From 449867e346bfd52c5df6bba5b706a795c35e78d4 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Tue, 26 Nov 2013 15:19:24 +0200 Subject: [PATCH] perf symbols: Fix not finding kcore in buildid cache The logic was not looking in the buildid cache for kcore if the host kernel buildid did not match the recorded kernel buildid. This affects the non-live case i.e. the kernel has changed and we are looking at a special copy of kcore that we placed in the buildid cache (using "perf buildid-cache -v -k /proc/kcore") when the data was recorded. After this fix kernel symbols get resolved/annotated correctly. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1385471964-4037-1-git-send-email-adrian.hunter@intel.com [ Added further explanation extracted from conversation between Ingo & Adrian on lkml ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/symbol.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index ce9ce101adf4..360eefecb81d 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -1526,14 +1526,15 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map) build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id); + scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", buildid_dir, + sbuild_id); + /* Use /proc/kallsyms if possible */ if (is_host) { DIR *d; int fd; /* If no cached kcore go with /proc/kallsyms */ - scnprintf(path, sizeof(path), "%s/[kernel.kcore]/%s", - buildid_dir, sbuild_id); d = opendir(path); if (!d) goto proc_kallsyms; @@ -1558,6 +1559,10 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map) goto proc_kallsyms; } + /* Find kallsyms in build-id cache with kcore */ + if (!find_matching_kcore(map, path, sizeof(path))) + return strdup(path); + scnprintf(path, sizeof(path), "%s/[kernel.kallsyms]/%s", buildid_dir, sbuild_id); -- 2.39.5