[PATCH v2 3/4] perf: symbol: generalize vmlinux path searching

Changbin Du
2024-06-15T09:20:44Z

This generalizes the vmlinux path searching logic. Later we will add
another instance for vdso.

The search pattern is described by struct dso_filename_pattern, and the
formatted paths are hold in struct dso_filename_paths.

Signed-off-by: Changbin Du <changbin.du@huawei.com>
---
tools/perf/util/machine.c | 4 +-
tools/perf/util/symbol.c | 112 +++++++++++++++++++++-----------------
tools/perf/util/symbol.h | 8 ++-
3 files changed, 70 insertions(+), 54 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 8477edefc299..68315520f15b 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -896,9 +896,9 @@ size_t machine__fprintf_vmlinux_path(struct machine *machine, FILE *fp)
printed += fprintf(fp, "[0] %s\n", filename);
}

- for (i = 0; i < vmlinux_path__nr_entries; ++i) {
+ for (i = 0; i < vmlinux_paths.nr_entries; ++i) {
printed += fprintf(fp, "[%d] %s\n", i + dso__has_build_id(kdso),
- vmlinux_path[i]);
+ vmlinux_paths.paths[i]);
}
return printed;
}
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index a90c647d37e1..83e5c3807a2c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -48,8 +48,7 @@ static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map);
static int dso__load_vdso_sym(struct dso *dso, struct map *map);
static bool symbol__is_idle(const char *name);

-int vmlinux_path__nr_entries;
-char **vmlinux_path;
+struct dso_filename_paths vmlinux_paths;

struct symbol_conf symbol_conf = {
.nanosecs = false,
@@ -2043,10 +2042,10 @@ int dso__load_vmlinux_path(struct dso *dso, struct map *map)
char *filename = NULL;

pr_debug("Looking at the vmlinux_path (%d entries long)\n",
- vmlinux_path__nr_entries + 1);
+ vmlinux_paths.nr_entries + 1);

- for (i = 0; i < vmlinux_path__nr_entries; ++i) {
- err = dso__load_vmlinux(dso, map, vmlinux_path[i], false);
+ for (i = 0; i < vmlinux_paths.nr_entries; ++i) {
+ err = dso__load_vmlinux(dso, map, vmlinux_paths.paths[i], false);
if (err > 0)
goto out;
}
@@ -2210,7 +2209,7 @@ static int dso__load_kernel_sym(struct dso *dso, struct map *map)
return err;
}

- if (!symbol_conf.ignore_vmlinux && vmlinux_path != NULL) {
+ if (!symbol_conf.ignore_vmlinux && vmlinux_paths.paths != NULL) {
err = dso__load_vmlinux_path(dso, map);
if (err > 0)
return err;
@@ -2285,57 +2284,55 @@ static int dso__load_guest_kernel_sym(struct dso *dso, struct map *map)
return err;
}

-static void vmlinux_path__exit(void)
-{
- while (--vmlinux_path__nr_entries >= 0)
- zfree(&vmlinux_path[vmlinux_path__nr_entries]);
- vmlinux_path__nr_entries = 0;
-
- zfree(&vmlinux_path);
-}
-
-static const char * const vmlinux_paths[] = {
- "vmlinux",
- "/boot/vmlinux"
+struct dso_filename_pattern {
+ const char *pattern;
+ /*
+ * 0 for matching directly,
+ * 1 for matching by kernel_version,
+ * 2 for matching by kernel_version + arch.
+ */
+ int match_type;
};

-static const char * const vmlinux_paths_upd[] = {
- "/boot/vmlinux-%s",
- "/usr/lib/debug/boot/vmlinux-%s",
- "/lib/modules/%s/build/vmlinux",
- "/usr/lib/debug/lib/modules/%s/vmlinux",
- "/usr/lib/debug/boot/vmlinux-%s.debug"
+struct dso_filename_pattern vmlinux_patterns[] = {
+ {"vmlinux", 0},
+ {"/boot/vmlinux", 0},
+ {"/boot/vmlinux-%s", 1},
+ {"/usr/lib/debug/boot/vmlinux-%s", 1},
+ {"/lib/modules/%s/build/vmlinux", 1},
+ {"/usr/lib/debug/lib/modules/%s/vmlinux", 1},
+ {"/usr/lib/debug/boot/vmlinux-%s.debug", 1},
};

-static int vmlinux_path__add(const char *new_entry)
+static int dso_filename_path__add(struct dso_filename_paths *paths, const char *new_entry)
{
- vmlinux_path[vmlinux_path__nr_entries] = strdup(new_entry);
- if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
+ paths->paths[paths->nr_entries] = strdup(new_entry);
+ if (paths->paths[paths->nr_entries] == NULL)
return -1;
- ++vmlinux_path__nr_entries;
+ ++paths->nr_entries;

return 0;
}

-static int vmlinux_path__init(struct perf_env *env)
+static void dso_filename_path__exit(struct dso_filename_paths *paths)
{
- struct utsname uts;
- char bf[PATH_MAX];
- char *kernel_version;
- unsigned int i;
+ while (--paths->nr_entries >= 0)
+ zfree(&paths->paths[paths->nr_entries]);
+ paths->nr_entries = 0;

- vmlinux_path = malloc(sizeof(char *) * (ARRAY_SIZE(vmlinux_paths) +
- ARRAY_SIZE(vmlinux_paths_upd)));
- if (vmlinux_path == NULL)
- return -1;
-
- for (i = 0; i < ARRAY_SIZE(vmlinux_paths); i++)
- if (vmlinux_path__add(vmlinux_paths[i]) < 0)
- goto out_fail;
+ zfree(&paths->paths);
+}

- /* only try kernel version if no symfs was given */
- if (symbol_conf.symfs[0] != 0)
- return 0;
+static int dso_filename_path__init(struct dso_filename_paths *paths,
+ struct dso_filename_pattern *patterns,
+ int nr_patterns,
+ struct perf_env *env)
+{
+ struct utsname uts;
+ char bf[PATH_MAX];
+ const char *kernel_version;
+ const char *arch = perf_env__arch(env);
+ int i;

if (env) {
kernel_version = env->os_release;
@@ -2346,16 +2343,28 @@ static int vmlinux_path__init(struct perf_env *env)
kernel_version = uts.release;
}

- for (i = 0; i < ARRAY_SIZE(vmlinux_paths_upd); i++) {
- snprintf(bf, sizeof(bf), vmlinux_paths_upd[i], kernel_version);
- if (vmlinux_path__add(bf) < 0)
+ paths->paths = malloc(sizeof(char *) * nr_patterns);
+ if (paths->paths == NULL)
+ return -1;
+
+ for (i = 0; i < nr_patterns; i++) {
+ if (patterns[i].match_type == 0)
+ strlcpy(bf, patterns[i].pattern, sizeof(bf));
+ else if (symbol_conf.symfs[0] == 0) {
+ /* only try kernel version if no symfs was given */
+ if (patterns[i].match_type == 1)
+ snprintf(bf, sizeof(bf), patterns[i].pattern, kernel_version);
+ else if (patterns[i].match_type == 2)
+ snprintf(bf, sizeof(bf), patterns[i].pattern, kernel_version, arch);
+ }
+ if (dso_filename_path__add(paths, bf) < 0)
goto out_fail;
}

return 0;

out_fail:
- vmlinux_path__exit();
+ dso_filename_path__exit(paths);
return -1;
}

@@ -2551,8 +2560,11 @@ int symbol__init(struct perf_env *env)

symbol__elf_init();

- if (symbol_conf.try_vmlinux_path && vmlinux_path__init(env) < 0)
+ if (symbol_conf.try_vmlinux_path &&
+ dso_filename_path__init(&vmlinux_paths, vmlinux_patterns,
+ ARRAY_SIZE(vmlinux_patterns), env) < 0) {
return -1;
+ }

if (symbol_conf.field_sep && *symbol_conf.field_sep == '.') {
pr_err("'.' is the only non valid --field-separator argument\n");
@@ -2629,7 +2641,7 @@ void symbol__exit(void)
intlist__delete(symbol_conf.tid_list);
intlist__delete(symbol_conf.pid_list);
intlist__delete(symbol_conf.addr_list);
- vmlinux_path__exit();
+ dso_filename_path__exit(&vmlinux_paths);
symbol_conf.sym_list = symbol_conf.dso_list = symbol_conf.comm_list = NULL;
symbol_conf.bt_stop_list = NULL;
symbol_conf.initialized = false;
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 3fb5d146d9b1..30056884945b 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -101,8 +101,12 @@ static inline int __symbol__join_symfs(char *bf, size_t size, const char *path)

#define symbol__join_symfs(bf, path) __symbol__join_symfs(bf, sizeof(bf), path)

-extern int vmlinux_path__nr_entries;
-extern char **vmlinux_path;
+struct dso_filename_paths {
+ int nr_entries;
+ char **paths;
+};
+
+extern struct dso_filename_paths vmlinux_paths;

static inline void *symbol__priv(struct symbol *sym)
{
--
2.34.1