All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v1] perf session: fix loading of compressed data split across adjacent records
@ 2019-07-09 14:48 Alexey Budankov
  2019-07-14 15:49 ` Jiri Olsa
  2019-07-23 21:50 ` [tip:perf/urgent] perf session: Fix " tip-bot for Alexey Budankov
  0 siblings, 2 replies; 7+ messages in thread
From: Alexey Budankov @ 2019-07-09 14:48 UTC (permalink / raw)
  To: Arnaldo Carvalho de Melo
  Cc: Jiri Olsa, Namhyung Kim, Alexander Shishkin, Peter Zijlstra,
	Ingo Molnar, Andi Kleen, linux-kernel


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>
---
 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 d0fd6c614e68..37efa1f43d8b 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 dd8920b745bc..863dbad87849 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 23bdb9884576..d2202392ffdb 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;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2019-07-23 21:51 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-07-09 14:48 [PATCH v1] perf session: fix loading of compressed data split across adjacent records Alexey Budankov
2019-07-14 15:49 ` Jiri Olsa
2019-07-15 12:30   ` Alexey Budankov
2019-07-16 18:49     ` Arnaldo Carvalho de Melo
2019-07-16 20:59       ` Jiri Olsa
2019-07-17 12:34         ` Arnaldo Carvalho de Melo
2019-07-23 21:50 ` [tip:perf/urgent] perf session: Fix " tip-bot for Alexey Budankov

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.