if (access(linkname, F_OK))
goto out_free;
- if (readlink(linkname, filename, size) < 0)
+ if (readlink(linkname, filename, size - 1) < 0)
goto out_free;
if (unlink(linkname))
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;
if (perf_header__read_build_ids(ph, fd, section->offset, section->size))
pr_debug("Failed to read buildids, continuing...\n");
break;
+
+ case HEADER_HOSTNAME:
+ case HEADER_OSRELEASE:
+ case HEADER_VERSION:
+ case HEADER_ARCH:
+ case HEADER_NRCPUS:
+ case HEADER_CPUDESC:
+ case HEADER_CPUID:
+ case HEADER_TOTAL_MEM:
+ case HEADER_CMDLINE:
+ case HEADER_EVENT_DESC:
+ case HEADER_CPU_TOPOLOGY:
+ case HEADER_NUMA_TOPOLOGY:
+ break;
+
default:
pr_debug("unknown feature %d, continuing...\n", feat);
}
struct perf_session *session __unused)
{
union perf_event ev;
+ struct tracing_data *tdata;
ssize_t size = 0, aligned_size = 0, padding;
int err __used = 0;
+ /*
+ * We are going to store the size of the data followed
+ * by the data contents. Since the fd descriptor is a pipe,
+ * we cannot seek back to store the size of the data once
+ * we know it. Instead we:
+ *
+ * - write the tracing data to the temp file
+ * - get/write the data size to pipe
+ * - write the tracing data from the temp file
+ * to the pipe
+ */
+ tdata = tracing_data_get(&evlist->entries, fd, true);
+ if (!tdata)
+ return -1;
+
memset(&ev, 0, sizeof(ev));
ev.tracing_data.header.type = PERF_RECORD_HEADER_TRACING_DATA;
- size = read_tracing_data_size(fd, &evlist->entries);
- if (size <= 0)
- return size;
+ size = tdata->size;
aligned_size = ALIGN(size, sizeof(u64));
padding = aligned_size - size;
ev.tracing_data.header.size = sizeof(ev.tracing_data);
process(&ev, NULL, session);
- err = read_tracing_data(fd, &evlist->entries);
+ /*
+ * The put function will copy all the tracing data
+ * stored in temp file to the pipe.
+ */
+ tracing_data_put(tdata);
+
write_padded(fd, NULL, 0, padding);
return aligned_size;