c7a5592e8e
Guilherme reported a crash in perf mem record. It's because the perf_mem_event->name was NULL on his machine. It should just return a NULL string when it has no format string in the name. The backtrace at the crash is below: Program received signal SIGSEGV, Segmentation fault. __strchrnul_avx2 () at ../sysdeps/x86_64/multiarch/strchr-avx2.S:67 67 vmovdqu (%rdi), %ymm2 (gdb) bt #0 __strchrnul_avx2 () at ../sysdeps/x86_64/multiarch/strchr-avx2.S:67 #1 0x00007ffff6c982de in __find_specmb (format=0x0) at printf-parse.h:82 #2 __printf_buffer (buf=buf@entry=0x7fffffffc760, format=format@entry=0x0, ap=ap@entry=0x7fffffffc880, mode_flags=mode_flags@entry=0) at vfprintf-internal.c:649 #3 0x00007ffff6cb7840 in __vsnprintf_internal (string=<optimized out>, maxlen=<optimized out>, format=0x0, args=0x7fffffffc880, mode_flags=mode_flags@entry=0) at vsnprintf.c:96 #4 0x00007ffff6cb787f in ___vsnprintf (string=<optimized out>, maxlen=<optimized out>, format=<optimized out>, args=<optimized out>) at vsnprintf.c:103 #5 0x00005555557b9391 in scnprintf (buf=0x555555fe9320 <mem_loads_name> "", size=100, fmt=0x0) at ../lib/vsprintf.c:21 #6 0x00005555557b74c3 in perf_pmu__mem_events_name (i=0, pmu=0x555556832180) at util/mem-events.c:106 #7 0x00005555557b7ab9 in perf_mem_events__record_args (rec_argv=0x55555684c000, argv_nr=0x7fffffffca20) at util/mem-events.c:252 #8 0x00005555555e370d in __cmd_record (argc=3, argv=0x7fffffffd760, mem=0x7fffffffcd80) at builtin-mem.c:156 #9 0x00005555555e49c4 in cmd_mem (argc=4, argv=0x7fffffffd760) at builtin-mem.c:514 #10 0x000055555569716c in run_builtin (p=0x555555fcde80 <commands+672>, argc=8, argv=0x7fffffffd760) at perf.c:349 #11 0x0000555555697402 in handle_internal_command (argc=8, argv=0x7fffffffd760) at perf.c:402 #12 0x0000555555697560 in run_argv (argcp=0x7fffffffd59c, argv=0x7fffffffd590) at perf.c:446 #13 0x00005555556978a6 in main (argc=8, argv=0x7fffffffd760) at perf.c:562 Reported-by: Guilherme Amadio <amadio@cern.ch> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Closes: https://lore.kernel.org/linux-perf-users/Zlns_o_IE5L28168@cern.ch Signed-off-by: Namhyung Kim <namhyung@kernel.org> Link: https://lore.kernel.org/r/20240621170528.608772-5-namhyung@kernel.org
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.