diff options
| -rw-r--r-- | tools/perf/util/header.c | 122 |
1 files changed, 94 insertions, 28 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 6d580267d04..c851495b9b4 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1803,35 +1803,101 @@ out_free: return err; } -static int check_magic_endian(u64 *magic, struct perf_file_header *header, - struct perf_header *ph) +static const int attr_file_abi_sizes[] = { + [0] = PERF_ATTR_SIZE_VER0, + [1] = PERF_ATTR_SIZE_VER1, + 0, +}; + +/* + * In the legacy file format, the magic number is not used to encode endianness. + * hdr_sz was used to encode endianness. But given that hdr_sz can vary based + * on ABI revisions, we need to try all combinations for all endianness to + * detect the endianness. + */ +static int try_all_file_abis(uint64_t hdr_sz, struct perf_header *ph) { - int ret; + uint64_t ref_size, attr_size; + int i; - /* 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; + for (i = 0 ; attr_file_abi_sizes[i]; i++) { + ref_size = attr_file_abi_sizes[i] + + sizeof(struct perf_file_section); + if (hdr_sz != ref_size) { + attr_size = bswap_64(hdr_sz); + if (attr_size != ref_size) + continue; - if (header->attr_size != sizeof(struct perf_file_attr)) { - u64 attr_size = bswap_64(header->attr_size); + ph->needs_swap = true; + } + pr_debug("ABI%d perf.data file detected, need_swap=%d\n", + i, + ph->needs_swap); + return 0; + } + /* could not determine endianness */ + return -1; +} - if (attr_size != sizeof(struct perf_file_attr)) - return -1; +#define PERF_PIPE_HDR_VER0 16 + +static const size_t attr_pipe_abi_sizes[] = { + [0] = PERF_PIPE_HDR_VER0, + 0, +}; + +/* + * In the legacy pipe format, there is an implicit assumption that endiannesss + * between host recording the samples, and host parsing the samples is the + * same. This is not always the case given that the pipe output may always be + * redirected into a file and analyzed on a different machine with possibly a + * different endianness and perf_event ABI revsions in the perf tool itself. + */ +static int try_all_pipe_abis(uint64_t hdr_sz, struct perf_header *ph) +{ + u64 attr_size; + int i; + + for (i = 0 ; attr_pipe_abi_sizes[i]; i++) { + if (hdr_sz != attr_pipe_abi_sizes[i]) { + attr_size = bswap_64(hdr_sz); + if (attr_size != hdr_sz) + continue; ph->needs_swap = true; } + pr_debug("Pipe ABI%d perf.data file detected\n", i); return 0; } + return -1; +} + +static int check_magic_endian(u64 magic, uint64_t hdr_sz, + bool is_pipe, 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 (is_pipe) + return try_all_pipe_abis(hdr_sz, ph); + + return try_all_file_abis(hdr_sz, ph); + } + /* + * the new magic number serves two purposes: + * - unique number to identify actual perf.data files + * - encode endianness of file + */ - /* check magic number with same endianness */ - if (*magic == __perf_magic2) + /* check magic number with one endianness */ + if (magic == __perf_magic2) return 0; - /* check magic number but opposite endianness */ - if (*magic != __perf_magic2_sw) + /* check magic number with opposite endianness */ + if (magic != __perf_magic2_sw) return -1; ph->needs_swap = true; @@ -1850,8 +1916,11 @@ int perf_file_header__read(struct perf_file_header *header, if (ret <= 0) return -1; - if (check_magic_endian(&header->magic, header, ph) < 0) + if (check_magic_endian(header->magic, + header->attr_size, false, ph) < 0) { + pr_debug("magic/endian check failed\n"); return -1; + } if (ph->needs_swap) { mem_bswap_64(header, offsetof(struct perf_file_header, @@ -1938,21 +2007,17 @@ static int perf_file_header__read_pipe(struct perf_pipe_file_header *header, if (ret <= 0) return -1; - if (check_magic_endian(&header->magic, NULL, ph) < 0) + if (check_magic_endian(header->magic, header->size, true, ph) < 0) { + pr_debug("endian/magic failed\n"); return -1; + } + + if (ph->needs_swap) + header->size = bswap_64(header->size); if (repipe && do_write(STDOUT_FILENO, header, sizeof(*header)) < 0) return -1; - if (header->size != sizeof(*header)) { - u64 size = bswap_64(header->size); - - if (size != sizeof(*header)) - return -1; - - ph->needs_swap = true; - } - return 0; } @@ -1992,6 +2057,7 @@ static int read_attr(int fd, struct perf_header *ph, /* on file perf_event_attr size */ sz = attr->size; + if (ph->needs_swap) sz = bswap_32(sz); |