[ Upstream commit 872c8ee8f0f47222f7b10da96eea84d0486540a3 ]
Fix decompression failure found during the loading of compressed trace collected on larger scale systems (>48 cores).
The error happened due to lack of decompression space for a mmaped buffer data chunk split across adjacent PERF_RECORD_COMPRESSED records.
$ perf report -i bt.16384.data --stats failed to decompress (B): 63869 -> 0 : Destination buffer is too small user stack dump failure Can't parse sample, err = -14 0x2637e436 [0x4080]: failed to process type: 9 Error: failed to process sample
$ perf test 71 71: Zstd perf.data compression/decompression : Ok
Signed-off-by: Alexey Budankov alexey.budankov@linux.intel.com Acked-by: Jiri Olsa jolsa@kernel.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: http://lkml.kernel.org/r/4d839e1b-9c48-89c4-9702-a12217420611@linux.intel.co... Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/session.c | 22 ++++++++++++++-------- tools/perf/util/session.h | 1 + tools/perf/util/zstd.c | 4 ++-- 3 files changed, 17 insertions(+), 10 deletions(-)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 2e61dd6a3574e..d789840960444 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -36,10 +36,16 @@ static int perf_session__process_compressed_event(struct perf_session *session, void *src; size_t decomp_size, src_size; u64 decomp_last_rem = 0; - size_t decomp_len = session->header.env.comp_mmap_len; + size_t mmap_len, decomp_len = session->header.env.comp_mmap_len; struct decomp *decomp, *decomp_last = session->decomp_last;
- decomp = mmap(NULL, sizeof(struct decomp) + decomp_len, PROT_READ|PROT_WRITE, + if (decomp_last) { + decomp_last_rem = decomp_last->size - decomp_last->head; + decomp_len += decomp_last_rem; + } + + mmap_len = sizeof(struct decomp) + decomp_len; + decomp = mmap(NULL, mmap_len, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, 0); if (decomp == MAP_FAILED) { pr_err("Couldn't allocate memory for decompression\n"); @@ -47,10 +53,10 @@ static int perf_session__process_compressed_event(struct perf_session *session, }
decomp->file_pos = file_offset; + decomp->mmap_len = mmap_len; decomp->head = 0;
- if (decomp_last) { - decomp_last_rem = decomp_last->size - decomp_last->head; + if (decomp_last_rem) { memcpy(decomp->data, &(decomp_last->data[decomp_last->head]), decomp_last_rem); decomp->size = decomp_last_rem; } @@ -61,7 +67,7 @@ static int perf_session__process_compressed_event(struct perf_session *session, decomp_size = zstd_decompress_stream(&(session->zstd_data), src, src_size, &(decomp->data[decomp_last_rem]), decomp_len - decomp_last_rem); if (!decomp_size) { - munmap(decomp, sizeof(struct decomp) + decomp_len); + munmap(decomp, mmap_len); pr_err("Couldn't decompress data\n"); return -1; } @@ -255,15 +261,15 @@ static void perf_session__delete_threads(struct perf_session *session) static void perf_session__release_decomp_events(struct perf_session *session) { struct decomp *next, *decomp; - size_t decomp_len; + size_t mmap_len; next = session->decomp; - decomp_len = session->header.env.comp_mmap_len; do { decomp = next; if (decomp == NULL) break; next = decomp->next; - munmap(decomp, decomp_len + sizeof(struct decomp)); + mmap_len = decomp->mmap_len; + munmap(decomp, mmap_len); } while (1); }
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h index dd8920b745bce..863dbad878496 100644 --- a/tools/perf/util/session.h +++ b/tools/perf/util/session.h @@ -46,6 +46,7 @@ struct perf_session { struct decomp { struct decomp *next; u64 file_pos; + size_t mmap_len; u64 head; size_t size; char data[]; diff --git a/tools/perf/util/zstd.c b/tools/perf/util/zstd.c index 23bdb98845760..d2202392ffdbb 100644 --- a/tools/perf/util/zstd.c +++ b/tools/perf/util/zstd.c @@ -99,8 +99,8 @@ size_t zstd_decompress_stream(struct zstd_data *data, void *src, size_t src_size while (input.pos < input.size) { ret = ZSTD_decompressStream(data->dstream, &output, &input); if (ZSTD_isError(ret)) { - pr_err("failed to decompress (B): %ld -> %ld : %s\n", - src_size, output.size, ZSTD_getErrorName(ret)); + pr_err("failed to decompress (B): %ld -> %ld, dst_size %ld : %s\n", + src_size, output.size, dst_size, ZSTD_getErrorName(ret)); break; } output.dst = dst + output.pos;