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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
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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>
|
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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>
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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>
|
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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>
|
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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>
|
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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>
|
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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>
|
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Extend the total_bw selftest to validate the fair/ext dl_server
auto-attach/detach operations.
After the existing consistency checks, the test now doubles the
fair_server's runtime on every CPU via debugfs and verifies that:
1. total_bw grew after the customization (proves fair_server was
attached and apply_params() honored the dl_bw_attached flag),
2. with the minimal BPF scheduler loaded, total_bw drops back to the
baseline value (proves fair_server was detached and ext_server was
attached at its own default runtime),
3. after unload total_bw matches the doubled value from step 1 (proves
fair_server was re-attached with the runtime customization preserved
across the load/unload cycle).
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260526164420.638711-3-arighi@nvidia.com
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slab->partial is assigned by get_obj("partial") and then immediately
overwritten by get_obj_and_str("partial", &t). Remove the first
redundant assignment.
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn>
Link: https://patch.msgid.link/20260518062159.80664-4-wangxuewen@kylinos.cn
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
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The assignment `x = NULL` sets the local parameter variable instead of
`*x`, which is a no-op since `*x` was already set to NULL on the line
above. Remove the dead assignment.
Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn>
Reviewed-by: SeongJae Park <sj@kernel.org>
Link: https://patch.msgid.link/20260518062159.80664-3-wangxuewen@kylinos.cn
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
|
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The disable trace path in slab_debug() had a logic error where it would
set trace=1 instead of trace=0. This made trace functionality permanently
enabled once turned on for any slab cache.
Fixes: a87615b8f9e2 ("SLUB: slabinfo upgrade")
Cc: stable@vger.kernel.org
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn>
WARNING: From:/Signed-off-by: email address mismatch: 'From: wangxuewen <18810879172@163.com>' != 'Signed-off-by: wangxuewen <wangxuewen@kylinos.cn>'
Link: https://patch.msgid.link/20260518062159.80664-2-wangxuewen@kylinos.cn
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
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RTLA tests are not documented anywhere. Mention both runtime and unit
tests in the README, with instructions on how to run them and a list of
dependencies and required system configuration.
Link: https://lore.kernel.org/r/20260514073038.204428-1-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
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The only user of msg->msg_iocb was AF_ALG, but that's deprecated.
It can be removed entirely at the cost of only supporting synchronous
operations. This doesn't break userspace, which will silently block
(for a bounded amount of time) in io_submit instead of operating
asynchronously.
This also makes struct msghdr smaller, helping every other caller of
sendmsg().
Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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In sigtrap_threads(), the return value of mmap() is checked against NULL.
mmap() returns MAP_FAILED, which is (void *)-1, not NULL, when it fails.
Since MAP_FAILED is non-zero and non-NULL, the condition "p == NULL" will
never be true on failure, causing the program to proceed with an invalid
pointer and segfault if mmap() actually fails under memory pressure.
Link: https://lore.kernel.org/20260513025838.594945-1-lihongfu@kylinos.cn
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mickael Salaun <mic@digikod.net>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Kyle Huey <khuey@kylehuey.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Tell git to ignore the generated binary for the test.
Link: https://lore.kernel.org/20260226-selftest-filelock-ktap-v4-3-db8ae192ff42@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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The filelock test checks four different things but only reports an overall
status, convert to use ksft_test_result() for these individual tests.
Each test depends on the previous ones so we still bail out if any of them
fail but we get a bit more information from UIs parsing the results.
Link: https://lore.kernel.org/20260226-selftest-filelock-ktap-v4-2-db8ae192ff42@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Patch series "selftests/filelock: Make output more kselftestish", v4.
This series makes the output from the ofdlocks test a bit easier for
tooling to work with, and also ignores the generated file while we're
here.
This patch (of 3):
The ofdlocks test reports some errors via perror() which does not produce
KTAP output, convert to ksft_perror() which does.
Link: https://lore.kernel.org/20260226-selftest-filelock-ktap-v4-0-db8ae192ff42@kernel.org
Link: https://lore.kernel.org/20260226-selftest-filelock-ktap-v4-1-db8ae192ff42@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Add a kselftest for the taskstats TGID aggregation fix.
The test creates a worker thread, snapshots TGID taskstats while the
worker is still alive, lets the worker exit, and then verifies that the
TGID CPU total does not regress after the thread has been reaped.
The pass/fail check intentionally keys off ac_utime + ac_stime only, which
is the primary user-visible regression fixed by the taskstats change and
is less sensitive to scheduling noise than context-switch counters.
Link: https://lore.kernel.org/0d55354911c54cd1b9f10a09f6fd378af85c8d43.1776094300.git.cyyzero16@gmail.com
Signed-off-by: Yiyang Chen <cyyzero16@gmail.com>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Cc: Dr. Thomas Orgis <thomas.orgis@uni-hamburg.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Reproduce with GCC 13.3.0:
$ cd tools/accounting
$ make
This emits:
getdelays.c: In function `format_timespec':
getdelays.c:218:67: warning: `:' directive output may be truncated writing 1 byte into a region of size between 0 and 16 [-Wformat-truncation=]
218 | snprintf(buffer, sizeof(buffer), "%04d-%02d-%02dT%02d:%02d:%02d",
|
getdelays.c:218:9: note: `snprintf' output between 20 and 72 bytes into a destination of size 32
The problem is that %04d and %02d specify minimum field widths only. GCC
cannot prove that formatting tm_year + 1900 and the other struct tm
fields will always fit in the fixed 32-byte buffer, so it warns about
possible truncation.
Fix this by replacing the manual snprintf() formatting with
strftime("%Y-%m-%dT%H:%M:%S", ...). That matches the data we already have
in struct tm, keeps the intended timestamp format, and avoids the warning
when building tools/accounting with GCC.
Link: https://lore.kernel.org/87d9723e0b59d816ee2e4bd7cddd58a54c6c9f91.1776956545.git.cyyzero16@gmail.com
Signed-off-by: Yiyang Chen <cyyzero16@gmail.com>
Cc: Fan Yu <fan.yu9@zte.com.cn>
Cc: Wang Yaxin <wang.yaxin@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Add a regression test for the per-scan verbose dedup added in the
preceding commit. The test loads samples/kmemleak's helper module
(CONFIG_SAMPLE_KMEMLEAK=m) to generate orphan allocations, several of
which share an allocation backtrace, runs four kmemleak scans with verbose
printing enabled, then walks dmesg looking for two "unreferenced object"
reports within a single scan that share an identical backtrace - which
would mean dedup failed to collapse them.
The test is intentionally permissive on detection but strict on
regressions:
- PASS when no duplicates are observed, regardless of whether the
dedup summary line ("... and N more object(s) with the same
backtrace") was actually emitted. Per-CPU chunk reuse, slab
freelist pointers, kernel stack residue and CONFIG_DEBUG_KMEMLEAK_
AUTO_SCAN can all keep most of the orphans "still referenced" or
reported across many separate scans, so the dedup path may have
nothing to fold within one scan. That is not a regression.
- PASS reports whether dedup actually fired, so a passing run on a
well-behaved environment is still informative.
- FAIL when two same-backtrace reports land in a single scan (clear
dedup regression).
- FAIL when kmemleak's own per-scan tally counts leaks but the
verbose path emits zero "unreferenced object" lines - that catches
a regression in the verbose printer itself, which would otherwise
pass the duplicate check trivially.
- SKIP when kmemleak is absent, disabled at runtime, or the helper
module is not built.
The dmesg parser anchors stack-frame matching to the indentation kmemleak
uses for them (4+ spaces under "kmemleak: ") so unrelated kmemleak
warnings landing between reports do not get lumped into the backtrace key
and mask a duplicate.
Link: https://lore.kernel.org/20260506-kmemleak_dedup-v3-2-2d36aafc34da@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
test_percpu_basic() currently compares memory.current against only
memory.stat:percpu after creating 1000 child cgroups.
Observed failure:
#./test_kmem
ok 1 test_kmem_basic
ok 2 test_kmem_memcg_deletion
ok 3 test_kmem_proc_kpagecgroup
ok 4 test_kmem_kernel_stacks
ok 5 test_kmem_dead_cgroups
memory.current 11530240
percpu 8440000
not ok 6 test_percpu_basic
That assumption is too strict: child cgroup creation also allocates
slab-backed metadata, so memory.current is expected to be larger than
percpu alone. One visible path is:
cgroup_mkdir()
cgroup_create()
cgroup_addrm_file()
cgroup_add_file()
__kernfs_create_file()
__kernfs_new_node()
kmem_cache_zalloc()
These kernfs allocations are charged as slab and show up in
memory.stat:slab.
Update the check to compare memory.current against (percpu + slab)
within MAX_VMSTAT_ERROR, and print slab/delta in the failure message to
improve diagnostics.
Link: https://lore.kernel.org/20260501022058.18024-3-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sayali Patil <sayalip@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Patch series "selftests/cgroup: Fix false positive failures in
test_percpu_basic", v2.
This patch series addresses two separate issues that cause false
positive failures in the test_percpu_basic test within the cgroup
kmem selftests.
The first issue stems from a hardcoded assumption about the system
page size, which breaks the test on architectures with larger page
sizes.
The second issue is an overly strict memory check that fails to
account for the slab metadata allocated during cgroup creation.
This patch (of 2):
MAX_VMSTAT_ERROR uses a hardcoded page size of 4096, which assumes 4K
pages. This causes test_percpu_basic to fail on systems where the kernel
is configured with a larger page size, such as aarch64 systems using 16K
or 64K pages, where the maximum permissible discrepancy between
memory.current and percpu charges is proportionally larger.
Replace the hardcoded 4096 with sysconf(_SC_PAGESIZE) to correctly derive
the page size at runtime regardless of the underlying architecture or
kernel configuration.
Link: https://lore.kernel.org/20260501022058.18024-1-li.wang@linux.dev
Link: https://lore.kernel.org/20260501022058.18024-2-li.wang@linux.dev
Signed-off-by: Li Wang <li.wang@linux.dev>
Acked-by: Waiman Long <longman@redhat.com>
Reviewed-by: Sayali Patil <sayalip@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
file_setup_area() currently allocates anonymous memory, fills it, and
writes it into the backing file used for collapse testing.
Instead of copying data through write(), resize the file with ftruncate(),
map it directly with MAP_SHARED, and initialize the mapped area in place.
This simplifies the setup path and avoids the need for explicit partial
write handling.
Link: https://lore.kernel.org/20260429115816.98824-1-agarwal.vineet2006@gmail.com
Signed-off-by: Vineet Agarwal <agarwal.vineet2006@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Tested-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The sysfs.py test commits DAMON parameters, dump the internal DAMON state,
and show if the parameters are committed as expected using the dumped
state. While the dumping is ongoing, DAMON is alive. It can make
internal changes including addition and removal of regions. It can
therefore make a race that can result in false test results. Pause DAMON
execution during the state dumping to avoid such races.
Link: https://lore.kernel.org/20260427151231.113429-11-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
Extend sysfs.py tests to confirm damon_ctx->pause can be set using the
pause sysfs file.
Link: https://lore.kernel.org/20260427151231.113429-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
drgn_dump_damon_status is not dumping the damon_ctx->pause parameter
value, so it cannot be tested. Dump it for future tests.
Link: https://lore.kernel.org/20260427151231.113429-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
DAMON test-purpose sysfs interface control Python module, _damon_sysfs, is
not supporting the newly added pause file. Add the support of the file,
for future test and use of the feature.
Link: https://lore.kernel.org/20260427151231.113429-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
process_madvise() used to validate the advice while walking each imported
iovec. If the vector has zero total length, vector_madvise() does not
enter the loop and can return success without checking whether the advice
value is valid.
For a local mm, such as process_madvise(PIDFD_SELF, ...), the remote-only
process_madvise_remote_valid() check is skipped. As a result, an invalid
advice can be reported as success when the vector has zero total length.
This differs from madvise(), which rejects an invalid advice before
returning success for a zero-length range.
Validate the generic madvise behavior at the syscall-facing entry points
before any vector walk. In process_madvise(), do this before the
remote-only advice restriction so unsupported advice is rejected with the
same priority for local and remote mm.
Use an errno-returning helper for address/length validation, and handle
zero-length ranges explicitly at the call sites. Requests with valid
advice and zero total length remain a noop and continue to return 0. Add
a selftest that covers invalid advice with a zero-length iovec and an
empty vector, while also checking that a request with valid advice and
zero length still succeeds.
Link: https://lore.kernel.org/tencent_C3AEB0E769C5F4F9370F9411B69B7F8B2907@qq.com
Fixes: 021781b01275 ("mm/madvise: unrestrict process_madvise() for current process")
Signed-off-by: fujunjie <fujunjie1@qq.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jann Horn <jannh@google.com>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
This patch set introces a new action: DAMOS_COLLAPSE.
For DAMOS_HUGEPAGE and DAMOS_NOHUGEPAGE to work, khugepaged should be
working, since it relies on hugepage_madvise to add a new slot. This slot
should be picked up by khugepaged and eventually collapse (or not, if we
are using DAMOS_NOHUGEPAGE) the pages. If THP is not enabled, khugepaged
will not be working, and therefore no collapse will happen.
DAMOS_COLLAPSE eventually calls madvise_collapse, which will collapse the
address range synchronously. In cases where there is a large VMA
(databases, for example), DAMOS_COLLAPSE allows us to collapse only the
hot region, and not the entire VMA.
This new action may be required to support autotuning with hugepage
as a goal[1].
=========
Benchmarks:
=========
MySQL
=====
Tests were performed in an ARM physical server with MariaDB 10.5 and
sysbench. Read only benchmark was perform with gaussian row hitting,
which follows a normal distribution.
T n, D h: THP set to never, DAMON action set to hugepage
T m, D h: THP set to madvise, DAMON action set to hugepage
T n, D c: THP set to never, DAMON action set to collapse
Memory consumption. Lower is better.
+------------------+----------+----------+----------+
| | T n, D h | T m, D h | T n, D c |
+------------------+----------+----------+----------+
| Total memory use | 2.13 | 2.20 | 2.20 |
| Huge pages | 0 | 1.3 | 1.27 |
+------------------+----------+----------+----------+
Performance in TPS (Transactions Per Second). Higher is better.
T n, D h: 18225.58
T m, D h 18252.93
T n, D c: 18270.21
Performance counter
I got the number of L1 D/I TLB accesses and the number a D/I TLB
accesses that triggered a page walk. I divided the second by the
first to get the percentage of page walkes per TLB access. The
lower the better.
+---------------+--------------+--------------+--------------+
| | T n, D h | T m, D h | T n, D c |
+---------------+--------------+--------------+--------------+
| L1 DTLB | 127248242753 | 125431020479 | 125327001821 |
| L1 ITLB | 80332558619 | 79346759071 | 79298139590 |
| DTLB walk | 75011087 | 52800418 | 55895794 |
| ITLB walk | 71577076 | 71505137 | 67262140 |
| DTLB % misses | 0.058948623 | 0.042095183 | 0.044599961 |
| ITLB % misses | 0.089100954 | 0.090117275 | 0.084821839 |
+---------------+--------------+--------------+--------------+
Masim
=====
I used masim with the "demo" configuration, but changing the times
to 100 seconds for the initial phase and 50 seconds for the rest of
the phases.
Memory consumption:
+------------------+----------+----------+----------+
| | T n, D h | T m, D h | T n, D c |
+------------------+----------+----------+----------+
| Total memory use | 2.38 GB | 2.36 GB | 2.37 GB |
| Huge pages | 0 | 190 MB | 188 MB |
+------------------+----------+----------+----------+
Performance:
THP never, DAMOS_HUGEPAGE
initial phase: 40,491 accesses/msec, 100001 msecs run
low phase 0: 39,658 accesses/msec, 50002 msecs run
high phase 0: 41,678 accesses/msec, 50000 msecs run
low phase 1: 39,625 accesses/msec, 50003 msecs run
high phase 1: 41,658 accesses/msec, 50002 msecs run
low phase 2: 39,642 accesses/msec, 50002 msecs run
high phase 2: 41,640 accesses/msec, 50001 msecs run
THP madvise, DAMOS_HUGEPAGE
initial phase: 51,977 accesses/msec, 100000 msecs run
low phase 0: 86,953 accesses/msec, 50000 msecs run
high phase 0: 94,812 accesses/msec, 50000 msecs run
low phase 1: 101,017 accesses/msec, 50000 msecs run
high phase 1: 94,841 accesses/msec, 50000 msecs run
low phase 2: 100,993 accesses/msec, 50000 msecs run
high phase 2: 94,791 accesses/msec, 50001 msecs run
THP never, DAMOS_COLLAPSE
initial phase: 93,678 accesses/msec, 100001 msecs run
low phase 0: 101,475 accesses/msec, 50000 msecs run
high phase 0: 98,589 accesses/msec, 50000 msecs run
low phase 1: 101,531 accesses/msec, 50001 msecs run
high phase 1: 98,506 accesses/msec, 50001 msecs run
low phase 2: 101,458 accesses/msec, 50001 msecs run
high phase 2: 98,555 accesses/msec, 50000 msecs run
Memory consumption dynamic (how quickly collapses occur):
It shows in seconds how many huge pages are allocated.
+----+----------+----------+
| | T m, D h | T n, D c |
+----+----------+----------+
| 5 | 32 | 188 |
| 10 | 48 | 188 |
| 15 | 64 | 188 |
| 20 | 96 | 188 |
| 30 | 112 | 188 |
| 35 | 144 | 188 |
| 40 | 160 | 188 |
| 45 | 190 | 188 |
| 50 | 190 | 188 |
| 55 | 190 | 188 |
| 60 | 190 | 188 |
+----+----------+----------+
=========
- We can see that DAMOS "hugepage" action works only when THP is set
to madvise. "collapse" action works even when THP is set to never.
- Performance for "collapse" action is slightly lower than "hugepage"
action and THP madvise. This is due to the fact that collapases
occur synchronously. With "hugepage" they may occur during page
faults.
- Memory consumption is slighly lower for "collapse" than "hugepage"
with THP madvise. This is due to the khugepage collapses all VMAs,
while "collapse" action only collapses the VMAs in the hot region.
- There is an improvement in TLB utilization when collapse through
"hugepage" or "collapse" actions are triggered. The amount of
TLB misses is lower.
- "collapse" action is performance synchronously, which means that
page collapses happen earlier and more rapidly. This can be
useful or not, depending on the scenario.
- "hugepage" action may trigger a VMA split in some scenarios, since
it needs to change the flag of the VMA to THP enabled. This may
lead to additional overhead.
Collapse action just adds a new option to chose the correct system
balance.
Link: https://lore.kernel.org/20260426231619.107231-5-sj@kernel.org
Link: https://lore.kernel.org/damon/20260313000816.79933-1-sj@kernel.org/ [1]
Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Cheng-Han Wu <hank20010209@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liew Rui Yan <aethernet65535@gmail.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The original version of mremap_test (7df666253f26: "kselftests: vm: add
mremap tests") validated remapped contents byte-by-byte and printed a
mismatch index in case the bytes streams didn't match. That was rather
inefficient, especially also if the test passed.
Later, commit 7033c6cc9620 ("selftests/mm: mremap_test: optimize execution
time from minutes to seconds using chunkwise memcmp") used memcmp() on
bigger chunks, to fallback to byte-wise scanning to detect the problematic
index only if it discovered a problem.
However, the implementation is overly complicated (e.g., get_sqrt() is
currently not optimal) and we don't really have to report the exact index:
whoever debugs the failing test can figure that out.
Let's simplify by just comparing both byte streams with memcmp() and not
detecting the exact failed index.
Link: https://lore.kernel.org/20260415044509.579428-1-dev.jain@arm.com
Signed-off-by: Dev Jain <dev.jain@arm.com>
Reported-by: Sarthak Sharma <sarthak.sharma@arm.com>
Tested-by: Sarthak Sharma <sarthak.sharma@arm.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
