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-rw-r--r--tools/perf/util/probe-event.c48
1 files changed, 47 insertions, 1 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 542e6472c4d7..4a57c8a60bd9 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -610,6 +610,51 @@ error:
return ret ? : -ENOENT;
}
+/*
+ * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions
+ * and generate new symbols with suffixes such as .constprop.N or .isra.N
+ * etc. Since those symbols are not recorded in DWARF, we have to find
+ * correct generated symbols from offline ELF binary.
+ * For online kernel or uprobes we don't need this because those are
+ * rebased on _text, or already a section relative address.
+ */
+static int
+post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
+ int ntevs, const char *pathname)
+{
+ struct symbol *sym;
+ struct map *map;
+ unsigned long stext = 0;
+ u64 addr;
+ int i;
+
+ /* Prepare a map for offline binary */
+ map = dso__new_map(pathname);
+ if (!map || get_text_start_address(pathname, &stext) < 0) {
+ pr_warning("Failed to get ELF symbols for %s\n", pathname);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < ntevs; i++) {
+ addr = tevs[i].point.address + tevs[i].point.offset - stext;
+ sym = map__find_symbol(map, addr);
+ if (!sym)
+ continue;
+ if (!strcmp(sym->name, tevs[i].point.symbol))
+ continue;
+ /* If we have no realname, use symbol for it */
+ if (!tevs[i].point.realname)
+ tevs[i].point.realname = tevs[i].point.symbol;
+ else
+ free(tevs[i].point.symbol);
+ tevs[i].point.symbol = strdup(sym->name);
+ tevs[i].point.offset = addr - sym->start;
+ }
+ map__put(map);
+
+ return 0;
+}
+
static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *exec)
{
@@ -671,7 +716,8 @@ post_process_kernel_probe_trace_events(struct probe_trace_event *tevs,
/* Skip post process if the target is an offline kernel */
if (symbol_conf.ignore_vmlinux_buildid)
- return 0;
+ return post_process_offline_probe_trace_events(tevs, ntevs,
+ symbol_conf.vmlinux_name);
reloc_sym = kernel_get_ref_reloc_sym();
if (!reloc_sym) {