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* [PATCH 1/3] Revert "perf session: Fix decompression of PERF_RECORD_COMPRESSED records"
@ 2020-11-24  9:59 Petr Malat
  2020-11-24  9:59 ` [PATCH 2/3] Revert "perf session: Avoid infinite loop when seeing invalid header.size" Petr Malat
                   ` (2 more replies)
  0 siblings, 3 replies; 15+ messages in thread
From: Petr Malat @ 2020-11-24  9:59 UTC (permalink / raw)
  To: linux-kernel
  Cc: Petr Malat, Peter Zijlstra, Ingo Molnar,
	Arnaldo Carvalho de Melo, Mark Rutland, Alexander Shishkin,
	Jiri Olsa, Namhyung Kim, Adrian Hunter, Kan Liang,
	Alexey Budankov

Both mmapped and compressed events can be split by the buffer boundary,
it doesn't make sense to handle them differently.

Fixes: bb1835a3b86c ("perf session: Fix decompression of PERF_RECORD_COMPRESSED records")
Fixes: 57fc032ad643 ("perf session: Avoid infinite loop when seeing invalid header.size")
Signed-off-by: Petr Malat <oss@malat.biz>
---
 tools/perf/util/session.c | 44 +++++++++++++++------------------------
 1 file changed, 17 insertions(+), 27 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 7a5f03764702..593d5a823eba 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -2024,8 +2024,8 @@ static int __perf_session__process_pipe_events(struct perf_session *session)
 }
 
 static union perf_event *
-prefetch_event(char *buf, u64 head, size_t mmap_size,
-	       bool needs_swap, union perf_event *error)
+fetch_mmaped_event(struct perf_session *session,
+		   u64 head, size_t mmap_size, char *buf)
 {
 	union perf_event *event;
 
@@ -2037,32 +2037,20 @@ prefetch_event(char *buf, u64 head, size_t mmap_size,
 		return NULL;
 
 	event = (union perf_event *)(buf + head);
-	if (needs_swap)
-		perf_event_header__bswap(&event->header);
-
-	if (head + event->header.size <= mmap_size)
-		return event;
 
-	/* We're not fetching the event so swap back again */
-	if (needs_swap)
+	if (session->header.needs_swap)
 		perf_event_header__bswap(&event->header);
 
-	pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx:"
-		 " fuzzed or compressed perf.data?\n",__func__, head, event->header.size, mmap_size);
-
-	return error;
-}
-
-static union perf_event *
-fetch_mmaped_event(u64 head, size_t mmap_size, char *buf, bool needs_swap)
-{
-	return prefetch_event(buf, head, mmap_size, needs_swap, ERR_PTR(-EINVAL));
-}
+	if (head + event->header.size > mmap_size) {
+		/* We're not fetching the event so swap back again */
+		if (session->header.needs_swap)
+			perf_event_header__bswap(&event->header);
+		pr_debug("%s: head=%#" PRIx64 " event->header_size=%#x, mmap_size=%#zx: fuzzed perf.data?\n",
+			 __func__, head, event->header.size, mmap_size);
+		return ERR_PTR(-EINVAL);
+	}
 
-static union perf_event *
-fetch_decomp_event(u64 head, size_t mmap_size, char *buf, bool needs_swap)
-{
-	return prefetch_event(buf, head, mmap_size, needs_swap, NULL);
+	return event;
 }
 
 static int __perf_session__process_decomp_events(struct perf_session *session)
@@ -2075,8 +2063,10 @@ static int __perf_session__process_decomp_events(struct perf_session *session)
 		return 0;
 
 	while (decomp->head < decomp->size && !session_done()) {
-		union perf_event *event = fetch_decomp_event(decomp->head, decomp->size, decomp->data,
-							     session->header.needs_swap);
+		union perf_event *event = fetch_mmaped_event(session, decomp->head, decomp->size, decomp->data);
+
+		if (IS_ERR(event))
+			return PTR_ERR(event);
 
 		if (!event)
 			break;
@@ -2176,7 +2166,7 @@ reader__process_events(struct reader *rd, struct perf_session *session,
 	}
 
 more:
-	event = fetch_mmaped_event(head, mmap_size, buf, session->header.needs_swap);
+	event = fetch_mmaped_event(session, head, mmap_size, buf);
 	if (IS_ERR(event))
 		return PTR_ERR(event);
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 15+ messages in thread
end of thread, other threads:[~2020-12-02 14:20 UTC | newest]

Thread overview: 15+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-11-24  9:59 [PATCH 1/3] Revert "perf session: Fix decompression of PERF_RECORD_COMPRESSED records" Petr Malat
2020-11-24  9:59 ` [PATCH 2/3] Revert "perf session: Avoid infinite loop when seeing invalid header.size" Petr Malat
2020-11-24  9:59 ` [PATCH 3/3] perf session: Avoid infinite loop if an event is truncated Petr Malat
2020-11-24 10:21   ` Petr Malat
2020-11-24 10:29 ` [PATCH v2 1/3] Revert "perf session: Fix decompression of PERF_RECORD_COMPRESSED records" Petr Malat
2020-11-24 10:29   ` [PATCH v2 2/3] Revert "perf session: Avoid infinite loop when seeing invalid header.size" Petr Malat
2020-11-24 10:29   ` [PATCH v2 3/3] perf session: Avoid infinite loop if an event is truncated Petr Malat
2020-11-24 14:36   ` [PATCH v2 1/3] Revert "perf session: Fix decompression of PERF_RECORD_COMPRESSED records" Jiri Olsa
2020-11-24 18:15     ` Petr Malat
2020-11-30 11:40       ` Petr Malat
2020-12-01 19:09         ` Jiri Olsa
2020-12-01 21:04           ` Alexei Budankov
2020-12-01 21:28             ` Alexei Budankov
2020-12-02 14:04               ` Bayduraev, Alexey V
2020-12-02 14:18                 ` Alexei Budankov

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