perf report: Handle vDSO symbols properly
We were not looking up vDSO symbols properly, because they
are in the kallsyms but are user-mode entries.
Pass negative addresses to the kernel dso object, this
way we resolve them properly:
0.05% [kernel]: vread_tsc
Cc: Peter Zijlstra <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: Marcelo Tosatti <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: John Kacur <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[email protected]>
diff --git a/Documentation/perf_counter/builtin-report.c b/Documentation/perf_counter/builtin-report.c
index a8d3905..0f88d9e 100644
--- a/Documentation/perf_counter/builtin-report.c
+++ b/Documentation/perf_counter/builtin-report.c
@@ -728,6 +728,8 @@
event->ip.pid,
(void *)(long)ip);
+ dprintf(" ... thread: %s:%d\n", thread->comm, thread->pid);
+
if (thread == NULL) {
fprintf(stderr, "problem processing %d event, skipping it.\n",
event->header.type);
@@ -740,6 +742,8 @@
dso = kernel_dso;
+ dprintf(" ...... dso: %s\n", dso->name);
+
} else if (event->header.misc & PERF_EVENT_MISC_USER) {
show = SHOW_USER;
@@ -749,11 +753,22 @@
if (map != NULL) {
dso = map->dso;
ip -= map->start + map->pgoff;
+ } else {
+ /*
+ * If this is outside of all known maps,
+ * and is a negative address, try to look it
+ * up in the kernel dso, as it might be a
+ * vsyscall (which executes in user-mode):
+ */
+ if ((long long)ip < 0)
+ dso = kernel_dso;
}
+ dprintf(" ...... dso: %s\n", dso ? dso->name : "<not found>");
} else {
show = SHOW_HV;
level = 'H';
+ dprintf(" ...... dso: [hypervisor]\n");
}
if (show & show_mask) {
