_after_hwframe+0x78/0xe2

   BUG: Bad rss-counter state mm:00000000452453e0 type:MM_FILEPAGES val:-1

The following syzkaller test case can be used to reproduce:

  r2 = creat(&(0x7f0000000000)='./file0\x00', 0x8)
  write$nbd(r2, &(0x7f0000000580)=ANY=[], 0x10)
  r4 = openat(0xffffffffffffff9c, &(0x7f0000000040)='./file0\x00', 0x42, 0x0)
  mmap$IORING_OFF_SQ_RING(&(0x7f0000ffd000/0x3000)=nil, 0x3000, 0x0, 0x12, r4, 0x0)
  r5 = userfaultfd(0x80801)
  ioctl$UFFDIO_API(r5, 0xc018aa3f, &(0x7f0000000040)={0xaa, 0x20})
  r6 = userfaultfd(0x80801)
  ioctl$UFFDIO_API(r6, 0xc018aa3f, &(0x7f0000000140))
  ioctl$UFFDIO_REGISTER(r6, 0xc020aa00, &(0x7f0000000100)={{&(0x7f0000ffc000/0x4000)=nil, 0x4000}, 0x2})
  ioctl$UFFDIO_ZEROPAGE(r5, 0xc020aa04, &(0x7f0000000000)={{&(0x7f0000ffd000/0x1000)=nil, 0x1000}})
  r7 = bpf$PROG_LOAD(0x5, &(0x7f0000000140)={0x2, 0x3, &(0x7f0000000200)=ANY=[@ANYBLOB="1800000000120000000000000000000095"], &(0x7f0000000000)='GPL\x00', 0x7, 0x0, 0x0, 0x0, 0x0, '\x00', 0x0, @fallback=0x30, 0xffffffffffffffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x10, 0x0, @void, @value}, 0x94)
  bpf$BPF_LINK_CREATE_XDP(0x1c, &(0x7f0000000040)={r7, 0x0, 0x30, 0x1e, @val=@uprobe_multi={&(0x7f0000000080)='./file0\x00', &(0x7f0000000100)=[0x2], 0x0, 0x0, 0x1}}, 0x40)

The cause is that zero pfn is set to the PTE without increasing the RSS
count in mfill_atomic_pte_zeropage() and the refcount of zero folio does
not increase accordingly. Then, the operation on the same pfn is performed
in uprobe_write_opcode()->__replace_page() to unconditional decrease the
RSS count and old_folio's refcount.

Therefore, two bugs are introduced:

 1. The RSS count is incorrect, when process exit, the check_mm() report
    error "Bad rss-count".

 2. The reserved folio (zero folio) is freed when folio->refcount is zero,
    then free_pages_prepare->free_page_is_bad() report error
    "Bad page state".

There is more, the following warning could also theoretically be triggered:

  __replace_page()
    -> ...
      -> folio_remove_rmap_pte()
        -> VM_WARN_ON_FOLIO(is_zero_folio(folio), folio)

Considering that uprobe hit on the zero folio is a very rare case, just
reject zero old folio immediately after get_user_page_vma_remote().

[ mingo: Cleaned up the changelog ]

Fixes: 7396fa818d ("uprobes/core: Make background page replacement logic account for rss_stat counters")
Fixes: 2b14449835 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20250224031149.1598949-1-tongtiangen@huawei.com
2025-02-24 20:37:45 +01:00
Ingo Molnar
e6e21a9a39 Merge branch 'perf/urgent' into perf/core, to pick up fixes before merging new patches
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-02-21 14:52:19 +01:00
Thomas Weißschuh
ec5fd50aef uprobes: Don't use %pK through printk
Restricted pointers ("%pK") are not meant to be used through printk().
It can unintentionally expose security sensitive, raw pointer values.

Use regular pointer formatting instead.

For more background, see:

  https://lore.kernel.org/lkml/20250113171731-dc10e3c1-da64-4af0-b767-7c7070468023@linutronix.de/

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250217-restricted-pointers-uprobes-v1-1-e8cbe5bb22a7@linutronix.de
2025-02-18 09:48:02 +01:00
Liao Chang
83179cd678 uprobes: Remove the spinlock within handle_singlestep()
This patch introduces a flag to track TIF_SIGPENDING is suppress
temporarily during the uprobe single-step. Upon uprobe singlestep is
handled and the flag is confirmed, it could resume the TIF_SIGPENDING
directly without acquiring the siglock in most case, then reducing
contention and improving overall performance.

I've use the script developed by Andrii in [1] to run benchmark. The CPU
used was Kunpeng916 (Hi1616), 4 NUMA nodes, 64 cores@2.4GHz running the
kernel on next tree + the optimization for get_xol_insn_slot() [2].

before-opt
----------
uprobe-nop      ( 1 cpus):    0.907 ± 0.003M/s  (  0.907M/s/cpu)
uprobe-nop      ( 2 cpus):    1.676 ± 0.008M/s  (  0.838M/s/cpu)
uprobe-nop      ( 4 cpus):    3.210 ± 0.003M/s  (  0.802M/s/cpu)
uprobe-nop      ( 8 cpus):    4.457 ± 0.003M/s  (  0.557M/s/cpu)
uprobe-nop      (16 cpus):    3.724 ± 0.011M/s  (  0.233M/s/cpu)
uprobe-nop      (32 cpus):    2.761 ± 0.003M/s  (  0.086M/s/cpu)
uprobe-nop      (64 cpus):    1.293 ± 0.015M/s  (  0.020M/s/cpu)

uprobe-push     ( 1 cpus):    0.883 ± 0.001M/s  (  0.883M/s/cpu)
uprobe-push     ( 2 cpus):    1.642 ± 0.005M/s  (  0.821M/s/cpu)
uprobe-push     ( 4 cpus):    3.086 ± 0.002M/s  (  0.771M/s/cpu)
uprobe-push     ( 8 cpus):    3.390 ± 0.003M/s  (  0.424M/s/cpu)
uprobe-push     (16 cpus):    2.652 ± 0.005M/s  (  0.166M/s/cpu)
uprobe-push     (32 cpus):    2.713 ± 0.005M/s  (  0.085M/s/cpu)
uprobe-push     (64 cpus):    1.313 ± 0.009M/s  (  0.021M/s/cpu)

uprobe-ret      ( 1 cpus):    1.774 ± 0.000M/s  (  1.774M/s/cpu)
uprobe-ret      ( 2 cpus):    3.350 ± 0.001M/s  (  1.675M/s/cpu)
uprobe-ret      ( 4 cpus):    6.604 ± 0.000M/s  (  1.651M/s/cpu)
uprobe-ret      ( 8 cpus):    6.706 ± 0.005M/s  (  0.838M/s/cpu)
uprobe-ret      (16 cpus):    5.231 ± 0.001M/s  (  0.327M/s/cpu)
uprobe-ret      (32 cpus):    5.743 ± 0.003M/s  (  0.179M/s/cpu)
uprobe-ret      (64 cpus):    4.726 ± 0.016M/s  (  0.074M/s/cpu)

after-opt
---------
uprobe-nop      ( 1 cpus):    0.985 ± 0.002M/s  (  0.985M/s/cpu)
uprobe-nop      ( 2 cpus):    1.773 ± 0.005M/s  (  0.887M/s/cpu)
uprobe-nop      ( 4 cpus):    3.304 ± 0.001M/s  (  0.826M/s/cpu)
uprobe-nop      ( 8 cpus):    5.328 ± 0.002M/s  (  0.666M/s/cpu)
uprobe-nop      (16 cpus):    6.475 ± 0.002M/s  (  0.405M/s/cpu)
uprobe-nop      (32 cpus):    4.831 ± 0.082M/s  (  0.151M/s/cpu)
uprobe-nop      (64 cpus):    2.564 ± 0.053M/s  (  0.040M/s/cpu)

uprobe-push     ( 1 cpus):    0.964 ± 0.001M/s  (  0.964M/s/cpu)
uprobe-push     ( 2 cpus):    1.766 ± 0.002M/s  (  0.883M/s/cpu)
uprobe-push     ( 4 cpus):    3.290 ± 0.009M/s  (  0.823M/s/cpu)
uprobe-push     ( 8 cpus):    4.670 ± 0.002M/s  (  0.584M/s/cpu)
uprobe-push     (16 cpus):    5.197 ± 0.004M/s  (  0.325M/s/cpu)
uprobe-push     (32 cpus):    5.068 ± 0.161M/s  (  0.158M/s/cpu)
uprobe-push     (64 cpus):    2.605 ± 0.026M/s  (  0.041M/s/cpu)

uprobe-ret      ( 1 cpus):    1.833 ± 0.001M/s  (  1.833M/s/cpu)
uprobe-ret      ( 2 cpus):    3.384 ± 0.003M/s  (  1.692M/s/cpu)
uprobe-ret      ( 4 cpus):    6.677 ± 0.004M/s  (  1.669M/s/cpu)
uprobe-ret      ( 8 cpus):    6.854 ± 0.005M/s  (  0.857M/s/cpu)
uprobe-ret      (16 cpus):    6.508 ± 0.006M/s  (  0.407M/s/cpu)
uprobe-ret      (32 cpus):    5.793 ± 0.009M/s  (  0.181M/s/cpu)
uprobe-ret      (64 cpus):    4.743 ± 0.016M/s  (  0.074M/s/cpu)

Above benchmark results demonstrates a obivious improvement in the
scalability of trig-uprobe-nop and trig-uprobe-push, the peak throughput
of which are from 4.5M/s to 6.4M/s and 3.3M/s to 5.1M/s individually.

[1] https://lore.kernel.org/all/20240731214256.3588718-1-andrii@kernel.org
[2] https://lore.kernel.org/all/20240727094405.1362496-1-liaochang1@huawei.com

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250124093826.2123675-3-liaochang1@huawei.com
2025-02-05 10:29:12 +01:00
Liao Chang
eae8a56ae0 uprobes: Remove redundant spinlock in uprobe_deny_signal()
Since clearing a bit in thread_info is an atomic operation, the spinlock
is redundant and can be removed, reducing lock contention is good for
performance.

Signed-off-by: Liao Chang <liaochang1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20250124093826.2123675-2-liaochang1@huawei.com
2025-02-03 11:46:06 +01:00
Liam R. Howlett
64c37e134b kernel: be more careful about dup_mmap() failures and uprobe registering
If a memory allocation fails during dup_mmap(), the maple tree can be left
in an unsafe state for other iterators besides the exit path.  All the
locks are dropped before the exit_mmap() call (in mm/mmap.c), but the
incomplete mm_struct can be reached through (at least) the rmap finding
the vmas which have a pointer back to the mm_struct.

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

Although 8ac662f5da ("fork: avoid inappropriate uprobe access to
invalid mm") fixed the uprobe access, it does not completely remove the
race.

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

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

Link: https://lore.kernel.org/all/6756d273.050a0220.2477f.003d.GAE@google.com/
Link: https://lkml.kernel.org/r/20250127170221.1761366-1-Liam.Howlett@oracle.com
Fixes: d240629148 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-01 03:53:25 -08:00
Linus Torvalds
6c4aa896eb Performance events changes for v6.14:
- Seqlock optimizations that arose in a perf context and were
    merged into the perf tree:
 
    - seqlock: Add raw_seqcount_try_begin (Suren Baghdasaryan)
    - mm: Convert mm_lock_seq to a proper seqcount ((Suren Baghdasaryan)
    - mm: Introduce mmap_lock_speculate_{try_begin|retry} (Suren Baghdasaryan)
    - mm/gup: Use raw_seqcount_try_begin() (Peter Zijlstra)
 
  - Core perf enhancements:
 
    - Reduce 'struct page' footprint of perf by mapping pages
      in advance (Lorenzo Stoakes)
    - Save raw sample data conditionally based on sample type (Yabin Cui)
    - Reduce sampling overhead by checking sample_type in
      perf_sample_save_callchain() and perf_sample_save_brstack() (Yabin Cui)
    - Export perf_exclude_event() (Namhyung Kim)
 
  - Uprobes scalability enhancements: (Andrii Nakryiko)
 
    - Simplify find_active_uprobe_rcu() VMA checks
    - Add speculative lockless VMA-to-inode-to-uprobe resolution
    - Simplify session consumer tracking
    - Decouple return_instance list traversal and freeing
    - Ensure return_instance is detached from the list before freeing
    - Reuse return_instances between multiple uretprobes within task
    - Guard against kmemdup() failing in dup_return_instance()
 
  - AMD core PMU driver enhancements:
 
    - Relax privilege filter restriction on AMD IBS (Namhyung Kim)
 
  - AMD RAPL energy counters support: (Dhananjay Ugwekar)
 
    - Introduce topology_logical_core_id() (K Prateek Nayak)
 
    - Remove the unused get_rapl_pmu_cpumask() function
    - Remove the cpu_to_rapl_pmu() function
    - Rename rapl_pmu variables
    - Make rapl_model struct global
    - Add arguments to the init and cleanup functions
    - Modify the generic variable names to *_pkg*
    - Remove the global variable rapl_msrs
    - Move the cntr_mask to rapl_pmus struct
    - Add core energy counter support for AMD CPUs
 
  - Intel core PMU driver enhancements:
 
    - Support RDPMC 'metrics clear mode' feature (Kan Liang)
    - Clarify adaptive PEBS processing (Kan Liang)
    - Factor out functions for PEBS records processing (Kan Liang)
    - Simplify the PEBS records processing for adaptive PEBS (Kan Liang)
 
  - Intel uncore driver enhancements: (Kan Liang)
 
    - Convert buggy pmu->func_id use to pmu->registered
    - Support more units on Granite Rapids
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
 -----BEGIN PGP SIGNATURE-----
 
 iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmeOJdQRHG1pbmdvQGtl
 cm5lbC5vcmcACgkQEnMQ0APhK1i2yQ/+MXl7yfJOgdbwjBpgGGzH4burEO7ppak+
 ktzz+YjpNgjODe/xMAJGjjblouuYArCnRolc1UPvPm6M7jSY76wi42Y6c4dRtFoB
 2ReSrRqnreLOcrRS9nsTjvWRHfJHqJDVSd9TfHX6ILfzbaizCZOGYk558ZxAKRqu
 Lw7FOvLEe/Y3tg4z8dDg083jsasalKySP9wIPc0BkSqQTOfusd3KXju/Fux/9wkn
 hZcUgF4ds+0bH7xtO1/G9ILqGyeq97X1McIR9bAjln5Mxykclen4hSjRaWWHHo9O
 mzBKmd/blIATisfuuW+QLDQow3M1k3688cz7e9QOeWHHd/dJiMb9RLV90jdND/T/
 uLINC5vNemzyWEfnNiYQ31LjhG3SeuDiKWzRp36MbQcCh6EBdRXWLBgtmxq1L/3o
 ZCaCdtFu5+6epycdyOVZEpWDnjdx4GmLXMZi5WJfZ7fZ/IFjNkjk4OdzI1iRQ+i3
 Sbi75ep59ayTUhm5AB7gCJsP3R7EsZsiPHUenQdA2n9Sj6xE+IuhlS/QDQ9g5mdY
 Ijs0jHeVCGmhYoOD1xWnCZSzlnkEVU3zwfypAK+MC7pgtFMwDy5/Bu1USGxXXDy+
 aKsrJRSgHbtZ1gwoHstqkV+DeCTfElCLYkvigzI5Nmyib5Zp4vkwy2ZLWQjaNjm7
 mqRI7PugUkU=
 =c8XB
 -----END PGP SIGNATURE-----

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

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

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

  Core perf enhancements:

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

  Uprobes scalability enhancements: (Andrii Nakryiko)

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

  AMD core PMU driver enhancements:

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

  AMD RAPL energy counters support: (Dhananjay Ugwekar)

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

  Intel core PMU driver enhancements:

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

  Intel uncore driver enhancements: (Kan Liang)

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

* tag 'perf-core-2025-01-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  perf: map pages in advance
  perf/x86/intel/uncore: Support more units on Granite Rapids
  perf/x86/intel/uncore: Clean up func_id
  perf/x86/intel: Support RDPMC metrics clear mode
  uprobes: Guard against kmemdup() failing in dup_return_instance()
  perf/x86: Relax privilege filter restriction on AMD IBS
  perf/core: Export perf_exclude_event()
  uprobes: Reuse return_instances between multiple uretprobes within task
  uprobes: Ensure return_instance is detached from the list before freeing
  uprobes: Decouple return_instance list traversal and freeing
  uprobes: Simplify session consumer tracking
  uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
  uprobes: simplify find_active_uprobe_rcu() VMA checks
  mm: introduce mmap_lock_speculate_{try_begin|retry}
  mm: convert mm_lock_seq to a proper seqcount
  mm/gup: Use raw_seqcount_try_begin()
  seqlock: add raw_seqcount_try_begin
  perf/x86/rapl: Add core energy counter support for AMD CPUs
  perf/x86/rapl: Move the cntr_mask to rapl_pmus struct
  perf/x86/rapl: Remove the global variable rapl_msrs
  ...
2025-01-21 10:52:03 -08:00
Jiri Olsa
b583ef82b6 uprobes: Fix race in uprobe_free_utask
Max Makarov reported kernel panic [1] in perf user callchain code.

The reason for that is the race between uprobe_free_utask and bpf
profiler code doing the perf user stack unwind and is triggered
within uprobe_free_utask function:
  - after current->utask is freed and
  - before current->utask is set to NULL

 general protection fault, probably for non-canonical address 0x9e759c37ee555c76: 0000 [#1] SMP PTI
 RIP: 0010:is_uprobe_at_func_entry+0x28/0x80
 ...
  ? die_addr+0x36/0x90
  ? exc_general_protection+0x217/0x420
  ? asm_exc_general_protection+0x26/0x30
  ? is_uprobe_at_func_entry+0x28/0x80
  perf_callchain_user+0x20a/0x360
  get_perf_callchain+0x147/0x1d0
  bpf_get_stackid+0x60/0x90
  bpf_prog_9aac297fb833e2f5_do_perf_event+0x434/0x53b
  ? __smp_call_single_queue+0xad/0x120
  bpf_overflow_handler+0x75/0x110
  ...
  asm_sysvec_apic_timer_interrupt+0x1a/0x20
 RIP: 0010:__kmem_cache_free+0x1cb/0x350
 ...
  ? uprobe_free_utask+0x62/0x80
  ? acct_collect+0x4c/0x220
  uprobe_free_utask+0x62/0x80
  mm_release+0x12/0xb0
  do_exit+0x26b/0xaa0
  __x64_sys_exit+0x1b/0x20
  do_syscall_64+0x5a/0x80

It can be easily reproduced by running following commands in
separate terminals:

  # while :; do bpftrace -e 'uprobe:/bin/ls:_start  { printf("hit\n"); }' -c ls; done
  # bpftrace -e 'profile:hz:100000 { @[ustack()] = count(); }'

Fixing this by making sure current->utask pointer is set to NULL
before we start to release the utask object.

[1] https://github.com/grafana/pyroscope/issues/3673

Fixes: cfa7f3d2c5 ("perf,x86: avoid missing caller address in stack traces captured in uprobe")
Reported-by: Max Makarov <maxpain@linux.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20250109141440.2692173-1-jolsa@kernel.org
2025-01-10 09:28:01 +01:00
Andrii Nakryiko
02c56362a7 uprobes: Guard against kmemdup() failing in dup_return_instance()
If kmemdup() failed to alloc memory, don't proceed with extra_consumers
copy.

Fixes: e62f2d492728 ("uprobes: Simplify session consumer tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20241206183436.968068-1-andrii@kernel.org
2024-12-09 15:50:32 +01:00
Andrii Nakryiko
8622e45b5d uprobes: Reuse return_instances between multiple uretprobes within task
Instead of constantly allocating and freeing very short-lived
struct return_instance, reuse it as much as possible within current
task. For that, store a linked list of reusable return_instances within
current->utask.

The only complication is that ri_timer() might be still processing such
return_instance. And so while the main uretprobe processing logic might
be already done with return_instance and would be OK to immediately
reuse it for the next uretprobe instance, it's not correct to
unconditionally reuse it just like that.

Instead we make sure that ri_timer() can't possibly be processing it by
using seqcount_t, with ri_timer() being "a writer", while
free_ret_instance() being "a reader". If, after we unlink return
instance from utask->return_instances list, we know that ri_timer()
hasn't gotten to processing utask->return_instances yet, then we can be
sure that immediate return_instance reuse is OK, and so we put it
onto utask->ri_pool for future (potentially, almost immediate) reuse.

This change shows improvements both in single CPU performance (by
avoiding relatively expensive kmalloc/free combon) and in terms of
multi-CPU scalability, where you can see that per-CPU throughput doesn't
decline as steeply with increased number of CPUs (which were previously
attributed to kmalloc()/free() through profiling):

	BASELINE (latest perf/core)
	===========================
	uretprobe-nop         ( 1 cpus):    1.898 ± 0.002M/s  (  1.898M/s/cpu)
	uretprobe-nop         ( 2 cpus):    3.574 ± 0.011M/s  (  1.787M/s/cpu)
	uretprobe-nop         ( 3 cpus):    5.279 ± 0.066M/s  (  1.760M/s/cpu)
	uretprobe-nop         ( 4 cpus):    6.824 ± 0.047M/s  (  1.706M/s/cpu)
	uretprobe-nop         ( 5 cpus):    8.339 ± 0.060M/s  (  1.668M/s/cpu)
	uretprobe-nop         ( 6 cpus):    9.812 ± 0.047M/s  (  1.635M/s/cpu)
	uretprobe-nop         ( 7 cpus):   11.030 ± 0.048M/s  (  1.576M/s/cpu)
	uretprobe-nop         ( 8 cpus):   12.453 ± 0.126M/s  (  1.557M/s/cpu)
	uretprobe-nop         (10 cpus):   14.838 ± 0.044M/s  (  1.484M/s/cpu)
	uretprobe-nop         (12 cpus):   17.092 ± 0.115M/s  (  1.424M/s/cpu)
	uretprobe-nop         (14 cpus):   19.576 ± 0.022M/s  (  1.398M/s/cpu)
	uretprobe-nop         (16 cpus):   22.264 ± 0.015M/s  (  1.391M/s/cpu)
	uretprobe-nop         (24 cpus):   33.534 ± 0.078M/s  (  1.397M/s/cpu)
	uretprobe-nop         (32 cpus):   43.262 ± 0.127M/s  (  1.352M/s/cpu)
	uretprobe-nop         (40 cpus):   53.252 ± 0.080M/s  (  1.331M/s/cpu)
	uretprobe-nop         (48 cpus):   55.778 ± 0.045M/s  (  1.162M/s/cpu)
	uretprobe-nop         (56 cpus):   56.850 ± 0.227M/s  (  1.015M/s/cpu)
	uretprobe-nop         (64 cpus):   62.005 ± 0.077M/s  (  0.969M/s/cpu)
	uretprobe-nop         (72 cpus):   66.445 ± 0.236M/s  (  0.923M/s/cpu)
	uretprobe-nop         (80 cpus):   68.353 ± 0.180M/s  (  0.854M/s/cpu)

	THIS PATCHSET (on top of latest perf/core)
	==========================================
	uretprobe-nop         ( 1 cpus):    2.253 ± 0.004M/s  (  2.253M/s/cpu)
	uretprobe-nop         ( 2 cpus):    4.281 ± 0.003M/s  (  2.140M/s/cpu)
	uretprobe-nop         ( 3 cpus):    6.389 ± 0.027M/s  (  2.130M/s/cpu)
	uretprobe-nop         ( 4 cpus):    8.328 ± 0.005M/s  (  2.082M/s/cpu)
	uretprobe-nop         ( 5 cpus):   10.353 ± 0.001M/s  (  2.071M/s/cpu)
	uretprobe-nop         ( 6 cpus):   12.513 ± 0.010M/s  (  2.086M/s/cpu)
	uretprobe-nop         ( 7 cpus):   14.525 ± 0.017M/s  (  2.075M/s/cpu)
	uretprobe-nop         ( 8 cpus):   15.633 ± 0.013M/s  (  1.954M/s/cpu)
	uretprobe-nop         (10 cpus):   19.532 ± 0.011M/s  (  1.953M/s/cpu)
	uretprobe-nop         (12 cpus):   21.405 ± 0.009M/s  (  1.784M/s/cpu)
	uretprobe-nop         (14 cpus):   24.857 ± 0.020M/s  (  1.776M/s/cpu)
	uretprobe-nop         (16 cpus):   26.466 ± 0.018M/s  (  1.654M/s/cpu)
	uretprobe-nop         (24 cpus):   40.513 ± 0.222M/s  (  1.688M/s/cpu)
	uretprobe-nop         (32 cpus):   54.180 ± 0.074M/s  (  1.693M/s/cpu)
	uretprobe-nop         (40 cpus):   66.100 ± 0.082M/s  (  1.652M/s/cpu)
	uretprobe-nop         (48 cpus):   70.544 ± 0.068M/s  (  1.470M/s/cpu)
	uretprobe-nop         (56 cpus):   74.494 ± 0.055M/s  (  1.330M/s/cpu)
	uretprobe-nop         (64 cpus):   79.317 ± 0.029M/s  (  1.239M/s/cpu)
	uretprobe-nop         (72 cpus):   84.875 ± 0.020M/s  (  1.179M/s/cpu)
	uretprobe-nop         (80 cpus):   92.318 ± 0.224M/s  (  1.154M/s/cpu)

For reference, with uprobe-nop we hit the following throughput:

	uprobe-nop            (80 cpus):  143.485 ± 0.035M/s  (  1.794M/s/cpu)

So now uretprobe stays a bit closer to that performance.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-5-andrii@kernel.org
2024-12-09 15:50:30 +01:00
Andrii Nakryiko
0cf981de76 uprobes: Ensure return_instance is detached from the list before freeing
Ensure that by the time we call free_ret_instance() to clean up an
instance of struct return_instance it isn't reachable from
utask->return_instances anymore.

free_ret_instance() is called in a few different situations, all but one
of which already are fine w.r.t. return_instance visibility:

  - uprobe_free_utask() guarantees that ri_timer() won't be called
    (through timer_delete_sync() call), and so there is no need to
    unlink anything, because entire utask is being freed;
  - uprobe_handle_trampoline() is already unlinking to-be-freed
    return_instance with rcu_assign_pointer() before calling
    free_ret_instance().

Only cleanup_return_instances() violates this property, which so far is
not causing problems due to RCU-delayed freeing of return_instance,
which we'll change in the next patch. So make sure we unlink
return_instance before passing it into free_ret_instance(), as otherwise
reuse will be unsafe.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-4-andrii@kernel.org
2024-12-09 15:50:29 +01:00
Andrii Nakryiko
636666a1c7 uprobes: Decouple return_instance list traversal and freeing
free_ret_instance() has two unrelated responsibilities: actually
cleaning up return_instance's resources and freeing memory, and also
helping with utask->return_instances list traversal by returning the
next alive pointer.

There is no reason why these two aspects have to be mixed together, so
turn free_ret_instance() into void-returning function and make callers
do list traversal on their own.

We'll use this simplification in the next patch that will guarantee that
to-be-freed return_instance isn't reachable from utask->return_instances
list.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-3-andrii@kernel.org
2024-12-09 15:50:26 +01:00
Andrii Nakryiko
2ff913ab3f uprobes: Simplify session consumer tracking
In practice, each return_instance will typically contain either zero or
one return_consumer, depending on whether it has any uprobe session
consumer attached or not. It's highly unlikely that more than one uprobe
session consumers will be attached to any given uprobe, so there is no
need to optimize for that case. But the way we currently do memory
allocation and accounting is by pre-allocating the space for 4 session
consumers in contiguous block of memory next to struct return_instance
fixed part. This is unnecessarily wasteful.

This patch changes this to keep struct return_instance fixed-sized with one
pre-allocated return_consumer, while (in a highly unlikely scenario)
allowing for more session consumers in a separate dynamically
allocated and reallocated array.

We also simplify accounting a bit by not maintaining a separate
temporary capacity for consumers array, and, instead, relying on
krealloc() to be a no-op if underlying memory can accommodate a slightly
bigger allocation (but again, it's very uncommon scenario to even have
to do this reallocation).

All this gets rid of ri_size(), simplifies push_consumer() and removes
confusing ri->consumers_cnt re-assignment, while containing this
singular preallocated consumer logic contained within a few simple
preexisting helpers.

Having fixed-sized struct return_instance simplifies and speeds up
return_instance reuse that we ultimately add later in this patch set,
see follow up patches.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: https://lore.kernel.org/r/20241206002417.3295533-2-andrii@kernel.org
2024-12-09 15:50:23 +01:00
Andrii Nakryiko
e0925f2dc4 uprobes: add speculative lockless VMA-to-inode-to-uprobe resolution
Given filp_cachep is marked SLAB_TYPESAFE_BY_RCU (and FMODE_BACKING
files, a special case, now goes through RCU-delated freeing), we can
safely access vma->vm_file->f_inode field locklessly under just
rcu_read_lock() protection, which enables looking up uprobe from
uprobes_tree completely locklessly and speculatively without the need to
acquire mmap_lock for reads. In most cases, anyway, assuming that there
are no parallel mm and/or VMA modifications. The underlying struct
file's memory won't go away from under us (even if struct file can be
reused in the meantime).

We rely on newly added mmap_lock_speculate_{try_begin,retry}() helpers to
validate that mm_struct stays intact for entire duration of this
speculation. If not, we fall back to mmap_lock-protected lookup.
The speculative logic is written in such a way that it will safely
handle any garbage values that might be read from vma or file structs.

Benchmarking results speak for themselves.

BEFORE (latest tip/perf/core)
=============================
uprobe-nop            ( 1 cpus):    3.384 ± 0.004M/s  (  3.384M/s/cpu)
uprobe-nop            ( 2 cpus):    5.456 ± 0.005M/s  (  2.728M/s/cpu)
uprobe-nop            ( 3 cpus):    7.863 ± 0.015M/s  (  2.621M/s/cpu)
uprobe-nop            ( 4 cpus):    9.442 ± 0.008M/s  (  2.360M/s/cpu)
uprobe-nop            ( 5 cpus):   11.036 ± 0.013M/s  (  2.207M/s/cpu)
uprobe-nop            ( 6 cpus):   10.884 ± 0.019M/s  (  1.814M/s/cpu)
uprobe-nop            ( 7 cpus):    7.897 ± 0.145M/s  (  1.128M/s/cpu)
uprobe-nop            ( 8 cpus):   10.021 ± 0.128M/s  (  1.253M/s/cpu)
uprobe-nop            (10 cpus):    9.932 ± 0.170M/s  (  0.993M/s/cpu)
uprobe-nop            (12 cpus):    8.369 ± 0.056M/s  (  0.697M/s/cpu)
uprobe-nop            (14 cpus):    8.678 ± 0.017M/s  (  0.620M/s/cpu)
uprobe-nop            (16 cpus):    7.392 ± 0.003M/s  (  0.462M/s/cpu)
uprobe-nop            (24 cpus):    5.326 ± 0.178M/s  (  0.222M/s/cpu)
uprobe-nop            (32 cpus):    5.426 ± 0.059M/s  (  0.170M/s/cpu)
uprobe-nop            (40 cpus):    5.262 ± 0.070M/s  (  0.132M/s/cpu)
uprobe-nop            (48 cpus):    6.121 ± 0.010M/s  (  0.128M/s/cpu)
uprobe-nop            (56 cpus):    6.252 ± 0.035M/s  (  0.112M/s/cpu)
uprobe-nop            (64 cpus):    7.644 ± 0.023M/s  (  0.119M/s/cpu)
uprobe-nop            (72 cpus):    7.781 ± 0.001M/s  (  0.108M/s/cpu)
uprobe-nop            (80 cpus):    8.992 ± 0.048M/s  (  0.112M/s/cpu)

AFTER
=====
uprobe-nop            ( 1 cpus):    3.534 ± 0.033M/s  (  3.534M/s/cpu)
uprobe-nop            ( 2 cpus):    6.701 ± 0.007M/s  (  3.351M/s/cpu)
uprobe-nop            ( 3 cpus):   10.031 ± 0.007M/s  (  3.344M/s/cpu)
uprobe-nop            ( 4 cpus):   13.003 ± 0.012M/s  (  3.251M/s/cpu)
uprobe-nop            ( 5 cpus):   16.274 ± 0.006M/s  (  3.255M/s/cpu)
uprobe-nop            ( 6 cpus):   19.563 ± 0.024M/s  (  3.261M/s/cpu)
uprobe-nop            ( 7 cpus):   22.696 ± 0.054M/s  (  3.242M/s/cpu)
uprobe-nop            ( 8 cpus):   24.534 ± 0.010M/s  (  3.067M/s/cpu)
uprobe-nop            (10 cpus):   30.475 ± 0.117M/s  (  3.047M/s/cpu)
uprobe-nop            (12 cpus):   33.371 ± 0.017M/s  (  2.781M/s/cpu)
uprobe-nop            (14 cpus):   38.864 ± 0.004M/s  (  2.776M/s/cpu)
uprobe-nop            (16 cpus):   41.476 ± 0.020M/s  (  2.592M/s/cpu)
uprobe-nop            (24 cpus):   64.696 ± 0.021M/s  (  2.696M/s/cpu)
uprobe-nop            (32 cpus):   85.054 ± 0.027M/s  (  2.658M/s/cpu)
uprobe-nop            (40 cpus):  101.979 ± 0.032M/s  (  2.549M/s/cpu)
uprobe-nop            (48 cpus):  110.518 ± 0.056M/s  (  2.302M/s/cpu)
uprobe-nop            (56 cpus):  117.737 ± 0.020M/s  (  2.102M/s/cpu)
uprobe-nop            (64 cpus):  124.613 ± 0.079M/s  (  1.947M/s/cpu)
uprobe-nop            (72 cpus):  133.239 ± 0.032M/s  (  1.851M/s/cpu)
uprobe-nop            (80 cpus):  142.037 ± 0.138M/s  (  1.775M/s/cpu)

Previously total throughput was maxing out at 11mln/s, and gradually
declining past 8 cores. With this change, it now keeps growing with each
added CPU, reaching 142mln/s at 80 CPUs (this was measured on a 80-core
Intel(R) Xeon(R) Gold 6138 CPU @ 2.00GHz).

Suggested-by: Matthew Wilcox <willy@infradead.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20241122035922.3321100-3-andrii@kernel.org
2024-12-02 12:01:38 +01:00
Andrii Nakryiko
83e3dc9a5d uprobes: simplify find_active_uprobe_rcu() VMA checks
At the point where find_active_uprobe_rcu() is used we know that VMA in
question has triggered software breakpoint, so we don't need to validate
vma->vm_flags. Keep only vma->vm_file NULL check.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20241122035922.3321100-2-andrii@kernel.org
2024-12-02 12:01:38 +01:00
Linus Torvalds
5c00ff742b - The series "zram: optimal post-processing target selection" from
Sergey Senozhatsky improves zram's post-processing selection algorithm.
   This leads to improved memory savings.
 
 - Wei Yang has gone to town on the mapletree code, contributing several
   series which clean up the implementation:
 
 	- "refine mas_mab_cp()"
 	- "Reduce the space to be cleared for maple_big_node"
 	- "maple_tree: simplify mas_push_node()"
 	- "Following cleanup after introduce mas_wr_store_type()"
 	- "refine storing null"
 
 - The series "selftests/mm: hugetlb_fault_after_madv improvements" from
   David Hildenbrand fixes this selftest for s390.
 
 - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng
   implements some rationaizations and cleanups in the page mapping code.
 
 - The series "mm: optimize shadow entries removal" from Shakeel Butt
   optimizes the file truncation code by speeding up the handling of shadow
   entries.
 
 - The series "Remove PageKsm()" from Matthew Wilcox completes the
   migration of this flag over to being a folio-based flag.
 
 - The series "Unify hugetlb into arch_get_unmapped_area functions" from
   Oscar Salvador implements a bunch of consolidations and cleanups in the
   hugetlb code.
 
 - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain
   takes away the wp-fault time practice of turning a huge zero page into
   small pages.  Instead we replace the whole thing with a THP.  More
   consistent cleaner and potentiall saves a large number of pagefaults.
 
 - The series "percpu: Add a test case and fix for clang" from Andy
   Shevchenko enhances and fixes the kernel's built in percpu test code.
 
 - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett
   optimizes mremap() by avoiding doing things which we didn't need to do.
 
 - The series "Improve the tmpfs large folio read performance" from
   Baolin Wang teaches tmpfs to copy data into userspace at the folio size
   rather than as individual pages.  A 20% speedup was observed.
 
 - The series "mm/damon/vaddr: Fix issue in
   damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting.
 
 - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt
   removes the long-deprecated memcgv2 charge moving feature.
 
 - The series "fix error handling in mmap_region() and refactor" from
   Lorenzo Stoakes cleanup up some of the mmap() error handling and
   addresses some potential performance issues.
 
 - The series "x86/module: use large ROX pages for text allocations" from
   Mike Rapoport teaches x86 to use large pages for read-only-execute
   module text.
 
 - The series "page allocation tag compression" from Suren Baghdasaryan
   is followon maintenance work for the new page allocation profiling
   feature.
 
 - The series "page->index removals in mm" from Matthew Wilcox remove
   most references to page->index in mm/.  A slow march towards shrinking
   struct page.
 
 - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs
   interface tests" from Andrew Paniakin performs maintenance work for
   DAMON's self testing code.
 
 - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar
   improves zswap's batching of compression and decompression.  It is a
   step along the way towards using Intel IAA hardware acceleration for
   this zswap operation.
 
 - The series "kasan: migrate the last module test to kunit" from
   Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests
   over to the KUnit framework.
 
 - The series "implement lightweight guard pages" from Lorenzo Stoakes
   permits userapace to place fault-generating guard pages within a single
   VMA, rather than requiring that multiple VMAs be created for this.
   Improved efficiencies for userspace memory allocators are expected.
 
 - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses
   tracepoints to provide increased visibility into memcg stats flushing
   activity.
 
 - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky
   fixes a zram buglet which potentially affected performance.
 
 - The series "mm: add more kernel parameters to control mTHP" from
   Maíra Canal enhances our ability to control/configuremultisize THP from
   the kernel boot command line.
 
 - The series "kasan: few improvements on kunit tests" from Sabyrzhan
   Tasbolatov has a couple of fixups for the KASAN KUnit tests.
 
 - The series "mm/list_lru: Split list_lru lock into per-cgroup scope"
   from Kairui Song optimizes list_lru memory utilization when lockdep is
   enabled.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZzwFqgAKCRDdBJ7gKXxA
 jkeuAQCkl+BmeYHE6uG0hi3pRxkupseR6DEOAYIiTv0/l8/GggD/Z3jmEeqnZaNq
 xyyenpibWgUoShU2wZ/Ha8FE5WDINwg=
 =JfWR
 -----END PGP SIGNATURE-----

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

Pull MM updates from Andrew Morton:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

* tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits)
  cma: enforce non-zero pageblock_order during cma_init_reserved_mem()
  mm/kfence: add a new kunit test test_use_after_free_read_nofault()
  zram: fix NULL pointer in comp_algorithm_show()
  memcg/hugetlb: add hugeTLB counters to memcg
  vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event
  mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount
  zram: ZRAM_DEF_COMP should depend on ZRAM
  MAINTAINERS/MEMORY MANAGEMENT: add document files for mm
  Docs/mm/damon: recommend academic papers to read and/or cite
  mm: define general function pXd_init()
  kmemleak: iommu/iova: fix transient kmemleak false positive
  mm/list_lru: simplify the list_lru walk callback function
  mm/list_lru: split the lock to per-cgroup scope
  mm/list_lru: simplify reparenting and initial allocation
  mm/list_lru: code clean up for reparenting
  mm/list_lru: don't export list_lru_add
  mm/list_lru: don't pass unnecessary key parameters
  kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller
  kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW
  kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols
  ...
2024-11-23 09:58:07 -08:00
Nanyong Sun
f2f484085e mm: move mm flags to mm_types.h
The types of mm flags are now far beyond the core dump related features. 
This patch moves mm flags from linux/sched/coredump.h to linux/mm_types.h.
The linux/sched/coredump.h has include the mm_types.h, so the C files
related to coredump does not need to change head file inclusion.  In
addition, the inclusion of sched/coredump.h now can be deleted from the C
files that irrelevant to core dump.

Link: https://lkml.kernel.org/r/20240926074922.2721274-1-sunnanyong@huawei.com
Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:56:26 -08:00
Andrii Nakryiko
dd1a756778 uprobes: SRCU-protect uretprobe lifetime (with timeout)
Avoid taking refcount on uprobe in prepare_uretprobe(), instead take
uretprobe-specific SRCU lock and keep it active as kernel transfers
control back to user space.

Given we can't rely on user space returning from traced function within
reasonable time period, we need to make sure not to keep SRCU lock
active for too long, though. To that effect, we employ a timer callback
which is meant to terminate SRCU lock region after predefined timeout
(currently set to 100ms), and instead transfer underlying struct
uprobe's lifetime protection to refcounting.

This fallback to less scalable refcounting after 100ms is a fine
tradeoff from uretprobe's scalability and performance perspective,
because uretprobing *long running* user functions inherently doesn't run
into scalability issues (there is just not enough frequency to cause
noticeable issues with either performance or scalability).

The overall trick is in ensuring synchronization between current thread
and timer's callback fired on some other thread. To cope with that with
minimal logic complications, we add hprobe wrapper which is used to
contain all the synchronization related issues behind a small number of
basic helpers: hprobe_expire() for "downgrading" uprobe from SRCU-protected
state to refcounted state, and a hprobe_consume() and hprobe_finalize()
pair of single-use consuming helpers. Other than that, whatever current
thread's logic is there stays the same, as timer thread cannot modify
return_instance state (or add new/remove old return_instances). It only
takes care of SRCU unlock and uprobe refcounting, which is hidden from
the higher-level uretprobe handling logic.

We use atomic xchg() in hprobe_consume(), which is called from
performance critical handle_uretprobe_chain() function run in the
current context. When uncontended, this xchg() doesn't seem to hurt
performance as there are no other competing CPUs fighting for the same
cache line. We also mark struct return_instance as ____cacheline_aligned
to ensure no false sharing can happen.

Another technical moment. We need to make sure that the list of return
instances can be safely traversed under RCU from timer callback, so we
delay return_instance freeing with kfree_rcu() and make sure that list
modifications use RCU-aware operations.

Also, given SRCU lock survives transition from kernel to user space and
back we need to use lower-level __srcu_read_lock() and
__srcu_read_unlock() to avoid lockdep complaining.

Just to give an impression of a kind of performance improvements this
change brings, below are benchmarking results with and without these
SRCU changes, assuming other uprobe optimizations (mainly RCU Tasks
Trace for entry uprobes, lockless RB-tree lookup, and lockless VMA to
uprobe lookup) are left intact:

WITHOUT SRCU for uretprobes
===========================
uretprobe-nop         ( 1 cpus):    2.197 ± 0.002M/s  (  2.197M/s/cpu)
uretprobe-nop         ( 2 cpus):    3.325 ± 0.001M/s  (  1.662M/s/cpu)
uretprobe-nop         ( 3 cpus):    4.129 ± 0.002M/s  (  1.376M/s/cpu)
uretprobe-nop         ( 4 cpus):    6.180 ± 0.003M/s  (  1.545M/s/cpu)
uretprobe-nop         ( 8 cpus):    7.323 ± 0.005M/s  (  0.915M/s/cpu)
uretprobe-nop         (16 cpus):    6.943 ± 0.005M/s  (  0.434M/s/cpu)
uretprobe-nop         (32 cpus):    5.931 ± 0.014M/s  (  0.185M/s/cpu)
uretprobe-nop         (64 cpus):    5.145 ± 0.003M/s  (  0.080M/s/cpu)
uretprobe-nop         (80 cpus):    4.925 ± 0.005M/s  (  0.062M/s/cpu)

WITH SRCU for uretprobes
========================
uretprobe-nop         ( 1 cpus):    1.968 ± 0.001M/s  (  1.968M/s/cpu)
uretprobe-nop         ( 2 cpus):    3.739 ± 0.003M/s  (  1.869M/s/cpu)
uretprobe-nop         ( 3 cpus):    5.616 ± 0.003M/s  (  1.872M/s/cpu)
uretprobe-nop         ( 4 cpus):    7.286 ± 0.002M/s  (  1.822M/s/cpu)
uretprobe-nop         ( 8 cpus):   13.657 ± 0.007M/s  (  1.707M/s/cpu)
uretprobe-nop         (32 cpus):   45.305 ± 0.066M/s  (  1.416M/s/cpu)
uretprobe-nop         (64 cpus):   42.390 ± 0.922M/s  (  0.662M/s/cpu)
uretprobe-nop         (80 cpus):   47.554 ± 2.411M/s  (  0.594M/s/cpu)

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241024044159.3156646-3-andrii@kernel.org
2024-10-30 22:42:19 +01:00
Andrii Nakryiko
2bf8e5acef uprobes: allow put_uprobe() from non-sleepable softirq context
Currently put_uprobe() might trigger mutex_lock()/mutex_unlock(), which
makes it unsuitable to be called from more restricted context like softirq.

Let's make put_uprobe() agnostic to the context in which it is called,
and use work queue to defer the mutex-protected clean up steps.

RB tree removal step is also moved into work-deferred callback to avoid
potential deadlock between softirq-based timer callback, added in the
next patch, and the rest of uprobe code.

We can rework locking altogher as a follow up, but that's significantly
more tricky, so warrants its own patch set. For now, we need to make
sure that changes in the next patch that add timer thread work correctly
with existing approach, while concentrating on SRCU + timeout logic.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20241024044159.3156646-2-andrii@kernel.org
2024-10-30 22:42:19 +01:00
Jiri Olsa
4d756095d3 uprobe: Add support for session consumer
This change allows the uprobe consumer to behave as session which
means that 'handler' and 'ret_handler' callbacks are connected in
a way that allows to:

  - control execution of 'ret_handler' from 'handler' callback
  - share data between 'handler' and 'ret_handler' callbacks

The session concept fits to our common use case where we do filtering
on entry uprobe and based on the result we decide to run the return
uprobe (or not).

It's also convenient to share the data between session callbacks.

To achive this we are adding new return value the uprobe consumer
can return from 'handler' callback:

  UPROBE_HANDLER_IGNORE
  - Ignore 'ret_handler' callback for this consumer.

And store cookie and pass it to 'ret_handler' when consumer has both
'handler' and 'ret_handler' callbacks defined.

We store shared data in the return_consumer object array as part of
the return_instance object. This way the handle_uretprobe_chain can
find related return_consumer and its shared data.

We also store entry handler return value, for cases when there are
multiple consumers on single uprobe and some of them are ignored and
some of them not, in which case the return probe gets installed and
we need to have a way to find out which consumer needs to be ignored.

The tricky part is when consumer is registered 'after' the uprobe
entry handler is hit. In such case this consumer's 'ret_handler' gets
executed as well, but it won't have the proper data pointer set,
so we can filter it out.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241018202252.693462-3-jolsa@kernel.org
2024-10-23 20:52:27 +02:00
Jiri Olsa
da09a9e0c3 uprobe: Add data pointer to consumer handlers
Adding data pointer to both entry and exit consumer handlers and all
its users. The functionality itself is coming in following change.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241018202252.693462-2-jolsa@kernel.org
2024-10-23 20:52:27 +02:00
Oleg Nesterov
6c74ca7aa8 uprobes: fold xol_take_insn_slot() into xol_get_insn_slot()
After the previous change xol_take_insn_slot() becomes trivial, kill it.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241001142503.GA13633@redhat.com
2024-10-07 09:28:45 +02:00
Oleg Nesterov
7a166094bd uprobes: kill xol_area->slot_count
Add the new helper, xol_get_slot_nr() which does
find_first_zero_bit() + test_and_set_bit().

xol_take_insn_slot() can wait for the "xol_get_slot_nr() < UINSNS_PER_PAGE"
event instead of "area->slot_count < UINSNS_PER_PAGE".

So we can kill area->slot_count and avoid atomic_inc() + atomic_dec(), this
simplifies the code and can slightly improve the performance.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20241001142458.GA13629@redhat.com
2024-10-07 09:28:45 +02:00
Oleg Nesterov
c16e2fdd74 uprobes: deny mremap(xol_vma)
kernel/events/uprobes.c assumes that xol_area->vaddr is always correct but
a malicious application can remap its "[uprobes]" vma to another adress to
confuse the kernel. Introduce xol_mremap() to make this impossible.

With this change utask->xol_vaddr in xol_free_insn_slot() can't be invalid,
we can turn the offset check into WARN_ON_ONCE(offset >= PAGE_SIZE).

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144258.GA9492@redhat.com
2024-10-07 09:28:45 +02:00
Oleg Nesterov
c5356ab1db uprobes: pass utask to xol_get_insn_slot() and xol_free_insn_slot()
Add the "struct uprobe_task *utask" argument to xol_get_insn_slot() and
xol_free_insn_slot(), their callers already have it so we can avoid the
unnecessary dereference and simplify the code.

Kill the "tsk" argument of xol_free_insn_slot(), it is always current.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144253.GA9487@redhat.com
2024-10-07 09:28:45 +02:00
Oleg Nesterov
1cee988c1d uprobes: move the initialization of utask->xol_vaddr from pre_ssout() to xol_get_insn_slot()
This simplifies the code and makes xol_get_insn_slot() symmetric with
xol_free_insn_slot() which clears utask->xol_vaddr.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144248.GA9483@redhat.com
2024-10-07 09:28:45 +02:00
Oleg Nesterov
6ffe8c7d87 uprobes: simplify xol_take_insn_slot() and its caller
The do / while (slot_nr >= UINSNS_PER_PAGE) loop in xol_take_insn_slot()
makes no sense, the checked condition is always true. Change this code
to use the "for (;;)" loop, this way we do not need to change slot_nr if
test_and_set_bit() fails.

Also, kill the unnecessary xol_vaddr != NULL check in xol_get_insn_slot(),
xol_take_insn_slot() never returns NULL.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144244.GA9480@redhat.com
2024-10-07 09:28:44 +02:00
Oleg Nesterov
430af825ba uprobes: kill the unnecessary put_uprobe/xol_free_insn_slot in uprobe_free_utask()
If pre_ssout() succeeds and sets utask->active_uprobe and utask->xol_vaddr
the task must not exit until it calls handle_singlestep() which does the
necessary put_uprobe() and xol_free_insn_slot().

Remove put_uprobe() and xol_free_insn_slot() from uprobe_free_utask(). With
this change xol_free_insn_slot() can't hit xol_area/utask/xol_vaddr == NULL,
we can kill the unnecessary checks checks and simplify this function more.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144239.GA9475@redhat.com
2024-10-07 09:28:44 +02:00
Oleg Nesterov
c7b4133c48 uprobes: sanitiize xol_free_insn_slot()
1. Clear utask->xol_vaddr unconditionally, even if this addr is not valid,
   xol_free_insn_slot() should never return with utask->xol_vaddr != NULL.

2. Add a comment to explain why do we need to validate slot_addr.

3. Simplify the validation above. We can simply check offset < PAGE_SIZE,
   unsigned underflows are fine, it should work if slot_addr < area->vaddr.

4. Kill the unnecessary "slot_nr >= UINSNS_PER_PAGE" check, slot_nr must
   be valid if offset < PAGE_SIZE.

The next patches will cleanup this function even more.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144235.GA9471@redhat.com
2024-10-07 09:28:44 +02:00
Oleg Nesterov
b302d5a6ff uprobes: don't abuse get_utask() in pre_ssout() and prepare_uretprobe()
handle_swbp() calls get_utask() before prepare_uretprobe() or pre_ssout()
can be called, they can simply use current->utask which can't be NULL.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240929144230.GA9468@redhat.com
2024-10-07 09:28:44 +02:00
Andrii Nakryiko
87195a1ee3 uprobes: switch to RCU Tasks Trace flavor for better performance
This patch switches uprobes SRCU usage to RCU Tasks Trace flavor, which
is optimized for more lightweight and quick readers (at the expense of
slower writers, which for uprobes is a fine tradeof) and has better
performance and scalability with number of CPUs.

Similarly to baseline vs SRCU, we've benchmarked SRCU-based
implementation vs RCU Tasks Trace implementation.

SRCU
====
uprobe-nop      ( 1 cpus):    3.276 ± 0.005M/s  (  3.276M/s/cpu)
uprobe-nop      ( 2 cpus):    4.125 ± 0.002M/s  (  2.063M/s/cpu)
uprobe-nop      ( 4 cpus):    7.713 ± 0.002M/s  (  1.928M/s/cpu)
uprobe-nop      ( 8 cpus):    8.097 ± 0.006M/s  (  1.012M/s/cpu)
uprobe-nop      (16 cpus):    6.501 ± 0.056M/s  (  0.406M/s/cpu)
uprobe-nop      (32 cpus):    4.398 ± 0.084M/s  (  0.137M/s/cpu)
uprobe-nop      (64 cpus):    6.452 ± 0.000M/s  (  0.101M/s/cpu)

uretprobe-nop   ( 1 cpus):    2.055 ± 0.001M/s  (  2.055M/s/cpu)
uretprobe-nop   ( 2 cpus):    2.677 ± 0.000M/s  (  1.339M/s/cpu)
uretprobe-nop   ( 4 cpus):    4.561 ± 0.003M/s  (  1.140M/s/cpu)
uretprobe-nop   ( 8 cpus):    5.291 ± 0.002M/s  (  0.661M/s/cpu)
uretprobe-nop   (16 cpus):    5.065 ± 0.019M/s  (  0.317M/s/cpu)
uretprobe-nop   (32 cpus):    3.622 ± 0.003M/s  (  0.113M/s/cpu)
uretprobe-nop   (64 cpus):    3.723 ± 0.002M/s  (  0.058M/s/cpu)

RCU Tasks Trace
===============
uprobe-nop      ( 1 cpus):    3.396 ± 0.002M/s  (  3.396M/s/cpu)
uprobe-nop      ( 2 cpus):    4.271 ± 0.006M/s  (  2.135M/s/cpu)
uprobe-nop      ( 4 cpus):    8.499 ± 0.015M/s  (  2.125M/s/cpu)
uprobe-nop      ( 8 cpus):   10.355 ± 0.028M/s  (  1.294M/s/cpu)
uprobe-nop      (16 cpus):    7.615 ± 0.099M/s  (  0.476M/s/cpu)
uprobe-nop      (32 cpus):    4.430 ± 0.007M/s  (  0.138M/s/cpu)
uprobe-nop      (64 cpus):    6.887 ± 0.020M/s  (  0.108M/s/cpu)

uretprobe-nop   ( 1 cpus):    2.174 ± 0.001M/s  (  2.174M/s/cpu)
uretprobe-nop   ( 2 cpus):    2.853 ± 0.001M/s  (  1.426M/s/cpu)
uretprobe-nop   ( 4 cpus):    4.913 ± 0.002M/s  (  1.228M/s/cpu)
uretprobe-nop   ( 8 cpus):    5.883 ± 0.002M/s  (  0.735M/s/cpu)
uretprobe-nop   (16 cpus):    5.147 ± 0.001M/s  (  0.322M/s/cpu)
uretprobe-nop   (32 cpus):    3.738 ± 0.008M/s  (  0.117M/s/cpu)
uretprobe-nop   (64 cpus):    4.397 ± 0.002M/s  (  0.069M/s/cpu)

Peak throughput for uprobes increases from 8 mln/s to 10.3 mln/s
(+28%!), and for uretprobes from 5.3 mln/s to 5.8 mln/s (+11%), as we
have more work to do on uretprobes side.

Even single-thread (no contention) performance is slightly better: 3.276
mln/s to 3.396 mln/s (+3.5%) for uprobes, and 2.055 mln/s to 2.174 mln/s
(+5.8%) for uretprobes.

We also select TASKS_TRACE_RCU for UPROBES in Kconfig due to the new
dependency.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20240910174312.3646590-1-andrii@kernel.org
2024-10-07 09:28:42 +02:00
Oleg Nesterov
34820304cc uprobes: fix kernel info leak via "[uprobes]" vma
xol_add_vma() maps the uninitialized page allocated by __create_xol_area()
into userspace. On some architectures (x86) this memory is readable even
without VM_READ, VM_EXEC results in the same pgprot_t as VM_EXEC|VM_READ,
although this doesn't really matter, debugger can read this memory anyway.

Link: https://lore.kernel.org/all/20240929162047.GA12611@redhat.com/

Reported-by: Will Deacon <will@kernel.org>
Fixes: d4b3b6384f ("uprobes/core: Allocate XOL slots for uprobes use")
Cc: stable@vger.kernel.org
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-09-30 08:19:11 +09:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZu1BBwAKCRDdBJ7gKXxA
 jlWNAQDYlqQLun7bgsAN4sSvi27VUuWv1q70jlMXTfmjJAvQqwD/fBFVR6IOOiw7
 AkDbKWP2k0hWPiNJBGwoqxdHHx09Xgo=
 =s0T+
 -----END PGP SIGNATURE-----

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Oleg Nesterov
2abbcc099e uprobes: turn xol_area->pages[2] into xol_area->page
Now that xol_mapping has its own ->fault() method we no longer need
xol_area->pages[1] == NULL, we need a single page.

Link: https://lkml.kernel.org/r/20240911131437.GC3448@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 01:07:01 -07:00
Oleg Nesterov
6d27a31ef1 uprobes: introduce the global struct vm_special_mapping xol_mapping
Currently each xol_area has its own instance of vm_special_mapping, this
is suboptimal and ugly.  Kill xol_area->xol_mapping and add a single
global instance of vm_special_mapping, the ->fault() method can use
area->pages rather than xol_mapping->pages.

As a side effect this fixes the problem introduced by the recent commit
223febc6e5 ("mm: add optional close() to struct vm_special_mapping"), if
special_mapping_close() is called from the __mmput() paths, it will use
vma->vm_private_data = &area->xol_mapping freed by uprobe_clear_state().

Link: https://lkml.kernel.org/r/20240911131407.GB3448@redhat.com
Fixes: 223febc6e5 ("mm: add optional close() to struct vm_special_mapping")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Sven Schnelle <svens@linux.ibm.com>
Closes: https://lore.kernel.org/all/yt9dy149vprr.fsf@linux.ibm.com/
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 01:07:01 -07:00
Oleg Nesterov
ed8d5b0ce1 Revert "uprobes: use vm_special_mapping close() functionality"
This reverts commit 08e28de116.

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

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