diff options
| -rw-r--r-- | tools/perf/util/header.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 3724707425e..6a9c041134b 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -1703,21 +1703,41 @@ int perf_file_header__read(struct perf_file_header *header, bitmap_zero(header->adds_features, HEADER_FEAT_BITS); else return -1; + } else if (ph->needs_swap) { + unsigned int i; + /* + * feature bitmap is declared as an array of unsigned longs -- + * not good since its size can differ between the host that + * generated the data file and the host analyzing the file. + * + * We need to handle endianness, but we don't know the size of + * the unsigned long where the file was generated. Take a best + * guess at determining it: try 64-bit swap first (ie., file + * created on a 64-bit host), and check if the hostname feature + * bit is set (this feature bit is forced on as of fbe96f2). + * If the bit is not, undo the 64-bit swap and try a 32-bit + * swap. If the hostname bit is still not set (e.g., older data + * file), punt and fallback to the original behavior -- + * clearing all feature bits and setting buildid. + */ + for (i = 0; i < BITS_TO_LONGS(HEADER_FEAT_BITS); ++i) + header->adds_features[i] = bswap_64(header->adds_features[i]); + + if (!test_bit(HEADER_HOSTNAME, header->adds_features)) { + for (i = 0; i < BITS_TO_LONGS(HEADER_FEAT_BITS); ++i) { + header->adds_features[i] = bswap_64(header->adds_features[i]); + header->adds_features[i] = bswap_32(header->adds_features[i]); + } + } + + if (!test_bit(HEADER_HOSTNAME, header->adds_features)) { + bitmap_zero(header->adds_features, HEADER_FEAT_BITS); + set_bit(HEADER_BUILD_ID, header->adds_features); + } } memcpy(&ph->adds_features, &header->adds_features, sizeof(ph->adds_features)); - /* - * FIXME: hack that assumes that if we need swap the perf.data file - * may be coming from an arch with a different word-size, ergo different - * DEFINE_BITMAP format, investigate more later, but for now its mostly - * safe to assume that we have a build-id section. Trace files probably - * have several other issues in this realm anyway... - */ - if (ph->needs_swap) { - memset(&ph->adds_features, 0, sizeof(ph->adds_features)); - perf_header__set_feat(ph, HEADER_BUILD_ID); - } ph->event_offset = header->event_types.offset; ph->event_size = header->event_types.size; |