Commit-ID: 3d03e2ea74103a50c23d6ab1906cf73399c0dafb
Gitweb: http://git.kernel.org/tip/3d03e2ea74103a50c23d6ab1906cf73399c0dafb
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Mon, 10 Jan 2011 21:37:57 -0200
Committer: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Mon, 10 Jan 2011 22:23:08 -0200
perf session: Fix infinite loop in __perf_session__process_events
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@xxxxxxxxxxxxxxxxxxxx>
Reported-by: Ingo Molnar <mingo@xxxxxxx>
Reported-by: David Ahern <daahern@xxxxxxxxx>
Bisected-by: David Ahern <daahern@xxxxxxxxx>
Tested-by: David Ahern <daahern@xxxxxxxxx>
Cc: David Ahern <daahern@xxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tom Zanussi <tzanussi@xxxxxxxxx>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
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;
--
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