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);