From 3d906ef10a539ff336010afab8f6f9c4fe379695 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 23 Jun 2009 11:23:07 +0200 Subject: [PATCH] perf_counter tools: Handle overlapping MMAP events Martin Schwidefsky reported "perf report" symbol resolution problems on S390. Since we only report MMAP, not MUNMAP, we have to deal with overlapping maps. We used to simply throw out the old map on the assumption whole maps got unmapped. This obviously doesn't deal with partial unmaps. However it appears some dynamic linkers do fancy partial unmaps (s390), so do something more elaborate and truncate the old maps, only removing them when they've been fully covered. This resolves (part of) the S390 symbol resolution problems. Reported-by: Martin Schwidefsky Tested-by: Martin Schwidefsky Signed-off-by: Peter Zijlstra Cc: Mike Galbraith Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo LKML-Reference: Signed-off-by: Ingo Molnar --- tools/perf/builtin-report.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c index ec230a0..b4e76f7 100644 --- a/tools/perf/builtin-report.c +++ b/tools/perf/builtin-report.c @@ -400,9 +400,27 @@ static void thread__insert_map(struct thread *self, struct map *map) list_for_each_entry_safe(pos, tmp, &self->maps, node) { if (map__overlap(pos, map)) { - list_del_init(&pos->node); - /* XXX leaks dsos */ - free(pos); + if (verbose >= 2) { + printf("overlapping maps:\n"); + map__fprintf(map, stdout); + map__fprintf(pos, stdout); + } + + if (map->start <= pos->start && map->end > pos->start) + pos->start = map->end; + + if (map->end >= pos->end && map->start < pos->end) + pos->end = map->start; + + if (verbose >= 2) { + printf("after collision:\n"); + map__fprintf(pos, stdout); + } + + if (pos->start >= pos->end) { + list_del_init(&pos->node); + free(pos); + } } } -- 1.8.2.3