[PATCH 6.18 009/752] perf tools: Get debug info of DSO properly

Sasha Levin
2026-02-28T17:48:06Z

From: Namhyung Kim <namhyung@kernel.org>

[ Upstream commit 069e603d8248dac98b1ef2909e2f1c4169b9da11 ]

The dso__debuginfo() just used the path name to open the file but it may
be outdated. It should check build-ID and use the file in the build-ID
cache if available rather than just using the path name.

Let's factor out dso__get_filename() to avoid code duplicate.

Fixes: 53a61a6ca279165d ("perf annotate: Add dso__debuginfo() helper")
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/perf/util/dso.c | 63 ++++++++++++++++++++++++++++++++-----------
tools/perf/util/dso.h | 11 ++------
2 files changed, 50 insertions(+), 24 deletions(-)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 344e689567ee1..dc202d4943721 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -111,7 +111,7 @@ bool dso__is_object_file(const struct dso *dso)

int dso__read_binary_type_filename(const struct dso *dso,
enum dso_binary_type type,
- char *root_dir, char *filename, size_t size)
+ const char *root_dir, char *filename, size_t size)
{
char build_id_hex[SBUILD_ID_SIZE];
int ret = 0;
@@ -563,20 +563,15 @@ char *dso__filename_with_chroot(const struct dso *dso, const char *filename)
return filename_with_chroot(nsinfo__pid(dso__nsinfo_const(dso)), filename);
}

-static int __open_dso(struct dso *dso, struct machine *machine)
- EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
+static char *dso__get_filename(struct dso *dso, const char *root_dir,
+ bool *decomp)
{
- int fd = -EINVAL;
- char *root_dir = (char *)"";
char *name = malloc(PATH_MAX);
- bool decomp = false;

- if (!name)
- return -ENOMEM;
+ *decomp = false;

- mutex_lock(dso__lock(dso));
- if (machine)
- root_dir = machine->root_dir;
+ if (name == NULL)
+ return NULL;

if (dso__read_binary_type_filename(dso, dso__binary_type(dso),
root_dir, name, PATH_MAX))
@@ -601,20 +596,38 @@ static int __open_dso(struct dso *dso, struct machine *machine)
size_t len = sizeof(newpath);

if (dso__decompress_kmodule_path(dso, name, newpath, len) < 0) {
- fd = -(*dso__load_errno(dso));
+ errno = *dso__load_errno(dso);
goto out;
}

- decomp = true;
+ *decomp = true;
strcpy(name, newpath);
}
+ return name;
+
+out:
+ free(name);
+ return NULL;
+}

- fd = do_open(name);
+static int __open_dso(struct dso *dso, struct machine *machine)
+ EXCLUSIVE_LOCKS_REQUIRED(_dso__data_open_lock)
+{
+ int fd = -EINVAL;
+ char *name;
+ bool decomp = false;
+
+ mutex_lock(dso__lock(dso));
+
+ name = dso__get_filename(dso, machine ? machine->root_dir : "", &decomp);
+ if (name)
+ fd = do_open(name);
+ else
+ fd = -errno;

if (decomp)
unlink(name);

-out:
mutex_unlock(dso__lock(dso));
free(name);
return fd;
@@ -1910,3 +1923,23 @@ const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
return __dso__read_symbol(dso, symfs_filename, start, len,
out_buf, out_buf_len, is_64bit);
}
+
+struct debuginfo *dso__debuginfo(struct dso *dso)
+{
+ char *name;
+ bool decomp = false;
+ struct debuginfo *dinfo = NULL;
+
+ mutex_lock(dso__lock(dso));
+
+ name = dso__get_filename(dso, "", &decomp);
+ if (name)
+ dinfo = debuginfo__new(name);
+
+ if (decomp)
+ unlink(name);
+
+ mutex_unlock(dso__lock(dso));
+ free(name);
+ return dinfo;
+}
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index f8ccb9816b89c..54e470dd07305 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -766,7 +766,7 @@ int dso__kernel_module_get_build_id(struct dso *dso, const char *root_dir);

char dso__symtab_origin(const struct dso *dso);
int dso__read_binary_type_filename(const struct dso *dso, enum dso_binary_type type,
- char *root_dir, char *filename, size_t size);
+ const char *root_dir, char *filename, size_t size);
bool is_kernel_module(const char *pathname, int cpumode);
bool dso__needs_decompress(struct dso *dso);
int dso__decompress_kmodule_fd(struct dso *dso, const char *name);
@@ -915,14 +915,7 @@ u64 dso__findnew_global_type(struct dso *dso, u64 addr, u64 offset);
bool perf_pid_map_tid(const char *dso_name, int *tid);
bool is_perf_pid_map_name(const char *dso_name);

-/*
- * In the future, we may get debuginfo using build-ID (w/o path).
- * Add this helper is for the smooth conversion.
- */
-static inline struct debuginfo *dso__debuginfo(struct dso *dso)
-{
- return debuginfo__new(dso__long_name(dso));
-}
+struct debuginfo *dso__debuginfo(struct dso *dso);

const u8 *dso__read_symbol(struct dso *dso, const char *symfs_filename,
const struct map *map, const struct symbol *sym,
--
2.51.0