perf tools: Allow synthesizing the build id for kernel/modules/tasks in PERF_RECORD_MMAP2

Adding build id to synthesized mmap2 events for everything -
kernel/modules/tasks, when symbol_conf.buildid_mmap2 is true.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201214105457.543111-11-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 126446de7bdddc100961cf92c1c6b111ea575f3f..69688f20db1196d64ea606d9298a0da682b33149 100644 (file)
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -347,6 +347,31 @@ static bool read_proc_maps_line(struct io *io, __u64 *start, __u64 *end,
        }
 }
 
+static void perf_record_mmap2__read_build_id(struct perf_record_mmap2 *event,
+                                            bool is_kernel)
+{
+       struct build_id bid;
+       int rc;
+
+       if (is_kernel)
+               rc = sysfs__read_build_id("/sys/kernel/notes", &bid);
+       else
+               rc = filename__read_build_id(event->filename, &bid) > 0 ? 0 : -1;
+
+       if (rc == 0) {
+               memcpy(event->build_id, bid.data, sizeof(bid.data));
+               event->build_id_size = (u8) bid.size;
+               event->header.misc |= PERF_RECORD_MISC_MMAP_BUILD_ID;
+               event->__reserved_1 = 0;
+               event->__reserved_2 = 0;
+       } else {
+               if (event->filename[0] == '/') {
+                       pr_debug2("Failed to read build ID for %s\n",
+                                 event->filename);
+               }
+       }
+}
+
 int perf_event__synthesize_mmap_events(struct perf_tool *tool,
                                       union perf_event *event,
                                       pid_t pid, pid_t tgid,
@@ -453,6 +478,9 @@ out:
                event->mmap2.pid = tgid;
                event->mmap2.tid = pid;
 
+               if (symbol_conf.buildid_mmap2)
+                       perf_record_mmap2__read_build_id(&event->mmap2, false);
+
                if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {
                        rc = -1;
                        break;
@@ -633,6 +661,8 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t
 
                        memcpy(event->mmap2.filename, pos->dso->long_name,
                               pos->dso->long_name_len + 1);
+
+                       perf_record_mmap2__read_build_id(&event->mmap2, false);
                } else {
                        size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
                        event->mmap.header.type = PERF_RECORD_MMAP;
@@ -1053,6 +1083,8 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
                event->mmap2.start = map->start;
                event->mmap2.len   = map->end - event->mmap.start;
                event->mmap2.pid   = machine->pid;
+
+               perf_record_mmap2__read_build_id(&event->mmap2, true);
        } else {
                size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
                                "%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;