Messages in this thread Patch in this message | | | From | Konstantin Khlebnikov <> | Date | Sat, 14 Dec 2019 14:16:21 +0300 | Subject | Re: [PATCH] perf map: fix infinite loop on map_groups__fixup_overlappings |
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On Wed, Dec 11, 2019 at 7:10 PM Matheus Marchini <mmarchini@netflix.com> wrote: >t > In some cases, when using perf inject and there are JIT_CODE_MOVE > records in the jitdump file, perf will end up in an infinite loop on > map_groups__fixup_overlappings, which will keep allocating memory > indefinitely. This issue was observed on Node.js (with changes to > generate JIT_CODE_MOVE records) and on Java.
Could you show what it prints with -vv ? I suppose map tree could be broken, like there is zero (or negative) size maps.
This should help to catch that
--- a/tools/perf/util/map.c +++ b/tools/perf/util/map.c @@ -848,13 +848,18 @@ static void __maps__insert(struct maps *maps, struct map *map) const u64 ip = map->start; struct map *m;
+ assert((map->start < map->end) || !map->end); + while (*p != NULL) { parent = *p; m = rb_entry(parent, struct map, rb_node); - if (ip < m->start) + if (ip < m->start) { + assert(map->end <= m->start); p = &(*p)->rb_left; - else + } else { + assert(m->end <= map->start); p = &(*p)->rb_right; + } }
rb_link_node(&map->rb_node, parent, p);
> > This issue started to occur after 6a9405b56c274 (perf map: > Optimize maps__fixup_overlappings()). To prevent it from happening, > partially revert those changes without losing the optimizations > introduced in it. > > Signed-off-by: Matheus Marchini <mmarchini@netflix.com> > --- > tools/perf/util/map.c | 17 +++++++++++++++++ > tools/perf/util/map.h | 1 + > 2 files changed, 18 insertions(+) > > diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c > index 744bfbaf35cf..8918fdb8ddab 100644 > --- a/tools/perf/util/map.c > +++ b/tools/perf/util/map.c > @@ -781,6 +781,21 @@ static void __map_groups__insert(struct map_groups *mg, struct map *map) > __maps__insert(&mg->maps, map); > } > > +int map__overlap(struct map *l, struct map *r) > +{ > + if (l->start > r->start) { > + struct map *t = l; > + > + l = r; > + r = t; > + } > + > + if (l->end > r->start) > + return 1; > + > + return 0; > +} > + > int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map, FILE *fp) > { > struct maps *maps = &mg->maps; > @@ -821,6 +836,8 @@ int map_groups__fixup_overlappings(struct map_groups *mg, struct map *map, FILE > */ > if (pos->start >= map->end) > break; > + if (!map__overlap(map, pos)) > + continue; > > if (verbose >= 2) { > > diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h > index 5e8899883231..1383571437aa 100644 > --- a/tools/perf/util/map.h > +++ b/tools/perf/util/map.h > @@ -132,6 +132,7 @@ static inline void __map__zput(struct map **map) > > #define map__zput(map) __map__zput(&map) > > +int map__overlap(struct map *l, struct map *r); > size_t map__fprintf(struct map *map, FILE *fp); > size_t map__fprintf_dsoname(struct map *map, FILE *fp); > char *map__srcline(struct map *map, u64 addr, struct symbol *sym); > -- > 2.17.1 >
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