Messages in this thread Patch in this message | | | From | Arnaldo Carvalho de Melo <> | Subject | [PATCH 6/6] perf session: Fix infinite loop in __perf_session__process_events | Date | Mon, 10 Jan 2011 22:28:12 -0200 |
| |
From: Arnaldo Carvalho de Melo <acme@redhat.com>
In this if statement:
if (head + event->header.size >= mmap_size) { if (mmaps[map_idx]) { munmap(mmaps[map_idx], mmap_size); mmaps[map_idx] = NULL; }
page_offset = page_size * (head / page_size); file_offset += page_offset; head -= page_offset; goto remap; }
With, for instance, these values:
head=2992 event->header.size=48 mmap_size=3040
We end up endlessly looping back to remap. Off by one.
Problem introduced in 55b4462.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Ingo Molnar <mingo@elte.hu> Reported-by: David Ahern <daahern@cisco.com> Bisected-by: David Ahern <daahern@cisco.com> Tested-by: David Ahern <daahern@cisco.com> Cc: David Ahern <daahern@cisco.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/session.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 6fb4694..313dac2 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1007,7 +1007,7 @@ more: if (size == 0) size = 8; - if (head + event->header.size >= mmap_size) { + if (head + event->header.size > mmap_size) { if (mmaps[map_idx]) { munmap(mmaps[map_idx], mmap_size); mmaps[map_idx] = NULL; -- 1.6.2.5
| |