perf probe: Support comp_dir to find an absolute source path
Gcc generates DW_AT_comp_dir and stores relative source path if building kernel
without O= option. In that case, perf probe --line sometimes doesn't work
without --source option, because it tries to access relative source path.
This adds DW_AT_comp_dir support to perf probe for finding an absolute source
path when no --source option.
LKML-Reference: <4C36EBE7.3060802@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 8d08e75..4445a1e 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -201,28 +201,38 @@
* a newly allocated path on success.
* Return 0 if file was found and readable, -errno otherwise.
*/
-static int get_real_path(const char *raw_path, char **new_path)
+static int get_real_path(const char *raw_path, const char *comp_dir,
+ char **new_path)
{
- if (!symbol_conf.source_prefix) {
- if (access(raw_path, R_OK) == 0) {
- *new_path = strdup(raw_path);
- return 0;
- } else
- return -errno;
+ const char *prefix = symbol_conf.source_prefix;
+
+ if (!prefix) {
+ if (raw_path[0] != '/' && comp_dir)
+ /* If not an absolute path, try to use comp_dir */
+ prefix = comp_dir;
+ else {
+ if (access(raw_path, R_OK) == 0) {
+ *new_path = strdup(raw_path);
+ return 0;
+ } else
+ return -errno;
+ }
}
- *new_path = malloc((strlen(symbol_conf.source_prefix) +
- strlen(raw_path) + 2));
+ *new_path = malloc((strlen(prefix) + strlen(raw_path) + 2));
if (!*new_path)
return -ENOMEM;
for (;;) {
- sprintf(*new_path, "%s/%s", symbol_conf.source_prefix,
- raw_path);
+ sprintf(*new_path, "%s/%s", prefix, raw_path);
if (access(*new_path, R_OK) == 0)
return 0;
+ if (!symbol_conf.source_prefix)
+ /* In case of searching comp_dir, don't retry */
+ return -errno;
+
switch (errno) {
case ENAMETOOLONG:
case ENOENT:
@@ -318,7 +328,7 @@
/* Convert source file path */
tmp = lr->path;
- ret = get_real_path(tmp, &lr->path);
+ ret = get_real_path(tmp, lr->comp_dir, &lr->path);
free(tmp); /* Free old path */
if (ret < 0) {
pr_warning("Failed to find source file. (%d)\n", ret);