perf session: Fix infinite loop in __perf_session__process_events
Commit-ID: 3d03e2ea74103a50c23d6ab1906cf73399c0dafb Gitweb: http://git.kernel.org/tip/3d03e2ea74103a50c23d6ab1906cf73399c0dafb Author: Arnaldo Carvalho de Melo <[email protected]> AuthorDate: Mon, 10 Jan 2011 21:37:57 -0200 Committer: Arnaldo Carvalho de Melo <[email protected]> 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 <[email protected]>
Reported-by Ingo Molnar <[email protected]>
Reported-by David Ahern <[email protected]>
Bisected-by David Ahern <[email protected]>
Tested-by David Ahern <[email protected]>
Cc David Ahern <[email protected]>
Cc Frederic Weisbecker <[email protected]>
Cc Ingo Molnar <[email protected]>
Cc Mike Galbraith <[email protected]>
Cc Paul Mackerras <[email protected]>
Cc Peter Zijlstra <[email protected]>
Cc Stephane Eranian <[email protected]>
Cc Thomas Gleixner <[email protected]>
Cc Tom Zanussi <[email protected]>
LKML-Reference: <new-submission>
Signed-off-by Arnaldo Carvalho de Melo <[email protected]>
--- tools/perf/util/session.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
tools/perf/util/session.c +1 -1
@@ -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 ;