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2026-06-17perf machine: Propagate machine__init() error to callersArnaldo Carvalho de Melo
machine__init() always returns 0 even when memory allocation fails, because commit 81f981d7ec43ed93 ("perf machine: Free root_dir in machine__init() error path") introduced 'int err = -ENOMEM' and an error cleanup path but left the final 'return 0' instead of 'return err'. Fix by returning err, check the return value in __machine__new_host() which was ignoring it, and change machines__init() from void to int so it too can propagate the error to perf_session__new(), aslr_tool__init() and test callers. The error cleanup also used zfree(&machine->kmaps), but kmaps is a refcounted maps structure — use maps__zput() to properly drop the reference, matching machine__exit(). Move dsos__init() and threads__init() before the first fallible allocation (maps__new) so that machine__exit() is safe to call on any machine struct that machine__init() touched, even on early failure. Fixes: 81f981d7ec43ed93 ("perf machine: Free root_dir in machine__init() error path") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-03perf env: Add perf_env__e_machine helper and use in perf_env__archIan Rogers
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>
2026-06-03perf session: Include file offset in event skip/stop messagesArnaldo Carvalho de Melo
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>
2026-06-03perf sample: Add file_offset field to struct perf_sampleArnaldo Carvalho de Melo
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>
2026-05-29perf session: Snapshot event->header.size in process_user_event()Arnaldo Carvalho de Melo
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>
2026-05-29perf session: Bound nr_cpus_avail and validate sample CPUArnaldo Carvalho de Melo
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>
2026-05-29perf session: Add byte-swap handler for PERF_RECORD_COMPRESSED2Arnaldo Carvalho de Melo
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>
2026-05-29perf header: Validate null-termination in PERF_RECORD_EVENT_UPDATE string fieldsArnaldo Carvalho de Melo
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>
2026-05-29perf session: Add byte-swap and bounds check for PERF_RECORD_BPF_METADATA eventsArnaldo Carvalho de Melo
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>
2026-05-29perf auxtrace: Harden auxtrace_error event handlingArnaldo Carvalho de Melo
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>
2026-05-29perf header: Byte-swap build ID event pid and bounds check section entriesArnaldo Carvalho de Melo
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>
2026-05-29perf session: Validate nr fields against event size on both swap and common ↵Arnaldo Carvalho de Melo
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>
2026-05-29perf session: Validate HEADER_ATTR attr.size before swappingArnaldo Carvalho de Melo
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>
2026-05-29perf session: Use bounded copy for PERF_RECORD_TIME_CONVArnaldo Carvalho de Melo
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>
2026-05-29perf session: Add validated swap infrastructure with null-termination checksArnaldo Carvalho de Melo
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>
2026-05-29perf session: Fix swap_sample_id_all() crash on crafted eventsArnaldo Carvalho de Melo
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>
2026-05-29perf session: Fix PERF_RECORD_READ swap and dump for variable-length eventsArnaldo Carvalho de Melo
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>
2026-05-29perf session: Bounds-check one_mmap event pointer in peek_eventArnaldo Carvalho de Melo
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>
2026-05-29perf session: Add minimum event size and alignment validationArnaldo Carvalho de Melo
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>
2026-05-20perf tool: Remove evsel from tool APIs that pass the sampleIan Rogers
As struct perf_sample now directly contains its own resolved evsel pointer, passing the evsel separately is redundant and clutters the interface. Remove the redundant evsel parameter from tool-specific handlers and structures, ensuring the tool always directly accesses the evsel bound to the sample. This simplifies the API signatures and eliminates the risk of passing an inconsistent evsel. Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Anup Patel <anup@brainfault.org> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Blake Jones <blakejones@google.com> Cc: Chen Ni <nichen@iscas.ac.cn> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Derek Foreman <derek.foreman@collabora.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Howard Chu <howardchu95@gmail.com> Cc: Hrishikesh Suresh <hrishikesh123s@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@arm.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quan Zhou <zhouquan@iscas.ac.cn> Cc: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Tianyou Li <tianyou.li@intel.com> Cc: Yujie Liu <yujie.liu@intel.com> Cc: tanze <tanze@kylinos.cn> [ Fixed up conflict with "perf inject: Fix itrace branch stack synthesis" series ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-04-08perf data: Clean up use_stdio and structuresIan Rogers
use_stdio was associated with struct perf_data and not perf_data_file meaning there was implicit use of fd rather than fptr that may not be safe. For example, in perf_data_file__write. Reorganize perf_data_file to better abstract use_stdio, add kernel-doc and more consistently use perf_data__ accessors so that use_stdio is better respected. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2026-04-08perf tools: Use calloc() where applicableArnaldo Carvalho de Melo
Instead of using zalloc(nr_entries * sizeof_entry) that is what calloc() does. In some places where linux/zalloc.h isn't needed, remove it, add when needed and was getting it indirectly. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2026-04-05perf sample: Add evsel to struct perf_sampleIan Rogers
Add the evsel from evsel__parse_sample into the struct perf_sample. Sometimes we want to alter the evsel associated with a sample, such as with off-cpu bpf-output events. In general the evsel and perf_sample are passed as a pair, but this makes an altered evsel something of a chore to keep checking for and setting up. Later patches will remove passing an evsel with the perf_sample and switch to just using the perf_sample's value. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2026-04-05perf sample: Make sure perf_sample__init/exit are usedIan Rogers
The deferred stack trace code wasn't using perf_sample__init/exit. Add the deferred stack trace clean up to perf_sample__exit which requires proper NULL initialization in perf_sample__init. Make the perf_sample__exit robust to being called more than once by using zfree. Make the error paths in evsel__parse_sample exit the sample. Add a merged_callchain boolean to capture that callchain is allocated, deferred_callchain doen't suffice for this. Pack the struct variables to avoid padding bytes for this. Similiarly powerpc_vpadtl_sample wasn't using perf_sample__init/exit, use it for consistency and potential issues with uninitialized variables. Similarly guest_session__inject_events in builtin-inject wasn't using perf_sample_init/exit. The lifetime management for fetched events is somewhat complex there, but when an event is fetched the sample should be initialized and needs exiting on error. The sample may be left in place so that future injects have access to it. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2026-04-02perf session: Extra logging for failed to process eventsIan Rogers
Print log information in ordered event processing so that the cause of finished round failing is clearer. Print the event name along with its number when an event isn't processed. Add extra detail about where the failure happened. The following log lines come from running `perf data convert`. Before: 0xa250 [0x10]: failed to process type: 80 After: 0xa250 [0x10]: piped event processing failed for event of type: FEATURE (80) Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2026-04-01libperf cpumap: Make index and nr types unsignedIan Rogers
The index into the cpumap array and the number of entries within the array can never be negative, so let's make them unsigned. This is prompted by reports that gcc 13 with -O6 is giving a alloc-size-larger-than errors. The change makes the cpumap changes and then updates the declaration of index variables throughout perf and libperf to be unsigned. The two things are hard to separate as compiler warnings about mixing signed and unsigned types breaks the build. Reported-by: Chingbin Li <liqb365@163.com> Closes: https://lore.kernel.org/lkml/20260212025127.841090-1-liqb365@163.com/ Tested-by: Chingbin Li <liqb365@163.com> Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2026-02-03perf thread: Don't require machine to compute the e_machineIan Rogers
The machine can be calculated from a thread via its maps. Don't require the machine argument to simplify callers and also to delay computing the machine until a little later. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Anubhav Shelat <ashelat@redhat.com> Cc: Anup Patel <anup@brainfault.org> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Blake Jones <blakejones@google.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quan Zhou <zhouquan@iscas.ac.cn> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yunseong Kim <ysk@kzalloc.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-02-03perf header: Add e_machine/e_flags to the headerIan Rogers
Add 64-bits of feature data to record the ELF machine and flags. This allows readers to initialize based on the data. For example, `perf kvm stat` wants to initialize based on the kind of data to be read, but at initialization time there are no threads to base this data upon and using the host means cross platform support won't work. The values in the perf_env also act as a cache for these within the session. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Anubhav Shelat <ashelat@redhat.com> Cc: Anup Patel <anup@brainfault.org> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Blake Jones <blakejones@google.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quan Zhou <zhouquan@iscas.ac.cn> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yunseong Kim <ysk@kzalloc.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-02-03perf session: Add e_flags to the e_machine helperIan Rogers
Allow e_flags as well as e_machine to be computed using the e_machine helper. This isn't currently used, the argument is always NULL, but it will be used for a new header feature. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Anubhav Shelat <ashelat@redhat.com> Cc: Anup Patel <anup@brainfault.org> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Blake Jones <blakejones@google.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dapeng Mi <dapeng1.mi@linux.intel.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quan Zhou <zhouquan@iscas.ac.cn> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yunseong Kim <ysk@kzalloc.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-27perf session: Don't write to memory pointed to a const pointerArnaldo Carvalho de Melo
Since it is freshly allocated just attribute it to a non-const pointer and then change it via that pointer. That way we avoid const-correctness warnings in recent glibc versions. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-26perf session: Print all machines in session dumpHrishikesh Suresh
perf_session__fprintf() prints only the host. This has been changed to print details of host and all guests, by traversing through the RB-Tree. These are visible when using high verbosity (-vvvv) in KVM environments, during perf report dumps. Testing: - Test 1: Record the local machine and guest VM using 'perf kvm record' and generate the report using 'perf kvm report -vvvv -D'. The dump should show the threads and other details related to local and guest machine. - 1 Ubuntu VM running on Fedora host - VM is running a noisy program => $ dd if=/dev/urandom of=/dev/null - On host run => $ sudo ./perf kvm --guestvmlinux=/tmp/shared/guest_vmlinux \ --guestkallsyms=/tmp/shared/guest_kallsyms \ --guestmodules=/tmp/shared/guest_modules \ record -a -g -o perf.data.guest and exit after a few seconds. [ perf record: Woken up 9 times to write data ] [ perf record: Captured and wrote 3.150 MB perf.data.guest \ (29311 samples) ] - Generate dump => $ sudo ./perf kvm --guestkallsyms /tmp/shared/guest_kallsyms \ report -vvvv -D -i perf.data.guest > output.txt - Check for threads associated with guest machine. $ grep "Thread 0" output.txt Thread 0 swapper Thread 0 [guest/0] PASS - Test 2: Record the local machine and guest VM using 'perf kvm record' and generate the report using 'perf kvm report'. The functions running on guest VM should be seen in the report. - Same setup as Test 1 but the test looks at the performance profile, to check if the function names are visible. - Peek into profile using => $ sudo ./perf kvm --guestkallsyms /tmp/shared/guest_kallsyms \ report -i perf.data.guest - Samples: 29K of event 'cycles', Event count (approx.): 28711693142 Children Self Command Shared Object Symbol 35.69% 35.69% :5820 [guest.kernel.kallsyms] [g] chacha_permute 11.56% 11.56% :5820 [guest.kernel.kallsyms] [g] entry_SYSRETQ_unsXXX 11.12% 11.12% :5820 [guest.kernel.kallsyms] [g] syscall_return_viXXX 7.36% 7.36% :5820 [guest.kernel.kallsyms] [g] entry_SYSCALL_64_XXX 6.07% 6.07% :5820 [guest.kernel.kallsyms] [g] chacha_block_generic 5.40% 5.40% :5820 [guest.kernel.kallsyms] [g] _copy_to_iter .... PASS - Test 3: Record the local and 2 guest VMs using 'perf kvm record' and generate the report using 'perf kvm report -vvvv -D'. The dump should show the threads and other details related to local and guest machines. - 1 Ubuntu and 1 Alpine VMs running on Fedora host. - Find PIDs of qemu instances and use them during record and report $ pgrep qemu 5816 25098 - Record the activity => $ sudo ./perf kvm record -p 5816,25098 -a -g -o perf.data.guests Warning: PID/TID switch overriding SYSTEM [ perf record: Woken up 325927 times to write data ] [ perf record: Captured and wrote 3.692 MB perf.data.guests \ (57389 samples) ] - Generate dump => $ sudo ./perf kvm report -vvvv -D -i perf.data.guests > output.txt - Check if the threads related to the local machine and guest VMs are present => $ grep "Thread 0" output.txt Thread 0 swapper Thread 0 [guest/0] NOTE: Threads from Ubuntu and Alpine VMs are bundled together and appear as one guest machine. Looking into output.txt => Threads: 6 Thread 0 [guest/0] Thread 5816 :5816 Thread 25098 :25098 Thread 5819 :5819 Thread 5820 :5820 Thread 25103 :25103 To conclude, information is collected for both VMs and not listed as two different guest machines. PASS - Test 4: Check if any guest-related information is printed in perf annotate. This test is included because the command calls perf_session__fprintf() in its code path when using -vvvv option. This could be explained by inability / lack of options for 'perf annotate' to look into guest VM from host machine, due to no option to specify the guest's kallsyms or modules. A similar explanation for 'perf mem' could be used, as perf_session__fprintf() is also present in its code path. - Run annotate => $ sudo ./perf annotate -i perf.data.guest -vvvv > output.txt - Check for threads from local machine or guest VM => $ grep "Thread 0" output.txt Thread 0 swapper Threads from local machine are found while threads from guest VM are not found. It is possibly because of a lack of a guest kallsyms option for DSO matching in perf annotate. PASS - Test 5: Run kvm test available on perf path - $ sudo ./perf test kvm 89: perf kvm tests : Ok PASS Signed-off-by: Hrishikesh Suresh <hrishikesh123s@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Blake Jones <blakejones@google.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.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: Leo Yan <leo.yan@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> [ Declare 'nd' in the 'for' line and and 'pos' inside the loop body, to make it more compact ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-26perf perf_regs: Accurately compute register names for CSKYIan Rogers
CSKY needs the e_flags to determine the ABI level and know whether additional registers are encoded or not. Wire this up now that the e_flags for a thread can be determined. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Guo Ren <guoren@kernel.org> Cc: Howard Chu <howardchu95@gmail.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: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Tianyou Li <tianyou.li@intel.com> [ Conditionally define EF_CSKY_ABIMASK and EF_CSKY_ABIV2 for older distros ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-26perf thread: Add optional e_flags output argument to thread__e_machineIan Rogers
The e_flags are needed to accurately compute complete perf register information for CSKY. Add the ability to read and have this value associated with a thread. This change doesn't wire up the use of the e_flags except in disasm where use already exists but just wasn't set up yet. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Guo Ren <guoren@kernel.org> Cc: Howard Chu <howardchu95@gmail.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: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Swapnil Sapkal <swapnil.sapkal@amd.com> Cc: Tianyou Li <tianyou.li@intel.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-22perf sched stats: Add record and rawdump supportSwapnil Sapkal
Define new, perf tool only, sample types and their layouts. Add logic to parse /proc/schedstat, convert it to perf sample format and save samples to perf.data file with `perf sched stats record` command. Also add logic to read perf.data file, interpret schedstat samples and print rawdump of samples with `perf script -D`. Note that, /proc/schedstat file output is standardized with version number. The patch supports v15 but older or newer version can be added easily. Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com> Tested-by: Chen Yu <yu.c.chen@intel.com> Tested-by: James Clark <james.clark@linaro.org> Acked-by: Ian Rogers <irogers@google.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Anubhav Shelat <ashelat@redhat.com> Cc: Ben Gainey <ben.gainey@arm.com> Cc: Blake Jones <blakejones@google.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: David Vernet <void@manifault.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Gautham Shenoy <gautham.shenoy@amd.com> Cc: Graham Woodward <graham.woodward@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@arm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: K Prateek Nayak <kprateek.nayak@amd.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@arm.com> Cc: Madadi Vineeth Reddy <vineethr@linux.ibm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Santosh Shukla <santosh.shukla@amd.com> Cc: Shrikanth Hegde <sshegde@linux.ibm.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Yang Jihong <yangjihong@bytedance.com> Cc: Yujie Liu <yujie.liu@intel.com> Cc: Zhongqiu Han <quic_zhonhan@quicinc.com> [ PRIu64 needs uint64_t, not 'unsigned long' to work on both 32-bit and 64-bit ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-20perf perf_regs: Switch from arch string to int e_machineIan Rogers
The arch string requires multiple strcmp to identify things like the IP and SP. Switch to passing in an e_machine that in the bulk of cases is computed using a current thread load. The e_machine also allows identification of 32-bit vs 64-bit processes. Signed-off-by: Ian Rogers <irogers@google.com> Cc: Aditya Bodkhe <aditya.b1@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Andi Kleen <ak@linux.intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Guo Ren <guoren@kernel.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Cc: Krzysztof Łopatowski <krzysztof.m.lopatowski@gmail.com> Cc: Leo Yan <leo.yan@linux.dev> Cc: Mark Wielaard <mark@klomp.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Walmsley <pjw@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergei Trofimovich <slyich@gmail.com> Cc: Shimin Guo <shimin.guo@skydio.com> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Will Deacon <will@kernel.org> [ Include dwarf-regs.h to get conditional defines for EM_CSKY and EM_LOONGARCH, not available in old distros ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-14perf tools: Switch printf("...%s", strerror(errno)) to printf("...%m")Ian Rogers
strerror() has thread safety issues, strerror_r() requires stack allocated buffers. Code in perf has already been using the "%m" formatting flag that is a widely support glibc extension to print the current errno's description. Expand the usage of this formatting flag and remove usage of strerror()/strerror_r(). Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Blake Jones <blakejones@google.com> Cc: Chun-Tse Shao <ctshao@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Dr. David Alan Gilbert <linux@treblig.org> Cc: Haibo Xu <haibo1.xu@intel.com> Cc: Howard Chu <howardchu95@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Leo Yan <leo.yan@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Cc: Thomas Falcon <thomas.falcon@intel.com> Cc: Yunseong Kim <ysk@kzalloc.com> Cc: Zhongqiu Han <quic_zhonhan@quicinc.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-01-13perf tools: Dump callchain context marker namesJames Clark
These are hard to interpret in the raw output because they are printed as hex but are defined in perf_event.h as decimal. Make it much easier to read the raw callchains by just printing their names. For example: $ perf report -D 1798195372321 0x4638 [0xb0]: PERF_RECORD_SAMPLE(IP, 0x4002): 44922/44922: 0x7c8046dd3400 period: 120218 addr: 0 ... FP chain: nr:12 ..... 0: fffffffffffffe00 (PERF_CONTEXT_USER) ..... 1: 00007c8046dd3400 ..... 2: 00007c8046db86d3 Reviewed-by: Ian Rogers <irogers@google.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: Leo Yan <leo.yan@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> [ Add PERF_CONTEXT_USER_DEFERRED too, as per Namhyung's review comment ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-12-02perf tools: Flush remaining samples w/o deferred callchainsNamhyung Kim
It's possible that some kernel samples don't have matching deferred callchain records when the profiling session was ended before the threads came back to userspace. Let's flush the samples before finish the session. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-12-02perf tools: Merge deferred user callchainsNamhyung Kim
Save samples with deferred callchains in a separate list and deliver them after merging the user callchains. If users don't want to merge they can set tool->merge_deferred_callchains to false to prevent the behavior. With previous result, now perf script will show the merged callchains. $ perf script ... pwd 2312 121.163435: 249113 cpu/cycles/P: ffffffff845b78d8 __build_id_parse.isra.0+0x218 ([kernel.kallsyms]) ffffffff83bb5bf6 perf_event_mmap+0x2e6 ([kernel.kallsyms]) ffffffff83c31959 mprotect_fixup+0x1e9 ([kernel.kallsyms]) ffffffff83c31dc5 do_mprotect_pkey+0x2b5 ([kernel.kallsyms]) ffffffff83c3206f __x64_sys_mprotect+0x1f ([kernel.kallsyms]) ffffffff845e6692 do_syscall_64+0x62 ([kernel.kallsyms]) ffffffff8360012f entry_SYSCALL_64_after_hwframe+0x76 ([kernel.kallsyms]) 7f18fe337fa7 mprotect+0x7 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) 7f18fe330e0f _dl_sysdep_start+0x7f (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) 7f18fe331448 _dl_start_user+0x0 (/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2) ... The old output can be get using --no-merge-callchain option. Also perf report can get the user callchain entry at the end. $ perf report --no-children --stdio -q -S __build_id_parse.isra.0 # symbol: __build_id_parse.isra.0 8.40% pwd [kernel.kallsyms] | ---__build_id_parse.isra.0 perf_event_mmap mprotect_fixup do_mprotect_pkey __x64_sys_mprotect do_syscall_64 entry_SYSCALL_64_after_hwframe mprotect _dl_sysdep_start _dl_start_user Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-12-02perf tools: Minimal DEFERRED_CALLCHAIN supportNamhyung Kim
Add a new event type for deferred callchains and a new callback for the struct perf_tool. For now it doesn't actually handle the deferred callchains but it just marks the sample if it has the PERF_CONTEXT_ USER_DEFFERED in the callchain array. At least, perf report can dump the raw data with this change. Actually this requires the next commit to enable attr.defer_callchain, but if you already have a data file, it'll show the following result. $ perf report -D ... 0x2158@perf.data [0x40]: event: 22 . . ... raw event: size 64 bytes . 0000: 16 00 00 00 02 00 40 00 06 00 00 00 0b 00 00 00 ......@......... . 0010: 03 00 00 00 00 00 00 00 a7 7f 33 fe 18 7f 00 00 ..........3..... . 0020: 0f 0e 33 fe 18 7f 00 00 48 14 33 fe 18 7f 00 00 ..3.....H.3..... . 0030: 08 09 00 00 08 09 00 00 e6 7a e7 35 1c 00 00 00 .........z.5.... 121163447014 0x2158 [0x40]: PERF_RECORD_CALLCHAIN_DEFERRED(IP, 0x2): 2312/2312: 0xb00000006 ... FP chain: nr:3 ..... 0: 00007f18fe337fa7 ..... 1: 00007f18fe330e0f ..... 2: 00007f18fe331448 : unhandled! Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-11-07perf tool: Add the perf_tool argument to all callbacksIan Rogers
Getting context for what a tool is doing, such as the perf_inject instance, using container_of the tool is a common pattern in the code. This isn't possible event_op2, event_op3 and event_op4 callbacks as the tool isn't passed. Add the argument and then fix function signatures to match. As tools maybe reading a tool from somewhere else, change that code to use the passed in tool. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-09-19perf session: Fix handling when buffer exceeds 2 GiBLeo Yan
If a user specifies an AUX buffer larger than 2 GiB, the returned size may exceed 0x80000000. Since the err variable is defined as a signed 32-bit integer, such a value overflows and becomes negative. As a result, the perf record command reports an error: 0x146e8 [0x30]: failed to process type: 71 [Unknown error 183711232] Change the type of the err variable to a signed 64-bit integer to accommodate large buffer sizes correctly. Fixes: d5652d865ea734a1 ("perf session: Add ability to skip 4GiB or more") Reported-by: Tamas Zsoldos <tamas.zsoldos@arm.com> Signed-off-by: Leo Yan <leo.yan@arm.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20250808-perf_fix_big_buffer_size-v1-1-45f45444a9a4@arm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-07-25perf sample: Remove arch notion of sample parsingIan Rogers
By definition arch sample parsing and synthesis will inhibit certain kinds of cross-platform record then analysis (report, script, etc.). Remove arch_perf_parse_sample_weight and arch_perf_synthesize_sample_weight replacing with a common implementation. Combine perf_sample p_stage_cyc and retire_lat as weight3 to capture the differing uses regardless of compiled for architecture. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250724163302.596743-21-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-25perf env: Remove global perf_envIan Rogers
The global perf_env was used for the host, but if a perf_env wasn't easy to come by it was used in a lot of places where potentially recorded and host data could be confused. Remove the global variable as now the majority of accesses retrieve the perf_env for the host from the session. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250724163302.596743-20-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-25perf session: Add host_env argument to perf_session__newIan Rogers
When creating a perf_session the host perf_env may or may not want to be used. For example, `perf top` uses a host perf_env while `perf inject` does not. Add a host_env argument to perf_session__new so that sessions requiring a host perf_env can pass it in. Currently if none is specified the global perf_env variable is used, but this will change in later patches. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250724163302.596743-14-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-25perf evlist: Change env variable to sessionIan Rogers
The session holds a perf_env pointer env. In UI code container_of is used to turn the env to a session, but this assumes the session header's env is in use. Rather than a dubious container_of, hold the session in the evlist and derive the env from the session with evsel__env, perf_session__env, etc. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250724163302.596743-11-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-07-25perf session: Add accessor for session->header.envIan Rogers
The perf_env from the header in the session is frequently accessed, add an accessor function rather than access directly. Cache the value to avoid repeated calls. No behavioral change. Signed-off-by: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/r/20250724163302.596743-10-irogers@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-06-20perf tools: display the new PERF_RECORD_BPF_METADATA eventBlake Jones
Here's some example "perf script -D" output for the new event type. The ": unhandled!" message is from tool.c, analogous to other behavior there. I've elided some rows with all NUL characters for brevity, and I wrapped one of the >75-column lines to fit in the commit guidelines. 0x50fc8@perf.data [0x260]: event: 84 . . ... raw event: size 608 bytes . 0000: 54 00 00 00 00 00 60 02 62 70 66 5f 70 72 6f 67 T.....`.bpf_prog . 0010: 5f 31 65 30 61 32 65 33 36 36 65 35 36 66 31 61 _1e0a2e366e56f1a . 0020: 32 5f 70 65 72 66 5f 73 61 6d 70 6c 65 5f 66 69 2_perf_sample_fi . 0030: 6c 74 65 72 00 00 00 00 00 00 00 00 00 00 00 00 lter............ . 0040: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [...] . 0110: 74 65 73 74 5f 76 61 6c 75 65 00 00 00 00 00 00 test_value...... . 0120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [...] . 0150: 34 32 00 00 00 00 00 00 00 00 00 00 00 00 00 00 42.............. . 0160: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [...] 0 0x50fc8 [0x260]: PERF_RECORD_BPF_METADATA \ prog bpf_prog_1e0a2e366e56f1a2_perf_sample_filter entry 0: test_value = 42 : unhandled! Signed-off-by: Blake Jones <blakejones@google.com> Link: https://lore.kernel.org/r/20250612194939.162730-5-blakejones@google.com Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2025-05-16perf record: Add 8-byte aligned event type PERF_RECORD_COMPRESSED2Chun-Tse Shao
The original PERF_RECORD_COMPRESS is not 8-byte aligned, which can cause asan runtime error: # Build with asan $ make -C tools/perf O=/tmp/perf DEBUG=1 EXTRA_CFLAGS="-O0 -g -fno-omit-frame-pointer -fsanitize=undefined" # Test success with many asan runtime errors: $ /tmp/perf/perf test "Zstd perf.data compression/decompression" -vv 83: Zstd perf.data compression/decompression: ... util/session.c:1959:13: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 13 byte alignment 0x7f69e3f99653: note: pointer points here d0 3a 50 69 44 00 00 00 00 00 08 00 bb 07 00 00 00 00 00 00 44 00 00 00 00 00 00 00 ff 07 00 00 ^ util/session.c:2163:22: runtime error: member access within misaligned address 0x7f69e3f99653 for type 'union perf_event', which requires 8 byte alignment 0x7f69e3f99653: note: pointer points here d0 3a 50 69 44 00 00 00 00 00 08 00 bb 07 00 00 00 00 00 00 44 00 00 00 00 00 00 00 ff 07 00 00 ^ ... Since there is no way to align compressed data in zstd compression, this patch add a new event type `PERF_RECORD_COMPRESSED2`, which adds a field `data_size` to specify the actual compressed data size. The `header.size` contains the total record size, including the padding at the end to make it 8-byte aligned. Tested with `Zstd perf.data compression/decompression` Signed-off-by: Chun-Tse Shao <ctshao@google.com> 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: Ben Gainey <ben.gainey@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> 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: Kan Liang <kan.liang@linux.intel.com> Cc: Leo Yan <leo.yan@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nick Terrell <terrelln@fb.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250303183646.327510-1-ctshao@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2025-04-25perf session: Skip unsupported new event typesChun-Tse Shao
`perf report` currently halts with an error when encountering unsupported new event types (`event.type >= PERF_RECORD_HEADER_MAX`). This patch modifies the behavior to skip these samples and continue processing the remaining events. Additionally, stops reporting if the new event size is not 8-byte aligned. Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org> Suggested-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Chun-Tse Shao <ctshao@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ben Gainey <ben.gainey@arm.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20250414173921.2905822-1-ctshao@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>