diff options
| author | Adrian Hunter <adrian.hunter@intel.com> | 2022-07-11 12:31:44 +0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-07-19 22:19:00 +0300 |
| commit | 68566a7cf56bf3148797c218ed45a9de078ef47c (patch) | |
| tree | 7818323d1dc90cd540a234acedd227bc5f8b5eeb /tools/perf/util/dsos.c | |
| parent | a6bd98c45d1aeec59493617b02a86de39d384535 (diff) | |
| download | linux-68566a7cf56bf3148797c218ed45a9de078ef47c.tar.xz | |
perf tools: Fix dso_id inode generation comparison
Synthesized MMAP events have zero ino_generation, so do not compare
them to DSOs with a real ino_generation otherwise we end up with a DSO
without a build id.
Fixes: 0e3149f86b99ddab ("perf dso: Move dso_id from 'struct map' to 'struct dso'")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: kvm@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220711093218.10967-2-adrian.hunter@intel.com
[ Added clarification to the comment from Ian + more detailed explanation from Adrian ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/dsos.c')
| -rw-r--r-- | tools/perf/util/dsos.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/tools/perf/util/dsos.c b/tools/perf/util/dsos.c index b97366f77bbf..2bd23e4cf19e 100644 --- a/tools/perf/util/dsos.c +++ b/tools/perf/util/dsos.c @@ -23,8 +23,19 @@ static int __dso_id__cmp(struct dso_id *a, struct dso_id *b) if (a->ino > b->ino) return -1; if (a->ino < b->ino) return 1; - if (a->ino_generation > b->ino_generation) return -1; - if (a->ino_generation < b->ino_generation) return 1; + /* + * Synthesized MMAP events have zero ino_generation, avoid comparing + * them with MMAP events with actual ino_generation. + * + * I found it harmful because the mismatch resulted in a new + * dso that did not have a build ID whereas the original dso did have a + * build ID. The build ID was essential because the object was not found + * otherwise. - Adrian + */ + if (a->ino_generation && b->ino_generation) { + if (a->ino_generation > b->ino_generation) return -1; + if (a->ino_generation < b->ino_generation) return 1; + } return 0; } |