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__init()
{
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 bounds were off-by-one.
Signed-off-by: Stephane Eranian <[email protected]>
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index b709059..9e2c71e 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,
@@ -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);
On Fri, Oct 03, 2014 at 12:47:07PM +0200, Stephane Eranian wrote:
>
SNIP
> Signed-off-by: Stephane Eranian <[email protected]>
>
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index b709059..9e2c71e 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,
> @@ -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);
hum, do we also need this one then?
---
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index 9e2c71e51fce..186418ba18db 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -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);
On Sun, Oct 5, 2014 at 9:23 PM, Jiri Olsa <[email protected]> wrote:
> On Fri, Oct 03, 2014 at 12:47:07PM +0200, Stephane Eranian wrote:
>>
>
> SNIP
>
>> Signed-off-by: Stephane Eranian <[email protected]>
>>
>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>> index b709059..9e2c71e 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,
>> @@ -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);
>
> hum, do we also need this one then?
>
> ---
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index 9e2c71e51fce..186418ba18db 100644
> --- a/tools/perf/util/map.c
> +++ b/tools/perf/util/map.c
> @@ -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;
Start is first byte of next range, so it is pointing to one byte after
the end of the before range.
So, yes, I think we need your fix as well. I missed it. Will repost.
> map_groups__insert(mg, before);
> if (verbose >= 2)
> map__fprintf(before, fp);
Em Fri, Oct 03, 2014 at 12:47:07PM +0200, Stephane Eranian escreveu:
>
> 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__init()
> {
> 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
I thought map->end should be the end of the range, not something after
the end, is that really the case?
I.e. the bug would be in that call to map__init, that should instead be:
map__init(map, type, start, start + len - 1, pgoff, dso);
no? Isn't that clearer, i.e. to keep the semantics of 'end'?
- Arnaldo
> fixes two bugs where upper bounds were off-by-one.
>
> Signed-off-by: Stephane Eranian <[email protected]>
>
> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
> index b709059..9e2c71e 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,
> @@ -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);
Arnaldo,
On Mon, Oct 6, 2014 at 5:18 PM, Arnaldo Carvalho de Melo
<[email protected]> wrote:
> Em Fri, Oct 03, 2014 at 12:47:07PM +0200, Stephane Eranian escreveu:
>>
>> 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__init()
>> {
>> 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
>
> I thought map->end should be the end of the range, not something after
> the end, is that really the case?
>
map->start = start;
map->end = start + len;
Thus map->end is the first byte after the end.
> I.e. the bug would be in that call to map__init, that should instead be:
>
> map__init(map, type, start, start + len - 1, pgoff, dso);
Yeah, that is the alternative. But are you sure this is the only place
where a map
is initialized. And this is not really C like.
>
> no? Isn't that clearer, i.e. to keep the semantics of 'end'?
>
Yeah, it all depends on what you meant by end: last byte or first byte after.
But then everything needs to be consistent. That is what I am trying to fix
in this patch.
> - Arnaldo
>
>> fixes two bugs where upper bounds were off-by-one.
>>
>> Signed-off-by: Stephane Eranian <[email protected]>
>>
>> diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
>> index b709059..9e2c71e 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,
>> @@ -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);