105 Commits
Author SHA1 Message Date
Linus Torvalds c5fd5e67c7 Merge tag 'mm-stable-2026-10-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:

 - "selftests/mm: improve khugepaged coverage" (Kiryl Shutsemau):

   Give khugepaged a proper workout. Extend the tests to all supported
   mTHP orders, check exactly which windows collapsed, and make scan
   completion deterministic. Race collapse against faults, pinning, fork
   and remap; verify that the contents survive.

   Add coverage for whole-page-table zaps and memory pressure too.

 - "selftests/mm: separate GUP microbenchmarking from functional testing"
   (Sarthak Sharma):

   Untangle GUP benchmarking from correctness testing. Move the
   benchmark into tools/mm, add a standalone harness-based GUP selftest,
   and move shared helpers into tools/lib/mm. Give each tool one job
   instead of mixing timing measurements with correctness checks.

   Cover the mapping, pinning and batch-size combinations explicitly.

 - "mm: Switch device DAX to section-based vmemmap optimization" (Muchun
   Song):

   Apply section-based vmemmap optimization to device DAX. Rework the
   backing metadata layout to save memory while preserving the handling
   of device memory hotplug and its different alignment and lifetime
   requirements.

 - "mm: Introduce section-based vmemmap optimization for HugeTLB"
   (Muchun Song):

   Cut the memory consumed by HugeTLB's struct page array with
   section-based vmemmap optimization. Arrange the metadata so large
   huge pages need fewer backing pages, while keeping initialization,
   teardown and the various hugepage configurations straight.

 - "mm/huge_memory: clean up and decouple the anon and file split
   helpers" (Kairui Song):

   Separate anonymous and file-backed folio splitting, which have rather
   different locking and bookkeeping requirements. Move the work into
   separate helpers, drop dead checks and tidy swap-cache handling. Fix
   error paths, including one that could leave a folio frozen.

   Keep the swap cache cases separate from file-cache splitting.

 - "mm: Unconditional per-VMA locks and cleanups" (Dave Hansen):

   Make per-VMA locking unconditional and clean up the old conditional
   code around it. This removes configuration-dependent plumbing and
   lets callers depend on one locking model rather than carrying both
   cases along.

 - "memcg: remove the v1 soft limit" (Shakeel Butt):

   Remove the old cgroup v1 memory soft-limit machinery. This has long
   since been superseded by the newer memory-control interfaces; hauling
   around a separate reclaim scheme for it no longer buys us much.

 - "read proc/pid/smaps_rollup under per-vma lock" (Suren Baghdasaryan):

   Read /proc/PID/smaps_rollup using per-VMA locks where possible,
   rather than holding mmap_lock across the entire walk. Retain the
   contention fallback and add tearing tests. This considerably reduces
   latency when another thread is busy changing its mappings.

 - "mm/damon: introduce data access-as-a-data attribute" (SJ Park):

   Teach DAMON to expose memory access observations as data attributes,
   making them available to the probe and filtering machinery. Extend
   the interfaces, documentation and tests so the new information can be
   used rather than merely collected.

 - "Remove PG_private by using page/folio->private checks instead" (Zi
   Yan):

   Get rid of PG_private and use the folio's private pointer to say
   whether private data is attached. Convert the filesystem users,
   including erofs, f2fs and md, and clean up the old accessors and
   flags. There are a few special cases, notably swapcache and hugetlb,
   which need explicit care.

 - "mm: make userland page table freeing RCU-safe" (Lorenzo Stoakes):

   Make freeing userspace page tables safe against RCU readers. Sort out
   the page-table lifetime and locking rules so walkers cannot stumble
   over freed tables while mappings are being torn down.

 - "make unused huge shrinker memcg aware" (Qi Zheng):

   Make shmem's unused-huge-folio shrinker aware of memory cgroups, so
   reclaim can find those folios under the right memcg. Wire up the
   per-memcg tracking and its lifetime rules, and give the shrinklist
   its own lockdep class to avoid spurious dependency reports.

 - "mm: Drop pxd_ERROR()" (Anshuman Khandual):

   Remove the old pxd_ERROR() page-table checks and their
   architecture-specific baggage. Simplify the common page-table
   interfaces and callers now that these checks no longer serve a
   useful purpose.

 - "memcg: group struct fields by access pattern" (Shakeel Butt):

   Rearrange memcg's hot and cold fields according to how they're
   actually accessed. Keep frequently updated counters and their
   neighboring state from fighting over cachelines and reduce needless
   cacheline traffic.

 - "mm/damon/core: fix the size charged for a filter-trimmed region"
   (Donggeun Yoo):

   Fix DAMOS quota accounting when a filter trims a monitoring region.
   Charge only the part left after filtering, not the original region,
   and add KUnit coverage. Previously the excluded memory could eat into
   the quota and make schemes run more slowly than requested.

 - "mm/damon: add kunit and selftests for probes and probe weights" (SJ
   Park):

   Add more tests for DAMON probes and their weights, including
   validation and the results reported to userspace. This is mostly
   about catching regressions in the newer probe infrastructure before
   they become harder to diagnose.

 - "mm: memcontrol: constify the read side of the read side of the memcg
   API" (Tal Zussman):

   Mark the read-only parts of the memcg interface const, from folio and
   lruvec accessors to counters and swap helpers. Most of this is
   mechanical, but it makes the contracts clearer and lets the compiler
   catch accidental writes.

 - "mm/damon/vaddr: support {prep,apply}_probes" (SJ Park):

   Support the new prepare/apply probe operations in DAMON's
   virtual-address backend. This brings vaddr monitoring into line with
   the probe infrastructure and makes the added probe types useful there
   too.

 - "mm/mglru: clean up folio counters and flag usage" (Kairui Song):

   Simplify MGLRU's folio counters and flag handling. Remove redundant
   accounting paths and make the state transitions easier to follow
   without changing the intended reclaim policy.

 - "arch, mm/execmem: resolve confusion about set_direct_map_valid_noflush()"
   (Mike Rapoport (Microsoft)):

   Clarify and straighten out the set_direct_map_valid_noflush()
   interface across architectures and execmem. Make the requested
   mapping changes and the callers' expectations agree, rather than
   relying on subtly different architecture behavior.

 - "mm: zswap: free cold writeback folios promptly" (Alexandre Ghiti):

   Free zswap writeback folios as soon as their disk write completes.
   They are cold temporary buffers, so putting them on the LRU only
   makes reclaim rediscover them later. Extend swap-cache dropbehind and
   let zswap keep these folios off the LRU altogether.

 - "mm: gup: cleanup gup_fast call chain" (Aristeu Rozanski):

   Clean up the GUP-fast call chain and simplify how the fast-path
   helpers pass their arguments and results around. Keep the page-pin
   behavior the same while making the call sequence easier to maintain.

 - "mm: optimize zone-device memmap initialization" (Li Zhe):

   Speed up initialization of zone-device struct pages. Avoid redundant
   work when setting up large device-memory ranges, where touching every
   descriptor can get expensive.

 - "mm/zswap: shrink zswap_entry via a pool id" (Jianyue Wu):

   Reduce the size of zswap_entry by storing a compact pool identifier
   instead of a full pointer. Keep the pool lookup and lifetime handling
   correct while saving per-entry metadata.

 - "mm/damon: support access monitoring of hugetlb-backed memory"
   (Krishna Iyer):

   Let DAMON monitor hugetlb-backed memory too. Extend the relevant
   access checks and add coverage so those mappings no longer fall
   through a hole in the monitoring machinery.

 - "mm/execmem: fixes and cleanups for the ROX cache" (Mike Rapoport):

   Tidy execmem's read-only-executable cache and fix its handling of the
   awkward allocation and release cases. The aim is to make the cache's
   ownership and permission transitions more predictable.

 - "zsmallc: remove old object read API" (Sergey Senozhatsky):

   Drop zsmalloc's old object-read API and move its remaining users to
   the supported access mechanism. This removes a duplicate interface
   which we no longer need.

 - "mm/mempolicy: stop copying state in the interleave paths" (Gregory
   Price):

   Stop copying mempolicy state in the interleave paths when a reference
   to the existing policy will do. This avoids extra work and makes the
   ownership rules less obscure.

 - "mm/mglru: speed up inc_min_seq() and fix cold/hot inversions" (Barry
   Song):

   Make MGLRU's generation advancement cheaper and fix cases where cold
   and hot folios end up in the wrong order. Adjust the counter and list
   handling so reclaim doesn't keep passing over the better eviction
   candidates.

 - "mm: Fix MF_DELAYED handling on memory failure" (Lisa Wang):

   Treat MF_DELAYED as a partially completed memory-failure operation,
   not an outright failure. Propagate that result correctly through
   shmem and the generic handler, fix the extra-reference accounting,
   and add tests for the resulting SIGBUS behavior.

 - "tools/mm/page_owner_sort: fix --sort, add module filter, improve
   usage" (Ye Liu):

   Fix page_owner_sort's --sort handling, add module-based filtering and
   make the usage output more helpful. This makes the tool less
   frustrating when tracking down who is holding on to pages.

 - "mm/damon: move damos filter range arguments validation to core" (SJ
   Park):

   Move DAMOS filter range validation into the core, where all callers
   can share it. Also close the sysfs read-twice races which could pass
   inconsistent ranges, and add tests for invalid input.

 - "mm/damon: misc cleanups" (Zenghui Yu):

   Clean up a collection of small DAMON rough edges in the core,
   interfaces and tests. No large behavior change here, just simpler
   code and fewer opportunities for confusion.

 - "mm/damon: cleanup code, add test cases, and update guidances in
   docs" (SJ Park):

   Clean up DAMON's core and interfaces, add missing test cases and
   bring the documentation into line with the code. These changes should
   make the newer facilities easier to understand and maintain.

 - "mm/damon: introduce hugepage_size probe filter" (SJ Park):

   Add a DAMON probe filter for hugepage size. Let users select a range
   of folio sizes through sysfs, validate the range and document the new
   interface, so monitoring can concentrate on memory backed by the
   desired hugepage sizes.

 - "selftests/mm: pagemap_ioctl test fixes and cleanups" (Zenghui Yu):

   Fix some pagemap ioctl test assumptions and clean up their setup and
   reporting. Make failures point to the operation that went wrong
   rather than to test harness bookkeeping.

 - "mm: avoid large folio splits when swap is unavailable" (Johannes
   Weiner):

   Avoid splitting large folios merely to attempt swap when no swap
   space is available. There is little point paying for an expensive
   split when reclaim cannot actually swap the resulting pages out.

 - "mm: workingset: fix the shadow node budget under MGLRU" (Hui Zhu):

   Fix the workingset shadow-node budget with MGLRU enabled. Keep the
   shadow entries within the intended limits so refault tracking does
   not quietly consume more metadata than it should.

 - "selftests/mm: TAP output and global-state fixes" (Song Hu):

   Fix selftests which produce misleading TAP output or fail to restore
   global settings after a run. A test ought to leave the system as it
   found it, particularly when a whole suite follows behind.

 - "mm: remove page_swap_entry()" (Tal Zussman):

   Remove page_swap_entry() and convert its remaining users to the folio
   and swap-entry helpers. Lose an old page-level interface and make the
   swap paths a little more consistent.

 - "mm: refactor zonelist constructors and iterators" (Gregory Price):

   Refactor the zonelist construction and walk helpers to reduce
   duplicated logic. Keep the allocation ordering rules intact while
   making it clearer how zones are selected.

 - "mm: kmemleak: batch the struct page scan" (Breno Leitao):

   Scan adjacent struct pages in batches instead of taking kmemleak_lock
   once for every single page. This preserves scan coverage and the
   lock-hold bound, while cutting overhead substantially on debug
   kernels.

 - "mm/damon: misc improvements in tests and documents" (Zenghui Yu):

   Fix some DAMON selftests which leave kdamond running or fail under
   Python safe-path mode, and improve the KUnit coverage and
   documentation. Nothing especially glamorous, but these are worth
   doing.

 - "mm/damon: introduce probe_hits_wsum DAMOS core filter" (SJ Park):

   Add a DAMOS core filter using weighted probe-hit counts. This gives
   schemes another way to select regions based on what the monitoring
   probes observed.

 - "mm/mglru: fix ineffective memory protection for non-kswapd reclaim"
   (Ridong Chen):

   Fix MGLRU's memory protection handling for reclaim outside kswapd.
   The protection settings weren't having the intended effect in these
   paths, leaving protected memory more exposed than requested.

 - "mm/damon: improve readability, clarity and test coverage" (SJ Park):

   Simplify a handful of DAMON core helpers, clarify their behavior and
   expand test coverage. There are no intended userspace-visible changes
   in this batch.

 - "mm: replace PF_KCOMPACTD/PF_KSWAPD with kthread_func()" (Kefeng
   Wang):

   Stop identifying reclaim and compaction workers through the PF_KSWAPD
   and PF_KCOMPACTD task flags. Use their kthread functions instead and
   remove the redundant flag plumbing.

 - "mm/hugetlb: fix surplus accounting and availability checks during
   demotion" (Longlong Xia):

   Fix HugeTLB surplus accounting and availability checks when demoting
   huge pages. Keep the counters and reservation decisions consistent as
   one huge page turns into several smaller ones.

 - "mm/damon: add kunit tests for probe_hits handling and probe params
   validation" (Jason Angelov):

   Add KUnit tests for DAMON probe-hit handling and invalid probe
   parameters. These cover edge cases that were too easy to miss in
   ordinary monitoring tests.

 - "mm/damon: fix misc bugs in kunit, quota goals and sysfs refresh_ms"
   (SJ Park):

   Fix a few DAMON bugs in KUnit tests, quota-goal handling and the
   sysfs refresh interval. Small fixes, but the incorrect results and
   control behavior were real.

 - "mm: zswap: optimize zswap invalidate and store" (Kefeng Wang):

   Simplify zswap's invalidate and store paths to avoid avoidable
   lookups and work. Keep the entry lifetime rules intact while making
   those frequent operations cheaper.

 - "mm: replace custom ratelimiting logic" (Pedro Falcato):

   Replace hand-rolled MM rate limiting with the common kernel helpers.
   There is no need to maintain another local version of the same
   mechanism.

 - "mm/vmalloc: minor cleanups" (Ye Liu):

   Tidy some vmalloc initialization and reporting code, and pull
   duplicated vmap-area insertion work into a helper. No functional
   changes are intended.

 - "mm/mglru: clean up isolate_folios for readability and clarity"
   (Ridong Chen):

   Clean up MGLRU's isolate_folios() so the decisions are easier to read
   and verify. Keep reclaim behavior unchanged while removing
   unnecessary twists in the control flow.

 - "Catch automatic storage in IDA and Maple Tree definitions" (Yury
   Norov):

   Catch IDA and maple-tree definitions placed in automatic storage
   where the lifetime rules are wrong or easy to get wrong. Add checks
   so such mistakes are harder to slip through unnoticed.

 - "mm, swap: some random fixes and cleanups" (Kemeng Shi):

   Fix and simplify a few unrelated swap paths, removing redundant work
   and tidying up error handling. A small collection of things which
   were better fixed than left lying around.

 - "mm/page_io: folio conversion cleanups" (Tal Zussman):

   Finish some page-to-folio conversions in swap I/O, removing obsolete
   wrappers and using folio operations consistently. The I/O behavior is
   intended to remain the same.

 - "mm/swap: skip empty clusters in the swapoff scan" (Youngjun Park):

   Skip empty swap clusters during swapoff instead of walking slots
   which have nothing to release. This avoids pointless work on sparsely
   used swap devices.

 - "mm: trace: decode architecture-specific VMA flags" (Meijing Zhao):

   Teach the VMA trace output to decode architecture-specific flags,
   rather than leaving them as unexplained bits. That should make
   tracing a good deal more useful when debugging unusual mappings.

 - "mm, swap: don't spin on a bad swap entry" (Breno Leitao):

   Stop repeatedly retrying a swap entry which is already known to be
   bad. Make the error path terminate cleanly instead of wasting CPU
   chasing an entry that cannot be used.

 - "mm/page_isolation: fix UBSAN shift-out-of-bounds in
   isolate_single_pageblock" (Qi Xi):

   Fix an out-of-range shift in isolate_single_pageblock() and tighten
   its associated boundary handling. UBSAN found the issue; the result
   should be more robust pageblock isolation.

 - "mm: khugepaged: fix tracepoint UAF" (Vernon Yang):

   Fix a use-after-free in khugepaged tracepoint handling. Make sure the
   information recorded by tracing stays valid for as long as the trace
   event needs it.

 - "mm/damon: fix DAMOS bugs in core, paddr and vaddr" (SJ Park):

   Fix several DAMOS problems across the core and physical- and
   virtual-address backends. The changes close error cases and bring the
   implementations back into agreement.

 - "mm/hugetlb_cgroup: move the per-node usage along with the folio"
   (Hongfu Li):

   Move HugeTLB per-node usage accounting when folios migrate between
   nodes or are reparented to another cgroup. Otherwise numa_stat can
   retain stale charges and even underflow when the folio is freed.

 - "docs/core-api: memory-allocation: add k[mz]alloc_obj() and clarify
   kmalloc" (Mike Rapoport):

   Document the typed k[mz]alloc_obj() allocation helpers and clear up
   some kmalloc guidance. Make it easier for callers to choose the right
   interface.

 - "selftests/mm: Validate selections and scope memfd_secret setup"
   (Tianyi Chen):

   Check selftest selections before running and confine memfd_secret
   setup to the cases that actually need it. Avoid confusing failures
   caused by the test harness itself.

 - "mm/damon: move zero damos quota target_value handling to the core
   layer" (SJ Park):

   Handle a zero DAMOS quota goal target in the core rather than making
   each user of the interface invent its own rule. Keep quota decisions
   consistent across callers.

 - "mm/damon: Introduce a huge page collapsing mechanism using auto
   tuning" (Asier Gutierrez):

   Add an auto-tuned DAMON mechanism for collapsing huge pages. Use
   monitoring feedback to decide when collapse is worthwhile rather than
   forcing one fixed policy onto every workload.

 - "kmemleak: fix stale documentation and raise the verbose default"
   (Breno Leitao):

   Bring the kmemleak documentation up to date and require a third
   confirming scan before verbose kernels print a suspected leak. The
   extra scan helps suppress transient false positives in noisy debug
   builds.

 - "mm/memory: improve insert_pages() error handling" (Avi Weiss):

   Tighten insert_pages() error handling so partial failures are
   reported and cleaned up consistently. The caller should not have to
   guess how far the operation got.

 - "mm/damon: allow NULL or unstarted damon_ctx parameter for
   damon_call()" (SJ Park):

   Make damon_call() handle NULL and not-yet-started contexts safely.
   Simplify the rules for callers and avoid an indefinite wait on an
   invalid state.

 - "mm/damon: introduce pgidle_set probe filter type" (SJ Park):

   Add a pgidle_set DAMON probe filter, giving monitoring users another
   way to select pages by their idle-tracking state. Wire it through the
   filter interfaces and tests.

 - "mm/damon/core: remove unused helper functions" (Cheng-Han Wu):

   Remove DAMON core helpers which no longer have callers. Keep the API
   surface smaller rather than retaining dead code just in case.

 - "mm: stop calling pmd_folio() on special PMDs" (Gregory Price):

   Avoid calling pmd_folio() on special PMD mappings that have no struct
   page. The old assumption could fault in procfs walkers; use the
   normal-folio checks and handle those mappings properly.

 - "mm: remove three unused helpers from mm.h" (Tal Zussman):

   Remove three unused helpers from mm.h. Fewer obsolete interfaces for
   the next person to stumble over.

 - "mm/damon: improvements in efficiency, error handling, documents"
   (Liew Rui Yan):

   Skip needless DAMOS quota work once the quota is full, propagate a
   missing sysfs error and tidy a couple of comments. The ignored error
   could make a monitoring-start request appear successful when it
   wasn't.

 - "docs/mm/damon/design: add explanation of nr_snapshots" (Liew Rui
   Yan):

   Explain DAMON's nr_snapshots accounting in the design documentation
   and straighten out the associated terminology. Make it clearer what
   users should expect from that counter.

 - "selftests/cgroup: fixes for test_zswap on single core VM" (Wilson
   Felipe Pereira):

   Fix two test_zswap failures on single-CPU VMs. Wait for the exiting
   child's cgroup to become unpopulated before reconfiguring it, and
   avoid another test assumption which breaks under constrained
   scheduling.

 - "docs/ksm: fix advisor documentation and comment" (Jinjiang Tu):

   Correct the KSM advisor documentation and a misleading code comment.
   Keep the description aligned with how the advisor actually works.

 - "Fix bugs in HugeTLB allocation when mem_cgroup_charge_hugetlb()
   fails" (Ackerley Tng):

   Fix HugeTLB allocation cleanup when the memcg charge fails. Make sure
   failure exits undo what was allocated rather than leaving stale
   accounting or resources behind.

 - "mm, memcg: fix memory.peak reset clobbering other fds' watermark"
   (Ridong Chen):

   Fix memory.peak reset handling so resetting one file descriptor
   doesn't overwrite the watermark kept for another. Keep those per-open
   measurements independent as intended.

 - "mm: reject zone device folios in more folio walkers" (Gregory
   Price):

   Reject zone-device folios in page walkers that cannot safely handle
   them. Extend the existing checks rather than assuming every folio has
   ordinary system-memory backing.

 - "percpu: remove code with no effect" (Sang-Heon Jeon):

   Remove a few pieces of percpu code which no longer do anything. There
   is no reason to keep maintaining dead paths.

* tag 'mm-stable-2026-10-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (539 commits)
  mm: shmem: assign a lock class to the unused huge shrinklist
  mm: vmscan: put rotation-missed folios at the LRU tail
  mm: kmemleak: scan the struct page array in MAX_SCAN_SIZE batches
  mm: kmemleak: move the struct page scan into a helper
  mm/damon: document that a zero sample_interval is accepted
  mm/damon: fix typos in comments
  mm/damon/sysfs: propagate damon_call() error in turn_damon_on
  mm/damon/core: skip quota score setup when the quota is full
  mm/damon/tests/core-kunit: test the size charged for a filter-trimmed region
  mm/damon/core: charge only the part of a region the filter left
  mm: disallow raw PFN mappings of huge/shared zeropage
  selftests/mm: zap whole PTE tables in the khugepaged race harness
  selftests/mm: add memory-pressure threads to the khugepaged race harness
  selftests/mm: race the collapse of windows with holes
  selftests/mm: add khugepaged race harness
  selftests/mm: check that one khugepaged pass collapses one window
  selftests/mm: run every supported collapse order by default
  selftests/mm: cover a shared-source collapse write race
  selftests/mm: parameterize the mixed-source collapse case by source order
  selftests/mm: add order-parameterized khugepaged collapse cases
  ...
2026-10-23 07:42:11 -10:00
Zi Yan a0319334a9 perf/ring_buffer: stop using PG_private as AUX page high-order marker
A high-order AUX page sets PG_private on its first page and stores the
order in first_page->private.  Stop using PG_private and check
first_page->private for AUX page order only in the ring buffer and its
users.  This is fine because page->private is 0 for order-0 AUX pages,
matching the page order.

It prepares for a future commit that remove PG_private.

No functional change intended.

Link: https://lore.kernel.org/20260920-remove-pg_private-v5-2-bb68b6a21869@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
2026-10-08 22:55:14 -07:00
Ian Rogers b9d1fdc6f4 perf: Replace perf_event_header__init_id with full header init
perf_iterate_sb() invokes its callback for each matching perf_event on
the CPU and task context, passing a shared caller-allocated event
structure.

perf_event_header__init_id() mutated header->size in place by adding
event->id_header_size, requiring sideband output callbacks to save and
restore header fields across iterations. Three sideband callbacks failed
to save and restore header.size around perf_event_header__init_id():
 - perf_event_ksymbol_output()
 - perf_event_bpf_output()
 - perf_event_text_poke_output()

When multiple events with attr.ksymbol, attr.bpf_event, or
attr.text_poke and sample_id_all are active on the same CPU, each
subsequent event receives a record whose header.size is inflated by all
preceding events' id_header_size values while only a single id_sample is
written, leaving uninitialized ring-buffer bytes at the end of the
record and causing userspace perf to fail with -EFAULT ("Bad address")
when parsing the sample_id trailer.

Similarly, perf_event_mmap_output() set PERF_RECORD_MISC_MMAP_BUILD_ID
in mmap_event->event_id.header.misc when event->attr.build_id was
enabled, but only saved and restored header.size and header.type. If an
event with attr.build_id was followed by an event with attr.mmap2 and
!attr.build_id, the second event received PERF_RECORD_MISC_MMAP_BUILD_ID
in header.misc while its payload contained maj/min/ino/ino_generation
instead of a build ID.

Rather than splitting header initialization between callers and output
callbacks and saving/restoring mutated header fields, replace
perf_event_header__init_id() with perf_event_header__init(), which
initializes header->type, header->misc, and header->size alongside the
sample_id fields on each invocation.

Fixes: 76193a9452 ("perf, bpf: Introduce PERF_RECORD_KSYMBOL")
Fixes: 6ee52e2a3f ("perf, bpf: Introduce PERF_RECORD_BPF_EVENT")
Fixes: e17d43b93e ("perf: Add perf text poke event")
Fixes: 88a16a1309 ("perf: Add build id data in mmap2 event")
Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260929222332.973435-1-irogers@google.com
Cc: stable@vger.kernel.org
2026-10-01 14:02:06 +02:00
Leo Yan 8a7f5b5e86 perf/core: Skip empty AUX records with only format flags
perf_aux_output_end() emits a PERF_RECORD_AUX when the recorded size is
nonzero or when any flag other than PERF_AUX_FLAG_OVERWRITE is set.

PMU format flags describe how an AUX payload is encoded. TRBE driver
sets PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW for raw trace buffers, causing
an AUX record to be emitted even when no trace data.

This is noticeable when tracing a task with strace. Ptrace stops
repeatedly end empty AUX transactions, producing many zero-sized
PERF_RECORD_AUX records. For example:

  perf record -e cs_etm//u -m,128M -- strace ls

  perf script -D 2>&1 |
     awk '/PERF_RECORD_AUX offset/ {
        for (i = 1; i <= NF; i++)
                if ($i == "size:" && $(i + 1) == "0")
                        count++
     }
     END { print count }'
  165

This recording contains 165 zero-sized AUX records which provide no
useful information to userspace.

Ignore PERF_AUX_FLAG_PMU_FORMAT_TYPE_MASK, together with
PERF_AUX_FLAG_OVERWRITE, when deciding whether an empty AUX record is
useful. Zero-sized records carrying TRUNCATED, PARTIAL or COLLISION
are still emitted.

Fixes: 547b60988e ("perf: aux: Add flags for the buffer format")
Reported-by: Tamas Petz <tamas.petz@arm.com>
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260825-perf_core_fix_zero_aux_records-v1-1-23b95e8d5df3@arm.com
2026-09-02 09:18:00 +02:00
Peter Zijlstra c69df06e4e perf/core: Fix deadlock in perf_mmap() failure path
Ian noted that commit 77de62ad3d ("perf/core: Fix refcount bug and
potential UAF in perf_mmap") would cause a deadlock due to
event->mmap_mutex recursion.

This happens because we're now calling perf_mmap_close() under
mmap_mutex, while that function itself can also take mmap_mutex.

Solve this by noting that perf_mmap_close() is far more complicated
than we need at this particular point, since it deals with scenarios
that cannot happen in this particular case.

Replace the call to perf_mmap_close() with a very narrow undo for the
case of first-exposure. If this is not the first mmap(), there is no
race and it is fine to drop the lock and call perf_mmap_close() to
handle to more complicated scenarios.

Note: move the rb->mmap_user (namespace) handling into the rb
init/free code such that it does not complicate the mmap handling.

Fixes: 77de62ad3d ("perf/core: Fix refcount bug and potential UAF in perf_mmap")
Reported-by: Ian Rogers <irogers@google.com>
Closes: https://patch.msgid.link/CAP-5%3DfVJyVMZw%3DDqP53Kxg58nUmJ_0bxoaeOKAbC03BVc11HaA%40mail.gmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260326112821.GK3738786@noisy.programming.kicks-ass.net
2026-05-05 12:47:20 +02:00
Thomas Gleixner 2e4b28c48f treewide: Update email address
In a vain attempt to consolidate the email zoo switch everything to the
kernel.org account.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-01-11 06:09:11 -10:00
Thomas Gleixner 448f97fba9 perf: Convert mmap() refcounts to refcount_t
The recently fixed reference count leaks could have been detected by using
refcount_t and refcount_t would have mitigated the potential overflow at
least.

Now that the code is properly structured, convert the mmap() related
mmap_count variants over to refcount_t.

No functional change intended.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/r/20250812104020.071507932@infradead.org
2025-08-15 13:13:02 +02:00
Leo Yan 1476b21832 perf/aux: Fix pending disable flow when the AUX ring buffer overruns
If an AUX event overruns, the event core layer intends to disable the
event by setting the 'pending_disable' flag. Unfortunately, the event
is not actually disabled afterwards.

In commit:

  ca6c21327c ("perf: Fix missing SIGTRAPs")

the 'pending_disable' flag was changed to a boolean. However, the
AUX event code was not updated accordingly. The flag ends up holding a
CPU number. If this number is zero, the flag is taken as false and the
IRQ work is never triggered.

Later, with commit:

  2b84def990 ("perf: Split __perf_pending_irq() out of perf_pending_irq()")

a new IRQ work 'pending_disable_irq' was introduced to handle event
disabling. The AUX event path was not updated to kick off the work queue.

To fix this bug, when an AUX ring buffer overrun is detected, call
perf_event_disable_inatomic() to initiate the pending disable flow.

Also update the outdated comment for setting the flag, to reflect the
boolean values (0 or 1).

Fixes: 2b84def990 ("perf: Split __perf_pending_irq() out of perf_pending_irq()")
Fixes: ca6c21327c ("perf: Fix missing SIGTRAPs")
Signed-off-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Liang Kan <kan.liang@linux.intel.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-perf-users@vger.kernel.org
Link: https://lore.kernel.org/r/20250625170737.2918295-1-leo.yan@arm.com
2025-06-26 10:50:37 +02:00
Yabin Cui 18049c8cff perf/aux: Allocate non-contiguous AUX pages by default
perf always allocates contiguous AUX pages based on aux_watermark.
However, this contiguous allocation doesn't benefit all PMUs. For
instance, ARM SPE and TRBE operate with virtual pages, and Coresight
ETR allocates a separate buffer. For these PMUs, allocating contiguous
AUX pages unnecessarily exacerbates memory fragmentation. This
fragmentation can prevent their use on long-running devices.

This patch modifies the perf driver to be memory-friendly by default,
by allocating non-contiguous AUX pages. For PMUs requiring contiguous
pages (Intel BTS and some Intel PT), the existing
PERF_PMU_CAP_AUX_NO_SG capability can be used. For PMUs that don't
require but can benefit from contiguous pages (some Intel PT), a new
capability, PERF_PMU_CAP_AUX_PREFER_LARGE, is added to maintain their
existing behavior.

Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20250508232642.148767-1-yabinc@google.com
2025-05-15 18:07:19 +02:00
Tao Chen c96fff391c perf/ring_buffer: Allow the EPOLLRDNORM flag for poll
The poll man page says POLLRDNORM is equivalent to POLLIN. For poll(),
it seems that if user sets pollfd with POLLRDNORM in userspace, perf_poll
will not return until timeout even if perf_output_wakeup called,
whereas POLLIN returns.

Fixes: 76369139ce ("perf: Split up buffer handling from core code")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250314030036.2543180-1-chen.dylane@linux.dev
2025-03-17 08:31:04 +01:00
Peter Zijlstra (Intel) 8ce939a0fa perf: Avoid the read if the count is already updated
The event may have been updated in the PMU-specific implementation,
e.g., Intel PEBS counters snapshotting. The common code should not
read and overwrite the value.

The PERF_SAMPLE_READ in the data->sample_type can be used to detect
whether the PMU-specific value is available. If yes, avoid the
pmu->read() in the common code. Add a new flag, skip_read, to track the
case.

Factor out a perf_pmu_read() to clean up the code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250121152303.3128733-3-kan.liang@linux.intel.com
2025-02-05 10:29:45 +01:00
Lorenzo Stoakes b709eb872e perf: map pages in advance
We are adjusting struct page to make it smaller, removing unneeded fields
which correctly belong to struct folio.

Two of those fields are page->index and page->mapping. Perf is currently
making use of both of these. This is unnecessary. This patch eliminates
this.

Perf establishes its own internally controlled memory-mapped pages using
vm_ops hooks. The first page in the mapping is the read/write user control
page, and the rest of the mapping consists of read-only pages.

The VMA is backed by kernel memory either from the buddy allocator or
vmalloc depending on configuration. It is intended to be mapped read/write,
but because it has a page_mkwrite() hook, vma_wants_writenotify() indicates
that it should be mapped read-only.

When a write fault occurs, the provided page_mkwrite() hook,
perf_mmap_fault() (doing double duty handing faults as well) uses the
vmf->pgoff field to determine if this is the first page, allowing for the
desired read/write first page, read-only rest mapping.

For this to work the implementation has to carefully work around faulting
logic. When a page is write-faulted, the fault() hook is called first, then
its page_mkwrite() hook is called (to allow for dirty tracking in file
systems).

On fault we set the folio's mapping in perf_mmap_fault(), this is because
when do_page_mkwrite() is subsequently invoked, it treats a missing mapping
as an indicator that the fault should be retried.

We also set the folio's index so, given the folio is being treated as faux
user memory, it correctly references its offset within the VMA.

This explains why the mapping and index fields are used - but it's not
necessary.

We preallocate pages when perf_mmap() is called for the first time via
rb_alloc(), and further allocate auxiliary pages via rb_aux_alloc() as
needed if the mapping requires it.

This allocation is done in the f_ops->mmap() hook provided in perf_mmap(),
and so we can instead simply map all the memory right away here - there's
no point in handling (read) page faults when we don't demand page nor need
to be notified about them (perf does not).

This patch therefore changes this logic to map everything when the mmap()
hook is called, establishing a PFN map. It implements vm_ops->pfn_mkwrite()
to provide the required read/write vs. read-only behaviour, which does not
require the previously implemented workarounds.

While it is not ideal to use a VM_PFNMAP here, doing anything else will
result in the page_mkwrite() hook need to be provided, which requires the
same page->mapping hack this patch seeks to undo.

It will also result in the pages being treated as folios and placed on the
rmap, which really does not make sense for these mappings.

Semantically it makes sense to establish this as some kind of special
mapping, as the pages are managed by perf and are not strictly user pages,
but currently the only means by which we can do so functionally while
maintaining the required R/W and R/O behaviour is a PFN map.

There should be no change to actual functionality as a result of this
change.

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250103153151.124163-1-lorenzo.stoakes@oracle.com
2025-01-10 18:16:50 +01:00
Peter Zijlstra 2ab9d83026 perf/aux: Fix AUX buffer serialization
Ole reported that event->mmap_mutex is strictly insufficient to
serialize the AUX buffer, add a per RB mutex to fully serialize it.

Note that in the lock order comment the perf_event::mmap_mutex order
was already wrong, that is, it nesting under mmap_lock is not new with
this patch.

Fixes: 45bfb2e504 ("perf: Add AUX area to ring buffer for raw data streams")
Reported-by: Ole <ole@binarygecko.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-09-04 18:22:56 +02:00
Adrian Hunter 0ca4da2412 perf: Make rb_alloc_aux() return an error immediately if nr_pages <= 0
rb_alloc_aux() should not be called with nr_pages <= 0. Make it more robust
and readable by returning an error immediately in that case.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-8-adrian.hunter@intel.com
2024-07-04 16:00:23 +02:00
Adrian Hunter 43deb76b19 perf: Fix default aux_watermark calculation
The default aux_watermark is half the AUX area buffer size. In general,
on a 64-bit architecture, the AUX area buffer size could be a bigger than
fits in a 32-bit type, but the calculation does not allow for that
possibility.

However the aux_watermark value is recorded in a u32, so should not be
more than U32_MAX either.

Fix by doing the calculation in a correctly sized type, and limiting the
result to U32_MAX.

Fixes: d68e6799a5 ("perf: Cap allocation order at aux_watermark")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240624201101.60186-7-adrian.hunter@intel.com
2024-07-04 16:00:23 +02:00
Kyle Huey fd20bb51ed perf/ring_buffer: Trigger IO signals for watermark_wakeup
perf_output_wakeup() already marks the perf event fd available for polling.
Trigger IO signals with FASYNC too.

Signed-off-by: Kyle Huey <khuey@kylehuey.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20240413141618.4160-3-khuey@kylehuey.com
2024-04-14 22:26:32 +02:00
Kirill A. Shutemov 5e0a760b44 mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDER
commit 23baf831a3 ("mm, treewide: redefine MAX_ORDER sanely") has
changed the definition of MAX_ORDER to be inclusive.  This has caused
issues with code that was not yet upstream and depended on the previous
definition.

To draw attention to the altered meaning of the define, rename MAX_ORDER
to MAX_PAGE_ORDER.

Link: https://lkml.kernel.org/r/20231228144704.14033-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-01-08 15:27:15 -08:00
Shuai Xue 54aee5f15b perf/core: Bail out early if the request AUX area is out of bound
When perf-record with a large AUX area, e.g 4GB, it fails with:

    #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
    failed to mmap with 12 (Cannot allocate memory)

and it reveals a WARNING with __alloc_pages():

	------------[ cut here ]------------
	WARNING: CPU: 44 PID: 17573 at mm/page_alloc.c:5568 __alloc_pages+0x1ec/0x248
	Call trace:
	 __alloc_pages+0x1ec/0x248
	 __kmalloc_large_node+0xc0/0x1f8
	 __kmalloc_node+0x134/0x1e8
	 rb_alloc_aux+0xe0/0x298
	 perf_mmap+0x440/0x660
	 mmap_region+0x308/0x8a8
	 do_mmap+0x3c0/0x528
	 vm_mmap_pgoff+0xf4/0x1b8
	 ksys_mmap_pgoff+0x18c/0x218
	 __arm64_sys_mmap+0x38/0x58
	 invoke_syscall+0x50/0x128
	 el0_svc_common.constprop.0+0x58/0x188
	 do_el0_svc+0x34/0x50
	 el0_svc+0x34/0x108
	 el0t_64_sync_handler+0xb8/0xc0
	 el0t_64_sync+0x1a4/0x1a8

'rb->aux_pages' allocated by kcalloc() is a pointer array which is used to
maintains AUX trace pages. The allocated page for this array is physically
contiguous (and virtually contiguous) with an order of 0..MAX_ORDER. If the
size of pointer array crosses the limitation set by MAX_ORDER, it reveals a
WARNING.

So bail out early with -ENOMEM if the request AUX area is out of bound,
e.g.:

    #perf record -C 0 -m ,4G -e arm_spe_0// -- sleep 1
    failed to mmap with 12 (Cannot allocate memory)

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2023-09-12 17:46:31 +02:00
Uros Bizjak 1af61adb3a perf/ring_buffer: Use local_try_cmpxchg in __perf_output_begin
Use local_try_cmpxchg instead of local_cmpxchg (*ptr, old, new) == old
in __perf_output_begin.  x86 CMPXCHG instruction returns success in ZF
flag, so this change saves a compare after cmpxchg (and related move
instruction in front of cmpxchg).

Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails. There is no need to re-read the value in the loop.

No functional change intended.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230708090048.63046-2-ubizjak@gmail.com
2023-07-10 09:52:36 +02:00
Kirill A. Shutemov 23baf831a3 mm, treewide: redefine MAX_ORDER sanely
MAX_ORDER currently defined as number of orders page allocator supports:
user can ask buddy allocator for page order between 0 and MAX_ORDER-1.

This definition is counter-intuitive and lead to number of bugs all over
the kernel.

Change the definition of MAX_ORDER to be inclusive: the range of orders
user can ask from buddy allocator is 0..MAX_ORDER now.

[kirill@shutemov.name: fix min() warning]
  Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box
[akpm@linux-foundation.org: fix another min_t warning]
[kirill@shutemov.name: fixups per Zi Yan]
  Link: https://lkml.kernel.org/r/20230316232144.b7ic4cif4kjiabws@box.shutemov.name
[akpm@linux-foundation.org: fix underlining in docs]
  Link: https://lore.kernel.org/oe-kbuild-all/202303191025.VRCTk6mP-lkp@intel.com/
Link: https://lkml.kernel.org/r/20230315113133.11326-11-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Michael Ellerman <mpe@ellerman.id.au>	[powerpc]
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:46 -07:00
Kirill A. Shutemov 934487e98f perf/core: fix MAX_ORDER usage in rb_alloc_aux_page()
MAX_ORDER is not inclusive: the maximum allocation order buddy allocator
can deliver is MAX_ORDER-1.

Fix MAX_ORDER usage in rb_alloc_aux_page().

Link: https://lkml.kernel.org/r/20230315113133.11326-7-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:45 -07:00
Peter Zijlstra ca6c21327c perf: Fix missing SIGTRAPs
Marco reported:

Due to the implementation of how SIGTRAP are delivered if
perf_event_attr::sigtrap is set, we've noticed 3 issues:

  1. Missing SIGTRAP due to a race with event_sched_out() (more
     details below).

  2. Hardware PMU events being disabled due to returning 1 from
     perf_event_overflow(). The only way to re-enable the event is
     for user space to first "properly" disable the event and then
     re-enable it.

  3. The inability to automatically disable an event after a
     specified number of overflows via PERF_EVENT_IOC_REFRESH.

The worst of the 3 issues is problem (1), which occurs when a
pending_disable is "consumed" by a racing event_sched_out(), observed
as follows:

		CPU0			|	CPU1
	--------------------------------+---------------------------
	__perf_event_overflow()		|
	 perf_event_disable_inatomic()	|
	  pending_disable = CPU0	| ...
					| _perf_event_enable()
					|  event_function_call()
					|   task_function_call()
					|    /* sends IPI to CPU0 */
	<IPI>				| ...
	 __perf_event_enable()		+---------------------------
	  ctx_resched()
	   task_ctx_sched_out()
	    ctx_sched_out()
	     group_sched_out()
	      event_sched_out()
	       pending_disable = -1
	</IPI>
	<IRQ-work>
	 perf_pending_event()
	  perf_pending_event_disable()
	   /* Fails to send SIGTRAP because no pending_disable! */
	</IRQ-work>

In the above case, not only is that particular SIGTRAP missed, but also
all future SIGTRAPs because 'event_limit' is not reset back to 1.

To fix, rework pending delivery of SIGTRAP via IRQ-work by introduction
of a separate 'pending_sigtrap', no longer using 'event_limit' and
'pending_disable' for its delivery.

Additionally; and different to Marco's proposed patch:

 - recognise that pending_disable effectively duplicates oncpu for
   the case where it is set. As such, change the irq_work handler to
   use ->oncpu to target the event and use pending_* as boolean toggles.

 - observe that SIGTRAP targets the ctx->task, so the context switch
   optimization that carries contexts between tasks is invalid. If
   the irq_work were delayed enough to hit after a context switch the
   SIGTRAP would be delivered to the wrong task.

 - observe that if the event gets scheduled out
   (rotation/migration/context-switch/...) the irq-work would be
   insufficient to deliver the SIGTRAP when the event gets scheduled
   back in (the irq-work might still be pending on the old CPU).

   Therefore have event_sched_out() convert the pending sigtrap into a
   task_work which will deliver the signal at return_to_user.

Fixes: 97ba62b278 ("perf: Add support for SIGTRAP on perf events")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Debugged-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Marco Elver <elver@google.com>
Debugged-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
2022-10-17 16:32:05 +02:00
Namhyung Kim 119a784c81 perf/core: Add a new read format to get a number of lost samples
Sometimes we want to know an accurate number of samples even if it's
lost.  Currenlty PERF_RECORD_LOST is generated for a ring-buffer which
might be shared with other events.  So it's hard to know per-event
lost count.

Add event->lost_samples field and PERF_FORMAT_LOST to retrieve it from
userspace.

Original-patch-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220616180623.1358843-1-namhyung@kernel.org
2022-06-28 09:08:31 +02:00
Zhipeng Xie 60490e7966 perf/core: Fix perf_mmap fail when CONFIG_PERF_USE_VMALLOC enabled
This problem can be reproduced with CONFIG_PERF_USE_VMALLOC enabled on
both x86_64 and aarch64 arch when using sysdig -B(using ebpf)[1].
sysdig -B works fine after rebuilding the kernel with
CONFIG_PERF_USE_VMALLOC disabled.

I tracked it down to the if condition event->rb->nr_pages != nr_pages
in perf_mmap is true when CONFIG_PERF_USE_VMALLOC is enabled where
event->rb->nr_pages = 1 and nr_pages = 2048 resulting perf_mmap to
return -EINVAL. This is because when CONFIG_PERF_USE_VMALLOC is
enabled, rb->nr_pages is always equal to 1.

Arch with CONFIG_PERF_USE_VMALLOC enabled by default:
	arc/arm/csky/mips/sh/sparc/xtensa

Arch with CONFIG_PERF_USE_VMALLOC disabled by default:
	x86_64/aarch64/...

Fix this problem by using data_page_nr()

[1] https://github.com/draios/sysdig

Fixes: 906010b213 ("perf_event: Provide vmalloc() based mmap() backing")
Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220209145417.6495-1-xiezhipeng1@huawei.com
2022-04-19 21:15:42 +02:00
Alexander Shishkin d68e6799a5 perf: Cap allocation order at aux_watermark
Currently, we start allocating AUX pages half the size of the total
requested AUX buffer size, ignoring the attr.aux_watermark setting. This,
in turn, makes intel_pt driver disregard the watermark also, as it uses
page order for its SG (ToPA) configuration.

Now, this can be fixed in the intel_pt PMU driver, but seeing as it's the
only one currently making use of high order allocations, there is no
reason not to fix the allocator instead. This way, any other driver
wishing to add this support would not have to worry about this.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210414154955.49603-2-alexander.shishkin@linux.intel.com
2021-04-16 16:32:39 +02:00
Namhyung Kim 9483409ab5 perf core: Allocate perf_buffer in the target node memory
I found the ring buffer pages are allocated in the node but the ring
buffer itself is not.  Let's convert it to use kzalloc_node() too.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210315033436.682438-1-namhyung@kernel.org
2021-03-16 21:44:42 +01:00
Peter Zijlstra 267fb27352 perf: Reduce stack usage of perf_output_begin()
__perf_output_begin() has an on-stack struct perf_sample_data in the
unlikely case it needs to generate a LOST record. However, every call
to perf_output_begin() must already have a perf_sample_data on-stack.

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151954.985416146@infradead.org
2020-11-09 18:12:33 +01:00
Steven Rostedt (VMware) 56de4e8f91 perf: Make struct ring_buffer less ambiguous
eBPF requires needing to know the size of the perf ring buffer structure.
But it unfortunately has the same name as the generic ring buffer used by
tracing and oprofile. To make it less ambiguous, rename the perf ring buffer
structure to "perf_buffer".

As other parts of the ring buffer code has "perf_" as the prefix, it only
makes sense to give the ring buffer the "perf_" prefix as well.

Link: https://lore.kernel.org/r/20191213153553.GE20583@krava
Acked-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13 13:19:38 -05:00
Alexander Shishkin a4faf00d99 perf/aux: Allow using AUX data in perf samples
AUX data can be used to annotate perf events such as performance counters
or tracepoints/breakpoints by including it in sample records when
PERF_SAMPLE_AUX flag is set. Such samples would be instrumental in debugging
and profiling by providing, for example, a history of instruction flow
leading up to the event's overflow.

The implementation makes use of grouping an AUX event with all the events
that wish to take samples of the AUX data, such that the former is the
group leader. The samplees should also specify the desired size of the AUX
sample via attr.aux_sample_size.

AUX capable PMUs need to explicitly add support for sampling, because it
relies on a new callback to take a snapshot of the buffer without touching
the event states.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Cc: mathieu.poirier@linaro.org
Link: https://lkml.kernel.org/r/20191025140835.53665-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-13 11:06:14 +01:00
Yunfeng Ye d7e78706e4 perf/ring_buffer: Matching the memory allocate and free, in rb_alloc()
Currently perf_mmap_alloc_page() is used to allocate memory in
rb_alloc(), but using free_page() to free memory in the failure path.

It's better to use perf_mmap_free_page() instead.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.co>
Cc: <acme@kernel.org>
Cc: <mingo@redhat.com>
Cc: <mark.rutland@arm.com>
Cc: <namhyung@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/575c7e8c-90c7-4e3a-b41d-f894d8cdbd7f@huawei.com
2019-10-17 21:31:55 +02:00
Yunfeng Ye 8a9f91c51e perf/ring_buffer: Modify the parameter type of perf_mmap_free_page()
In perf_mmap_free_page(), the unsigned long type is converted to the
pointer type, but where the call is made, the pointer type is converted
to the unsigned long type. There is no need to do these operations.

Modify the parameter type of perf_mmap_free_page() to pointer type.

Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <jolsa@redhat.co>
Cc: <acme@kernel.org>
Cc: <mingo@redhat.com>
Cc: <mark.rutland@arm.com>
Cc: <namhyung@kernel.org>
Cc: <alexander.shishkin@linux.intel.com>
Link: https://lkml.kernel.org/r/e6ae3f0c-d04c-50f9-544a-aee3b30330cd@huawei.com
2019-10-17 21:31:55 +02:00
Peter Zijlstra 5322ea58a0 perf/ring-buffer: Use regular variables for nesting
While the IRQ/NMI will nest, the nest-count will be invariant over the
actual exception, since it will decrement equal to increment.

This means we can -- carefully -- use a regular variable since the
typical LOAD-STORE race doesn't exist (similar to preempt_count).

This optimizes the ring-buffer for all LOAD-STORE architectures, since
they need to use atomic ops to implement local_t.

Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: mark.rutland@arm.com
Cc: namhyung@kernel.org
Cc: yabinc@google.com
Link: http://lkml.kernel.org/r/20190517115418.481392777@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24 09:00:11 +02:00
Peter Zijlstra 4d839dd9e4 perf/ring-buffer: Always use {READ,WRITE}_ONCE() for rb->user_page data
We must use {READ,WRITE}_ONCE() on rb->user_page data such that
concurrent usage will see whole values. A few key sites were missing
this.

Suggested-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: mark.rutland@arm.com
Cc: namhyung@kernel.org
Fixes: 7b732a7504 ("perf_counter: new output ABI - part 1")
Link: http://lkml.kernel.org/r/20190517115418.394192145@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24 09:00:11 +02:00
Peter Zijlstra 3f9fbe9bd8 perf/ring_buffer: Add ordering to rb->nest increment
Similar to how decrementing rb->next too early can cause data_head to
(temporarily) be observed to go backward, so too can this happen when
we increment too late.

This barrier() ensures the rb->head load happens after the increment,
both the one in the 'goto again' path, as the one from
perf_output_get_handle() -- albeit very unlikely to matter for the
latter.

Suggested-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: mark.rutland@arm.com
Cc: namhyung@kernel.org
Fixes: ef60777c9a ("perf: Optimize the perf_output() path by removing IRQ-disables")
Link: http://lkml.kernel.org/r/20190517115418.309516009@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24 09:00:10 +02:00
Yabin Cui 1b038c6e05 perf/ring_buffer: Fix exposing a temporarily decreased data_head
In perf_output_put_handle(), an IRQ/NMI can happen in below location and
write records to the same ring buffer:

	...
	local_dec_and_test(&rb->nest)
	...                          <-- an IRQ/NMI can happen here
	rb->user_page->data_head = head;
	...

In this case, a value A is written to data_head in the IRQ, then a value
B is written to data_head after the IRQ. And A > B. As a result,
data_head is temporarily decreased from A to B. And a reader may see
data_head < data_tail if it read the buffer frequently enough, which
creates unexpected behaviors.

This can be fixed by moving dec(&rb->nest) to after updating data_head,
which prevents the IRQ/NMI above from updating data_head.

[ Split up by peterz. ]

Signed-off-by: Yabin Cui <yabinc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: mark.rutland@arm.com
Fixes: ef60777c9a ("perf: Optimize the perf_output() path by removing IRQ-disables")
Link: http://lkml.kernel.org/r/20190517115418.224478157@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-24 09:00:10 +02:00
Alexander Shishkin 26ae4f4406 perf/ring_buffer: Fix AUX software double buffering
This recent commit:

  5768402fd9 ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")

overlooked the fact that the previous one page granularity of the AUX buffer
provided an implicit double buffering capability to the PMU driver, which
went away when the entire buffer became one high-order page.

Always make the full-trace mode AUX allocation at least two-part to preserve
the previous behavior and allow the implicit double buffering to continue.

Reported-by: Ammy Yi <ammy.yi@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: adrian.hunter@intel.com
Fixes: 5768402fd9 ("perf/ring_buffer: Use high order allocations for AUX buffers optimistically")
Link: http://lkml.kernel.org/r/20190503085536.24119-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-05-03 12:46:10 +02:00
Alexander Shishkin 339bc41835 perf/ring_buffer: Fix AUX record suppression
The following commit:

  1627314fb5 ("perf: Suppress AUX/OVERWRITE records")

has an unintended side-effect of also suppressing all AUX records with no flags
and non-zero size, so all the regular records in the full trace mode.
This breaks some use cases for people.

Fix this by restoring "regular" AUX records.

Reported-by: Ben Gainey <Ben.Gainey@arm.com>
Tested-by: Ben Gainey <Ben.Gainey@arm.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 1627314fb5 ("perf: Suppress AUX/OVERWRITE records")
Link: https://lkml.kernel.org/r/20190329091338.29999-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-16 12:13:57 +02:00
Peter Zijlstra 1d54ad9440 perf/core: Fix perf_event_disable_inatomic() race
Thomas-Mich Richter reported he triggered a WARN()ing from event_function_local()
on his s390. The problem boils down to:

	CPU-A				CPU-B

	perf_event_overflow()
	  perf_event_disable_inatomic()
	    @pending_disable = 1
	    irq_work_queue();

	sched-out
	  event_sched_out()
	    @pending_disable = 0

					sched-in
					perf_event_overflow()
					  perf_event_disable_inatomic()
					    @pending_disable = 1;
					    irq_work_queue(); // FAILS

	irq_work_run()
	  perf_pending_event()
	    if (@pending_disable)
	      perf_event_disable_local(); // WHOOPS

The problem exists in generic, but s390 is particularly sensitive
because it doesn't implement arch_irq_work_raise(), nor does it call
irq_work_run() from it's PMU interrupt handler (nor would that be
sufficient in this case, because s390 also generates
perf_event_overflow() from pmu::stop). Add to that the fact that s390
is a virtual architecture and (virtual) CPU-A can stall long enough
for the above race to happen, even if it would self-IPI.

Adding a irq_work_sync() to event_sched_in() would work for all hardare
PMUs that properly use irq_work_run() but fails for software PMUs.

Instead encode the CPU number in @pending_disable, such that we can
tell which CPU requested the disable. This then allows us to detect
the above scenario and even redirect the IPI to make up for the failed
queue.

Reported-by: Thomas-Mich Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-12 08:55:55 +02:00
Alexander Shishkin 5768402fd9 perf/ring_buffer: Use high order allocations for AUX buffers optimistically
Currently, the AUX buffer allocator will use high-order allocations
for PMUs that don't support hardware scatter-gather chaining to ensure
large contiguous blocks of pages, and always use an array of single
pages otherwise.

There is, however, a tangible performance benefit in using larger chunks
of contiguous memory even in the latter case, that comes from not having
to fetch the next page's address at every page boundary. In particular,
a task running under Intel PT on an Atom CPU shows 1.5%-2% less runtime
penalty with a single multi-page output region in snapshot mode (no PMI)
than with multiple single-page output regions, from ~6% down to ~4%. For
the snapshot mode it does make a difference as it is intended to run over
long periods of time.

For this reason, change the allocation policy to always optimistically
start with the highest possible order when allocating pages for the AUX
buffer, desceding until the allocation succeeds or order zero allocation
fails.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: https://lkml.kernel.org/r/20190215114727.62648-2-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-03-09 14:10:30 +01:00
Ingo Molnar 9ed8f1a6e7 Merge branch 'linus' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 08:27:17 +01:00
Ingo Molnar 528871b456 perf/core: Fix impossible ring-buffer sizes warning
The following commit:

  9dff0aa95a ("perf/core: Don't WARN() for impossible ring-buffer sizes")

results in perf recording failures with larger mmap areas:

  root@skl:/tmp# perf record -g -a
  failed to mmap with 12 (Cannot allocate memory)

The root cause is that the following condition is buggy:

	if (order_base_2(size) >= MAX_ORDER)
		goto fail;

The problem is that @size is in bytes and MAX_ORDER is in pages,
so the right test is:

	if (order_base_2(size) >= PAGE_SHIFT+MAX_ORDER)
		goto fail;

Fix it.

Reported-by: "Jin, Yao" <yao.jin@linux.intel.com>
Bisected-by: Borislav Petkov <bp@alien8.de>
Analyzed-by: Peter Zijlstra <peterz@infradead.org>
Cc: Julien Thierry <julien.thierry@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Fixes: 9dff0aa95a ("perf/core: Don't WARN() for impossible ring-buffer sizes")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-13 08:05:02 +01:00
Mathieu Poirier 840018668c perf/aux: Make perf_event accessible to setup_aux()
When pmu::setup_aux() is called the coresight PMU needs to know which
sink to use for the session by looking up the information in the
event's attr::config2 field.

As such simply replace the cpu information by the complete perf_event
structure and change all affected customers.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/20190131184714.20388-2-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-02-06 10:00:39 -03:00
Elena Reshetova ca3bb3d027 perf/ring_buffer: Convert ring_buffer.aux_refcount to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:

 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable ring_buffer.aux_refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

** Important note for maintainers:

Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts. Please check Documentation/core-api/refcount-vs-atomic.rst
for more information.

Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.

For the ring_buffer.aux_refcount it might make a difference
in following places:

 - perf_aux_output_begin(): increment in refcount_inc_not_zero() only
   guarantees control dependency on success vs. fully ordered
   atomic counterpart
 - rb_free_aux(): decrement in refcount_dec_and_test() only
   provides RELEASE ordering and ACQUIRE ordering + control dependency
   on success vs. fully ordered atomic counterpart

Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: namhyung@kernel.org
Link: https://lkml.kernel.org/r/1548678448-24458-4-git-send-email-elena.reshetova@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 08:46:17 +01:00
Elena Reshetova fecb8ed2ce perf/ring_buffer: Convert ring_buffer.refcount to refcount_t
atomic_t variables are currently used to implement reference
counters with the following properties:

 - counter is initialized to 1 using atomic_set()
 - a resource is freed upon counter reaching zero
 - once counter reaches zero, its further
   increments aren't allowed
 - counter schema uses basic atomic operations
   (set, inc, inc_not_zero, dec_and_test, etc.)

Such atomic variables should be converted to a newly provided
refcount_t type and API that prevents accidental counter overflows
and underflows. This is important since overflows and underflows
can lead to use-after-free situation and be exploitable.

The variable ring_buffer.refcount is used as pure reference counter.
Convert it to refcount_t and fix up the operations.

** Important note for maintainers:

Some functions from refcount_t API defined in lib/refcount.c
have different memory ordering guarantees than their atomic
counterparts. Please check Documentation/core-api/refcount-vs-atomic.rst
for more information.

Normally the differences should not matter since refcount_t provides
enough guarantees to satisfy the refcounting use cases, but in
some rare cases it might matter.
Please double check that you don't have some undocumented
memory guarantees for this variable usage.

For the ring_buffer.refcount it might make a difference
in following places:

 - ring_buffer_get(): increment in refcount_inc_not_zero() only
   guarantees control dependency on success vs. fully ordered
   atomic counterpart
 - ring_buffer_put(): decrement in refcount_dec_and_test() only
   provides RELEASE ordering and ACQUIRE ordering + control dependency
   on success vs. fully ordered atomic counterpart

Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: David Windsor <dwindsor@gmail.com>
Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: namhyung@kernel.org
Link: https://lkml.kernel.org/r/1548678448-24458-3-git-send-email-elena.reshetova@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 08:46:16 +01:00
Thomas Gleixner 8e86e01526 perf/core: Convert to SPDX license identifiers
Use proper SPDX license identifiers instead of the bogus reference to
kernel-base/COPYING.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20190116111308.012666937@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 08:46:11 +01:00
Mark Rutland 9dff0aa95a perf/core: Don't WARN() for impossible ring-buffer sizes
The perf tool uses /proc/sys/kernel/perf_event_mlock_kb to determine how
large its ringbuffer mmap should be. This can be configured to arbitrary
values, which can be larger than the maximum possible allocation from
kmalloc.

When this is configured to a suitably large value (e.g. thanks to the
perf fuzzer), attempting to use perf record triggers a WARN_ON_ONCE() in
__alloc_pages_nodemask():

   WARNING: CPU: 2 PID: 5666 at mm/page_alloc.c:4511 __alloc_pages_nodemask+0x3f8/0xbc8

Let's avoid this by checking that the requested allocation is possible
before calling kzalloc.

Reported-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20190110142745.25495-1-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-04 08:45:25 +01:00
Alexander Shishkin 1627314fb5 perf: Suppress AUX/OVERWRITE records
It has been pointed out to me many times that it is useful to be able to
switch off AUX records to save the bandwidth for records that actually
matter, for example, in AUX overwrite mode.

The usefulness of PERF_RECORD_AUX is in some of its flags, like the
TRUNCATED flag that tells the decoder where exactly gaps in the trace
are.  The OVERWRITE flag, on the other hand will be set on every single
record in overwrite mode. However, a PERF_RECORD_AUX[flags=OVERWRITE] is
generated on every target task's sched_out, which over time adds up to a
lot of useless information.

If any folks out there have userspace that depends on a constant stream
of OVERWRITE records for a good reason, they'll have to let us know.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Link: http://lkml.kernel.org/r/20180404145323.28651-1-alexander.shishkin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-09-18 17:21:13 -03:00
Linus Torvalds c81b995f00 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
 "A pile of perf updates:

  Kernel side:

   - Remove an incorrect warning in uprobe_init_insn() when
     insn_get_length() fails. The error return code is handled at the
     call site.

   - Move the inline keyword to the right place in the perf ringbuffer
     code to address a W=1 build warning.

  Tooling:

  perf stat:

   - Fix metric column header display alignment

   - Improve error messages for default attributes, providing better
     output for error in command line.

   - Add --interval-clear option, to provide a 'watch' like printing

  perf script:

   - Show hw-cache events too

  perf c2c:

   - Fix data dependency problem in layout of 'struct c2c_hist_entry'

  Core:

   - Do not blindly assume that 'struct perf_evsel' can be obtained via
     a straight forward container_of() as there are call sites which
     hand in a plain 'struct hist' which is not part of a container.

   - Fix error index in the PMU event parser, so that error messages can
     point to the problematic token"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Move the inline keyword at the beginning of the function declaration
  uprobes/x86: Remove incorrect WARN_ON() in uprobe_init_insn()
  perf script: Show hw-cache events
  perf c2c: Keep struct hist_entry at the end of struct c2c_hist_entry
  perf stat: Add event parsing error handling to add_default_attributes
  perf stat: Allow to specify specific metric column len
  perf stat: Fix metric column header display alignment
  perf stat: Use only color_fprintf call in print_metric_only
  perf stat: Add --interval-clear option
  perf tools: Fix error index for pmu event parser
  perf hists: Reimplement hists__has_callchains()
  perf hists browser gtk: Use hist_entry__has_callchains()
  perf hists: Make hist_entry__has_callchains() work with 'perf c2c'
  perf hists: Save the callchain_size in struct hist_entry
2018-06-24 20:29:15 +08:00
Mathieu Malaterre 57d6a7938a perf/core: Move the inline keyword at the beginning of the function declaration
When building perf with W=1 the following warning triggers:

  CC      kernel/events/ring_buffer.o
  kernel/events/ring_buffer.c:105:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration]
   static bool __always_inline
   ^~~~~~
  ...

Move the inline keyword to the beginning of the function declaration.

Signed-off-by: Mathieu Malaterre <malat@debian.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: trival@kernel.org
Link: http://lkml.kernel.org/r/20180308202856.9378-1-malat@debian.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-06-22 11:07:47 +02:00
Kees Cook 590b5b7d86 treewide: kzalloc_node() -> kcalloc_node()
The kzalloc_node() function has a 2-factor argument form, kcalloc_node(). This
patch replaces cases of:

        kzalloc_node(a * b, gfp, node)

with:
        kcalloc_node(a * b, gfp, node)

as well as handling cases of:

        kzalloc_node(a * b * c, gfp, node)

with:

        kzalloc_node(array3_size(a, b, c), gfp, node)

as it's slightly less ugly than:

        kcalloc_node(array_size(a, b), c, gfp, node)

This does, however, attempt to ignore constant size factors like:

        kzalloc_node(4 * 1024, gfp, node)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
  kzalloc_node(
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  kzalloc_node(
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  kzalloc_node(
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  kzalloc_node(
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc_node
+ kcalloc_node
  (
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  kzalloc_node(
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc_node(
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc_node(
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc_node(
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  kzalloc_node(
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc_node(
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc_node(
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  kzalloc_node(
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  kzalloc_node(
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc_node(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  kzalloc_node(
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc_node(
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  kzalloc_node(
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  kzalloc_node(
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
  kzalloc_node(
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  kzalloc_node(
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  kzalloc_node(C1 * C2 * C3, ...)
|
  kzalloc_node(
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc_node(
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc_node(
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  kzalloc_node(
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  kzalloc_node(sizeof(THING) * C2, ...)
|
  kzalloc_node(sizeof(TYPE) * C2, ...)
|
  kzalloc_node(C1 * C2 * C3, ...)
|
  kzalloc_node(C1 * C2, ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	(E1) * E2
+	E1, E2
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- kzalloc_node
+ kcalloc_node
  (
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00