perf tools: Set build-id using build-id header on new mmap records

MMAP records that occur after the build-id header is parsed do not have
their build-id set even if the filename matches an entry from the
header. Set the build-id on these dsos as long as the MMAP record
doesn't have its own build-id set.

This fixes an issue with off target analysis where the local version of
a dso is loaded rather than one from ~/.debug via a build-id.

Reported-by: Denis Nikitin <denik@chromium.org>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: coresight@lists.linaro.org
Link: https://lore.kernel.org/r/20220304090956.2048712-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 011da39..3a9fd4d 100644 (file)
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -167,6 +167,7 @@ struct dso {
        enum dso_load_errno     load_errno;
        u8               adjust_symbols:1;
        u8               has_build_id:1;
+       u8               header_build_id:1;
        u8               has_srcline:1;
        u8               hit:1;
        u8               annotate_warned:1;

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 6da12e5..571d73d 100644 (file)
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2200,6 +2200,7 @@ static int __event_process_build_id(struct perf_record_header_build_id *bev,
 
                build_id__init(&bid, bev->data, size);
                dso__set_build_id(dso, &bid);
+               dso->header_build_id = 1;
 
                if (dso_space != DSO_SPACE__USER) {
                        struct kmod_path m = { .name = NULL, };

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 1803d38..e0aa4a2 100644 (file)
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -127,7 +127,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
 
        if (map != NULL) {
                char newfilename[PATH_MAX];
-               struct dso *dso;
+               struct dso *dso, *header_bid_dso;
                int anon, no_dso, vdso, android;
 
                android = is_android_lib(filename);
@@ -183,9 +183,23 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
                }
                dso->nsinfo = nsi;
 
-               if (build_id__is_defined(bid))
+               if (build_id__is_defined(bid)) {
                        dso__set_build_id(dso, bid);
-
+               } else {
+                       /*
+                        * If the mmap event had no build ID, search for an existing dso from the
+                        * build ID header by name. Otherwise only the dso loaded at the time of
+                        * reading the header will have the build ID set and all future mmaps will
+                        * have it missing.
+                        */
+                       down_read(&machine->dsos.lock);
+                       header_bid_dso = __dsos__find(&machine->dsos, filename, false);
+                       up_read(&machine->dsos.lock);
+                       if (header_bid_dso && header_bid_dso->header_build_id) {
+                               dso__set_build_id(dso, &header_bid_dso->bid);
+                               dso->header_build_id = 1;
+                       }
+               }
                dso__put(dso);
        }
        return map;