[PATCH 07/26] perf tools: Add check for existing link in buildid dir

Jiri Olsa
2020-09-13T21:04:25Z

When adding new build id link we fail if the link is already
there. Adding check for existing link and warn/replace the
link with new target.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
tools/perf/util/build-id.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
index bdee4e08e60d..ecdc167aa1a0 100644
--- a/tools/perf/util/build-id.c
+++ b/tools/perf/util/build-id.c
@@ -751,8 +751,26 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name,
tmp = dir_name + strlen(buildid_dir) - 5;
memcpy(tmp, "../..", 5);

- if (symlink(tmp, linkname) == 0)
+ if (symlink(tmp, linkname) == 0) {
err = 0;
+ } else if (errno == EEXIST) {
+ char path[PATH_MAX];
+
+ if (readlink(linkname, path, sizeof(path)) == -1) {
+ pr_err("Cant read link: %s\n", linkname);
+ goto out_free;
+ }
+ if (strcmp(tmp, path)) {
+ pr_err("Inconsistent .debug record, updating [%s]\n",
+ linkname);
+
+ unlink(linkname);
+
+ if (symlink(tmp, linkname))
+ goto out_free;
+ }
+ err = 0;
+ }

/* Update SDT cache : error is just warned */
if (realname &&
--
2.26.2