1 files changed, 114 insertions, 16 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 39ce9adbaaf0..95e249779931 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -410,7 +410,7 @@ struct symbol *dso__find_symbol(struct dso *dso,
 	return symbols__find(&dso->symbols[type], addr);
 }
 
-struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
+static struct symbol *dso__first_symbol(struct dso *dso, enum map_type type)
 {
 	return symbols__first(&dso->symbols[type]);
 }
@@ -627,7 +627,7 @@ static int dso__split_kallsyms_for_kcore(struct dso *dso, struct map *map,
  * kernel range is broken in several maps, named [kernel].N, as we don't have
  * the original ELF section names vmlinux have.
  */
-static int dso__split_kallsyms(struct dso *dso, struct map *map,
+static int dso__split_kallsyms(struct dso *dso, struct map *map, u64 delta,
 			       symbol_filter_t filter)
 {
 	struct map_groups *kmaps = map__kmap(map)->kmaps;
@@ -692,6 +692,12 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map,
 			char dso_name[PATH_MAX];
 			struct dso *ndso;
 
+			if (delta) {
+				/* Kernel was relocated at boot time */
+				pos->start -= delta;
+				pos->end -= delta;
+			}
+
 			if (count == 0) {
 				curr_map = map;
 				goto filter_symbol;
@@ -721,6 +727,10 @@ static int dso__split_kallsyms(struct dso *dso, struct map *map,
 			curr_map->map_ip = curr_map->unmap_ip = identity__map_ip;
 			map_groups__insert(kmaps, curr_map);
 			++kernel_range;
+		} else if (delta) {
+			/* Kernel was relocated at boot time */
+			pos->start -= delta;
+			pos->end -= delta;
 		}
 filter_symbol:
 		if (filter && filter(curr_map, pos)) {
@@ -976,6 +986,23 @@ 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 +1046,8 @@ 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;
@@ -1113,15 +1140,41 @@ out_err:
 	return -EINVAL;
 }
 
+/*
+ * If the kernel is relocated at boot time, kallsyms won't match.  Compute the
+ * delta based on the relocation reference symbol.
+ */
+static int kallsyms__delta(struct map *map, const char *filename, u64 *delta)
+{
+	struct kmap *kmap = map__kmap(map);
+	u64 addr;
+
+	if (!kmap->ref_reloc_sym || !kmap->ref_reloc_sym->name)
+		return 0;
+
+	addr = kallsyms__get_function_start(filename,
+					    kmap->ref_reloc_sym->name);
+	if (!addr)
+		return -1;
+
+	*delta = addr - kmap->ref_reloc_sym->addr;
+	return 0;
+}
+
 int dso__load_kallsyms(struct dso *dso, const char *filename,
 		       struct map *map, symbol_filter_t filter)
 {
+	u64 delta = 0;
+
 	if (symbol__restricted_filename(filename, "/proc/kallsyms"))
 		return -1;
 
 	if (dso__load_all_kallsyms(dso, filename, map) < 0)
 		return -1;
 
+	if (kallsyms__delta(map, filename, &delta))
+		return -1;
+
 	symbols__fixup_duplicate(&dso->symbols[map->type]);
 	symbols__fixup_end(&dso->symbols[map->type]);
 
@@ -1133,7 +1186,7 @@ int dso__load_kallsyms(struct dso *dso, const char *filename,
 	if (!dso__load_kcore(dso, map, filename))
 		return dso__split_kallsyms_for_kcore(dso, map, filter);
 	else
-		return dso__split_kallsyms(dso, map, filter);
+		return dso__split_kallsyms(dso, map, delta, filter);
 }
 
 static int dso__load_perf_map(struct dso *dso, struct map *map,
@@ -1198,6 +1251,46 @@ out_failure:
 	return -1;
 }
 
+static bool dso__is_compatible_symtab_type(struct dso *dso, bool kmod,
+					   enum dso_binary_type type)
+{
+	switch (type) {
+	case DSO_BINARY_TYPE__JAVA_JIT:
+	case DSO_BINARY_TYPE__DEBUGLINK:
+	case DSO_BINARY_TYPE__SYSTEM_PATH_DSO:
+	case DSO_BINARY_TYPE__FEDORA_DEBUGINFO:
+	case DSO_BINARY_TYPE__UBUNTU_DEBUGINFO:
+	case DSO_BINARY_TYPE__BUILDID_DEBUGINFO:
+	case DSO_BINARY_TYPE__OPENEMBEDDED_DEBUGINFO:
+		return !kmod && dso->kernel == DSO_TYPE_USER;
+
+	case DSO_BINARY_TYPE__KALLSYMS:
+	case DSO_BINARY_TYPE__VMLINUX:
+	case DSO_BINARY_TYPE__KCORE:
+		return dso->kernel == DSO_TYPE_KERNEL;
+
+	case DSO_BINARY_TYPE__GUEST_KALLSYMS:
+	case DSO_BINARY_TYPE__GUEST_VMLINUX:
+	case DSO_BINARY_TYPE__GUEST_KCORE:
+		return dso->kernel == DSO_TYPE_GUEST_KERNEL;
+
+	case DSO_BINARY_TYPE__GUEST_KMODULE:
+	case DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE:
+		/*
+		 * kernel modules know their symtab type - it's set when
+		 * creating a module dso in machine__new_module().
+		 */
+		return kmod && dso->symtab_type == type;
+
+	case DSO_BINARY_TYPE__BUILD_ID_CACHE:
+		return true;
+
+	case DSO_BINARY_TYPE__NOT_FOUND:
+	default:
+		return false;
+	}
+}
+
 int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 {
 	char *name;
@@ -1208,6 +1301,7 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 	int ss_pos = 0;
 	struct symsrc ss_[2];
 	struct symsrc *syms_ss = NULL, *runtime_ss = NULL;
+	bool kmod;
 
 	dso__set_loaded(dso, map->type);
 
@@ -1248,7 +1342,11 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 	if (!name)
 		return -1;
 
-	/* Iterate over candidate debug images.
+	kmod = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
+		dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
+
+	/*
+	 * Iterate over candidate debug images.
 	 * Keep track of "interesting" ones (those which have a symtab, dynsym,
 	 * and/or opd section) for processing.
 	 */
@@ -1258,6 +1356,9 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 
 		enum dso_binary_type symtab_type = binary_type_symtab[i];
 
+		if (!dso__is_compatible_symtab_type(dso, kmod, symtab_type))
+			continue;
+
 		if (dso__read_binary_type_filename(dso, symtab_type,
 						   root_dir, name, PATH_MAX))
 			continue;
@@ -1283,6 +1384,8 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 
 			if (syms_ss && runtime_ss)
 				break;
+		} else {
+			symsrc__destroy(ss);
 		}
 
 	}
@@ -1298,15 +1401,10 @@ int dso__load(struct dso *dso, struct map *map, symbol_filter_t filter)
 	if (!runtime_ss && syms_ss)
 		runtime_ss = syms_ss;
 
-	if (syms_ss) {
-		int km;
-
-		km = dso->symtab_type == DSO_BINARY_TYPE__SYSTEM_PATH_KMODULE ||
-		     dso->symtab_type == DSO_BINARY_TYPE__GUEST_KMODULE;
-		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, km);
-	} else {
+	if (syms_ss)
+		ret = dso__load_sym(dso, map, syms_ss, runtime_ss, filter, kmod);
+	else
 		ret = -1;
-	}
 
 	if (ret > 0) {
 		int nr_plt;
@@ -1424,7 +1522,7 @@ 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 +1577,7 @@ 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;
 		}