Namhyung Kim 2d7f5540b8 perf script: Initialize buffer for regs_map() ... The buffer is used to save register mapping in a sample. Normally perf samples don't have any register so the string should be empty. But it missed to initialize the buffer when the size is 0. And it's passed to PyUnicode_FromString() with a garbage data. So it returns NULL due to invalid input (instead of an empty unicode string object) which causes a segfault like below: Thread 2.1 "perf" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7ffff7c83780 (LWP 193775)] 0x00007ffff6dbca2e in PyDict_SetItem () from /lib/x86_64-linux-gnu/libpython3.11.so.1.0 (gdb) bt #0 0x00007ffff6dbca2e in PyDict_SetItem () from /lib/x86_64-linux-gnu/libpython3.11.so.1.0 #1 0x00007ffff6dbf848 in PyDict_SetItemString () from /lib/x86_64-linux-gnu/libpython3.11.so.1.0 #2 0x000055555575824d in pydict_set_item_string_decref (val=0x0, key=0x5555557f96e3 "iregs", dict=0x7ffff5f7f780) at util/scripting-engines/trace-event-python.c:145 #3 set_regs_in_dict (evsel=0x555555efc370, sample=0x7fffffffb870, dict=0x7ffff5f7f780) at util/scripting-engines/trace-event-python.c:776 #4 get_perf_sample_dict (sample=sample@entry=0x7fffffffb870, evsel=evsel@entry=0x555555efc370, al=al@entry=0x7fffffffb2e0, addr_al=addr_al@entry=0x0, callchain=callchain@entry=0x7ffff63ef440) at util/scripting-engines/trace-event-python.c:923 #5 0x0000555555758ec1 in python_process_tracepoint (sample=0x7fffffffb870, evsel=0x555555efc370, al=0x7fffffffb2e0, addr_al=0x0) at util/scripting-engines/trace-event-python.c:1044 #6 0x00005555555c5db8 in process_sample_event (tool=<optimized out>, event=<optimized out>, sample=<optimized out>, evsel=0x555555efc370, machine=0x555555ef4d68) at builtin-script.c:2421 #7 0x00005555556b7793 in perf_session__deliver_event (session=0x555555ef4b60, event=0x7ffff62ff7d0, tool=0x7fffffffc150, file_offset=30672, file_path=0x555555efb8a0 "perf.data") at util/session.c:1639 #8 0x00005555556bc864 in do_flush (show_progress=true, oe=0x555555efb700) at util/ordered-events.c:245 #9 __ordered_events__flush (oe=oe@entry=0x555555efb700, how=how@entry=OE_FLUSH__FINAL, timestamp=timestamp@entry=0) at util/ordered-events.c:324 #10 0x00005555556bd06e in ordered_events__flush (oe=oe@entry=0x555555efb700, how=how@entry=OE_FLUSH__FINAL) at util/ordered-events.c:342 #11 0x00005555556b9d63 in __perf_session__process_events (session=0x555555ef4b60) at util/session.c:2465 #12 perf_session__process_events (session=0x555555ef4b60) at util/session.c:2627 #13 0x00005555555cb1d0 in __cmd_script (script=0x7fffffffc150) at builtin-script.c:2839 #14 cmd_script (argc=<optimized out>, argv=<optimized out>) at builtin-script.c:4365 #15 0x0000555555650811 in run_builtin (p=p@entry=0x555555ed8948 <commands+456>, argc=argc@entry=4, argv=argv@entry=0x7fffffffe240) at perf.c:323 #16 0x0000555555597eb3 in handle_internal_command (argv=0x7fffffffe240, argc=4) at perf.c:377 #17 run_argv (argv=<synthetic pointer>, argcp=<synthetic pointer>) at perf.c:421 #18 main (argc=4, argv=0x7fffffffe240) at perf.c:537 Fixes: 51cfe7a3e8 ("perf python: Avoid 2 leak sanitizer issues") Cc: Peter Zijlstra <peterz@infradead.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: Ian Rogers <irogers@google.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org>		2023-06-22 22:10:51 -07:00
..
Build	perf script: Fix Python support when no libtraceevent	2023-03-15 10:27:07 -03:00
trace-event-perl.c	perf callchain: Use pthread keys for tls callchain_cursor	2023-06-12 15:57:54 -03:00
trace-event-python.c	perf script: Initialize buffer for regs_map()	2023-06-22 22:10:51 -07:00