1 files changed, 84 insertions, 32 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 8e6627e6b778..381999dd5c1f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -161,7 +161,7 @@ static size_t symbol__fprintf(struct symbol *self, FILE *fp)
                        self->start, self->end, self->name);
 }
 
-static void dso__set_long_name(struct dso *self, char *name)
+void dso__set_long_name(struct dso *self, char *name)
 {
         if (name == NULL)
                 return;
@@ -176,7 +176,7 @@ static void dso__set_basename(struct dso *self)
 
 struct dso *dso__new(const char *name)
 {
-        struct dso *self = malloc(sizeof(*self) + strlen(name) + 1);
+        struct dso *self = zalloc(sizeof(*self) + strlen(name) + 1);
 
         if (self != NULL) {
                 int i;
@@ -500,13 +500,17 @@ static int dso__split_kallsyms(struct dso *self, struct map *map,
 
                         *module++ = '\0';
 
-                        if (strcmp(self->name, module)) {
+                        if (strcmp(curr_map->dso->short_name, module)) {
                                 curr_map = map_groups__find_by_name(&session->kmaps, map->type, module);
                                 if (curr_map == NULL) {
                                         pr_debug("/proc/{kallsyms,modules} "
-                                                 "inconsistency!\n");
+                                                 "inconsistency while looking "
+                                                 "for \"%s\" module!\n", module);
                                         return -1;
                                 }
+
+                                if (curr_map->dso->loaded)
+                                        goto discard_symbol;
                         }
                         /*
                          * So that we look just like we get from .ko files,
@@ -1343,13 +1347,33 @@ struct map *map_groups__find_by_name(struct map_groups *self,
         for (nd = rb_first(&self->maps[type]); nd; nd = rb_next(nd)) {
                 struct map *map = rb_entry(nd, struct map, rb_node);
 
-                if (map->dso && strcmp(map->dso->name, name) == 0)
+                if (map->dso && strcmp(map->dso->short_name, name) == 0)
                         return map;
         }
 
         return NULL;
 }
 
+static int dso__kernel_module_get_build_id(struct dso *self)
+{
+        char filename[PATH_MAX];
+        /*
+         * kernel module short names are of the form "[module]" and
+         * we need just "module" here.
+         */
+        const char *name = self->short_name + 1;
+
+        snprintf(filename, sizeof(filename),
+                 "/sys/module/%.*s/notes/.note.gnu.build-id",
+                 (int)strlen(name - 1), name);
+
+        if (sysfs__read_build_id(filename, self->build_id,
+                                 sizeof(self->build_id)) == 0)
+                self->has_build_id = true;
+
+        return 0;
+}
+
 static int perf_session__set_modules_path_dir(struct perf_session *self, char *dirname)
 {
         struct dirent *dent;
@@ -1395,6 +1419,7 @@ static int perf_session__set_modules_path_dir(struct perf_session *self, char *d
                         if (long_name == NULL)
                                 goto failure;
                         dso__set_long_name(map->dso, long_name);
+                        dso__kernel_module_get_build_id(map->dso);
                 }
         }
 
@@ -1437,6 +1462,24 @@ static struct map *map__new2(u64 start, struct dso *dso, enum map_type type)
         return self;
 }
 
+struct map *perf_session__new_module_map(struct perf_session *self, u64 start,
+                                         const char *filename)
+{
+        struct map *map;
+        struct dso *dso = __dsos__findnew(&dsos__kernel, filename);
+
+        if (dso == NULL)
+                return NULL;
+
+        map = map__new2(start, dso, MAP__FUNCTION);
+        if (map == NULL)
+                return NULL;
+
+        dso->origin = DSO__ORIG_KMODULE;
+        map_groups__insert(&self->kmaps, map);
+        return map;
+}
+
 static int perf_session__create_module_maps(struct perf_session *self)
 {
         char *line = NULL;
@@ -1450,7 +1493,6 @@ static int perf_session__create_module_maps(struct perf_session *self)
         while (!feof(file)) {
                 char name[PATH_MAX];
                 u64 start;
-                struct dso *dso;
                 char *sep;
                 int line_len;
 
@@ -1476,26 +1518,10 @@ static int perf_session__create_module_maps(struct perf_session *self)
                 *sep = '\0';
 
                 snprintf(name, sizeof(name), "[%s]", line);
-                dso = dso__new(name);
-
-                if (dso == NULL)
-                        goto out_delete_line;
-
-                map = map__new2(start, dso, MAP__FUNCTION);
-                if (map == NULL) {
-                        dso__delete(dso);
+                map = perf_session__new_module_map(self, start, name);
+                if (map == NULL)
                         goto out_delete_line;
-                }
-
-                snprintf(name, sizeof(name),
-                         "/sys/module/%s/notes/.note.gnu.build-id", line);
-                if (sysfs__read_build_id(name, dso->build_id,
-                                         sizeof(dso->build_id)) == 0)
-                        dso->has_build_id = true;
-
-                dso->origin = DSO__ORIG_KMODULE;
-                map_groups__insert(&self->kmaps, map);
-                dsos__add(&dsos__kernel, dso);
+                dso__kernel_module_get_build_id(map->dso);
         }
 
         free(line);
@@ -1573,10 +1599,28 @@ static int dso__load_kernel_sym(struct dso *self, struct map *map,
                 }
         }
 
+        /*
+         * Say the kernel DSO was created when processing the build-id header table,
+         * we have a build-id, so check if it is the same as the running kernel,
+         * using it if it is.
+         */
+        if (self->has_build_id) {
+                u8 kallsyms_build_id[BUILD_ID_SIZE];
+
+                if (sysfs__read_build_id("/sys/kernel/notes", kallsyms_build_id,
+                                         sizeof(kallsyms_build_id)) == 0)
+
+                is_kallsyms = dso__build_id_equal(self, kallsyms_build_id);
+                if (is_kallsyms)
+                        goto do_kallsyms;
+                goto do_vmlinux;
+        }
+
         is_kallsyms = self->long_name[0] == '[';
         if (is_kallsyms)
                 goto do_kallsyms;
 
+do_vmlinux:
         err = dso__load_vmlinux(self, map, session, self->long_name, filter);
         if (err <= 0) {
                 pr_info("The file %s cannot be used, "
@@ -1694,16 +1738,12 @@ out_delete_kernel_dso:
         return NULL;
 }
 
-static int map_groups__create_kernel_maps(struct map_groups *self,
-                                          struct map *vmlinux_maps[MAP__NR_TYPES],
-                                          const char *vmlinux)
+int __map_groups__create_kernel_maps(struct map_groups *self,
+                                     struct map *vmlinux_maps[MAP__NR_TYPES],
+                                     struct dso *kernel)
 {
-        struct dso *kernel = dsos__create_kernel(vmlinux);
         enum map_type type;
 
-        if (kernel == NULL)
-                return -1;
-
         for (type = 0; type < MAP__NR_TYPES; ++type) {
                 vmlinux_maps[type] = map__new2(0, kernel, type);
                 if (vmlinux_maps[type] == NULL)
@@ -1717,6 +1757,18 @@ static int map_groups__create_kernel_maps(struct map_groups *self,
         return 0;
 }
 
+static int map_groups__create_kernel_maps(struct map_groups *self,
+                                          struct map *vmlinux_maps[MAP__NR_TYPES],
+                                          const char *vmlinux)
+{
+        struct dso *kernel = dsos__create_kernel(vmlinux);
+
+        if (kernel == NULL)
+                return -1;
+
+        return __map_groups__create_kernel_maps(self, vmlinux_maps, kernel);
+}
+
 static void vmlinux_path__exit(void)
 {
         while (--vmlinux_path__nr_entries >= 0) {