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Subject[tip:perf/urgent] perf tools: fix off-by-one error in maps
Commit-ID:  77faf4d060e3ee1fd2ff6cd39f2b2eb887100422
Gitweb: http://git.kernel.org/tip/77faf4d060e3ee1fd2ff6cd39f2b2eb887100422
Author: Stephane Eranian <eranian@google.com>
AuthorDate: Mon, 6 Oct 2014 10:35:32 +0200
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 14 Oct 2014 17:50:55 -0300

perf tools: fix off-by-one error in maps

This patch fixes off-by-one errors in the management of maps.

A map is defined by start address and length as implemented by
map__new():

map__init(map, type, start, start + len, pgoff, dso);

map->start = addr;
map->end = end;

Consequently, the actual address range is [start; end[ map->end is the
first byte outside the range.

This patch fixes two bugs where upper bound checking was off-by-one.

In V2, we fix map_groups__fixup_overlappings() some more where
map->start was off-by-one as reported by Jiri.

Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20141006083532.GA4850@quad
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/map.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index b709059..186418b 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -556,7 +556,7 @@ struct symbol *map_groups__find_symbol_by_name(struct map_groups *mg,

int map_groups__find_ams(struct addr_map_symbol *ams, symbol_filter_t filter)
{
- if (ams->addr < ams->map->start || ams->addr > ams->map->end) {
+ if (ams->addr < ams->map->start || ams->addr >= ams->map->end) {
if (ams->map->groups == NULL)
return -1;
ams->map = map_groups__find(ams->map->groups, ams->map->type,
@@ -664,7 +664,7 @@ int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map,
goto move_map;
}

- before->end = map->start - 1;
+ before->end = map->start;
map_groups__insert(mg, before);
if (verbose >= 2)
map__fprintf(before, fp);
@@ -678,7 +678,7 @@ int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map,
goto move_map;
}

- after->start = map->end + 1;
+ after->start = map->end;
map_groups__insert(mg, after);
if (verbose >= 2)
map__fprintf(after, fp);

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