lkml.org 
[lkml]   [2014]   [Oct]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v2] 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>
---
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);
--
1.9.1


\
 
 \ /
  Last update: 2014-10-06 11:01    [W:0.099 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site