kernel/linux.git/tools/perf/util/python.c, branch v5.15.209

perf python: Check if there is space to copy all the event

2025-04-10T12:32:02+00:00

[ Upstream commit 89aaeaf84231157288035b366cb6300c1c6cac64 ] The pyrf_event__new() method copies the event obtained from the perf ring buffer to a structure that will then be turned into a python object for further consumption, so it copies perf_event.header.size bytes to its 'event' member: $ pahole -C pyrf_event /tmp/build/perf-tools-next/python/perf.cpython-312-x86_64-linux-gnu.so struct pyrf_event { PyObject ob_base; /* 0 16 */ struct evsel * evsel; /* 16 8 */ struct perf_sample sample; /* 24 312 */ /* XXX last struct has 7 bytes of padding, 2 holes */ /* --- cacheline 5 boundary (320 bytes) was 16 bytes ago --- */ union perf_event event; /* 336 4168 */ /* size: 4504, cachelines: 71, members: 4 */ /* member types with holes: 1, total: 2 */ /* paddings: 1, sum paddings: 7 */ /* last cacheline: 24 bytes */ }; $ It was doing so without checking if the event just obtained has more than that space, fix it. This isn't a proper, final solution, as we need to support larger events, but for the time being we at least bounds check and document it. Fixes: 877108e42b1b9ba6 ("perf tools: Initial python binding") Signed-off-by: Arnaldo Carvalho de Melo Reviewed-by: Ian Rogers Link: https://lore.kernel.org/r/20250312203141.285263-7-acme@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf python: Don't keep a raw_data pointer to consumed ring buffer space

2025-04-10T12:32:02+00:00

[ Upstream commit f3fed3ae34d606819d87a63d970cc3092a5be7ab ] When processing tracepoints the perf python binding was parsing the event before calling perf_mmap__consume(&md->core) in pyrf_evlist__read_on_cpu(). But part of this event parsing was to set the perf_sample->raw_data pointer to the payload of the event, which then could be overwritten by other event before tracepoint fields were asked for via event.prev_comm in a python program, for instance. This also happened with other fields, but strings were were problems were surfacing, as there is UTF-8 validation for the potentially garbled data. This ended up showing up as (with some added debugging messages): ( field 'prev_comm' ret=0x7f7c31f65110, raw_size=68 ) ( field 'prev_pid' ret=0x7f7c23b1bed0, raw_size=68 ) ( field 'prev_prio' ret=0x7f7c239c0030, raw_size=68 ) ( field 'prev_state' ret=0x7f7c239c0250, raw_size=68 ) time 14771421785867 prev_comm= prev_pid=1919907691 prev_prio=796026219 prev_state=0x303a32313175 ==> ( XXX '��' len=16, raw_size=68) ( field 'next_comm' ret=(nil), raw_size=68 ) Traceback (most recent call last): File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 51, in main() File "/home/acme/git/perf-tools-next/tools/perf/python/tracepoint.py", line 46, in main event.next_comm, ^^^^^^^^^^^^^^^ AttributeError: 'perf.sample_event' object has no attribute 'next_comm' When event.next_comm was asked for, the PyUnicode_FromString() python API would fail and that tracepoint field wouldn't be available, stopping the tools/perf/python/tracepoint.py test tool. But, since we already do a copy of the whole event in pyrf_event__new, just use it and while at it remove what was done in in e8968e654191390a ("perf python: Fix pyrf_evlist__read_on_cpu event consuming") because we don't really need to wait for parsing the sample before declaring the event as consumed. This copy is questionable as is now, as it limits the maximum event + sample_type and tracepoint payload to sizeof(union perf_event), this all has been "working" because 'struct perf_event_mmap2', the largest entry in 'union perf_event' is: $ pahole -C perf_event ~/bin/perf | grep mmap2 struct perf_record_mmap2 mmap2; /* 0 4168 */ $ Fixes: bae57e3825a3dded ("perf python: Add support to resolve tracepoint fields") Signed-off-by: Arnaldo Carvalho de Melo Reviewed-by: Ian Rogers Link: https://lore.kernel.org/r/20250312203141.285263-6-acme@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf python: Decrement the refcount of just created event on failure

2025-04-10T12:32:02+00:00

[ Upstream commit 3de5a2bf5b4847f7a59a184568f969f8fe05d57f ] To avoid a leak if we have the python object but then something happens and we need to return the operation, decrement the offset of the newly created object. Fixes: 377f698db12150a1 ("perf python: Add struct evsel into struct pyrf_event") Signed-off-by: Arnaldo Carvalho de Melo Reviewed-by: Ian Rogers Link: https://lore.kernel.org/r/20250312203141.285263-5-acme@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

perf python: Fixup description of sample.id event member

2025-04-10T12:32:02+00:00

[ Upstream commit 1376c195e8ad327bb9f2d32e0acc5ac39e7cb30a ] Some old cut'n'paste error, its "ip", so the description should be "event ip", not "event type". Fixes: 877108e42b1b9ba6 ("perf tools: Initial python binding") Signed-off-by: Arnaldo Carvalho de Melo Reviewed-by: Ian Rogers Link: https://lore.kernel.org/r/20250312203141.285263-2-acme@kernel.org Signed-off-by: Namhyung Kim Signed-off-by: Sasha Levin

libperf: Move 'idx' from tools/perf to perf_evsel::idx

2021-07-09T17:04:28+00:00

Move evsel::idx to perf_evsel::idx, so we can move the group interface to libperf. Committer notes: Fixup evsel->idx usage in tools/perf/util/bpf_counter_cgroup.c, that appeared in my tree in my local tree. Also fixed up these: $ find tools/perf/ -name "*.[ch]" | xargs grep 'evsel->idx' tools/perf/ui/gtk/annotate.c: evsel->idx + i); tools/perf/ui/gtk/annotate.c: evsel->idx); $ That running 'make -C tools/perf build-test' caught. Signed-off-by: Jiri Olsa Requested-by: Shunsuke Nakamura Cc: Alexander Shishkin Cc: Ian Rogers Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lore.kernel.org/lkml/20210706151704.73662-3-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Introduce bpf_counter_ops->disable()

2021-04-29T13:30:58+00:00

Introduce bpf_counter_ops->disable(), which is used stop counting the event. Committer notes: Added a dummy bpf_counter__disable() to the python binding to avoid having 'perf test python' failing. bpf_counter isn't supported in the python binding. Signed-off-by: Song Liu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Song Liu Cc: kernel-team@fb.com Link: https://lore.kernel.org/r/20210425214333.1090950-6-song@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf stat: Enable counting events for BPF programs

2021-01-20T17:25:28+00:00

Introduce 'perf stat -b' option, which counts events for BPF programs, like: [root@localhost ~]# ~/perf stat -e ref-cycles,cycles -b 254 -I 1000 1.487903822 115,200 ref-cycles 1.487903822 86,012 cycles 2.489147029 80,560 ref-cycles 2.489147029 73,784 cycles 3.490341825 60,720 ref-cycles 3.490341825 37,797 cycles 4.491540887 37,120 ref-cycles 4.491540887 31,963 cycles The example above counts 'cycles' and 'ref-cycles' of BPF program of id 254. This is similar to bpftool-prog-profile command, but more flexible. 'perf stat -b' creates per-cpu perf_event and loads fentry/fexit BPF programs (monitor-progs) to the target BPF program (target-prog). The monitor-progs read perf_event before and after the target-prog, and aggregate the difference in a BPF map. Then the user space reads data from these maps. A new 'struct bpf_counter' is introduced to provide a common interface that uses BPF programs/maps to count perf events. Committer notes: Removed all but bpf_counter.h includes from evsel.h, not needed at all. Also BPF map lookups for PERCPU_ARRAYs need to have as its value receive buffer passed to the kernel libbpf_num_possible_cpus() entries, not evsel__nr_cpus(evsel), as the former uses /sys/devices/system/cpu/possible while the later uses /sys/devices/system/cpu/online, which may be less than the 'possible' number making the bpf map lookup overwrite memory and cause hard to debug memory corruption. We need to continue using evsel__nr_cpus(evsel) when accessing the perf_counts array tho, not to overwrite another are of memory :-) Signed-off-by: Song Liu Tested-by: Arnaldo Carvalho de Melo Link: https://lore.kernel.org/lkml/20210120163031.GU12699@kernel.org/ Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Mark Rutland Cc: Peter Zijlstra Cc: kernel-team@fb.com Link: http://lore.kernel.org/lkml/20201229214214.3413833-4-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Use the right prefix for 'struct evlist' sample id lookup methods

2020-11-30T17:17:57+00:00

perf_evlist__ is for 'struct perf_evlist' methods, in tools/lib/perf/, go on completing this split. Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo

perf evlist: Use the right prefix for 'struct evlist' methods: evlist__set_leader()

2020-11-30T12:22:07+00:00

perf tools: Copy metric events properly when expand cgroups

2020-09-28T12:16:21+00:00

The metricgroup__copy_metric_events() is to handle metrics events when expanding event for cgroups. As the metric events keep pointers to evsel, it should be refreshed when events are cloned during the operation. The perf_stat__collect_metric_expr() is also called in case an event has a metric directly. During the copy, it references evsel by index as the evlist now has cloned evsels for the given cgroup. Also kernel test robot found an issue in the python module import so add empty implementations of those two functions to fix it. Reported-by: kernel test robot Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: Ian Rogers Cc: John Garry Cc: Kajol Jain Cc: Mark Rutland Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lore.kernel.org/lkml/20200924124455.336326-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo