Ian Rogers [Sun, 31 May 2026 01:09:24 +0000 (18:09 -0700)]
tools build: Fix feature checks to touch target files on success
In tools/build/feature/Makefile, test-clang-bpf-co-re.bin and
test-bpftool-skeletons.bin redirected grep output but never touched or
created the $@ target file upon success.
Because the target file was never created on disk, Kbuild could never cache
the result of the check. Consequently, Make treated the prerequisite as
missing and continuously re-executed the Clang BPF backend and bpftool
feature checks on every single sub-make evaluation during build startup, or
on every incremental build.
Refactor both feature check recipes to touch $@ on success. For
test-clang-bpf-co-re.bin, group the shell pipeline within curly braces
and redirect both stdout and stderr to .make.output to allow errors to
be inspected and not appear in build output.
List test-clang-bpf-co-re.bin's input C file as a dependency so
modification triggers a rebuild. For test-bpftool-skeletons.bin, add it
to the FILES list so that it will be cleaned.
Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers <irogers@google.com> Tested-by: James Clark <james.clark@linaro.org> Cc: Bill Wendling <morbo@google.com> Cc: Costa Shulyupin <costa.shul@redhat.com> Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Justin Stitt <justinstitt@google.com> Cc: Leo Yan <leo.yan@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com> Cc: Yuzhuo Jing <yuzhuo@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The lock_contention BPF program uses __sync_val_compare_and_swap() to
atomically update the max_time and min_time fields in contention_data.
This builtin lowers to the BPF_CMPXCHG instruction, which is only
available in BPF ISA v3. Without an explicit -mcpu flag, Clang targets
BPF v1/v2 by default on older toolchains (Clang < 18), causing build
errors when v3 instructions are emitted.
Add -mcpu=v3 to CLANG_OPTIONS, which is used exclusively in the BPF
skeleton compilation rule.
Reviewed-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Suchit Karunakaran <suchitkarunakaran@gmail.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Suchit Karunakaran <suchitkarunakaran@gmail.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf lock: Fix non-atomic max/time and min_time updates in contention_data
The update_contention_data() had a FIXME noting that max_time and
min_time updates lacked atomicity. Two CPUs could simultaneously read a
stale value, pass the comparison check and race on the write-back, with
the smaller value potentially overwriting the larger one and silently
corrupting the statistics.
Fix this by replacing the bare conditional assignments with a
bpf_loop()-based CAS retry loop. Each field tracks its own convergence
independently via max_done/min_done flags in cas_ctx, so a successful
CAS on one field is never retried even if the other field needs more
attempts.
Signed-off-by: Suchit Karunakaran <suchitkarunakaran@gmail.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Breno Leitao [Wed, 3 Jun 2026 10:35:07 +0000 (03:35 -0700)]
perf bench: Add --write-size option to sched pipe
The default ping-pong uses sizeof(int) (4 bytes) per iteration, which
exercises only the pipe-buffer merge path and keeps allocation entirely
out of the picture. That makes the bench a useful scheduler / context-
switch latency probe but unable to surface anything from the pipe
page-allocation hot path.
Add a -s/--write-size option that sets the bytes written and read per
ping-pong iteration. The buffer is allocated for each side via struct
thread_data and replaces the on-stack int previously used. The default
remains sizeof(int) so existing invocations are unchanged.
With --write-size set above PAGE_SIZE the bench drives anon_pipe_write()
through alloc_page() (or the bulk pre-alloc, if the relevant patch is
applied), which is what we want when measuring pipe locking and page
allocation work.
The bench is a ping-pong: both sides call write() before read(), so a
single write_size payload must fit entirely in the pipe buffer or both
sides deadlock waiting for the other to drain.
Resize the pipe via F_SETPIPE_SZ to match write_size (skipped at the
sizeof(int) default), and error out cleanly when the request exceeds
/proc/sys/fs/pipe-max-size.
Committer testing:
⬢ [acme@toolbx perf-tools-next]$ perf bench sched pipe
# Running 'sched/pipe' benchmark:
# Executed 1000000 pipe operations between two processes
Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:16 +0000 (08:25 -0700)]
perf symbol: Lazily compute idle
Switch from an idle boolean to a helper symbol__is_idle function. In
the function lazily compute whether a symbol is an idle function
taking into consideration the kernel version and architecture of the
machine. As symbols__insert no longer needs to know if a symbol is for
the kernel, remove the argument.
To protect against drop-filtering of legitimate setup, online, or hotplug
management functions (such as intel_idle_init), x86 matches are strictly
constrained to exact known run-loops (intel_idle, intel_idle_irq,
mwait_idle, mwait_idle_with_hints).
If the target environment OS release is unresolvable (such as on guest
traces), default to treating psw_idle as idle to prevent false
negatives and match legacy trace behavior safely.
This change is inspired by mailing list discussion, particularly from
Thomas Richter <tmricht@linux.ibm.com> and Heiko Carstens
<hca@linux.ibm.com>:
https://lore.kernel.org/lkml/20260219113850.354271-1-tmricht@linux.ibm.com/
Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:15 +0000 (08:25 -0700)]
perf symbol: Add setters for bitfields sharing a byte to avoid concurrent update issues
A problem with putting bitfields into struct symbol is that other bits in
the symbol could be updated concurrently and only one update to the
underlying storage unit happen, leading to lost updates.
To avoid this, use atomics to atomically read or set part of 16-bits
of flags in the symbol. Add accessors to simplify this.
The idle value has 3 values in preparation for a later change that
will lazily update it.
Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:14 +0000 (08:25 -0700)]
perf env: Add helper to lazily compute the os_release
In live mode the os_release isn't being initialized, make a lazy
initialization helper that assumes when the os_release isn't
initialized this is live mode.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:13 +0000 (08:25 -0700)]
perf env: Add mutex to protect lazy environment initialization
Introduce a mutex to 'struct perf_env' to safely protect lazy
metadata setup, such as os_release or e_machine resolution,
preventing concurrent initialization data races and memory leaks
during multi-threaded profiling or symbol loading.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:11 +0000 (08:25 -0700)]
perf env: Refactor perf_env__arch_strerrno
The previous approach maps an architecture string to a function
pointer to a function that takes an int errno value and returns a
string. The new approach takes an e_machine and an errno value and
returns a string.
As the only call site is in builtin-trace.c, the e_machine is already
present and potentially more specific than the perf_env arch string
that is a single global value.
Since the errno-to-name mapping is now generated statically and no
longer depends on libtraceevent, we can remove the HAVE_LIBTRACEEVENT
guards entirely, making perf_env__arch_strerrno unconditionally
available.
The major complication in this approach is having the shell script
that generates the C code map a linux directory name to the matching
ELF machine constants. To ensure compatibility with older hosts that
have older glibc versions, output fallback definitions for newer ELF
machine constants (EM_AARCH64, EM_CSKY, EM_LOONGARCH) if they are not
defined in the system <elf.h>.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:04 +0000 (08:25 -0700)]
perf machine: Use perf_env e_machine rather than arch
The arch string is derived from uname and may be normalized causing
potential differences meaning the ELF machine can be more
precise. Reduce the scope of machine__is as often it is better to use
a thread for the e_machine rather than the machine. Switch from string
to ELF machine constant comparisons.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:03 +0000 (08:25 -0700)]
perf symbol: Avoid use of machine__is
Switch to using the ELF machine from the dso or running machine rather
than the machine perf_env arch that may fall back on EM_HOST. This
also avoids potentially imprecise string comparisons.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:01 +0000 (08:25 -0700)]
perf capstone: Determine architecture from e_machine
Avoid the use of arch string that is imprecise and use the
e_machine. Do more e_machine to capstone machine translations adding
MIPS and RISCV. Remove unnecessary maybe_unused annotations.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:25:00 +0000 (08:25 -0700)]
perf env, dso, thread: Add _endian variants for e_machine helpers
Add perf_arch_is_big_endian(), dso__read_e_machine_endian(),
dso__e_machine_endian(), and thread__e_machine_endian() to support
bi-endianness and cross-architecture analysis without breaking the
existing API.
These helpers allow querying the absolute endianness of a DSO or
thread, which is required for tools like Capstone that need to set the
correct disassembly mode.
Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 2 Jun 2026 15:24:58 +0000 (08:24 -0700)]
perf env: Add perf_env__e_machine helper and use in perf_env__arch
Add a helper that lazily computes the e_machine and falls back to EM_HOST.
Use the perf_env's arch to compute the e_machine if available, using a
binary search for efficiency while handling duplicate rules.
Switch perf_env__arch to be derived from e_machine for consistency.
To support 32-bit compat binaries on 64-bit hosts during dynamic local
or live operations, unpopulated arch fallback paths query uname() at
runtime to dynamically resolve the correct host e_machine, safely
preventing bitness misclassification regressions.
Update session and header to use the helper to safely record e_machine
and flags without forcing premature thread scanning.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Honglei Wang <jameshongleiwang@126.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf test: Add file offset diagnostic test for corrupted perf.data
Add a shell test that verifies the file_offset diagnostic messages
work correctly when perf encounters corrupted events.
The test corrupts a MMAP2 event's size field in a recorded perf.data
file, then checks that perf report produces warning messages that
include both the file offset (e.g. "at offset 0x2738:") and the
event type name with numeric id (e.g. "MMAP2 (10)").
This exercises the diagnostic improvements from the file_offset
series, which retrofitted all skip/stop/error messages to include
the position and type of the problematic event.
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf sched: Replace BUG_ON on invalid CPU with graceful skip
latency_switch_event(), latency_runtime_event(), and map_switch_event()
use BUG_ON(cpu >= MAX_CPUS || cpu < 0) to validate the sample CPU.
When PERF_SAMPLE_CPU is absent from the sample type,
evsel__parse_sample() initializes sample->cpu to (u32)-1. Casting
this to int yields -1, which triggers the BUG_ON and aborts perf sched.
The central CPU validation in perf_session__deliver_event() intentionally
preserves the (u32)-1 sentinel for downstream tools like perf script
and perf inject, so leaf callbacks must handle it themselves.
Replace the three BUG_ON calls with graceful skips using pr_warning(),
matching the existing pattern in process_sched_switch_event() and
process_sched_runtime_event() earlier in the same file. Include the
file offset for cross-referencing with perf report -D.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf timechart: Fix cat_backtrace() use-after-free on corrupted callchain
cat_backtrace() uses open_memstream() to build a backtrace string.
When an invalid callchain context is encountered, zfree(&p) frees
the memstream buffer, then the exit path calls fclose(f), which
flushes to the already-freed buffer — a use-after-free. The function
then returns a dangling pointer that the caller passes to a handler
and subsequently double-frees.
Fix by replacing the zfree(&p) with a 'corrupted' flag. At the exit
label, always fclose(f) first (which finalizes the buffer), then
conditionally free it when corrupted. This ensures the memstream
contract is honored: the buffer remains valid until fclose().
While here, update the machine__resolve failure message to include
file_offset and the event type name, matching the pattern from the
preceding series. Also update the three legacy power event handlers
under SUPPORT_OLD_POWER_EVENTS to include file_offset in their
out-of-bounds CPU messages for consistency.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Include file offset and event type name in skip messages
Add the perf.data file offset and use perf_event__name() instead of raw
event type integers in the 'problem processing event, skipping it'
messages emitted by process_sample_event() callbacks across annotate,
c2c, diff, kmem, kvm, kwork, lock, report, script, and build-id.
This lets users cross-reference skipped events with 'perf report -D'
output. Also add explicit #include "util/event.h" and <inttypes.h>
where needed to avoid depending on transitive includes.
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf timechart: Include file offset in CPU bounds check messages
Add the perf.data file offset to the out-of-bounds CPU debug messages
in process_sample_cpu_idle(), process_sample_cpu_frequency(),
process_sample_sched_wakeup(), and process_sample_sched_switch().
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf sched: Include file offset in event skip messages
Add the perf.data file offset to the CPU out-of-bounds and
machine__resolve failure messages emitted when samples are skipped in
process_sched_switch_event(), process_sched_runtime_event(), and
timehist_sched_change_event(). Also switch event type from raw integer
to perf_event__name() string for readability.
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Include file offset in event skip/stop messages
Add 'at offset %#<hex>' to all warning and error messages in session.c
that fire when events are skipped or processing stops due to validation
failures. This lets users cross-reference with 'perf report -D' output
to inspect the surrounding records and understand the corruption context.
Covers messages in perf_session__process_event() (alignment, min size,
swap failure), perf_session__deliver_event() (no evsel, parse failure,
CPU clamping), machines__deliver_event() (NAMESPACES, TEXT_POKE,
null-terminated string checks for MMAP/MMAP2/COMM/CGROUP/KSYMBOL), and
perf_session__process_user_event() (THREAD_MAP, CPU_MAP, STAT_CONFIG,
BPF_METADATA, HEADER_BUILD_ID).
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf sample: Add file_offset field to struct perf_sample
Add a file_offset field to struct perf_sample so that event processing
callbacks can report the byte offset of the problematic event in
perf.data, letting users cross-reference with 'perf report -D' output.
Set sample.file_offset in perf_session__deliver_event(), which is the
common entry point for both file mode (mmap'd offset) and pipe mode
(running byte counter from __perf_session__process_pipe_events).
The assignment is placed after evsel__parse_sample(), which zeroes
the struct via memset.
Preserve file_offset through the deferred callchain delivery path by
storing it in struct deferred_event and restoring it after
evlist__parse_sample() in both evlist__deliver_deferred_callchain()
and session__flush_deferred_samples().
Subsequent patches will use this field in skip/stop warning messages.
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Thomas Falcon [Thu, 28 May 2026 15:36:37 +0000 (10:36 -0500)]
perf annotate: Fix missing branch counter column in TUI mode
'perf annotate' checks that evlist->nr_br_cntr has been incremented to
determine whether to show branch counter information.
However, this data is not populated until after the check when events
are processed.
Therefore, this counter will always be less than zero and the Branch
Count column is never shown. Do this check after events have been
processed and branch counter data is updated.
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Thomas Falcon <thomas.falcon@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When displaying branch counter (br_cntr) information, a "+" suffix
represents that event occurrences may have been lost due to branch
counter saturation. However, this indicator was missing in perf script.
Add it back.
Before:
# Branch counter abbr list:
# cpu_core/event=0xc4,umask=0x20/ppp = A
# cpu_core/instructions/ = B
# cpu_core/MEM_INST_RETIRED.ALL_LOADS/ = C
# cpu_core/MEM_LOAD_RETIRED.L2_MISS/ = D
# '-' No event occurs
# '+' Event occurrences may be lost due to branch counter saturated
...
datasym+190: 00005567f9951676 jz 0x5567f995162dr_cntr: BBBC # PRED 1 cycles [1]
...
After:
...
datasym+190: 00005567f9951676 jz 0x5567f995162dr_cntr: BBB+C # PRED 1 cycles [1]
...
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Thomas Falcon <thomas.falcon@intel.com> Acked-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
James Clark [Fri, 10 Apr 2026 11:05:12 +0000 (12:05 +0100)]
perf arm-spe: Don't warn about the discard bit if it doesn't exist
Opening an SPE event shows a warning that doesn't concern the user:
$ perf record -e arm_spe
Unknown/empty format name: discard
Perf only wants to know if the discard bit is set for configuring the
event, not in response to anything the user has done. Fix it by adding
another helper that returns if a config bit exists without warning.
We should probably keep the warning in evsel__get_config_val() to avoid
having every caller having to do it, and most format bits should never
be missing.
Add a test for the new helper. Rename the parent test function to be
more generic rather than adding a new one as it requires a lot of
boilerplate.
Reviewed-by: Ian Rogers <irogers@google.com> Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mike Leach <mike.leach@linaro.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf_exe() passes len to readlink() and then unconditionally writes a
trailing NUL at buf[n]. If readlink() returns len, the write lands one
byte past the buffer.
Read at most len - 1 bytes and keep the existing NUL termination. Also
guard the fallback path for tiny buffers so copying "perf" cannot
overflow.
Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Miguel Martín Gil <miguel.martin.gil.uni@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Chun-Tse Shao [Thu, 28 May 2026 23:44:55 +0000 (16:44 -0700)]
perf jevents: Add IOMMU metrics for Intel
Add IOMMU Translation Lookaside Buffer (TLB) and interrupt cache metrics
to perf jevents for Intel platforms. This enhances I/O performance
observability, allowing fleet-wide monitoring of IOMMU overhead.
These metrics are supported on platforms that expose the required uncore
IIO IOMMU events (such as Emerald Rapids and Granite Rapids).
The Intel implementation dynamically detects event availability at
generation time.
It requires at least the TLB events to expose the metric group, while
the interrupt cache events are optional. This allows platforms like
Emerald Rapids, which lack IOMMU interrupt cache events, to still expose
the IOMMU TLB metrics.
The following metrics are added:
- iotlb_total_hit: Total IOTLB hits (4K, 2M, 1G pages).
- iotlb_total_miss: Total IOTLB misses.
- iotlb_miss_rate: IOTLB miss rate.
- iotlb_interrupt_cache_hit: Interrupt cache hits.
- iotlb_interrupt_cache_miss: Interrupt cache misses (calculated as
lookup - hit, clamped to zero).
- iotlb_interrupt_cache_lookup: Interrupt cache lookups.
- iotlb_interrupt_cache_miss_rate: Interrupt cache miss rate.
Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Chun-Tse Shao <ctshao@google.com> Assisted-by: Gemini:gemini-3.1-pro-preview Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Dapeng Mi <dapeng1.mi@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Perry Taylor <perry.taylor@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandipan Das <sandipan.das@amd.com> Link: https://lore.kernel.org/r/20260528234455.434027-3-ctshao@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Chun-Tse Shao [Thu, 28 May 2026 23:44:54 +0000 (16:44 -0700)]
perf jevents: Add IOMMU metrics for AMD
Add IOMMU Translation Lookaside Buffer (TLB) and interrupt cache metrics
to perf jevents for AMD platforms. This enhances I/O performance
observability, allowing fleet-wide monitoring of IOMMU overhead.
These metrics are supported on Zen 2 and newer processors (Rome, Milan,
Genoa, Turin) and are implemented using the standard `amd_iommu` PMU
events. The implementation uses the existing `_zen_model` helper to
ensure these are only generated for Zen 2+. Note that the pde events on
AMD cover both 2M and 1G pages, so 1G pages are implicitly included in
the total hits/misses metrics (sum of pte and pde events).
The following metrics are added:
- iotlb_total_hit: Total IOTLB hits (4K, 2M, 1G pages).
- iotlb_total_miss: Total IOTLB misses.
- iotlb_miss_rate: IOTLB miss rate.
- iotlb_interrupt_cache_hit: Interrupt cache hits.
- iotlb_interrupt_cache_miss: Interrupt cache misses.
- iotlb_interrupt_cache_lookup: Interrupt cache lookups.
- iotlb_interrupt_cache_miss_rate: Interrupt cache miss rate.
Reviewed-by: Ian Rogers <irogers@google.com> Reviewed-by: Sandipan Das <sandipan.das@amd.com> Signed-off-by: Chun-Tse Shao <ctshao@google.com> Assisted-by: Gemini:gemini-3.1-pro-preview Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Dapeng Mi <dapeng1.mi@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Perry Taylor <perry.taylor@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com> Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andreas Färber <afaerber@suse.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Manivannan Sadhasivam <mani@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
James Clark [Mon, 11 May 2026 09:19:35 +0000 (10:19 +0100)]
perf test: Make leafloop workload immune to compiler options
Since the leafloop test program was moved into the main Perf binary as a
workload, it inherited the same compiler options as Perf. In this case
the -fstack-protector option broke the assumption that simple leaf
frames don't have a stack frame on Arm. This causes
test_arm_callgraph_fp.sh to pass even if the stack isn't augmented with
the link register, making the test useless.
Fix it by rewriting the leaf function in assembly seeing as it's so
simple. Adding -fno-stack-protector would also work, but wouldn't be
robust against other future compiler option additions.
The local variables and 'a' variable were never needed so remove them to
simplify.
Reviewed-by: Ian Rogers <irogers@google.com> Assisted-by: GitHub-Copilot:GPT-5.5 Signed-off-by: James Clark <james.clark@linaro.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf test: Add truncated perf.data robustness test
Add a shell test that verifies perf report handles truncated perf.data
files gracefully — exiting with an error code rather than crashing with
SIGSEGV or SIGABRT.
The test records a simple workload, then truncates the resulting
perf.data at four offsets that exercise different parsing stages:
8 bytes — file header magic only
64 bytes — partial file header (attr section incomplete)
256 bytes — into the first events (partial event headers)
75% size — mid-stream truncation (partial event data)
For each truncation, perf report is run and the exit code is checked:
- Exit code 0 (success) fails the test — a truncated file should
never parse without error.
- Crash signals are detected portably via kill -l, which maps the
signal number to a name on the running system. This handles
architectures where signal numbers differ (e.g. SIGBUS is 7 on
x86/ARM but 10 on MIPS/SPARC). Core-dump and fatal signals
(KILL, ILL, ABRT, BUS, FPE, SEGV, TRAP, SYS) fail the test.
- Higher exit codes (200+) are perf's own negative-errno returns
(e.g. -EINVAL = 234) and are expected.
This exercises the bounds checking, minimum-size validation, and error
propagation added by the preceding patches in this series.
Testing it:
root@number:~# perf test truncat
84: Test that perf report handles truncated perf.data gracefully (no crash, no segfault — clean error exit).: Ok
root@number:~# perf test -vv truncat
84: Test that perf report handles truncated perf.data gracefully (no crash, no segfault — clean error exit).:
--- start ---
test child forked, pid 62890
---- end(0) ----
84: Test that perf report handles truncated perf.data gracefully (no crash, no segfault — clean error exit).: Ok
root@number:~#
Changes in v2:
- Add SIGKILL to the list of fatal signals so OOM kills from
resource exhaustion bugs are detected (Reported-by: sashiko-bot@kernel.org)
Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m
[ Fixed the SPDX on the line where 'perf test' expects the test description, reviewed by Ian Rogers ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Snapshot event->header.size in process_user_event()
On native-endian files, events are read from MAP_SHARED memory.
Multiple reads of event->header.size can return different values
if the file is concurrently modified, allowing an attacker to
bypass bounds checks performed on an earlier read.
Snapshot header.size into a local variable at function entry using
READ_ONCE() to prevent compiler rematerialization, and use it for
all size-dependent arithmetic within the function. This ensures
every bounds calculation uses the same value that was validated
by the reader.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf kwork: Bounds check work->cpu before indexing cpus_runtime[]
work->cpu comes from sample->cpu which is (u32)-1 when
PERF_SAMPLE_CPU is absent. Stored as int, this becomes -1
which passes the signed BUG_ON(work->cpu >= MAX_NR_CPUS) but
causes an out-of-bounds access on cpus_runtime[-1].
Replace the BUG_ON in top_calc_total_runtime() with an unsigned
bounds check that skips entries with invalid CPU values, counting
them for a summary warning.
Guard the same index in profile_event_match() (bitmap OOB),
top_calc_idle_time(), top_calc_irq_runtime(), top_calc_cpu_usage(),
and top_calc_load_runtime(). Also guard against division by zero
in top_calc_cpu_usage() when no runtime was accumulated.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Yang Jihong <yangjihong@bytedance.com> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Bound nr_cpus_avail and validate sample CPU
Several downstream consumers (timechart, kwork, sched) use fixed-size
arrays indexed by CPU. A crafted perf.data can supply arbitrary CPU
values that index past these arrays, causing out-of-bounds access.
Validate sample.cpu against min(nr_cpus_avail, MAX_NR_CPUS) in
perf_session__deliver_event() before any tool callback runs. The
cap at MAX_NR_CPUS protects fixed-size downstream arrays; the true
nr_cpus_avail is preserved in env for header parsing (e.g.
process_cpu_topology) which needs the real count.
Fall back to MAX_NR_CPUS when HEADER_NRCPUS is missing (truncated
files, pipe mode, pre-2017 perf).
Only validate when PERF_SAMPLE_CPU is set in sample_type — when
absent, evsel__parse_sample() leaves sample.cpu as (u32)-1, a
sentinel that downstream tools (script, inject) check to identify
events without CPU info. Clamping it to 0 would break those checks.
Inline evlist__parse_sample() into perf_session__deliver_event()
so the evsel lookup needed for sample_type checking reuses the same
evsel that parsed the sample, avoiding a second evlist__event2evsel()
call on every event.
For pipe-mode streams where HEADER_NRCPUS may arrive late or not at
all, the MAX_NR_CPUS fallback ensures the bounds check is still
effective against the fixed-size downstream arrays.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Check for decompression buffer size overflow
On 32-bit systems, sizeof(struct decomp) + decomp_len can wrap
size_t when comp_mmap_len is large. The preceding patch validates
comp_mmap_len alignment but does not cap the upper bound, so two
additions can still overflow:
1. decomp_len += decomp_last_rem: on 32-bit, adding a u64 to
size_t silently truncates, producing a corrupted decomp_len
that would bypass the subsequent overflow check and result
in an undersized buffer allocation.
2. sizeof(struct decomp) + decomp_len: the final addition could
overflow on systems with small size_t.
Add explicit overflow checks before each addition as
defense-in-depth.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add several hardening checks to the compressed event decompression
pipeline:
1. Guard against decomp_last_rem underflow: check that
decomp_last->head does not exceed decomp_last->size before
subtracting. A u64 underflow here would produce a huge
decomp_len, causing an oversized mmap allocation.
2. Validate comp_mmap_len from the HEADER_COMPRESSED feature
section: reject values that are not 4K-aligned or smaller than
4096. The downstream decompression path checks allocation
sizes against SIZE_MAX, which handles 32-bit safety.
3. Validate COMPRESSED event header size: reject events where
header.size is too small to contain the fixed struct fields,
preventing underflow in the payload size calculation.
4. Validate COMPRESSED2 event data_size: check that data_size
does not exceed the available payload (header.size minus the
fixed struct fields) for the newer compressed format.
5. Reject compressed events when the HEADER_COMPRESSED feature
is missing from the file header, which means no decompression
context was initialized.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Add byte-swap handler for PERF_RECORD_COMPRESSED2
PERF_RECORD_COMPRESSED2 events carry a data_size field that must be
byte-swapped when reading cross-endian perf.data files. Without a
swap handler, reading COMPRESSED2 events on a different-endian machine
would misinterpret data_size as a garbage value, causing the
decompression path to read the wrong number of bytes.
The compressed payload itself is a raw byte stream and needs no
swapping.
Fixes: 208c0e16834472bb ("perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2") Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf header: Validate bitmap size before allocating in do_read_bitmap()
do_read_bitmap() reads a u64 bit count from the file and passes it
to bitmap_zalloc() without checking it against the remaining section
size. A crafted perf.data could trigger a large allocation that would
only fail later when the per-element reads exceed section bounds.
Additionally, bitmap_zalloc() takes an int parameter, so a crafted
size with bits set above bit 31 (e.g. 0x100000040) would pass the
section bounds check but truncate when passed to bitmap_zalloc(),
allocating a much smaller buffer than the subsequent read loop
expects.
Reject size values that exceed INT_MAX, and check that the data
needed (BITS_TO_U64(size) u64 values) fits in the remaining section
before allocating. Switch from bitmap_zalloc() to calloc() of u64
units so the allocation size matches the u64 read/write granularity
and avoids unsigned long vs u64 mismatch on 32-bit architectures.
Fix do_write_bitmap() to use memcpy to read u64-sized chunks from
the unsigned long bitmap, preventing out-of-bounds reads on 32-bit
systems where sizeof(unsigned long) is 4 but the bitmap is stored
in u64 units.
Fix process_mem_topology() minimum section size: the check used
nr * 2 * sizeof(u64) per node, but do_read_bitmap() reads an
additional u64 for the bitmap size, so the minimum is 3 * sizeof(u64).
Fix memory leak in process_mem_topology() error paths: replace
free(nodes) with memory_node__delete_nodes() to free per-node
bitmaps allocated by do_read_bitmap().
Currently used by process_mem_topology() for HEADER_MEM_TOPOLOGY.
Fixes: a881fc56038a ("perf header: Sanity check HEADER_MEM_TOPOLOGY") Closes: https://lore.kernel.org/linux-perf-users/20260414224622.2AE69C19425@smtp.kernel.org/ Closes: https://lore.kernel.org/linux-perf-users/20260410223242.DD76FC19421@smtp.kernel.org/ Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf header: Sanity check HEADER_EVENT_DESC attr.size before swap
read_event_desc() reads nre (event count), sz (attr size), and nr
(IDs per event) from the file and uses them to control allocations
and loops without validating them against the section size.
A crafted perf.data could trigger large allocations or many loop
iterations before __do_read() eventually rejects the reads.
Add bounds checks in read_event_desc():
- Reject sz smaller than PERF_ATTR_SIZE_VER0.
- Require at least one event (nre > 0).
- Check that nre events fit in the remaining section, using the
minimum per-event footprint of sz + sizeof(u32).
- Pre-swap attr->size to native byte order, then reject values
below PERF_ATTR_SIZE_VER0 or above sz before calling
perf_event__attr_swap() to prevent heap out-of-bounds access.
- Handle ABI0 (attr.size == 0): substitute PERF_ATTR_SIZE_VER0,
and on native-endian files write the value back so
free_event_desc() does not treat the zero as its end-of-array
sentinel (it iterates while attr.size != 0). The swap path
skips the write-back — perf_event__attr_swap() has its own
ABI0 fallback that sets VER0 after swapping.
- Check that nr IDs fit in the remaining section before allocating.
Fixes: b30b61729246 ("perf tools: Fix a problem when opening old perf.data with different byte order") Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Harden feature section parsing against crafted perf.data files:
1. perf_header__process_sections() reads the feature section table
and passes each section's offset and size directly to the
processing callbacks without validating them against the actual
file size. A crafted section size would make all downstream
bounds checks against ff->size ineffective since they compare
against the untrusted, inflated bound. Add an fstat() check
with S_ISREG() guard and verify that each section's offset +
size does not extend past EOF.
2. __do_read_buf() validates reads against ff->size (section size),
but __do_read_fd() had no such check, so a malformed perf.data
with an understated section size could cause reads past the end
of the current section into the next section's data. Add the
bounds check in __do_read(), the common caller of both helpers,
so it is enforced uniformly for both the fd and buf paths.
Track the section-relative offset in __do_read_fd() so the
check works for the fd path. Reject negative sizes which on
32-bit can occur when a u32 >= 0x80000000 is passed as ssize_t.
3. do_read_string() relied on file data being null-padded. Add
explicit null-termination (buf[len-1] = '\0') after reading
and validate length (>= 1, fits within section) before
allocating, so callers like process_cpu_topology() never
receive an unterminated string.
4. Initialize feat_fd.offset to 0 (section-relative) instead of
section->offset (file-absolute) so the bounds tracking is
consistent with __do_read()'s section-relative comparison.
Adjust process_build_id() to use lseek() for its file-absolute
offset needs since it cannot rely on ff->offset for that.
5. Propagate ff->size to perf_file_section__fprintf_info() so its
reads are also bounded.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf header: Validate f_attr.ids section before use in perf_session__read_header()
perf_session__read_header() reads f_attr.ids.size from the perf.data
file and divides it by sizeof(u64) to compute nr_ids, which is
declared as int. No validation is performed on the value before it
is used to allocate arrays and drive a read loop.
On 32-bit architectures, a crafted f_attr.ids.size of 0x100000000
(4 GB) produces nr_ids = 0x20000000, but the allocation size
1 * 0x20000000 * 8 overflows size_t to 0, so zalloc(0) returns a
valid pointer. The subsequent loop writes 0x20000000 IDs into that
zero-length buffer, corrupting the heap.
On 64-bit, the u64-to-int truncation silently drops high bits,
processing fewer IDs than the file claims. While not exploitable,
this is a data integrity issue.
Add validation before using f_attr.ids:
- Cap nr_attrs (attrs.size / attr_size) to MAX_NR_ATTRS (1 << 16)
with overflow-safe u64 comparison before assigning to int
- Reject ids.size not aligned to sizeof(u64)
- Cap ids.size / sizeof(u64) to MAX_IDS_PER_ATTR (1 << 24) to
prevent int truncation and size_t overflow on 32-bit
- Reject ids sections that extend past the end of the file,
guarded by S_ISREG() so non-regular files (block devices,
pipes) are not falsely rejected
Also fix perf_header__getbuffer64() to set errno = EIO when
readn() returns 0 (EOF). Without this, the out_errno path in
perf_session__read_header() returns -errno which is 0 (success)
on truncated files, causing downstream NULL dereferences.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf_session__read_header() discards the return value from
perf_header__process_sections(), so any error from a feature
section processor (process_nrcpus, process_compressed, etc.)
is silently ignored and the session opens as if nothing went
wrong.
This defeats the validation added by subsequent commits in this
series: a crafted perf.data that fails a feature section check
would still be processed with partially-initialized state.
Check the return value and fail the session if any feature
section processor returns an error.
For truncated files (data.size == 0, i.e. recording was
interrupted before the header was finalized), skip feature
section processing entirely and clear the feature bitmap so
tools use their "feature not present" fallbacks instead of
accessing uninitialized env fields.
Change the feature processor stubs for optional libraries
(libtraceevent, libbpf) from returning -1 to returning 0,
so that perf.data files containing these features can still be
opened on builds without the optional library — the feature is
simply skipped rather than causing a fatal error.
Also propagate evlist__prepare_tracepoint_events() failure as
-ENOMEM, since the function can fail due to strdup() allocation
failure inside evsel__prepare_tracepoint_event().
Fixes: 1c0b04d12ae9 ("perf tools: Add perf_session__read_header function") Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Bounds check perf_event_attr fields against attr.size before printing
perf_event_attr__fprintf() accessed all struct fields unconditionally,
but attrs from older perf.data files or BPF-captured syscall payloads
may have a smaller size than the current struct. Fields beyond the
recorded size contain uninitialized or zero-filled data.
Add size-guarded macros (PRINT_ATTRn, PRINT_ATTRn_bf) that compare
each field's offset against attr->size before accessing it.
Guard the bitfield block (disabled, inherit, ... defer_output) with
attr_size >= 48. These bitfields share a single __u64 at offset 40,
which is within PERF_ATTR_SIZE_VER0 for validated perf.data attrs,
but BPF-captured attrs from perf trace can have a smaller size when
the tracee passes a minimal struct to sys_perf_event_open.
Also fix the BPF trace path: when perf trace intercepts
sys_perf_event_open via BPF, the program copies PERF_ATTR_SIZE_VER0
bytes when the tracee passes size=0, but leaves the size field as 0.
Set attr->size to PERF_ATTR_SIZE_VER0 in the augmented syscall
handler so the bounds checks match the actual copied size.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf header: Validate null-termination in PERF_RECORD_EVENT_UPDATE string fields
strdup(ev->unit) and strdup(ev->name) read until '\0' with no
guarantee the string is null-terminated within event->header.size.
The dump_trace fprintf path has the same problem with %s.
Validate before either path runs — same class of bug fixed for
MMAP/MMAP2/COMM/CGROUP by perf_event__check_nul().
Also harden the event_update swap handler to:
- Validate SCALE event size before swapping the double at
offset 24, which exceeds the 24-byte min_size.
- Validate CPUS event size before accessing the cpu_map
type/nr/long_size fields, which also start at the min_size
boundary.
- Swap CPUS variant fields (type, nr, long_size) so the
processing path sees native byte order.
Add validation in perf_event__process_event_update() for all
event update variants (UNIT, NAME, SCALE, CPUS) before
dump_trace or processing.
Validate CPUS nr against payload size for both PERF_CPU_MAP__CPUS
and PERF_CPU_MAP__MASK types on the fprintf (dump_trace) path:
- CPUS: check nr does not exceed available cpu entries
- MASK: check nr does not exceed available mask entries for
both mask32 (long_size == 4) and mask64 (long_size == 8)
layouts, with underflow guards on the offsetof subtraction
Fix a missing break before the default case in the CPUS
switch path.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Add byte-swap and bounds check for PERF_RECORD_BPF_METADATA events
PERF_RECORD_BPF_METADATA has no entry in perf_event__swap_ops[], so its
nr_entries field is never byte-swapped when reading a cross-endian
perf.data file. Downstream processing in
perf_event__fprintf_bpf_metadata() loops over nr_entries, so a
foreign-endian value causes out-of-bounds reads.
Add a swap handler that byte-swaps nr_entries after validating that
header.size is large enough. The entries[] array contains only char
arrays (key/value strings), so no per-entry swap is needed — but ensure
NUL-termination on the writable cross-endian path.
Validate header.size, nr_entries, and string NUL-termination in the
common event delivery path so that native-endian files with malicious
values are also rejected. Snapshot nr_entries via READ_ONCE() before
validation — the event is on a MAP_SHARED mmap that could theoretically
change between the bounds check and the loop.
Changes in v2:
- Snapshot event->header.size via READ_ONCE() into a local variable
to prevent a double-fetch underflow in the max_entries calculation
(Reported-by: sashiko-bot@kernel.org)
- Write back clamped nr_entries to the event on the swap path,
consistent with NAMESPACES and STAT_CONFIG handlers — without
writeback the native path sees the inflated nr and skips the
event entirely (Reported-by: sashiko-bot@kernel.org)
Fixes: ab38e84ba9a8 ("perf record: collect BPF metadata from existing BPF programs") Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Blake Jones <blakejones@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix four issues in PERF_RECORD_AUXTRACE_ERROR handling:
1. auxtrace_error_name() takes a signed int parameter, but e->type
is __u32. A crafted value like 0xFFFFFFFF converts to -1, passes
the bounds check, and causes a negative array index. Fix by
changing the parameter to unsigned int.
2. The msg field is printed via %s without a length bound. The
min_size table only guarantees fields up to msg (offset 48), so
a truncated event has zero msg bytes within the event boundary.
Compute the available msg length from header.size, cap at
sizeof(e->msg), and use %.*s.
3. fmt >= 2 adds machine_pid and vcpu fields after msg[64]. Older
files may have fmt >= 2 but an event size that doesn't include
these fields. Add a size check in the swap handler to downgrade
fmt before the conditional field access, and a matching size
guard in the fprintf path for native-endian events (which are
mmap'd read-only and can't be modified in place).
4. python_process_auxtrace_error() had the same issues: msg was
passed to tuple_set_string() unbounded, and machine_pid/vcpu
were accessed unconditionally without checking fmt or event
size. Apply the same bounds checks.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf cpumap: Reject RANGE_CPUS with start_cpu > end_cpu
cpu_map__from_range() computes nr_cpus as end_cpu - start_cpu + 1.
When a crafted perf.data has start_cpu > end_cpu, this wraps to a
huge value, causing perf_cpu_map__empty_new() to attempt a massive
allocation.
Return NULL when the range is inverted.
Also clamp any_cpu to boolean (0 or 1) since it is added to the
allocation count — a crafted value > 1 would inflate the map size.
Harden cpu_map__from_mask() to reject unsupported long_size values
(anything other than 4 or 8), preventing misinterpretation of the
mask data layout.
Snapshot mmap'd fields via READ_ONCE() into locals to prevent
TOCTOU re-reads — the data pointer references MAP_SHARED mmap'd
memory that could theoretically change between reads on a
FUSE-backed file:
- cpu_map__from_range(): snapshot start_cpu, end_cpu, any_cpu
- cpu_map__from_entries(): snapshot nr and each cpu[i] element
- cpu_map__from_mask(): snapshot long_size (before validation,
closing the check-then-read gap), mask_nr
- perf_record_cpu_map_data__read_one_mask(): add u16 long_size
parameter so callers pass the validated copy instead of
re-reading data->mask32_data.long_size from mmap'd memory
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf header: Byte-swap build ID event pid and bounds check section entries
perf_header__read_build_ids() swaps the event header fields for cross-endian
perf.data files but not bev.pid. This causes perf_session__findnew_machine()
to look up the wrong machine for guest VM build IDs, misattributing them.
Swap bev.pid alongside the header fields.
Also add a build_id_swap callback for stream-mode build ID events,
and validate NUL-termination of build_id.filename on the native-endian
delivery path (perf_session__process_user_event) — events with
unterminated filenames are skipped.
Harden perf_header__read_build_ids() against crafted perf.data files:
- Add overflow check on offset + size to prevent wrap past ULLONG_MAX.
- Reject bev.header.size == 0 which would loop forever.
- Reject bev.header.size > remaining section to prevent reading past
the section boundary.
- Guard memcmp(filename, "nel.kallsyms]", 13) with len >= 13 to avoid
reading uninitialized stack memory on short filenames.
- Force NUL-termination of filename before passing it to functions
like machine__findnew_dso() that use strlen/strcmp.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Validate nr fields against event size on both swap and common paths
Several event types use an nr field to control iteration over
variable-length arrays. The swap handlers byte-swap and loop using
these fields without bounds checks, and the native processing path
trusts them as well.
Add bounds checks on both paths for:
- PERF_RECORD_THREAD_MAP: validate nr against payload, return -1
on the swap path. On the native path, reject with -EINVAL.
- PERF_RECORD_NAMESPACES: clamp nr on the swap path (safe because
each entry is indexed by type; missing entries just won't be
resolved). Skip the event on the native path.
- PERF_RECORD_CPU_MAP: clamp nr for CPUS and MASK sub-types on
the swap path. Add bounds checks for mask64 which previously
had no nr validation. Skip the event on the native path.
- PERF_RECORD_STAT_CONFIG: clamp nr on the swap path (safe because
each config entry is self-describing via its tag). Skip the
event on the native path.
The swap path (cross-endian, writable MAP_PRIVATE mapping) can
safely clamp by writing back to the event. The native path
(read-only MAP_SHARED mapping) must skip instead of clamping
because writing to the mmap'd event would segfault.
Also fix stat_config swap range: change size += 1 to
size += sizeof(event->stat_config.nr) for clarity. The old +1
happened to work because mem_bswap_64 processes 8-byte chunks,
but the intent is to include the 8-byte nr field in the swap
range.
Changes in v2:
- Document that PERF_RECORD_NAMESPACES max_nr includes trailing
sample_id space when sample_id_all is present — harmless on the
swap path because both per-element bswap_64 and swap_sample_id_all()
perform the same u64 byte swap (Reported-by: sashiko-bot@kernel.org)
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Validate HEADER_ATTR attr.size before swapping
Harden PERF_RECORD_HEADER_ATTR handling against crafted perf.data:
- Validate attr.size: must be >= PERF_ATTR_SIZE_VER0, a multiple
of sizeof(u64), and fit within the event payload.
- Copy only min(attr.size, sizeof(struct perf_event_attr)) bytes
into a local attr, zeroing the rest so legacy files don't leak
adjacent event data into new fields.
- Keep the original attr.size so perf_event__synthesize_attr()
uses it for both allocation and ID-array placement.
Fix perf_event__synthesize_attr() to use attr->size (not the
compiled sizeof) for event allocation and layout, so perf inject
correctly re-synthesizes attrs from files recorded by a different
perf version. Without this, the ID array destination pointer
(computed via perf_record_header_attr_id()) would be inconsistent
with the allocation when attr->size differs from sizeof.
Also fix the parse-no-sample-id-all test to set attr.size, which
is now validated, and improve error handling in read_attr() for
short reads and invalid attr sizes.
Handle ABI0 pipe/inject events where attr.size is 0: use a local
attr_size variable set to PERF_ATTR_SIZE_VER0 for both the bounded
copy and ID array position, instead of writing back to the event.
Native-endian files may be MAP_SHARED (read-only mmap), so writing
to the event buffer would SIGSEGV. The swap path handles ABI0 in
perf_event__attr_swap() which writes to the MAP_PRIVATE copy.
header.size alignment is now validated centrally in
perf_session__process_event() (see "Add minimum event size and
alignment validation").
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Use bounded copy for PERF_RECORD_TIME_CONV
session->time_conv = event->time_conv copies sizeof(struct
perf_record_time_conv) bytes unconditionally, but older kernels
emit shorter TIME_CONV events without the time_cycles, time_mask,
cap_user_time_zero, and cap_user_time_short fields.
For a 32-byte event (the original format), this reads 24 bytes
past the event boundary into adjacent mmap'd data. The garbage
values end up in session->time_conv and can cause incorrect TSC
conversion if cap_user_time_zero happens to be non-zero.
Replace the struct assignment with a bounded memcpy capped at
event->header.size, zeroing the remainder so extended fields
default to off when absent.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Add validated swap infrastructure with null-termination checks
Change swap callbacks from void to int return so handlers can
propagate errors. All 28 existing handlers are converted to
return 0 on success, -1 on error. Three new handlers (KSYMBOL,
BPF_EVENT, HEADER_FEATURE) are added returning int from the
start, with sample_id_all handling for the kernel event types.
event_swap() propagates the return to its callers (process_event
and peek_event), which skip events that fail to swap.
Add perf_event__check_nul() for null-termination enforcement
on the common event delivery path for MMAP, MMAP2, COMM,
CGROUP, and KSYMBOL events. Events with
unterminated strings are skipped — native-endian files are
mapped read-only, so writing a NUL byte in place would segfault.
Swap handler hardening:
- Use strnlen bounded by event size (instead of strlen) in
COMM/MMAP/MMAP2/CGROUP swap handlers, returning -1 on
unterminated strings.
- Bounds check text_poke old_len+new_len before computing the
sample_id offset, returning -1 on overflow. Use offsetof()
for the native-path check in machines__deliver_event() since
sizeof() includes struct padding past the flexible array.
- Fix PERF_RECORD_SWITCH sample_id_all: non-CPU_WIDE SWITCH
events have sample_id immediately after the 8-byte header,
not at sizeof(struct perf_record_switch) which is the
CPU_WIDE variant size.
- Fix perf_event__time_conv_swap(): decouple time_cycles and
time_mask into independent per-field event_contains() checks,
so each field is only swapped when the event is large enough
to contain it. The original code guarded both fields under
a single time_cycles check, which would swap time_mask on a
short event that contains time_cycles but not time_mask.
- Handle ABI0 (attr.size == 0) in perf_event__attr_swap()
by substituting PERF_ATTR_SIZE_VER0, so bswap_safe()
correctly swaps VER0 fields instead of skipping everything.
- peek_events: on swap failure, advance past the malformed
entry instead of aborting the loop.
Note: the nr-field bounds checks for namespaces, thread_map,
cpu_map, and stat_config arrays are added by a subsequent
patch ("perf session: Validate nr fields against event size
on both swap and common paths"). The HEADER_ATTR attr.size
validation is added by ("perf session: Validate HEADER_ATTR
attr.size before swapping").
By establishing the int-returning swap infrastructure first,
all subsequent hardening patches can use direct error returns
from day one — no poison values, no workarounds for void return.
Changes in v2:
- peek_events: abort instead of skip for AUXTRACE events on
validation failure — skipping only header.size would land
inside the raw trace payload, causing subsequent iterations
to misparse data as events (Reported-by: sashiko-bot@kernel.org)
Fixes: 9aa0bfa370b2 ("perf tools: Handle PERF_RECORD_KSYMBOL") Fixes: 45178a928a4b ("perf tools: Handle PERF_RECORD_BPF_EVENT") Fixes: e9def1b2e74e ("perf tools: Add feature header record to pipe-mode") Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Song Liu <songliubraving@fb.com> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Fix swap_sample_id_all() crash on crafted events
swap_sample_id_all() calls BUG_ON(size % sizeof(u64)) which kills
perf on any event where the sample_id_all tail is not 8-byte aligned.
A crafted perf.data can trigger this trivially.
Replace BUG_ON with a bounds check: skip the swap if the data pointer
is past the end of the event, and only swap when there are bytes
remaining.
Note: the strlen calls in string-field swap handlers (comm,
mmap, mmap2, cgroup) are replaced with bounded strnlen by the
next patch in this series ("perf session: Add validated swap
infrastructure with null-termination checks").
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Fix PERF_RECORD_READ swap and dump for variable-length events
The kernel dynamically sizes PERF_RECORD_READ based on
attr.read_format: only the fields enabled by PERF_FORMAT_TOTAL_TIME_ENABLED,
PERF_FORMAT_TOTAL_TIME_RUNNING, PERF_FORMAT_ID, and PERF_FORMAT_LOST
are emitted, packed with no gaps.
perf_event__read_swap() unconditionally byte-swapped time_enabled,
time_running, and id at their fixed struct offsets, causing
out-of-bounds access on smaller events and swapping the wrong
bytes when not all format fields are present. It also swapped
sample_id_all at a fixed offset past the full struct, which is
wrong for shorter events.
Replace the individual field swaps with a single mem_bswap_64()
over the entire tail from value onward. Since every field after
pid/tid is u64 regardless of which combination is present, this
correctly handles any read_format combination and any trailing
sample_id_all fields.
Similarly, dump_read() accessed optional fields via fixed struct
offsets, displaying values from wrong positions when not all
format bits are set. Walk the packed u64 array sequentially
instead, with bounds checks against event->header.size.
Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf zstd: Fix multi-iteration decompression and error handling
zstd_decompress_stream() has two bugs in its multi-iteration loop:
1. After each ZSTD_decompressStream() call, the code advances
output.dst by output.pos but doesn't reset output.pos to 0.
ZSTD interprets output.pos relative to output.dst, so the
next iteration writes at (dst + pos) + pos = dst + 2*pos,
skipping a gap and potentially writing out of bounds.
2. On ZSTD_decompressStream() error, the loop executes break
and returns output.pos (which is > 0 if some bytes were
decompressed before the error). The caller checks
!decomp_size and skips the error, silently accepting
truncated or corrupted data.
Fix both by removing the output buffer adjustment — ZSTD
correctly accumulates output.pos across calls without it.
Return 0 on decompression error so the caller detects it.
Add a no-progress guard to prevent infinite loops if the
output buffer fills before all input is consumed.
Note: the compressed event data_size is validated against
header.size by a subsequent patch in this series
("perf tools: Harden compressed event processing").
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf zstd: Fix compression error path in zstd_compress_stream_to_records()
The error fallback does memcpy(dst, src, src_size) intending to store
uncompressed data when compression fails, but this has three bugs:
1. dst has been advanced past the record header (and potentially
past earlier compressed records), so the copy writes to the
wrong offset in the output buffer.
2. src still points to the start of the input, not to the
remaining uncompressed data at src + input.pos. On a second
or later iteration, previously compressed data would be
duplicated.
3. No check that dst_size >= src_size — if the remaining output
space is smaller, this is an out-of-bounds write.
Replace with return -1 after resetting the ZSTD compression
context via ZSTD_initCStream(). The -1 propagates through
zstd_compress() -> record__pushfn() -> perf_mmap__push() to the
recording loop, which breaks out and terminates recording.
Add an out_child_no_flush label in __cmd_record() so the
mmap-read failure path skips the final record__mmap_read_all()
flush — retrying the same read that just failed would just fail
again, and the flush is only useful when the mmap data is intact
but the control path (auxtrace, switch_output) had an error.
Consolidate all error paths through a single 'reset' label to
ensure the compression context is always reset on failure —
including the output-buffer-full path, where a bare return
without resetting would leave stale stream state that corrupts
output if the caller retries.
Also guard against process_header() writing the event header
before the buffer-full check: add a sizeof(perf_event_header)
pre-check so the callback never writes past the output buffer.
Guard against ZSTD making no progress: if output.pos is zero
after ZSTD_compressStream(), calling process_header(record, 0)
would re-trigger header initialization, double-subtracting the
header size from dst_size and underflowing the unsigned counter.
Also fix two pre-existing issues in the same function:
- Add a dst_size guard before subtracting the record header
size: if the output buffer is nearly full, the unsigned
dst_size -= size underflows to a huge value, causing
ZSTD_compressStream to write past the buffer boundary.
- Check the ZSTD_initCStream() return value and log an error
if the context reset itself fails.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Fix event_contains() macro to verify full field extent
event_contains() checked whether a field's start offset was within
the event (header.size > offsetof), but not whether the full field
fit. A crafted event with header.size = offsetof(field) + 1 would
pass the check, but an 8-byte access (bswap_64, direct read) would
overrun the event boundary by up to 7 bytes.
Fix the macro to verify the complete field:
header.size >= offsetof(field) + sizeof(field)
Also update all callers that check event_contains(time_cycles) but
access later fields (time_mask, cap_user_time_zero,
cap_user_time_short) to check for cap_user_time_short — the last
field accessed — so the entire extended block is verified:
tsc.c, arm-spe.c, cs-etm.c, jitdump.c.
Note: session.c's perf_event__time_conv_swap() also guards on
time_cycles but accesses time_mask — a pre-existing issue not
introduced by this macro change. It is fixed by a later patch
in this series ("perf session: Add validated swap
infrastructure with null-termination checks"), which decouples
time_cycles and time_mask into independent per-field
event_contains() checks. The struct assignment overread
(session->time_conv = event->time_conv copies sizeof on a
potentially shorter event) is separately fixed by "perf
session: Use bounded copy for PERF_RECORD_TIME_CONV".
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Bounds-check one_mmap event pointer in peek_event
perf_session__peek_event() computes an event pointer directly from
file_offset when one_mmap is active, without verifying that file_offset
and the subsequent event->header.size fall within the mapped region.
A corrupted perf.data file could cause out-of-bounds memory reads.
Add one_mmap_size to the session struct and validate both the header
and full event fit within the mmap before dereferencing.
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf session: Add minimum event size and alignment validation
Add a per-type minimum size table (perf_event__min_size[]) and
enforce it before swap and processing, so that both cross-endian
and native-endian paths are protected from accessing fields past
the event boundary.
The table uses offsetof() for types with trailing variable-length
fields (filenames, strings, msg arrays) and sizeof() for
fixed-size types. Zero entries mean no minimum beyond the 8-byte
header already enforced by the reader.
Undersized events are skipped with a warning in process_event
and rejected in peek_event — both checked before the swap
handler runs, preventing OOB access on crafted event fields.
Also reject events whose header.size is not 8-byte aligned. The
kernel aligns all event sizes to sizeof(u64) — see
perf_event_comm_event() (ALIGN), perf_event_mmap_event(),
perf_event_cgroup(), perf_event_ksymbol() (IS_ALIGNED loops),
and perf_event_text_poke() (ALIGN) in kernel/events/core.c.
An unaligned size means the file is corrupted or crafted; reject
early so downstream code that divides by sizeof(u64) to compute
array element counts gets exact results.
Three legacy user events are exempted from the alignment check:
TRACING_DATA (66) had a 12-byte struct before commit b39c915a4f36
("libperf event: Ensure tracing data is multiple of 8 sized")
added padding, COMPRESSED (81) carries raw ZSTD output (already
superseded by COMPRESSED2 with PERF_ALIGN), and HEADER_FEATURE
(80) uses do_write_string() with a 4-byte length prefix.
Also guard event_swap() against crafted event types >=
PERF_RECORD_HEADER_MAX to prevent OOB reads on the
perf_event__swap_ops[] array.
Changes in v2:
- Fix double-skip for unsupported event types: return 0 instead
of event->header.size in perf_session__process_event() for
HEADER_MAX, since reader__read_event() already advances by
event->header.size (Reported-by: sashiko-bot@kernel.org)
- Exempt TRACING_DATA, COMPRESSED, and HEADER_FEATURE from the
alignment check — these legacy user events predate the 8-byte
alignment rule (Reported-by: sashiko-bot@kernel.org)
- peek_event: return 0 (skip) for unknown event types instead of
-1 (error), consistent with process_event which already skips
unsupported types gracefully (Reported-by: sashiko-bot@kernel.org)
Reported-by: sashiko-bot@kernel.org # Running on a local machine Reviewed-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6-1m Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tests hwmon_pmu: Use PRIu64 + (uint64_t) cast for a __u64 field to work more widely
While testing perf with an updated Debian experimental cross compiler
(gcc version 14.2.0 (Debian 14.2.0-13)) this started failing:
In file included from tests/hwmon_pmu.c:12:
tests/hwmon_pmu.c: In function 'do_test':
tests/hwmon_pmu.c:199:34: error: format '%lld' expects argument of type 'long long int', but argument 7 has type '__u64' {aka 'long unsigned int'} [-Werror=format=]
199 | pr_debug("FAILED %s:%d Unexpected config for '%s', %lld != %ld\n",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/git/perf-7.1.0-rc5/tools/perf/util/debug.h:20:21: note: in definition of macro 'pr_fmt'
20 | #define pr_fmt(fmt) fmt
| ^~~
tests/hwmon_pmu.c:199:25: note: in expansion of macro 'pr_debug'
199 | pr_debug("FAILED %s:%d Unexpected config for '%s', %lld != %ld\n",
| ^~~~~~~~
tests/hwmon_pmu.c:199:79: note: format string is defined here
199 | pr_debug("FAILED %s:%d Unexpected config for '%s', %lld != %ld\n",
| ~~~^
| |
| long long int
| %ld
LD /tmp/build/perf/util/intel-pt-decoder/perf-util-in.o
The usual make that %lld a PRIu64 (since arg7 is
evsel->core.attr.config, which is a __u64) but then on Fedora 44 (gcc
version 16.1.1 20260515 (Red Hat 16.1.1-2)) it ends up with:
In file included from tests/hwmon_pmu.c:13:
tests/hwmon_pmu.c: In function ‘do_test’:
tests/hwmon_pmu.c:200:34: error: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 7 has type ‘__u64’ {aka ‘long long unsigned int’} [-Werror=format=]
200 | pr_debug("FAILED %s:%d Unexpected config for '%s', %" PRIu64 " != %ld\n",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/acme/git/perf-tools-next2/tools/perf/util/debug.h:20:21: note: in definition of macro ‘pr_fmt’
20 | #define pr_fmt(fmt) fmt
| ^~~
tests/hwmon_pmu.c:200:25: note: in expansion of macro ‘pr_debug’
200 | pr_debug("FAILED %s:%d Unexpected config for '%s', %" PRIu64 " != %ld\n",
| ^~~~~~~~
cc1: all warnings being treated as errors
So the way to satisfy both compilers is to also add a (u64) cast to
arg7.
Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 22 May 2026 22:04:15 +0000 (15:04 -0700)]
perf script: Sort includes and add missed explicit dependencies
Fix missing #include of pmu.h found while cleaning the evsel/evlist
header files. Sort the remaining header files for consistency with the
rest of the code. Doing this exposed a missing forward declaration of
addr_location in print_insn.h, add this and sort the forward
declarations.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alice Rogers <alice.mei.rogers@gmail.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Leo Yan <leo.yan@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 22 May 2026 22:04:14 +0000 (15:04 -0700)]
perf tests: Sort includes and add missed explicit dependencies
Fix missing #includes found while cleaning the evsel/evlist header
files. Sort the remaining header files for consistency with the rest
of the code.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alice Rogers <alice.mei.rogers@gmail.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Leo Yan <leo.yan@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 22 May 2026 22:04:13 +0000 (15:04 -0700)]
perf arch x86: Sort includes and add missed explicit dependencies
Fix missing #includes found while cleaning the evsel/evlist header
files. Sort the remaining header files for consistency with the rest
of the code.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alice Rogers <alice.mei.rogers@gmail.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Leo Yan <leo.yan@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Fri, 22 May 2026 22:04:12 +0000 (15:04 -0700)]
perf arch arm: Sort includes and add missed explicit dependencies
Fix missing #includes found while cleaning the evsel/evlist header
files. Sort the remaining header files for consistency with the rest
of the code.
Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alice Rogers <alice.mei.rogers@gmail.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Leo Yan <leo.yan@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Rui Qi [Fri, 22 May 2026 08:26:04 +0000 (16:26 +0800)]
perf: Apply is_ignored_kernel_symbol() filter in ELF loading path for kernel DSOs
dso__load_sym_internal() had no filtering for .L* and L0* mapping
symbols while the kallsyms path already filters them via
is_ignored_kernel_symbol().
Add the same check gated by dso__kernel() so that kernel ELF objects
(vmlinux, .ko) have mapping symbols filtered across all architectures,
but userspace ELF objects are unaffected -- '$' is a valid prefix in
languages like Java and Scala.
The existing ARM/AArch64 and RISC-V architecture-specific mapping symbol
checks are preserved; the new is_ignored_kernel_symbol() check adds x86
local symbol (.L*, L0*) filtering and provides unified
cross-architecture coverage for kernel DSOs.
Signed-off-by: Rui Qi <qirui.001@bytedance.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Rui Qi [Fri, 22 May 2026 08:26:03 +0000 (16:26 +0800)]
perf: Extract is_ignored_kernel_symbol() for kernel mapping symbol filtering
Mapping symbol filtering is scattered across multiple files with
inconsistent checks. The kernel's own is_mapping_symbol() covers x86
local symbols ('.L*' and 'L0*') on top of the '$' prefix used by
ARM/AArch64/RISC-V, but the perf tool only checks '$'.
Extract is_ignored_kernel_symbol() into symbol.h matching the kernel
definition, and convert the kallsyms and ksymbol event paths to use it.
Add ksymbol event name validation and early mapping symbol filtering
before any state mutation.
Signed-off-by: Rui Qi <qirui.001@bytedance.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Athira Rajeev [Mon, 4 May 2026 15:13:20 +0000 (20:43 +0530)]
powerpc tools perf: Initialize error code in auxtrace_record_init function
perf trace record fails some cases in powerpc
# perf test "perf trace record and replay"
128: perf trace record and replay : FAILED!
# perf trace record sleep 1
# echo $?
32
This is happening because of non-zero err value from
auxtrace_record__init() function.
static int record__auxtrace_init(struct record *rec)
{
int err;
if ((rec->opts.auxtrace_snapshot_opts || rec->opts.auxtrace_sample_opts)
&& record__threads_enabled(rec)) {
pr_err("AUX area tracing options are not available in parallel streaming mode.\n");
return -EINVAL;
}
if (!rec->itr) {
rec->itr = auxtrace_record__init(rec->evlist, &err);
if (err)
return err;
}
Here "int err" is not initialised. The code expects "err" to be set from
auxtrace_record__init() function.
Update auxtrace_record__init() in arch/powerpc/util/auxtrace.c to clear
err value in the beginning.
- Clear err value in beginning of function. Any fail later will
set appropriate return code to err.
- Even if we haven't found any event for auxtrace, perf record
should continue for other events. NULL return
will indicate that there is no auxtrace record initialized.
- Not having "err" set here will affect monitoring of other events
also because perf record will fail seeing random value in err.
Set err to -EINVAL before invoking auxtrace_record__init() in
builtin-record.c
With the fix,
# perf trace record sleep 1
[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.033 MB perf.data (228 samples) ]
Fixes: 1dbfaf94cf66ec4b ("perf powerpc: Add basic CONFIG_AUXTRACE support for VPA pmu on powerpc") Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: linuxppc-dev@lists.ozlabs.org Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Shivani Nittor <shivani@linux.ibm.com> Cc: Tanushree Shah <tanushree.shah@ibm.com> Cc: Tejas Manhas <tejas.manhas1@ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 19 May 2026 15:27:16 +0000 (08:27 -0700)]
perf test: Add stat metrics --for-each-cgroup test
Add a new shell test `stat_metrics_cgrp.sh` to verify metric reporting
with `--for-each-cgroup`, both with and without `--bpf-counters`.
The test:
- Checks if system-wide monitoring is supported (skips if not).
- Finds cgroups to test.
- Runs `perf stat` with `insn_per_cycle` metric and verifies that the
metric is reported for each cgroup.
- Dynamically pairs and verifies instructions and cycles counts to
avoid false failures on idle cgroups.
- Tests both standard mode and BPF counters mode (if supported).
Assisted-by: Antigravity:gemini-3-flash Signed-off-by: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Svilen Kanev <skanev@google.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Ian Rogers [Tue, 19 May 2026 15:27:15 +0000 (08:27 -0700)]
perf stat: Propagate supported flag to follower cgroup BPF events
When using BPF counters with cgroups, follower events (for cgroups
other than the first one) are not opened. Because they are not opened,
their `supported` flag was left as `false`.
During metric calculation, `prepare_metric` checks if the event is
supported. If it is not supported (like the follower events), it
explicitly sets the value to `NAN`, which eventually causes the metric
to be reported as `nan %`.
Fix this by propagating the `supported` flag from the "leader" events
(the ones opened for the first cgroup) to the "follower" events.
Also add a validation check to `bperf_load_program` to ensure `nr_cgroups`
is not zero and the number of events is a multiple of `nr_cgroups`,
preventing a potential division-by-zero (SIGFPE) exception when
`num_events` evaluates to 0 (e.g., with a trailing comma in cgroups list).
Reported-by: Svilen Kanev <skanev@google.com> Assisted-by: Antigravity:gemini-3-flash Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linus Torvalds [Mon, 25 May 2026 19:45:40 +0000 (12:45 -0700)]
Merge tag 'for-7.1/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull device mapper fix from Mikulas Patocka:
- fix crashes in dm-vdo if GFP_NOWAIT allocation fails
* tag 'for-7.1/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm vdo: use GFP_NOIO for blkdev_issue_zeroout on format path
Linus Torvalds [Sun, 24 May 2026 19:50:36 +0000 (12:50 -0700)]
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"arm64:
- Fix ITS EventID sanitisation when restoring an interrupt
translation table.
- Fix PPI memory leak when failing to initialise a vcpu.
- Correctly return an error when the validation of a hypervisor trace
descriptor fails, and limit this validation to protected mode only.
RISC-V:
- Fix invalid HVA warning in steal-time recording
- Return SBI_ERR_FAILURE to guest upon OOM in pmu_event_info() and
pmu_snapshot_set_shmem()
- Fix NULL pointer dereference in SBI v0.1 SEND_IPI handler
- Fix sign extension of value for MMIO loads
s390:
- Fix bugs in vSIE (nested virtualization) and UCONTROL, caused by
the page table rewrite.
x86:
- Apply erratum #1235 workaround (disable AVIC IPI virtualization) on
Hygon Family 18h, just like on AMD Family 17h.
- When KVM_CAP_X86_APIC_BUS_CYCLES_NS is queried on a specific VM,
return the VM's configured APIC bus frequency instead of the
default. This is less confusing (read: not wrong) and makes it
easier to fill in CPUID information that communicates the APIC bus
frequency to the guest.
Selftests:
- Do not include glibc-internal <bits/endian.h>; it worked by chance
and broke building KVM selftests with musl"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: SVM: Disable AVIC IPI virtualization on Hygon Family 18h (erratum #1235)
KVM: selftests: Verify that KVM returns the configured APIC cycle length
KVM: x86: Return the VM's configured APIC bus frequency when queried
KVM: selftests: elf: Include <endian.h> instead of <bits/endian.h>
KVM: s390: Properly reset zero bit in PGSTE
KVM: s390: vsie: Fix redundant rmap entries
KVM: s390: vsie: Fix unshadowing logic
KVM: s390: Fix leaking kvm_s390_mmu_cache in case of errors
KVM: s390: vsie: Fix memory leak when unshadowing
KVM: arm64: Fix nVHE/pKVM hyp tracing error on invalid desc
KVM: arm64: vgic: Free private_irqs when init fails after allocation
KVM: arm64: vgic-its: Reject restored DTE with out-of-range num_eventid_bits
RISC-V: KVM: Fix sign extension for MMIO loads
RISC-V: KVM: Fix NULL pointer dereference in SBI v0.1 SEND_IPI handler
riscv: kvm: return SBI_ERR_FAILURE for pmu_event_info() when OOM
riscv: kvm: return SBI_ERR_FAILURE for pmu_snapshot_set_shmem() when OOM
RISC-V: KVM: Fix invalid HVA warning in steal-time recording
Linus Torvalds [Sun, 24 May 2026 18:00:45 +0000 (11:00 -0700)]
Merge tag 'x86-urgent-2026-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
- On SEV guests, handle set_memory_{encrypted,decrypted}() failures
more conservatively by assuming that all affected pages are
unencrypted (Carlos López)
- Disable broadcast TLB flush when PCID is disabled (Tom Lendacky)
- Fix VMX vs. hrtimer_rearm_deferred() regression (Peter Zijlstra)
- Move IRQ/NMI dispatch code from KVM into x86 core, to prepare for a
KVM x2apic fix (Peter Zijlstra)
* tag 'x86-urgent-2026-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
virt: sev-guest: Explicitly leak pages in unknown state
x86/mm: Disable broadcast TLB flush when PCID is disabled
x86/kvm/vmx: Fix VMX vs hrtimer_rearm_deferred()
x86/kvm/vmx: Move IRQ/NMI dispatch from KVM into x86 core
x86/vdso: Fix incorrect size in munmap() on map_vdso() failure
Linus Torvalds [Sun, 24 May 2026 17:55:21 +0000 (10:55 -0700)]
Merge tag 'irq-urgent-2026-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irqchip driver fixes from Ingo Molnar:
- Fix the hardware probing error path of the renesas-rzt2h
irqchip driver
- Fix the exynos-combiner irqchip driver on -rt kernels
by turning the IRQ controller spinlock into a raw spinlock
* tag 'irq-urgent-2026-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/renesas-rzt2h: Use pm_runtime_put_sync() in probe error path
irqchip/exynos-combiner: Switch to raw_spinlock
Linus Torvalds [Sun, 24 May 2026 17:48:55 +0000 (10:48 -0700)]
Merge tag 'core-urgent-2026-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull debugobjects fix from Ingo Molnar::
- Fix debugobjects regression on -rt kernels: don't fill the pool
(which uses a coarse lock) if ->pi_blocked_on, because that messes up
the priority inheritance of callers
* tag 'core-urgent-2026-05-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debugobjects: Do not fill_pool() if pi_blocked_on
projects / thirdparty / kernel / linux.git / log
