1 files changed, 56 insertions, 16 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index ceefa6568def..561db6361f57 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -41,6 +41,7 @@ struct symbol_conf symbol_conf = {
         .exclude_other    = true,
         .use_modules      = true,
         .try_vmlinux_path = true,
+        .symfs            = "",
 };
 
 int dso__name_len(const struct dso *self)
@@ -839,8 +840,11 @@ static int dso__synthesize_plt_symbols(struct  dso *self, struct map *map,
         char sympltname[1024];
         Elf *elf;
         int nr = 0, symidx, fd, err = 0;
+        char name[PATH_MAX];
 
-        fd = open(self->long_name, O_RDONLY);
+        snprintf(name, sizeof(name), "%s%s",
+                 symbol_conf.symfs, self->long_name);
+        fd = open(name, O_RDONLY);
         if (fd < 0)
                 goto out;
 
@@ -1452,16 +1456,19 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
              self->origin++) {
                 switch (self->origin) {
                 case DSO__ORIG_BUILD_ID_CACHE:
-                        if (dso__build_id_filename(self, name, size) == NULL)
+                        /* skip the locally configured cache if a symfs is given */
+                        if (symbol_conf.symfs[0] ||
+                            (dso__build_id_filename(self, name, size) == NULL)) {
                                 continue;
+                        }
                         break;
                 case DSO__ORIG_FEDORA:
-                        snprintf(name, size, "/usr/lib/debug%s.debug",
-                                 self->long_name);
+                        snprintf(name, size, "%s/usr/lib/debug%s.debug",
+                                 symbol_conf.symfs, self->long_name);
                         break;
                 case DSO__ORIG_UBUNTU:
-                        snprintf(name, size, "/usr/lib/debug%s",
-                                 self->long_name);
+                        snprintf(name, size, "%s/usr/lib/debug%s",
+                                 symbol_conf.symfs, self->long_name);
                         break;
                 case DSO__ORIG_BUILDID: {
                         char build_id_hex[BUILD_ID_SIZE * 2 + 1];
@@ -1473,19 +1480,26 @@ int dso__load(struct dso *self, struct map *map, symbol_filter_t filter)
                                           sizeof(self->build_id),
                                           build_id_hex);
                         snprintf(name, size,
-                                 "/usr/lib/debug/.build-id/%.2s/%s.debug",
-                                 build_id_hex, build_id_hex + 2);
+                                 "%s/usr/lib/debug/.build-id/%.2s/%s.debug",
+                                 symbol_conf.symfs, build_id_hex, build_id_hex + 2);
                         }
                         break;
                 case DSO__ORIG_DSO:
-                        snprintf(name, size, "%s", self->long_name);
+                        snprintf(name, size, "%s%s",
+                             symbol_conf.symfs, self->long_name);
                         break;
                 case DSO__ORIG_GUEST_KMODULE:
                         if (map->groups && map->groups->machine)
                                 root_dir = map->groups->machine->root_dir;
                         else
                                 root_dir = "";
-                        snprintf(name, size, "%s%s", root_dir, self->long_name);
+                        snprintf(name, size, "%s%s%s", symbol_conf.symfs,
+                                 root_dir, self->long_name);
+                        break;
+
+                case DSO__ORIG_KMODULE:
+                        snprintf(name, size, "%s%s", symbol_conf.symfs,
+                                 self->long_name);
                         break;
 
                 default:
@@ -1784,17 +1798,20 @@ static int dso__load_vmlinux(struct dso *self, struct map *map,
                              const char *vmlinux, symbol_filter_t filter)
 {
         int err = -1, fd;
+        char symfs_vmlinux[PATH_MAX];
 
-        fd = open(vmlinux, O_RDONLY);
+        snprintf(symfs_vmlinux, sizeof(symfs_vmlinux), "%s/%s",
+                 symbol_conf.symfs, vmlinux);
+        fd = open(symfs_vmlinux, O_RDONLY);
         if (fd < 0)
                 return -1;
 
         dso__set_loaded(self, map->type);
-        err = dso__load_sym(self, map, vmlinux, fd, filter, 0, 0);
+        err = dso__load_sym(self, map, symfs_vmlinux, fd, filter, 0, 0);
         close(fd);
 
         if (err > 0)
-                pr_debug("Using %s for symbols\n", vmlinux);
+                pr_debug("Using %s for symbols\n", symfs_vmlinux);
 
         return err;
 }
@@ -1872,6 +1889,10 @@ static int dso__load_kernel_sym(struct dso *self, struct map *map,
                         goto out_fixup;
         }
 
+        /* do not try local files if a symfs was given */
+        if (symbol_conf.symfs[0] != 0)
+                return -1;
+
         /*
          * 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,
@@ -2262,9 +2283,6 @@ static int vmlinux_path__init(void)
         struct utsname uts;
         char bf[PATH_MAX];
 
-        if (uname(&uts) < 0)
-                return -1;
-
         vmlinux_path = malloc(sizeof(char *) * 5);
         if (vmlinux_path == NULL)
                 return -1;
@@ -2277,6 +2295,14 @@ static int vmlinux_path__init(void)
         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
                 goto out_fail;
         ++vmlinux_path__nr_entries;
+
+        /* only try running kernel version if no symfs was given */
+        if (symbol_conf.symfs[0] != 0)
+                return 0;
+
+        if (uname(&uts) < 0)
+                return -1;
+
         snprintf(bf, sizeof(bf), "/boot/vmlinux-%s", uts.release);
         vmlinux_path[vmlinux_path__nr_entries] = strdup(bf);
         if (vmlinux_path[vmlinux_path__nr_entries] == NULL)
@@ -2336,6 +2362,8 @@ static int setup_list(struct strlist **list, const char *list_str,
 
 int symbol__init(void)
 {
+        const char *symfs;
+
         if (symbol_conf.initialized)
                 return 0;
 
@@ -2364,6 +2392,18 @@ int symbol__init(void)
                        symbol_conf.sym_list_str, "symbol") < 0)
                 goto out_free_comm_list;
 
+        /*
+         * A path to symbols of "/" is identical to ""
+         * reset here for simplicity.
+         */
+        symfs = realpath(symbol_conf.symfs, NULL);
+        if (symfs == NULL)
+                symfs = symbol_conf.symfs;
+        if (strcmp(symfs, "/") == 0)
+                symbol_conf.symfs = "";
+        if (symfs != symbol_conf.symfs)
+                free((void *)symfs);
+
         symbol_conf.initialized = true;
         return 0;