Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932732AbbKDN07 (ORCPT ); Wed, 4 Nov 2015 08:26:59 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:53282 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932067AbbKDN06 (ORCPT ); Wed, 4 Nov 2015 08:26:58 -0500 Date: Wed, 4 Nov 2015 10:26:46 -0300 From: Arnaldo Carvalho de Melo To: Jiri Olsa Cc: Markus Trippelsdorf , Ingo Molnar , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Andrew Morton Subject: Re: perf top segfaults on current git Message-ID: <20151104132646.GF13236@kernel.org> References: <20151104101533.GA332@x4> <20151104104929.GB332@x4> <20151104122740.GH29671@krava.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151104122740.GH29671@krava.brq.redhat.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5862 Lines: 128 Em Wed, Nov 04, 2015 at 01:27:40PM +0100, Jiri Olsa escreveu: > On Wed, Nov 04, 2015 at 11:49:30AM +0100, Markus Trippelsdorf wrote: > > On 2015.11.04 at 11:15 +0100, Markus Trippelsdorf wrote: > > > On 2015.11.03 at 11:02 +0100, Ingo Molnar wrote: > > > > > > > > Please pull the latest perf-core-for-linus git tree from: > > > > > > Since the current merge "perf top" segfaults on my machine: > > > > > > Program received signal SIGSEGV, Segmentation fault. > > > > > > __map__is_kernel (map=map@entry=0x1abb7a0) at util/map.c:238 > > > 238 return __machine__kernel_map(map->groups->machine, map->type) == map; > > > (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=0x1a88560) at builtin-top.c:658 > > > #2 0x00000000004fcd4d in dso__load_sym (dso=dso@entry=0x166dae0, map=map@entry=0x1abb7a0, syms_ss=0x7fffffff7680, runtime_ss=runtime_ss@entry=0x7fffffff7680, > > > filter=filter@entry=0x4393c0 , kmodule=0) at util/symbol-elf.c:1082 > > > #3 0x00000000004a64e0 in dso__load (dso=0x166dae0, map=map@entry=0x1abb7a0, filter=filter@entry=0x4393c0 ) at util/symbol.c:1530 > > > #4 0x00000000004b941f in map__load (filter=0x4393c0 , map=) at util/map.c:289 > > > #5 map__find_symbol (map=0x1abb7a0, addr=40188, filter=0x4393c0 ) at util/map.c:333 > > > #6 0x00000000004803b1 in perf_event__preprocess_sample (event=event@entry=0x7ffff6a7a5f0, machine=machine@entry=0x164c7b8, al=al@entry=0x7fffffff8a90, > > > sample=sample@entry=0x7fffffff8b20) at util/event.c:1045 > > > #7 0x0000000000439837 in perf_event__process_sample (machine=0x164c7b8, sample=0x7fffffff8b20, evsel=0x164c320, event=0x7ffff6a7a5f0, tool=0x7fffffff8ef0) > > > at builtin-top.c:737 > > > #8 perf_top__mmap_read_idx (top=top@entry=0x7fffffff8ef0, idx=idx@entry=0) at builtin-top.c:870 > > > #9 0x000000000043b9ef in perf_top__mmap_read (top=0x7fffffff8ef0) at builtin-top.c:887 > > > #10 __cmd_top (top=0x7fffffff8ef0) at builtin-top.c:1000 > > > #11 cmd_top (argc=, argv=, prefix=) at builtin-top.c:1329 > > > #12 0x00000000004756b3 in run_builtin (p=p@entry=0x5b0608 , argc=argc@entry=2, argv=argv@entry=0x7fffffffe500) at perf.c:386 > > > #13 0x00000000004203e2 in handle_internal_command (argv=0x7fffffffe500, argc=2) at perf.c:447 > > > #14 run_argv (argv=0x7fffffffe290, argcp=0x7fffffffe29c) at perf.c:491 > > > #15 main (argc=2, argv=0x7fffffffe500) at perf.c:608 > > > > > > It only happens occasionally (~every third or fourth run). > > > > Apparently it started with: > > > > commit cfc5acd4c80b875d2f739d6a93562034aee5563f > > Author: Arnaldo Carvalho de Melo > > Date: Wed Sep 23 15:15:54 2015 -0300 > > > > perf top: Filter symbols based on __map__is_kernel(map) > > > > Instead of using dso->kernel, this is equivalent at the moment, > > and helps in reducing the accesses to dso->kernel. > > > > Cc: Adrian Hunter > > Cc: Borislav Petkov > > Cc: David Ahern > > Cc: Frederic Weisbecker > > Cc: Jiri Olsa > > Cc: Namhyung Kim > > Cc: Stephane Eranian > > Cc: Wang Nan > > Link: http://lkml.kernel.org/n/tip-1pc2v63iphtifovw3bv0bo1v@git.kernel.org > > Signed-off-by: Arnaldo Carvalho de Melo > > > > diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c > > index bdaf44f24d5d..38d4d6cac823 100644 > > --- a/tools/perf/builtin-top.c > > +++ b/tools/perf/builtin-top.c > > @@ -655,7 +655,7 @@ static int symbol_filter(struct map *map, struct symbol *sym) > > { > > const char *name = sym->name; > > > > - if (!map->dso->kernel) > > + if (!__map__is_kernel(map)) > > return 0; > > /* > > * ppc64 uses function descriptors and appends a '.' to the > > > > I think it's correct to assume map->groups != NULL, > IMO the change just uncovered another bug > > I couldn't reproduce this, but I could find one place where this > assumption is broken.. could you please try attached patch? Looks correct, thanks for the quick fix! - Arnaldo > thanks, > jirka > > > --- > diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c > index 4e38c396a897..afc6b56cf749 100644 > --- a/tools/perf/util/map.c > +++ b/tools/perf/util/map.c > @@ -644,6 +644,12 @@ size_t map_groups__fprintf(struct map_groups *mg, FILE *fp) > 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) > { > 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; > - __maps__insert(maps, before); > + __map_groups__insert(pos->groups, before); > if (verbose >= 2) > 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; > - __maps__insert(maps, after); > + __map_groups__insert(pos->groups, after); > if (verbose >= 2) > map__fprintf(after, fp); > } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/