4 files changed, 46 insertions, 30 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 07b92c378ae2..6d770ac7be0b 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -948,7 +948,12 @@ static int symbol_filter(struct map *map, struct symbol *sym)
 
 static int parse_symbols(void)
 {
-        if (dsos__load_kernel(vmlinux_name, symbol_filter, 1) <= 0)
+        struct dso *kernel = dsos__load_kernel();
+
+        if (kernel == NULL)
+                return -1;
+
+        if (dso__load_kernel_sym(kernel, symbol_filter, 1) <= 0)
                 return -1;
 
         if (dump_symtab)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index d3d656f9a621..425a29ba01a9 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -241,6 +241,7 @@ perf_header__adds_write(struct perf_header *self, int fd)
 
                 buildid_sec = &feat_sec[idx++];
 
+                dsos__load_kernel();
                 /*
                  * Read the list of loaded modules with its build_ids
                  */
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 7b4cedeb3020..4d75e745288f 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1352,17 +1352,11 @@ static int dso__load_vmlinux(struct dso *self, struct map *map,
         return err;
 }
 
-int dsos__load_kernel(const char *vmlinux, symbol_filter_t filter,
-                      int use_modules)
+int dso__load_kernel_sym(struct dso *self, symbol_filter_t filter, int use_modules)
 {
         int err = -1;
-        struct dso *dso = dso__new(vmlinux);
 
-        if (dso == NULL)
-                return -1;
-
-        dso->short_name = "[kernel]";
-        kernel_map = map__new2(0, dso);
+        kernel_map = map__new2(0, self);
         if (kernel_map == NULL)
                 goto out_delete_dso;
 
@@ -1374,39 +1368,36 @@ int dsos__load_kernel(const char *vmlinux, symbol_filter_t filter,
                 use_modules = 0;
         }
 
-        if (vmlinux) {
-                err = dso__load_vmlinux(dso, kernel_map, vmlinux, filter);
-                if (err > 0 && use_modules) {
-                        int syms = dsos__load_modules_sym(filter);
+        err = dso__load_vmlinux(self, kernel_map, self->name, filter);
+        if (err > 0 && use_modules) {
+                int syms = dsos__load_modules_sym(filter);
 
-                        if (syms < 0)
-                                pr_warning("Failed to read module symbols!"
-                                           " Continuing...\n");
-                        else
-                                err += syms;
-                }
+                if (syms < 0)
+                        pr_warning("Failed to read module symbols!"
+                                   " Continuing...\n");
+                else
+                        err += syms;
         }
 
         if (err <= 0)
                 err = kernel_maps__load_kallsyms(filter, use_modules);
 
         if (err > 0) {
-                struct rb_node *node = rb_first(&dso->syms);
+                struct rb_node *node = rb_first(&self->syms);
                 struct symbol *sym = rb_entry(node, struct symbol, rb_node);
 
                 kernel_map->start = sym->start;
-                node = rb_last(&dso->syms);
+                node = rb_last(&self->syms);
                 sym = rb_entry(node, struct symbol, rb_node);
                 kernel_map->end = sym->end;
 
-                dso->origin = DSO__ORIG_KERNEL;
+                self->origin = DSO__ORIG_KERNEL;
                 kernel_maps__insert(kernel_map);
                 /*
                  * Now that we have all sorted out, just set the ->end of all
                  * maps:
                  */
                 kernel_maps__fixup_end();
-                dsos__add(dso);
 
                 if (verbose)
                         kernel_maps__fprintf(stderr);
@@ -1415,7 +1406,7 @@ int dsos__load_kernel(const char *vmlinux, symbol_filter_t filter,
         return err;
 
 out_delete_dso:
-        dso__delete(dso);
+        dso__delete(self);
         return -1;
 }
 
@@ -1475,18 +1466,36 @@ size_t dsos__fprintf_buildid(FILE *fp)
         return ret;
 }
 
-int load_kernel(symbol_filter_t filter)
+struct dso *dsos__load_kernel(void)
 {
-        if (dsos__load_kernel(vmlinux_name, filter, modules) <= 0)
-                return -1;
+        struct dso *kernel = dso__new(vmlinux_name);
 
+        if (kernel == NULL)
+                return NULL;
+
+        kernel->short_name = "[kernel]";
         vdso = dso__new("[vdso]");
         if (!vdso)
-                return -1;
+                return NULL;
+
+        if (sysfs__read_build_id("/sys/kernel/notes", kernel->build_id,
+                                 sizeof(kernel->build_id)) == 0)
+                kernel->has_build_id = true;
 
+        dsos__add(kernel);
         dsos__add(vdso);
 
-        return 0;
+        return kernel;
+}
+
+int load_kernel(symbol_filter_t filter)
+{
+        struct dso *kernel = dsos__load_kernel();
+
+        if (kernel == NULL)
+                return -1;
+
+        return dso__load_kernel_sym(kernel, filter, modules);
 }
 
 void symbol__init(unsigned int priv_size)
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index da7ec1af255a..f0593a649c3d 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -77,10 +77,10 @@ void dso__delete(struct dso *self);
 
 struct symbol *dso__find_symbol(struct dso *self, u64 ip);
 
-int dsos__load_kernel(const char *vmlinux, symbol_filter_t filter, int modules);
 int dsos__load_modules(void);
 struct dso *dsos__findnew(const char *name);
 int dso__load(struct dso *self, struct map *map, symbol_filter_t filter);
+int dso__load_kernel_sym(struct dso *self, symbol_filter_t filter, int modules);
 void dsos__fprintf(FILE *fp);
 size_t dsos__fprintf_buildid(FILE *fp);
 
@@ -94,6 +94,7 @@ int sysfs__read_build_id(const char *filename, void *bf, size_t size);
 bool dsos__read_build_ids(void);
 int build_id__sprintf(u8 *self, int len, char *bf);
 
+struct dso *dsos__load_kernel(void);
 int load_kernel(symbol_filter_t filter);
 
 void symbol__init(unsigned int priv_size);