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authorArnaldo Carvalho de Melo <acme@redhat.com>2011-03-22 13:36:45 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2011-03-23 19:29:40 -0300
commitb25114817a73bbd2b84ce9dba02ee1ef8989a947 (patch)
tree8eaad3eaa307a607f87b8ea631c5f1fc76ce4a82 /tools
parent9e69c210822c4035708a6111567c96364ca244d5 (diff)
perf build-id: Add quirk to deal with perf.data file format breakage
The a1645ce1 changeset: "perf: 'perf kvm' tool for monitoring guest performance from host" Added a field to struct build_id_event that broke the file format. Since the kernel build-id is the first entry, process the table using the old format if the well known '[kernel.kallsyms]' string for the kernel build-id has the first 4 characters chopped off (where the pid_t sits). Reported-by: Han Pingtian <phan@redhat.com> Cc: Avi Kivity <avi@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Tom Zanussi <tzanussi@gmail.com> Cc: Zhang Yanmin <yanmin_zhang@linux.intel.com> Cc: stable@kernel.org LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools')
-rw-r--r--tools/perf/util/header.c57
1 files changed, 56 insertions, 1 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index e5230c0ef95..93862a8027e 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -695,13 +695,50 @@ out:
return err;
}
+static int perf_header__read_build_ids_abi_quirk(struct perf_header *header,
+ int input, u64 offset, u64 size)
+{
+ struct perf_session *session = container_of(header, struct perf_session, header);
+ struct {
+ struct perf_event_header header;
+ u8 build_id[ALIGN(BUILD_ID_SIZE, sizeof(u64))];
+ char filename[0];
+ } old_bev;
+ struct build_id_event bev;
+ char filename[PATH_MAX];
+ u64 limit = offset + size;
+
+ while (offset < limit) {
+ ssize_t len;
+
+ if (read(input, &old_bev, sizeof(old_bev)) != sizeof(old_bev))
+ return -1;
+
+ if (header->needs_swap)
+ perf_event_header__bswap(&old_bev.header);
+
+ len = old_bev.header.size - sizeof(old_bev);
+ if (read(input, filename, len) != len)
+ return -1;
+
+ bev.header = old_bev.header;
+ bev.pid = 0;
+ memcpy(bev.build_id, old_bev.build_id, sizeof(bev.build_id));
+ __event_process_build_id(&bev, filename, session);
+
+ offset += bev.header.size;
+ }
+
+ return 0;
+}
+
static int perf_header__read_build_ids(struct perf_header *header,
int input, u64 offset, u64 size)
{
struct perf_session *session = container_of(header, struct perf_session, header);
struct build_id_event bev;
char filename[PATH_MAX];
- u64 limit = offset + size;
+ u64 limit = offset + size, orig_offset = offset;
int err = -1;
while (offset < limit) {
@@ -716,6 +753,24 @@ static int perf_header__read_build_ids(struct perf_header *header,
len = bev.header.size - sizeof(bev);
if (read(input, filename, len) != len)
goto out;
+ /*
+ * The a1645ce1 changeset:
+ *
+ * "perf: 'perf kvm' tool for monitoring guest performance from host"
+ *
+ * Added a field to struct build_id_event that broke the file
+ * format.
+ *
+ * Since the kernel build-id is the first entry, process the
+ * table using the old format if the well known
+ * '[kernel.kallsyms]' string for the kernel build-id has the
+ * first 4 characters chopped off (where the pid_t sits).
+ */
+ if (memcmp(filename, "nel.kallsyms]", 13) == 0) {
+ if (lseek(input, orig_offset, SEEK_SET) == (off_t)-1)
+ return -1;
+ return perf_header__read_build_ids_abi_quirk(header, input, offset, size);
+ }
__event_process_build_id(&bev, filename, session);