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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>
hifive-unleashed-5.1
Arnaldo Carvalho de Melo 2011-03-22 13:36:45 -03:00
parent 9e69c21082
commit b25114817a
1 changed files with 56 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

57
tools/perf/util/header.c
View File

@ -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);