perf symbols: Prevent the use of kcore if the kernel has moved

[~andy/linux] / tools / perf / util / symbol.c

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 39ce9adbaaf0bef120e0903e72ad1e98f8114527..4ac1f871ec273f8a2a1f58d5fffe617848ffac97 100644 (file)
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -976,6 +976,23 @@ static int validate_kcore_modules(const char *kallsyms_filename,
        return 0;
 }
 
+static int validate_kcore_addresses(const char *kallsyms_filename,
+                                   struct map *map)
+{
+       struct kmap *kmap = map__kmap(map);
+
+       if (kmap->ref_reloc_sym && kmap->ref_reloc_sym->name) {
+               u64 start;
+
+               start = kallsyms__get_function_start(kallsyms_filename,
+                                                    kmap->ref_reloc_sym->name);
+               if (start != kmap->ref_reloc_sym->addr)
+                       return -EINVAL;
+       }
+
+       return validate_kcore_modules(kallsyms_filename, map);
+}
+
 struct kcore_mapfn_data {
        struct dso *dso;
        enum map_type type;
@@ -1019,8 +1036,8 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
                                             kallsyms_filename))
                return -EINVAL;
 
-       /* All modules must be present at their original addresses */
-       if (validate_kcore_modules(kallsyms_filename, map))
+       /* Modules and kernel must be present at their original addresses */
+       if (validate_kcore_addresses(kallsyms_filename, map))
                return -EINVAL;
 
        md.dso = dso;
@@ -1424,7 +1441,7 @@ static int find_matching_kcore(struct map *map, char *dir, size_t dir_sz)
                        continue;
                scnprintf(kallsyms_filename, sizeof(kallsyms_filename),
                          "%s/%s/kallsyms", dir, dent->d_name);
-               if (!validate_kcore_modules(kallsyms_filename, map)) {
+               if (!validate_kcore_addresses(kallsyms_filename, map)) {
                        strlcpy(dir, kallsyms_filename, dir_sz);
                        ret = 0;
                        break;
@@ -1479,7 +1496,7 @@ static char *dso__find_kallsyms(struct dso *dso, struct map *map)
                if (fd != -1) {
                        close(fd);
                        /* If module maps match go with /proc/kallsyms */
-                       if (!validate_kcore_modules("/proc/kallsyms", map))
+                       if (!validate_kcore_addresses("/proc/kallsyms", map))
                                goto proc_kallsyms;
                }