• Arnaldo Carvalho de Melo's avatar
    perf evlist: Reference count the cpu and thread maps at set_maps() · a55e5663
    Arnaldo Carvalho de Melo authored
    We were dropping the reference we possibly held but not obtaining one
    for the new maps, which we will drop at perf_evlist__delete(), fix it.
    
    This was caught by Steven Noonan in some of the machines which would
    produce this output when caught by glibc debug mechanisms:
    
      $ sudo perf test 21
      21: Test object code reading                                 :***
      Error in `perf': corrupted double-linked list: 0x00000000023ffcd0 ***
      ======= Backtrace: =========
      /usr/lib/libc.so.6(+0x72055)[0x7f25be0f3055]
      /usr/lib/libc.so.6(+0x779b6)[0x7f25be0f89b6]
      /usr/lib/libc.so.6(+0x7a0ed)[0x7f25be0fb0ed]
      /usr/lib/libc.so.6(__libc_calloc+0xba)[0x7f25be0fceda]
      perf(parse_events_lex_init_extra+0x38)[0x4cfff8]
      perf(parse_events+0x55)[0x4a0615]
      perf(perf_evlist__config+0xcf)[0x4eeb2f]
      perf[0x479f82]
      perf(test__code_reading+0x1e)[0x47ad4e]
      perf(cmd_test+0x5dd)[0x46452d]
      perf[0x47f4e3]
      perf(main+0x603)[0x42c723]
      /usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7f25be0a1610]
      perf(_start+0x29)[0x42c859]
    
    Further investigation using valgrind led to the reference count imbalance fixed
    in this patch.
    Reported-and-Tested-by: default avatarSteven Noonan <steven@uplinklabs.net>
    Report-Link: http://lkml.kernel.org/r/CAKbGBLjC2Dx5vshxyGmQkcD+VwiAQLbHoXA9i7kvRB2-2opHZQ@mail.gmail.com
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Wang Nan <wangnan0@huawei.com>
    Fixes: f30a79b0 ("perf tools: Add reference counting for cpu_map object")
    Link: http://lkml.kernel.org/n/tip-j0u1bdhr47sa511sgg76kb8h@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    a55e5663
evlist.c 39.7 KB