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2026-06-10perf tools: Fix thread__set_comm_from_proc() on empty comm fileArnaldo Carvalho de Melo
thread__set_comm_from_proc() calls procfs__read_str() then strips the trailing newline via comm[sz - 1] = '\0'. procfs__read_str() allocates the buffer before reading, so on an empty /proc/pid/comm (reachable during late exit teardown) it returns success with sz = 0 and an unterminated heap buffer. The sz - 1 underflow was the original sashiko finding: it writes a null byte before the allocation. But even with a sz > 0 guard on the newline strip, the unterminated buffer would still be passed to thread__set_comm() which calls strlen() — an unbounded heap read. Fix by treating sz == 0 as failure: free the buffer and return -1. This is consistent with pmu.c's perf_pmu__parse_scale/unit which already treat len == 0 from filename__read_str as an error. Fixes: 2f3027ac28bf6bc3 ("perf thread: Introduce method to set comm from /proc/pid/self") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf intel-pt: Fix snprintf size tracking bug in insn decoderArnaldo Carvalho de Melo
dump_insn() tracks remaining buffer space with a 'left' variable, but the loop subtracts the cumulative offset 'n' each iteration instead of just the per-iteration delta: n += snprintf(x->out + n, left, "%02x ", inbuf[i]); left -= n; /* BUG: n is cumulative, not the delta */ After two iterations left goes massively negative, wrapping to a huge value when passed as size_t to snprintf(), disabling all bounds checking for the rest of the loop. Switch to scnprintf() accumulation using sizeof(x->out) - n as the remaining space, which is always correct and eliminates the separate 'left' variable entirely. Fixes: 48d02a1d5c137d36 ("perf script: Add 'brstackinsn' for branch stacks") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Andi Kleen <ak@linux.intel.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Use mkostemp() for O_CLOEXEC on temporary filesArnaldo Carvalho de Melo
mkstemp() creates file descriptors without the close-on-exec flag. These fds leak to child processes spawned during symbol resolution (addr2line, objdump), wasting descriptors and potentially exposing temporary file contents. Replace mkstemp() with mkostemp(tmpbuf, O_CLOEXEC) at all three call sites: - filename__decompress() in dso.c - read_gnu_debugdata() in symbol-elf.c - kcore__init() in symbol-elf.c Fixes: 42b3fa670825983f ("perf tools: Introduce dso__decompress_kmodule_{fd,path}") Fixes: b10f74308e130527 ("perf symbol: Support .gnu_debugdata for symbols") Fixes: afba19d9dc8eba66 ("perf symbols: Workaround objdump difficulties with kcore") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephen Brennan <stephen.s.brennan@oracle.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf symbols: Bounds-check .gnu_debuglink section dataArnaldo Carvalho de Melo
filename__read_debuglink() copies .gnu_debuglink section data into a caller-provided buffer via: strncpy(debuglink, data->d_buf, size); where size is PATH_MAX. If the ELF section is smaller than size and lacks a null terminator, strncpy reads past data->d_buf into adjacent memory. A malformed ELF file can trigger this, potentially causing a segfault or leaking heap data. Additionally, strncpy does not guarantee null termination when the source fills the buffer. Replace with an explicit memcpy bounded by both the output buffer size and the actual section data size (data->d_size), followed by explicit null termination. Fixes: e5a1845fc0aeca85 ("perf symbols: Split out util/symbol-elf.c") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf symbols: Fix signed overflow in sysfs__read_build_id() size checkArnaldo Carvalho de Melo
sysfs__read_build_id() reads ELF note headers from sysfs files. The note's namesz and descsz fields are used to compute the skip size: int n = namesz + descsz; if (n > (int)sizeof(bf)) Both namesz and descsz are size_t from NOTE_ALIGN() of 32-bit note header fields. Their sum can exceed INT_MAX, overflowing the signed int n to a negative value. The check n > sizeof(bf) then evaluates false (negative < positive in signed comparison), and read(fd, bf, n) reinterprets the negative n as a huge size_t count — the kernel writes up to MAX_RW_COUNT bytes into the 8192-byte stack buffer. In practice the overflow is bounded by the sysfs file's actual size, so a real sysfs notes file won't trigger it organically. But crafted input (e.g. via a mounted debugfs/sysfs image) could. Fix by validating namesz and descsz individually against the buffer size before summing, and change n to size_t to avoid the signed overflow entirely. Fixes: f1617b40596cb341 ("perf symbols: Record the build_ids of kernel modules too") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf pmu: Fix perf_pmu__parse_scale/unit() OOB access on empty sysfs fileArnaldo Carvalho de Melo
perf_pmu__parse_scale() reads a PMU scale file then accesses scale[sret - 1] to strip a trailing newline. Only sret < 0 is guarded, so an empty file (sret == 0) causes scale[-1] — a stack buffer underflow that reads and potentially writes out of bounds. perf_pmu__parse_unit() has the same pattern: alias->unit[sret - 1] with sret == 0 accesses the byte before the struct member, which may corrupt the adjacent pmu_name pointer field. Change both guards from sret < 0 to sret <= 0 so that empty files are treated as read errors. Fixes: 410136f5dd96b601 ("tools/perf/stat: Add event unit and scale support") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Stephane Eranian <eranian@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf pmu: Fix pmu_id() heap underwrite on empty identifier fileArnaldo Carvalho de Melo
pmu_id() calls filename__read_str() then strips the trailing newline via str[len - 1] = 0. If the PMU identifier file is empty, filename__read_str() succeeds with len = 0. len - 1 underflows size_t to SIZE_MAX, writing a null byte before the heap allocation. Add a len == 0 check before the newline stripping. Fixes: 51d548471510843e ("perf pmu: Add pmu_id()") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: John Garry <john.g.garry@oracle.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf jitdump: Fix a build error with ASANNamhyung Kim
I found this error when I pass EXTRA_CFLAGS=-fsanitize=address on Fedora 44 with GCC 16. Fix it by copying one less byte. CC util/jitdump.o util/jitdump.c: In function ‘jit_process’: util/jitdump.c:237:9: error: ‘__builtin_strncpy’ specified bound 4096 equals destination size [-Werror=stringop-truncation] 237 | strncpy(jd->dir, name, PATH_MAX); | ^ cc1: all warnings being treated as errors make[4]: *** [tools/build/Makefile.build:95: util/jitdump.o] Error 1 make[4]: *** Waiting for unfinished jobs.... make[3]: *** [tools/build/Makefile.build:158: util] Error 2 make[2]: *** [Makefile.perf:578: perf-util-in.o] Error 2 make[1]: *** [Makefile.perf:288: sub-make] Error 2 make: *** [Makefile:76: all] Error 2 Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Move existing tests to coresight folderJames Clark
There is a subfolder for Coresight tests so might as well keep them all in here. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Speed up disassembly testJames Clark
We can use exit snapshot to limit the amount of trace to decode here too. Also each call to objdump is quite expensive on kcore so limit it to 2 samples instead of 30. We only want to see if there is no data at all. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Add all branch instructions to testJames Clark
If we reduce the number of samples searched to speed up the test, then there will be less chance of hitting one of these branches. Extend the regex to cover all branches so the test will always pass. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Make disassembly test use kcoreJames Clark
Hits in modules return empty disassembly with vmlinux as an input to objdump. Make the disassembly test more reliable by always using kcore. And update the comments to say that this is supported by the script. Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leo Yan <leo.yan@arm.com> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Remove unused Coresight workloadsJames Clark
These are now unused and had various issues like not working with out of source builds and being slow to compile. Delete them. Signed-off-by: James Clark <james.clark@linaro.org> Tested-by: Leo Yan <leo.yan@arm.com> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Speed up basic testJames Clark
Like the name says, this should be the most basic test possible. Kernel recording is slow and already has coverage on the systemwide test. Perf report output also has coverage elsewhere. 'ls' also produces more trace than 'true'. We only want to test if the combination of recording options works at all, so fix all of these things to make it as fast as possible. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Reduce snapshot sizeJames Clark
The default buffer size for root is 4MB which is very slow to decode. We only need a few KB to verify that the dd process is hit so reduce the size to 128KB. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Skip if not rootJames Clark
Use the common idiom for skipping tests if not running as root, which is required for these tests. Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leo Yan <leo.yan@arm.com> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Remove duplicate branch testsJames Clark
We already test branch output in perf script mode, but then retest it in Perf report mode. This is more of a test of Perf itself than Coresight because Perf uses the same samples to generate both outputs. Also we're already testing instruction output in Perf report mode. Remove this test for a speedup. On the systemwide test also remove the Perf report test because systemwide mode records a lot more data so running multiple tests on it has a big runtime impact. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Test decoding for concurrent threads testJames Clark
The thread_loop test only looks for context IDs in the raw trace. There's a lot more that can go wrong when decoding these, so replace it with a test that looks at the final output for matching thread names and symbols. In the future we might use timestamps and context switch events to track threads, so looking at context IDs in the raw trace wouldn't always work. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Tested-by: Leo Yan <leo.yan@arm.com> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test: Add named_threads workloadJames Clark
Add a workload that runs X threads that run a unique function named "named_threads_thread[x]" which performs a multiplication in a loop for Y loops. Each thread sets its name to "thread[x]". This can be used to test that processor trace decoding handles concurrent threads correctly and the correct symbols and thread names are assigned to samples. Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leo Yan <leo.yan@arm.com> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Replace memcpy test with raw dump stress testJames Clark
Like asm_pure_loop, this memcpy test only checks that 10 of each of a few trace packet types occur after recording a lot of trace, which isn't more specific than other existing Coresight tests. Assume it was supposed to be a stress test for dumping and replace it with one that doesn't require a custom binary and checks for a specific amount of raw output. Don't bother checking for packets because the other tests that test decoding will catch issues with malformed data. This also adds coverage for exit snapshot mode which was missing. Signed-off-by: James Clark <james.clark@linaro.org> Tested-by: Leo Yan <leo.yan@arm.com> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Remove asm_pure_loop testJames Clark
It's not obvious what this test is for so remove it. It's not a stress test because it doesn't output lots of data and it's not a functional test because it only looks for raw trace output. It seems to imply that a program written in assembly influences whether trace would be generated by the CPU or not, but the CPU doesn't know what language the program is written in. We already have lots of Coresight tests that test the full pipeline including decoding, and in many more modes of operation than this one, so if no trace was collected they will already fail leaving this one redundant. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Replace unroll loop thread with deterministic decode testJames Clark
Testing a long sequence without branches seems like it would be better as a decoder unit test, and this test doesn't test decoding either, so it's not clear what bugs this is trying to catch. The new deterministic workload has somewhat long sequences when built unoptimized, and we can always increase them later if we want to. But now we test that decoding always gives the same result for the same sequence of code which we've never had before. Signed-off-by: James Clark <james.clark@linaro.org> Tested-by: Leo Yan <leo.yan@arm.com> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test: Add deterministic workloadJames Clark
Add a workload that does the same thing every time for testing CPU trace decoding. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test cs-etm: Test process attributionJames Clark
Run the context switch workload on one CPU and trace it to test that symbols are attributed to the correct process and that the attribution changes at the exact point that the context switch happened. Reviewed-by: Leo Yan <leo.yan@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test: Add a workload that forces context switchesJames Clark
This workload launches two processes that block when reading and writing to each other forcing the other process to be scheduled for each read/write pair. Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leo Yan <leo.yan@arm.com> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf test: Add workload-ctl optionJames Clark
Add a --workload-ctl=fifo:ctl-fifo[,ack-fifo] option for 'perf test -w'. When set, run_workload() opens the named FIFO, writes enable before invoking the builtin workload, writes disable before returning, and waits for ack responses when an ack FIFO is provided to ensure that the workload doesn't run until the events are enabled. This can be used to limit the scope of the recording to only the workload execution and avoid recording Perf setup and teardown code if Perf record is started with events disabled (-D 1). Assisted-by: Codex:GPT-5.5 Signed-off-by: James Clark <james.clark@linaro.org> Cc: Amir Ayupov <aaupov@meta.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Leo Yan <leo.yan@arm.com> Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf cs-etm: Queue context packets for frontendJames Clark
PE_CONTEXT elements update the context ID and exception level, but the decoder may still have prior packets cached for frontend processing. Updating the context immediately in the decoder backend can make those cached packets get consumed with the wrong thread or EL state. Add a CS_ETM_CONTEXT packet carrying the TID and EL to the frontend, this keeps context changes ordered with the rest of the packet stream and avoids mismatches when synthesizing samples from cached packets. Separate the memory access function into one for the frontend and one for decoding. The frontend also needs memory access to attach the instruction to samples. Because the frontend does memory access for both previous and current packets, change all the frontend memory access function signatures to take both a tidq and packet. But backend always uses the current backend EL and thread from the tidq. Treat context packets as a boundary for branch sample generation and remove tidq->prev_packet_thread because it's not possible to branch to a different thread, so only tracking the current thread is required for sample generation. Fixes: e573e978fb12e160 ("perf cs-etm: Inject capabilitity for CoreSight traces") Reported-by: Amir Ayupov <aaupov@meta.com> Closes: https://lore.kernel.org/linux-perf-users/20260515021135.1729028-1-aaupov@meta.com/ Co-authored-by: James Clark <james.clark@linaro.org> Signed-off-by: Leo Yan <leo.yan@arm.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Cc: Mike Leach <mike.leach@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paschalis Mpeis <Paschalis.Mpeis@arm.com> Cc: Robert Walker <robert.walker@arm.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suzuki Poulouse <suzuki.poulose@arm.com> Signed-off-by: James Clark <james.clark@linaro.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf pmu: Use scnprintf in buffer offset calculationsAthira Rajeev
Replace snprintf with scnprintf in buffer offset calculations to ensure the 'used' count will not exceed the "len". The current logic in perf_pmu__for_each_event uses an unconditional + 1 increment to buf_used to account for null terminators. This can cause a stack buffer overflow in the subsequent scnprintf call. When the local stack buffer buf (1024 bytes) is full, buf_used can reach 1025. This causes the subsequent remaining space calculation sizeof(buf) - buf_used to underflow. Use sub_non_neg() to see if space actually existed, and only increment the offset if remaining space is present. Changes includes: - Use sub_non_neg to check if space exists - Replacing snprintf with scnprintf to ensure the return value reflects the actual bytes written into the buffer. - Only increment buf_used by 1 if space exists - If a parameterized event uses a built-in perf keyword for its parameter name (eg, config=?), the lexer parses it as a predefined term token, which sets term->config to NULL. Add check to use parse_events__term_type_str() if term->config is NULL. Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Shivani Nittor <shivani@linux.ibm.com> Cc: Tanushree.Shah@ibm.com Cc: Tejas.Manhas1@ibm.com Cc: Thomas Richter <tmricht@linux.ibm.com> Cc: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Fix the check for parameterized field in event termAthira Rajeev
The format_alias() function in util/pmu.c has a check to detect whether the event has parameterized field ( =? ). The string alias->terms contains the event and if the event has user configurable parameter, there will be presence of sub string "=?" in the alias->terms. Snippet of code: /* Paramemterized events have the parameters shown. */ if (strstr(alias->terms, "=?")) { /* No parameters. */ snprintf(buf, len, "%.*s/%s/", (int)pmu_name_len, pmu->name, alias->name); if "strstr" contains the substring, it returns a pointer and hence enters the above check which is not the expected check. And hence "perf list" doesn't have the parameterized fields in the result. Fix this check to use: if (!strstr(alias->terms, "=?")) { With this change, perf list shows the events correctly with the strings showing parameters. Before the fix: # ./perf list|grep -w PM_PAU_CYC hv_24x7/PM_PAU_CYC/ [Kernel PMU event] With this fix: # ./perf list|grep -w PM_PAU_CYC hv_24x7/PM_PAU_CYC,chip=?/ [Kernel PMU event] Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Athira Rajeev <atrajeev@linux.ibm.com> Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Hari Bathini <hbathini@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Shivani Nittor <shivani@linux.ibm.com> Cc: Tanushree.Shah@ibm.com Cc: Tejas.Manhas1@ibm.com Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf data convert json: Fix addr_location leak on time-filtered samplesTanushree Shah
When samples are skipped due to time filtering in process_sample_event(), the early return path bypasses addr_location__exit(), causing memory leaks of thread, map, and maps references acquired by machine__resolve(). These references must be released through addr_location__exit() before returning. Fixes: 8e746e95c3e4eb56 ("perf data: Allow filtering conversion by time range") Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Tanushree Shah <tshah@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Athira Rajeev <atrajeev@linux.ibm.com> Cc: Derek Foreman <derek.foreman@collabora.com> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Petlan <mpetlan@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Shivani.Nittor@ibm.com Cc: Tanushree.Shah@ibm.com Cc: Tejas.Manhas1@ibm.com Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf s390: Fix TEXTREL in Python extension by compiling as PICJens Remus
On s390 the Python extension build fails as follows when using a linker that is configured to treat text relocations (TEXTREL) in shared libraries as error by default: GEN python/perf.cpython-314-s390x-linux-gnu.so /usr/bin/ld.bfd: error: read-only segment has dynamic relocations This occurrs because util/llvm-c-helpers.o is erroneously built from util/llvm-c-helpers.cpp without compiler option -fPIC but linked into the shared library (via libperf-util.a(perf-util-in.o)). On s390, object files must be compiled as position-indepedent code (PIC) in order to be linked into shared libraries. Commit a9a3f1d18a6c ("perf s390: Always build with -fPIC") added compiler option -fPIC to CFLAGS for s390, which is used in C compiles. Add -fPIC to CXXFLAGS for s390 as well, so that it is also used in C++ compiles. Fixes: a9a3f1d18a6c9ccf ("perf s390: Always build with -fPIC") Reported-by: Thomas Richter <tmricht@linux.ibm.com> Reviewed-by: Ian Rogers <irogers@google.com> Reviewed-by: James Clark <james.clark@linaro.org> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Bill Wendling <morbo@google.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hendrik Brueckner <brueckner@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Justin Stitt <justinstitt@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf build: Do not duplicate CFLAGS in Python extension buildsJens Remus
setuptools already uses CFLAGS. Passing CFLAGS with additional flags as extra compile arguments causes CFLAGS to effectively get passed twice: $ make -C tools/perf V=1 JOBS=1 ... building 'perf' extension gcc [CFLAGS] -fPIC -Iutil/include -I/usr/include/python3.14 \ -c /root/linux/tools/perf/util/python.c \ -o python_ext_build/tmp/root/linux/tools/perf/util/python.o \ [CFLAGS] \ -fno-strict-aliasing -Wno-write-strings -Wno-unused-parameter \ -Wno-redundant-decls -Wno-cast-function-type \ -Wno-declaration-after-statement Reviewed-by: James Clark <james.clark@linaro.org> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Hendrik Brueckner <brueckner@linux.ibm.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Polensky <japo@linux.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf build: Respect V=1 for Python extension buildsJens Remus
Make util/setup.py respect the verbose build flag (V=1) by conditionally passing --quiet only when not in verbose mode. This eases debugging of Python extension compilation issues and aligns with the existing perf build system behavior. Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Jens Remus <jremus@linux.ibm.com> Tested-by: Jan Polensky <japo@linux.ibm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Richter <tmricht@linux.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf riscv: fix register name stringsMartin Kaiser
On risc-v, pref probe generates an invalid syntax for a named register in a kprobe. $ perf probe --debug verbose --add "n_tty_write tty" ... Writing event: p:probe/n_tty_write _text+8922528 tty=%"%a0":x64 Failed to write event: Invalid argument The problem is the combination of #define REG_DWARFNUM_NAME(reg, idx) [idx] = "%" #reg and entries such as REG_DWARFNUM_NAME("%a0", 10) where #reg will escape the quotes of the first macro parameter. Update the macro definition to produce the correct syntax for a named register in a kprobe, i.e. the unquoted register name with only one leading %. Fixes: a90c4519186dfc08 ("perf riscv: Remove dwarf-regs.c and add dwarf-regs-table.h") Reviewed-by: Ian Rogers <irogers@google.com> Signed-off-by: Martin Kaiser <martin@kaiser.cx> Cc: Ian Rogers <irogers@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf dwarf: Avoid redefinition warnings for REG_DWARFNUM_NAMEMartin Kaiser
dwarf-regs.c includes an arch-specific dwarf-regs-table.h for several architectures. This pulls in different definitions of REG_DWARFNUM_NAME and causes compiler warnings for W=1 builds. In file included from util/dwarf-regs.c:23: .../dwarf-regs-table.h:5: error: "REG_DWARFNUM_NAME" redefined [-Werror] #define REG_DWARFNUM_NAME(reg, idx) [idx] = reg Undefine REG_DWARFNUM_NAME before each new definition. Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Martin Kaiser <martin@kaiser.cx> Cc: Ian Rogers <irogers@google.com> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Use scnprintf() in build_id__snprintf() and hwmon read_events()Arnaldo Carvalho de Melo
build_id__snprintf() and hwmon_pmu__read_events() accumulate formatted output via snprintf(), which returns the would-have-been-written count on truncation. In build_id__snprintf(), this inflates the return value beyond the buffer size. In hwmon_pmu__read_events(), len overshoots out_buf_len and the next 'out_buf_len - len' underflows. Switch both to scnprintf() which returns actual bytes written. In build_id__snprintf(), also tighten the loop guard from 'offs < bf_size' to 'offs + 1 < bf_size': since scnprintf() returns at most size-1, offs never reaches bf_size, and the original condition would spin doing zero-byte writes once the buffer fills. Fixes: fccaaf6fbbc59910 ("perf build-id: Change sprintf functions to snprintf") Fixes: 53cc0b351ec99278 ("perf hwmon_pmu: Add a tool PMU exposing events from hwmon in sysfs") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf hists: Fix snprintf() in hists__scnprintf_title() UID filter pathArnaldo Carvalho de Melo
hists__scnprintf_title() accumulates formatted output into a buffer using scnprintf() for all filter clauses except the UID filter, which uses snprintf(). If the buffer fills up and snprintf() returns more than the remaining space, printed exceeds size and the next 'size - printed' underflows, causing later scnprintf() calls to write past the buffer. Switch the UID filter clause to scnprintf() to match the rest of the function. Fixes: 25c312dbf88ca402 ("perf hists: Move hists__scnprintf_title() away from the TUI code") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf bpf: Use scnprintf() in snprintf_hex() and synthesize_bpf_prog_name()Arnaldo Carvalho de Melo
Both functions accumulate formatted output via ret += snprintf(buf + ret, size - ret, ...). If the buffer is too small and snprintf() returns more than the remaining space, ret exceeds size and the next 'size - ret' underflows, causing snprintf() to write past the buffer end. Switch to scnprintf() which returns the actual number of bytes written, making the accumulation safe. Fixes: 7b612e291a5affb1 ("perf tools: Synthesize PERF_RECORD_* for loaded BPF programs") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Song Liu <song@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Add O_CLOEXEC to open() calls in DSO and ELF codeArnaldo Carvalho de Melo
open() calls in dso.c and symbol-elf.c omit O_CLOEXEC, which leaks file descriptors to child processes spawned during symbol resolution (e.g., addr2line, objdump). This can exhaust the fd limit during long profiling sessions or when processing many DSOs. Add O_CLOEXEC to all open() calls in both files (12 call sites). Fixes: cdd059d731eeb466 ("perf tools: Move dso_* related functions into dso object") Fixes: e5a1845fc0aeca85 ("perf symbols: Split out util/symbol-elf.c") Reported-by: sashiko-bot <sashiko-bot@kernel.org> 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 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf sched: Fix idle-hist callchain display using wrong rb_first variantArnaldo Carvalho de Melo
timehist_print_idlehist_callchain() calls rb_first_cached() on sorted_root, but the sort function (callchain_param.sort) populates it via rb_insert_color() on the plain rb_root member — not the cached variant. This means rb_leftmost is never set, so rb_first_cached() always returns NULL and the entire callchain summary is silently dropped from --idle-hist output. The original code in ba957ebb54893aca ("perf sched timehist: Show callchains for idle stat") was correct — it used struct rb_root and rb_first(). The bug was introduced when sorted_root was converted to rb_root_cached without converting the sort insertion path to use rb_insert_color_cached(). Use rb_first(&root->rb_root) to match how the tree was populated. Fixes: cb4c13a5137766c3 ("perf sched: Use cached rbtrees") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Namhyung Kim <namhyung@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf sched: Bounds-check prio before test_bit() in timehistArnaldo Carvalho de Melo
timehist_skip_sample() reads prio from untrusted tracepoint data via perf_sample__intval(sample, "prev_prio") without bounds validation. A crafted perf.data with prev_prio >= MAX_PRIO (140) causes test_bit() to read past the end of the prio_bitmap, which is only MAX_PRIO bits. Add a prio >= 0 guard before the test_bit() call and skip out-of-range values (>= MAX_PRIO) that can never match the user's filter set. The original prio != -1 already let all negatives other than -1 through (after an undefined-behavior bitmap read); the new prio >= 0 guard preserves that pass-through behavior — negative means "no priority info", so the event is shown unfiltered — while fixing the OOB. Values >= MAX_PRIO are skipped because they cannot be represented in the filter bitmap. Fixes: 9b3a48bbe20d9692 ("perf sched timehist: Add --prio option") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Yang Jihong <yangjihong@bytedance.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: NULL bitmap pointers after bitmap_free()Arnaldo Carvalho de Melo
Two call sites free bitmaps without NULLing the pointer, risking double-free if the structure is reused or cleanup is called twice: - mmap__munmap(): map->affinity_mask.bits - record__mmap_cpu_mask_free(): mask->bits Set each pointer to NULL after bitmap_free(). Fixes: 8384a2600c7ddfc8 ("perf record: Adapt affinity to machines with #CPUs > 1K") Fixes: f466e5ed6c356d1d ("perf record: Extend --threads command line option") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Alexey Budankov <alexey.budankov@linux.intel.com> Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Use perf_env__get_cpu_topology() in machine__resolve()Arnaldo Carvalho de Melo
machine__resolve() accesses env->cpu[al->cpu].socket_id after checking al->cpu >= 0 and env->cpu != NULL, but without validating al->cpu against env->nr_cpus_avail. Since al->cpu comes from the untrusted perf.data sample, a crafted file with a large CPU index causes an out-of-bounds heap read. Use perf_env__get_cpu_topology() which validates both NULL and bounds. Also bounds-check al->cpu before the cast to struct perf_cpu (int16_t): without this, values like 65536 silently truncate to 0, bypassing the accessor's internal check and returning CPU 0's topology. Fixes: 0c4c4debb0adda4c ("perf tools: Add processor socket info to hist_entry and addr_location") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Use scnprintf() in cpu_map__snprint() to prevent overflowArnaldo Carvalho de Melo
cpu_map__snprint() accumulates snprintf() return values in ret. snprintf() returns the number of characters that *would have been written* on truncation, not the actual count. When a fragmented CPU list exceeds the buffer, ret grows past size, causing `size - ret` to underflow (both are size_t), and subsequent snprintf() calls write past the end of the caller's stack buffer. Switch to scnprintf() which returns the actual number of characters written, making ret accumulation safe by construction. Fixes: a24020e6b7cf6eb8 ("perf tools: Change cpu_map__fprintf output") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-10perf tools: Fix get_max_num() size_t underflow on empty sysfs fileArnaldo Carvalho de Melo
get_max_num() reads a sysfs file (cpu/possible, cpu/present, or node/possible) and scans backward from the end to find the last number. If the file is empty, filename__read_str() returns num == 0. The loop `while (--num)` decrements the size_t from 0 to SIZE_MAX, reading backward across the heap until a comma or hyphen is found or unmapped memory is hit. Add an early return for empty files before the backward scan. Fixes: 7780c25bae59fd04 ("perf tools: Allow ability to map cpus to nodes easily") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-06perf sched: Free callchain nodes in idle thread cleanupArnaldo Carvalho de Melo
free_idle_threads() relies on the thread priv destructor (free()) to clean up idle_thread_runtime structs. But free() doesn't walk the callchain_cursor linked list or the callchain_root tree allocated by callchain_cursor__copy() and callchain_append() during --idle-hist processing. Every idle thread with callchain data leaks these nodes. Introduce callchain_cursor_cleanup() to free the cursor's linked list of callchain_cursor_node entries, and call it together with free_callchain() in free_idle_threads() before thread__put(). Fixes: 225b24f569980ac9 ("perf sched timehist: Save callchain when entering idle") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-06perf tools: Fix int16_t truncation of max_cpu_num in set_max_cpu_num()Arnaldo Carvalho de Melo
set_max_cpu_num() assigns the sysfs "possible" CPU count to max_cpu_num.cpu which is int16_t (struct perf_cpu). On systems with >32767 possible CPUs the value silently truncates, potentially wrapping negative. This causes cpunode_map to be underallocated and subsequent cpu__get_node() calls to read out of bounds. The matching check for max_present_cpu_num was added by commit c760174401f6 ("perf cpumap: Reduce cpu size from int to int16_t") but max_cpu_num was missed. Add the same INT16_MAX guard. Fixes: c760174401f605cf ("perf cpumap: Reduce cpu size from int to int16_t") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-06perf timechart: Fix cpu2y() OOB read on untrusted CPU indexArnaldo Carvalho de Melo
cpu2y() indexes topology_map[cpu] without bounds checking. The array is allocated with nr_cpus entries (from env->nr_cpus_online), but callers pass sample CPU values from perf.data which can exceed that size with cross-machine recordings. Track the topology_map allocation size and bounds-check the CPU argument in cpu2y() before indexing. Out-of-bounds CPUs fall back to the identity mapping (cpu2slot(cpu)), which is the same behavior as when no topology is available. Fixes: c507999790438cde ("perf timechart: Add support for topology") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Stanislav Fomichev <stfomichev@yandex-team.ru> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-06perf c2c: Fix use-after-free in he__get_c2c_hists() error pathArnaldo Carvalho de Melo
he__get_c2c_hists() assigns c2c_he->hists before calling c2c_hists__init(). If init fails, the error path calls free(hists) but leaves c2c_he->hists pointing to freed memory. On teardown, c2c_he_free() finds the non-NULL pointer and calls hists__delete_entries() on it, causing a use-after-free. Set c2c_he->hists to NULL before freeing so teardown skips the already-freed allocation. Fixes: b2252ae67b687d2b ("perf c2c report: Decode c2c_stats for hist entries") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2026-06-06perf stat: Introduce perf_env__get_cpu_topology() to guard NULL env->cpuArnaldo Carvalho de Melo
process_cpu_topology() in header.c frees env->cpu on old-format perf.data files that predate topology information, but leaves nr_cpus_avail set. The six perf_env__get_*_aggr_by_cpu() functions in builtin-stat.c pass the bounds check but dereference a NULL env->cpu pointer, crashing on old recordings. Introduce perf_env__get_cpu_topology() as a safe accessor that validates env->cpu, cpu.cpu >= 0, and cpu.cpu < nr_cpus_avail in one place, returning a struct cpu_topology_map pointer or NULL. Convert all six topology aggregation callbacks to use it. Fixes: 88031a0de7d68d13 ("perf stat: Switch to cpu version of cpu_map__get()") Reported-by: sashiko-bot <sashiko-bot@kernel.org> Cc: Ian Rogers <irogers@google.com> Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>