diff options
| -rw-r--r-- | tools/perf/util/header.c | 77 |
1 files changed, 64 insertions, 13 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index ecd7f4dd7eea..6f4187de4b72 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -63,9 +63,20 @@ char *perf_header__find_event(u64 id) return NULL; } -static const char *__perf_magic = "PERFFILE"; +/* + * magic2 = "PERFILE2" + * must be a numerical value to let the endianness + * determine the memory layout. That way we are able + * to detect endianness when reading the perf.data file + * back. + * + * we check for legacy (PERFFILE) format. + */ +static const char *__perf_magic1 = "PERFFILE"; +static const u64 __perf_magic2 = 0x32454c4946524550ULL; +static const u64 __perf_magic2_sw = 0x50455246494c4532ULL; -#define PERF_MAGIC (*(u64 *)__perf_magic) +#define PERF_MAGIC __perf_magic2 struct perf_file_attr { struct perf_event_attr attr; @@ -1620,24 +1631,59 @@ out_free: return err; } +static int check_magic_endian(u64 *magic, struct perf_file_header *header, + struct perf_header *ph) +{ + int ret; + + /* check for legacy format */ + ret = memcmp(magic, __perf_magic1, sizeof(*magic)); + if (ret == 0) { + pr_debug("legacy perf.data format\n"); + if (!header) + return -1; + + if (header->attr_size != sizeof(struct perf_file_attr)) { + u64 attr_size = bswap_64(header->attr_size); + + if (attr_size != sizeof(struct perf_file_attr)) + return -1; + + ph->needs_swap = true; + } + return 0; + } + + /* check magic number with same endianness */ + if (*magic == __perf_magic2) + return 0; + + /* check magic number but opposite endianness */ + if (*magic != __perf_magic2_sw) + return -1; + + ph->needs_swap = true; + + return 0; +} + int perf_file_header__read(struct perf_file_header *header, struct perf_header *ph, int fd) { + int ret; + lseek(fd, 0, SEEK_SET); - if (readn(fd, header, sizeof(*header)) <= 0 || - memcmp(&header->magic, __perf_magic, sizeof(header->magic))) + ret = readn(fd, header, sizeof(*header)); + if (ret <= 0) return -1; - if (header->attr_size != sizeof(struct perf_file_attr)) { - u64 attr_size = bswap_64(header->attr_size); - - if (attr_size != sizeof(struct perf_file_attr)) - return -1; + if (check_magic_endian(&header->magic, header, ph) < 0) + return -1; + if (ph->needs_swap) { mem_bswap_64(header, offsetof(struct perf_file_header, - adds_features)); - ph->needs_swap = true; + adds_features)); } if (header->size != sizeof(*header)) { @@ -1873,8 +1919,13 @@ static int perf_file_header__read_pipe(struct perf_pipe_file_header *header, struct perf_header *ph, int fd, bool repipe) { - if (readn(fd, header, sizeof(*header)) <= 0 || - memcmp(&header->magic, __perf_magic, sizeof(header->magic))) + int ret; + + ret = readn(fd, header, sizeof(*header)); + if (ret <= 0) + return -1; + + if (check_magic_endian(&header->magic, NULL, ph) < 0) return -1; if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0) |