9 files changed, 212 insertions, 48 deletions

diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index 88c570c18e3e..4af7199c5af7 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -494,6 +494,11 @@ static int __cmd_kmem(void)
         if (!perf_session__has_traces(session, "kmem record"))
                 goto out_delete;
 
+        if (perf_session__create_kernel_maps(session) < 0) {
+                pr_err("Problems creating kernel maps\n");
+                return -1;
+        }
+
         setup_pager();
         err = perf_session__process_events(session, &event_ops);
         if (err != 0)
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 8f88420e066b..c130df2676f1 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -465,6 +465,11 @@ static int __cmd_record(int argc, const char **argv)
                 return -1;
         }
 
+        if (perf_session__create_kernel_maps(session) < 0) {
+                pr_err("Problems creating kernel maps\n");
+                return -1;
+        }
+
         if (!file_new) {
                 err = perf_header__read(&session->header, output);
                 if (err < 0)
@@ -558,6 +563,12 @@ static int __cmd_record(int argc, const char **argv)
                 return err;
         }
 
+        err = event__synthesize_modules(process_synthesized_event, session);
+        if (err < 0) {
+                pr_err("Couldn't record kernel reference relocation symbol.\n");
+                return err;
+        }
+
         if (!system_wide && profile_cpu == -1)
                 event__synthesize_thread(pid, process_synthesized_event,
                                          session);
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index ddc584b64871..6822b44ca4f9 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1165,6 +1165,11 @@ static int __cmd_top(void)
         if (session == NULL)
                 return -ENOMEM;
 
+        if (perf_session__create_kernel_maps(session) < 0) {
+                pr_err("Problems creating kernel maps\n");
+                return -1;
+        }
+
         if (target_pid != -1)
                 event__synthesize_thread(target_pid, event__process, session);
         else
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index bfb3d872b9f5..4f3e7ef33b83 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -154,6 +154,36 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
         return 0;
 }
 
+int event__synthesize_modules(event__handler_t process,
+                              struct perf_session *session)
+{
+        struct rb_node *nd;
+
+        for (nd = rb_first(&session->kmaps.maps[MAP__FUNCTION]);
+             nd; nd = rb_next(nd)) {
+                event_t ev;
+                size_t size;
+                struct map *pos = rb_entry(nd, struct map, rb_node);
+
+                if (pos->dso->kernel)
+                        continue;
+
+                size = ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
+                memset(&ev, 0, sizeof(ev));
+                ev.mmap.header.type = PERF_RECORD_MMAP;
+                ev.mmap.header.size = (sizeof(ev.mmap) -
+                                        (sizeof(ev.mmap.filename) - size));
+                ev.mmap.start = pos->start;
+                ev.mmap.len   = pos->end - pos->start;
+
+                memcpy(ev.mmap.filename, pos->dso->long_name,
+                       pos->dso->long_name_len + 1);
+                process(&ev, session);
+        }
+
+        return 0;
+}
+
 int event__synthesize_thread(pid_t pid, event__handler_t process,
                              struct perf_session *session)
 {
@@ -222,7 +252,9 @@ int event__synthesize_kernel_mmap(event__handler_t process,
                         "[kernel.kallsyms.%s]", symbol_name) + 1;
         size = ALIGN(size, sizeof(u64));
         ev.mmap.header.size = (sizeof(ev.mmap) - (sizeof(ev.mmap.filename) - size));
-        ev.mmap.start = args.start;
+        ev.mmap.pgoff = args.start;
+        ev.mmap.start = session->vmlinux_maps[MAP__FUNCTION]->start;
+        ev.mmap.len   = session->vmlinux_maps[MAP__FUNCTION]->end - ev.mmap.start ;
 
         return process(&ev, session);
 }
@@ -280,7 +312,6 @@ int event__process_mmap(event_t *self, struct perf_session *session)
 {
         struct thread *thread;
         struct map *map;
-        static const char kmmap_prefix[] = "[kernel.kallsyms.";
 
         dump_printf(" %d/%d: [%p(%p) @ %p]: %s\n",
                     self->mmap.pid, self->mmap.tid,
@@ -289,13 +320,61 @@ int event__process_mmap(event_t *self, struct perf_session *session)
                     (void *)(long)self->mmap.pgoff,
                     self->mmap.filename);
 
-        if (self->mmap.pid == 0 &&
-            memcmp(self->mmap.filename, kmmap_prefix,
-                   sizeof(kmmap_prefix) - 1) == 0) {
-                const char *symbol_name = (self->mmap.filename +
-                                           sizeof(kmmap_prefix) - 1);
-                perf_session__set_kallsyms_ref_reloc_sym(session, symbol_name,
-                                                         self->mmap.start);
+        if (self->mmap.pid == 0) {
+                static const char kmmap_prefix[] = "[kernel.kallsyms.";
+
+                if (self->mmap.filename[0] == '/') {
+                        char short_module_name[1024];
+                        char *name = strrchr(self->mmap.filename, '/'), *dot;
+
+                        if (name == NULL)
+                                goto out_problem;
+
+                        ++name; /* skip / */
+                        dot = strrchr(name, '.');
+                        if (dot == NULL)
+                                goto out_problem;
+
+                        snprintf(short_module_name, sizeof(short_module_name),
+                                 "[%.*s]", (int)(dot - name), name);
+                        strxfrchar(short_module_name, '-', '_');
+
+                        map = perf_session__new_module_map(session,
+                                                           self->mmap.start,
+                                                           short_module_name);
+                        if (map == NULL)
+                                goto out_problem;
+
+                        name = strdup(self->mmap.filename);
+                        if (name == NULL)
+                                goto out_problem;
+
+                        dso__set_long_name(map->dso, name);
+                        map->end = map->start + self->mmap.len;
+                } else if (memcmp(self->mmap.filename, kmmap_prefix,
+                                sizeof(kmmap_prefix) - 1) == 0) {
+                        const char *symbol_name = (self->mmap.filename +
+                                                   sizeof(kmmap_prefix) - 1);
+                        /*
+                         * Should be there already, from the build-id table in
+                         * the header.
+                         */
+                        struct dso *kernel = __dsos__findnew(&dsos__kernel,
+                                                             "[kernel.kallsyms]");
+                        if (kernel == NULL)
+                                goto out_problem;
+
+                        if (__map_groups__create_kernel_maps(&session->kmaps,
+                                                             session->vmlinux_maps,
+                                                             kernel) < 0)
+                                goto out_problem;
+
+                        session->vmlinux_maps[MAP__FUNCTION]->start = self->mmap.start;
+                        session->vmlinux_maps[MAP__FUNCTION]->end   = self->mmap.start + self->mmap.len;
+
+                        perf_session__set_kallsyms_ref_reloc_sym(session, symbol_name,
+                                                                 self->mmap.pgoff);
+                }
                 return 0;
         }
 
@@ -304,10 +383,13 @@ int event__process_mmap(event_t *self, struct perf_session *session)
                        session->cwd, session->cwdlen);
 
         if (thread == NULL || map == NULL)
-                dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
-        else
-                thread__insert_map(thread, map);
+                goto out_problem;
+
+        thread__insert_map(thread, map);
+        return 0;
 
+out_problem:
+        dump_printf("problem processing PERF_RECORD_MMAP, skipping event.\n");
         return 0;
 }
 
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index 80356da8216c..50a7132887f5 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -112,6 +112,8 @@ void event__synthesize_threads(event__handler_t process,
 int event__synthesize_kernel_mmap(event__handler_t process,
                                   struct perf_session *session,
                                   const char *symbol_name);
+int event__synthesize_modules(event__handler_t process,
+                              struct perf_session *session);
 
 int event__process_comm(event_t *self, struct perf_session *session);
 int event__process_lost(event_t *self, struct perf_session *session);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 378ac5422bcf..fd1c5a39a5bb 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -69,9 +69,6 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
         self->unknown_events = 0;
         map_groups__init(&self->kmaps);
 
-        if (perf_session__create_kernel_maps(self) < 0)
-                goto out_delete;
-
         if (mode == O_RDONLY && perf_session__open(self, force) < 0)
                 goto out_delete;
 
@@ -268,8 +265,11 @@ int perf_header__read_build_ids(int input, u64 offset, u64 size)
                         head = &dsos__kernel;
 
                 dso = __dsos__findnew(head, filename);
-                if (dso != NULL)
+                if (dso != NULL) {
                         dso__set_build_id(dso, &bev.build_id);
+                        if (head == &dsos__kernel && filename[0] == '[')
+                                dso->kernel = 1;
+                }
 
                 offset += bev.header.size;
         }
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) {
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index ee0b4593db7b..594156e43b10 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -134,6 +134,7 @@ size_t dsos__fprintf_buildid(FILE *fp);
 size_t dso__fprintf_buildid(struct dso *self, FILE *fp);
 size_t dso__fprintf(struct dso *self, enum map_type type, FILE *fp);
 char dso__symtab_origin(const struct dso *self);
+void dso__set_long_name(struct dso *self, char *name);
 void dso__set_build_id(struct dso *self, void *build_id);
 struct symbol *dso__find_symbol(struct dso *self, enum map_type type, u64 addr);
 struct symbol *dso__find_symbol_by_name(struct dso *self, enum map_type type,
@@ -151,5 +152,7 @@ bool symbol_type__is_a(char symbol_type, enum map_type map_type);
 
 int perf_session__create_kernel_maps(struct perf_session *self);
 
+struct map *perf_session__new_module_map(struct perf_session *self, u64 start,
+                                         const char *filename);
 extern struct dso *vdso;
 #endif /* __PERF_SYMBOL */
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index c206f72c8881..c06c13535a70 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -67,4 +67,8 @@ map_groups__find_function(struct map_groups *self, struct perf_session *session,
 
 struct map *map_groups__find_by_name(struct map_groups *self,
                                      enum map_type type, const char *name);
+
+int __map_groups__create_kernel_maps(struct map_groups *self,
+                                     struct map *vmlinux_maps[MAP__NR_TYPES],
+                                     struct dso *kernel);
 #endif  /* __PERF_THREAD_H */