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Subject[PATCH v3] 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.

In V3, we also fix:
- __map_groups__fixup_end()
- maps__find() as report by Namhyung

Signed-off-by: Stephane Eranian <eranian@google.com>
---
tools/perf/util/map.c | 8 ++++----
tools/perf/util/symbol.c | 2 +-
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index b709059..2137c45 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);
@@ -752,7 +752,7 @@ struct map *maps__find(struct rb_root *maps, u64 ip)
m = rb_entry(parent, struct map, rb_node);
if (ip < m->start)
p = &(*p)->rb_left;
- else if (ip > m->end)
+ else if (ip >= m->end)
p = &(*p)->rb_right;
else
return m;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index be84f7a..c787a43 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -207,7 +207,7 @@ void __map_groups__fixup_end(struct map_groups *mg, enum map_type type)
for (nd = rb_next(prevnd); nd; nd = rb_next(nd)) {
prev = curr;
curr = rb_entry(nd, struct map, rb_node);
- prev->end = curr->start - 1;
+ prev->end = curr->start;
}

/*
--
1.9.1


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