commit: b25114817a73bbd2b84ce9dba02ee1ef8989a947 From: Arnaldo Carvalho de Melo <[email protected]> Date: Tue, 22 Mar 2011 13:36:45 -0300 Subject: [PATCH] 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 <[email protected]> Cc: Avi Kivity <[email protected]> Cc: Frederic Weisbecker <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: Paul Mackerras <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Tom Zanussi <[email protected]> Cc: Zhang Yanmin <[email protected]> Cc: [email protected] LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/util/header.c | 57 +++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 56 insertions(+), 1 deletions(-) diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index e5230c0..93862a8 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); _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
