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perf tools: Insert split maps correctly into origin group

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When new maps are cloned out of split map they are added into origin
map's group, but their groups pointer is not updated.

This could lead to a segfault, because map->groups is expected to be
always set as reported by Markus:

  __map__is_kernel (map=map@entry=0x1abb7a0) at util/map.c:238
  238             return __machine__kernel_map(map->groups->machine, map->type) =
  (gdb) bt
  #0  __map__is_kernel (map=map@entry=0x1abb7a0) at util/map.c:238
  #1  0x00000000004393e4 in symbol_filter (map=map@entry=0x1abb7a0, sym=sym@entry
  #2  0x00000000004fcd4d in dso__load_sym (dso=dso@entry=0x166dae0, map=map@entry
  #3  0x00000000004a64e0 in dso__load (dso=0x166dae0, map=map@entry=0x1abb7a0, fi
  #4  0x00000000004b941f in map__load (filter=0x4393c0 <symbol_filter>, map=<opti
  #5  map__find_symbol (map=0x1abb7a0, addr=40188, filter=0x4393c0 <symbol_filter
  ...

Adding __map_groups__insert function to add map into groups together
with map->groups pointer update. It takes no lock as opposed to existing
map_groups__insert, as maps__fixup_overlappings(), where it is being
called, already has the necessary lock held.

Using __map_groups__insert to add new maps after map split.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20151104140811.GA32664@krava.brq.redhat.com
Fixes: cfc5acd4c80b ("perf top: Filter symbols based on __map__is_kernel(map)")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Jiri Olsa 2015-11-04 15:08:11 +01:00 committed by Arnaldo Carvalho de Melo
parent eedfcb4bc5
commit cb8382e058
1 changed files with 8 additions and 2 deletions
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10
tools/perf/util/map.c
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@ -644,6 +644,12 @@ size_t map_groups__fprintf(struct map_groups *mg, FILE *fp)
return printed; return printed;
} }
static void __map_groups__insert(struct map_groups *mg, struct map *map)
{
__maps__insert(&mg->maps[map->type], map);
map->groups = mg;
}
static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp) static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp)
{ {
struct rb_root *root; struct rb_root *root;
@ -682,7 +688,7 @@ static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp
} }
before->end = map->start; before->end = map->start;
__maps__insert(maps, before); __map_groups__insert(pos->groups, before);
if (verbose >= 2) if (verbose >= 2)
map__fprintf(before, fp); map__fprintf(before, fp);
} }
@ -696,7 +702,7 @@ static int maps__fixup_overlappings(struct maps *maps, struct map *map, FILE *fp
} }
after->start = map->end; after->start = map->end;
__maps__insert(maps, after); __map_groups__insert(pos->groups, after);
if (verbose >= 2) if (verbose >= 2)
map__fprintf(after, fp); map__fprintf(after, fp);
} }