perf tools: Handle relative paths while loading module symbols

Inform util/module.c::mod_dso__load_module_paths() that relative
paths do exist in some modules.dep, and make it fail noisily should
it encounter a path that it doesn't understand, or a module it
cannot open.

Reported-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: rostedt@goodmis.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <1253779628.10513.8.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/util/module.c b/tools/perf/util/module.c
index 3d567fe..8f81622 100644 (file)
--- a/tools/perf/util/module.c
+++ b/tools/perf/util/module.c
@@ -4,6 +4,7 @@
 #include "module.h"
 
 #include <libelf.h>
+#include <libgen.h>
 #include <gelf.h>
 #include <elf.h>
 #include <dirent.h>
@@ -409,35 +410,40 @@ out_failure:
 static int mod_dso__load_module_paths(struct mod_dso *self)
 {
        struct utsname uts;
-       int count = 0, len;
+       int count = 0, len, err = -1;
        char *line = NULL;
        FILE *file;
-       char *path;
+       char *dpath, *dir;
        size_t n;
 
        if (uname(&uts) < 0)
-               goto out_failure;
+               return err;
 
        len = strlen("/lib/modules/");
        len += strlen(uts.release);
        len += strlen("/modules.dep");
 
-       path = calloc(1, len);
-       if (path == NULL)
-               goto out_failure;
+       dpath = calloc(1, len);
+       if (dpath == NULL)
+               return err;
 
-       strcat(path, "/lib/modules/");
-       strcat(path, uts.release);
-       strcat(path, "/modules.dep");
+       strcat(dpath, "/lib/modules/");
+       strcat(dpath, uts.release);
+       strcat(dpath, "/modules.dep");
 
-       file = fopen(path, "r");
-       free(path);
+       file = fopen(dpath, "r");
        if (file == NULL)
                goto out_failure;
 
+       dir = dirname(dpath);
+       if (!dir)
+               goto out_failure;
+       strcat(dir, "/");
+
        while (!feof(file)) {
-               char *name, *tmp;
                struct module *module;
+               char *name, *path, *tmp;
+               FILE *modfile;
                int line_len;
 
                line_len = getline(&line, &n, file);
@@ -445,17 +451,41 @@ static int mod_dso__load_module_paths(struct mod_dso *self)
                        break;
 
                if (!line)
-                       goto out_failure;
+                       break;
 
                line[--line_len] = '\0'; /* \n */
 
-               path = strtok(line, ":");
+               path = strchr(line, ':');
+               if (!path)
+                       break;
+               *path = '\0';
+
+               path = strdup(line);
                if (!path)
-                       goto out_failure;
+                       break;
+
+               if (!strstr(path, dir)) {
+                       if (strncmp(path, "kernel/", 7))
+                               break;
+
+                       free(path);
+                       path = calloc(1, strlen(dir) + strlen(line) + 1);
+                       if (!path)
+                               break;
+                       strcat(path, dir);
+                       strcat(path, line);
+               }
+
+               modfile = fopen(path, "r");
+               if (modfile == NULL)
+                       break;
+               fclose(modfile);
 
                name = strdup(path);
-               name = strtok(name, "/");
+               if (!name)
+                       break;
 
+               name = strtok(name, "/");
                tmp = name;
 
                while (tmp) {
@@ -463,26 +493,25 @@ static int mod_dso__load_module_paths(struct mod_dso *self)
                        if (tmp)
                                name = tmp;
                }
+
                name = strsep(&name, ".");
+               if (!name)
+                       break;
 
-               /* Quirk: replace '-' with '_' in sound modules */
+               /* Quirk: replace '-' with '_' in all modules */
                for (len = strlen(name); len; len--) {
                        if (*(name+len) == '-')
                                *(name+len) = '_';
                }
 
                module = module__new(name, path);
-               if (!module) {
-                       fprintf(stderr, "load_module_paths: allocation error\n");
-                       goto out_failure;
-               }
+               if (!module)
+                       break;
                mod_dso__insert_module(self, module);
 
                module->sections = sec_dso__new_dso("sections");
-               if (!module->sections) {
-                       fprintf(stderr, "load_module_paths: allocation error\n");
-                       goto out_failure;
-               }
+               if (!module->sections)
+                       break;
 
                module->active = mod_dso__load_sections(module);
 
@@ -490,13 +519,20 @@ static int mod_dso__load_module_paths(struct mod_dso *self)
                        count++;
        }
 
-       free(line);
-       fclose(file);
-
-       return count;
+       if (feof(file))
+               err = count;
+       else
+               fprintf(stderr, "load_module_paths: modules.dep parsing failure!\n");
 
 out_failure:
-       return -1;
+       if (dpath)
+               free(dpath);
+       if (file)
+               fclose(file);
+       if (line)
+               free(line);
+
+       return err;
 }
 
 int mod_dso__load_modules(struct mod_dso *dso)