1 files changed, 40 insertions, 13 deletions

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 26441d0e571b..c3e5a3b817ab 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -199,9 +199,11 @@ static int write_buildid(char *name, size_t name_len, u8 *build_id,
 	return write_padded(fd, name, name_len + 1, len);
 }
 
-static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
-				u16 misc, int fd)
+static int __dsos__write_buildid_table(struct list_head *head,
+				       struct machine *machine,
+				       pid_t pid, u16 misc, int fd)
 {
+	char nm[PATH_MAX];
 	struct dso *pos;
 
 	dsos__for_each_with_build_id(pos, head) {
@@ -215,6 +217,10 @@ static int __dsos__write_buildid_table(struct list_head *head, pid_t pid,
 		if (is_vdso_map(pos->short_name)) {
 			name = (char *) VDSO__MAP_NAME;
 			name_len = sizeof(VDSO__MAP_NAME) + 1;
+		} else if (dso__is_kcore(pos)) {
+			machine__mmap_name(machine, nm, sizeof(nm));
+			name = nm;
+			name_len = strlen(nm) + 1;
 		} else {
 			name = pos->long_name;
 			name_len = pos->long_name_len + 1;
@@ -240,10 +246,10 @@ static int machine__write_buildid_table(struct machine *machine, int fd)
 		umisc = PERF_RECORD_MISC_GUEST_USER;
 	}
 
-	err = __dsos__write_buildid_table(&machine->kernel_dsos, machine->pid,
-					  kmisc, fd);
+	err = __dsos__write_buildid_table(&machine->kernel_dsos, machine,
+					  machine->pid, kmisc, fd);
 	if (err == 0)
-		err = __dsos__write_buildid_table(&machine->user_dsos,
+		err = __dsos__write_buildid_table(&machine->user_dsos, machine,
 						  machine->pid, umisc, fd);
 	return err;
 }
@@ -375,23 +381,31 @@ out_free:
 	return err;
 }
 
-static int dso__cache_build_id(struct dso *dso, const char *debugdir)
+static int dso__cache_build_id(struct dso *dso, struct machine *machine,
+			       const char *debugdir)
 {
 	bool is_kallsyms = dso->kernel && dso->long_name[0] != '/';
 	bool is_vdso = is_vdso_map(dso->short_name);
+	char *name = dso->long_name;
+	char nm[PATH_MAX];
 
-	return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id),
-				     dso->long_name, debugdir,
-				     is_kallsyms, is_vdso);
+	if (dso__is_kcore(dso)) {
+		is_kallsyms = true;
+		machine__mmap_name(machine, nm, sizeof(nm));
+		name = nm;
+	}
+	return build_id_cache__add_b(dso->build_id, sizeof(dso->build_id), name,
+				     debugdir, is_kallsyms, is_vdso);
 }
 
-static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
+static int __dsos__cache_build_ids(struct list_head *head,
+				   struct machine *machine, const char *debugdir)
 {
 	struct dso *pos;
 	int err = 0;
 
 	dsos__for_each_with_build_id(pos, head)
-		if (dso__cache_build_id(pos, debugdir))
+		if (dso__cache_build_id(pos, machine, debugdir))
 			err = -1;
 
 	return err;
@@ -399,8 +413,9 @@ static int __dsos__cache_build_ids(struct list_head *head, const char *debugdir)
 
 static int machine__cache_build_ids(struct machine *machine, const char *debugdir)
 {
-	int ret = __dsos__cache_build_ids(&machine->kernel_dsos, debugdir);
-	ret |= __dsos__cache_build_ids(&machine->user_dsos, debugdir);
+	int ret = __dsos__cache_build_ids(&machine->kernel_dsos, machine,
+					  debugdir);
+	ret |= __dsos__cache_build_ids(&machine->user_dsos, machine, debugdir);
 	return ret;
 }
 
@@ -2753,6 +2768,18 @@ int perf_session__read_header(struct perf_session *session)
 	if (perf_file_header__read(&f_header, header, fd) < 0)
 		return -EINVAL;
 
+	/*
+	 * Sanity check that perf.data was written cleanly; data size is
+	 * initialized to 0 and updated only if the on_exit function is run.
+	 * If data size is still 0 then the file contains only partial
+	 * information.  Just warn user and process it as much as it can.
+	 */
+	if (f_header.data.size == 0) {
+		pr_warning("WARNING: The %s file's data size field is 0 which is unexpected.\n"
+			   "Was the 'perf record' command properly terminated?\n",
+			   session->filename);
+	}
+
 	nr_attrs = f_header.attrs.size / f_header.attr_size;
 	lseek(fd, f_header.attrs.offset, SEEK_SET);