• Adrian Hunter's avatar
    perf build-id: Fix caching files with a wrong build ID · ab66fdac
    Adrian Hunter authored
    Build ID events associate a file name with a build ID.  However, when
    using perf inject, there is no guarantee that the file on the current
    machine at the current time has that build ID. Fix by comparing the
    build IDs and skip adding to the cache if they are different.
    
    Example:
    
      $ echo "int main() {return 0;}" > prog.c
      $ gcc -o prog prog.c
      $ perf record --buildid-all ./prog
      [ perf record: Woken up 1 times to write data ]
      [ perf record: Captured and wrote 0.019 MB perf.data ]
      $ file-buildid() { file $1 | awk -F= '{print $2}' | awk -F, '{print $1}' ; }
      $ file-buildid prog
      444ad9be165d8058a48ce2ffb4e9f55854a3293e
      $ file-buildid ~/.debug/$(pwd)/prog/444ad9be165d8058a48ce2ffb4e9f55854a3293e/elf
      444ad9be165d8058a48ce2ffb4e9f55854a3293e
      $ echo "int main() {return 1;}" > prog.c
      $ gcc -o prog prog.c
      $ file-buildid prog
      885524d5aaa24008a3e2b06caa3ea95d013c0fc5
    
    Before:
    
      $ perf buildid-cache --purge $(pwd)/prog
      $ perf inject -i perf.data -o junk
      $ file-buildid ~/.debug/$(pwd)/prog/444ad9be165d8058a48ce2ffb4e9f55854a3293e/elf
      885524d5aaa24008a3e2b06caa3ea95d013c0fc5
      $
    
    After:
    
      $ perf buildid-cache --purge $(pwd)/prog
      $ perf inject -i perf.data -o junk
      $ file-buildid ~/.debug/$(pwd)/prog/444ad9be165d8058a48ce2ffb4e9f55854a3293e/elf
    
      $
    
    Fixes: 454c407e ("perf: add perf-inject builtin")
    Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
    Cc: Jiri Olsa <jolsa@kernel.org>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Tom Zanussi <tzanussi@gmail.com>
    Link: https://lore.kernel.org/r/20220621125144.5623-1-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    ab66fdac
build-id.c 22.3 KB