Re: [PATCH] perf top: fix crash on annotate request

From: David Ahern
Date: Wed Oct 19 2011 - 14:45:01 EST




On 10/19/2011 12:38 PM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Oct 19, 2011 at 12:23:18PM -0600, David Ahern escreveu:
>> Hitting an annotate case where src is not set and
>> perf-top crashes.
>
> How did you got there?

One stack trace:
#0 0x0000000000434ba8 in list_add_tail (new=0x7fffec000c30, head=0x0)
at util/include/../../../../include/linux/list.h:76
#1 0x00000000004351a5 in objdump__add_line (head=0x0,
line=0x7fffec000c30) at util/annotate.c:101
#2 0x000000000043584f in symbol__parse_objdump_line (sym=0xf505f0,
map=0x98de00, file=0x7fffec000aa0,
privsize=40) at util/annotate.c:256
#3 0x0000000000435d45 in symbol__annotate (sym=0xf505f0, map=0x98de00,
privsize=40) at util/annotate.c:346
#4 0x00000000004829a0 in symbol__tui_annotate (sym=0xf505f0,
map=0x98de00, evidx=0, nr_events=1,
timer=0x426f9e <perf_top__sort_new_samples>, arg=0x77a300,
delay_secs=2) at util/ui/browsers/annotate.c:405
#5 0x0000000000482867 in hist_entry__tui_annotate (he=0x991ca0,
evidx=0, nr_events=1,
timer=0x426f9e <perf_top__sort_new_samples>, arg=0x77a300,
delay_secs=2) at util/ui/browsers/annotate.c:373
#6 0x0000000000485684 in perf_evsel__hists_browse (evsel=0x910710,
nr_events=1,
helpline=0x5201e8 "For a higher level overview, try: perf top --sort
comm,dso", ev_name=0x910990 "cycles",
left_exits=false, timer=0x426f9e <perf_top__sort_new_samples>,
arg=0x77a300, delay_secs=2)
at util/ui/browsers/hists.c:991
...


I was starting perf top, selecting a symbol and pressing 'a'. In the
crash case it was the perf command itself.

David


> Navigating thru callq? I wonder if in this case
> we'd instead shouldn't call
>
> symbol__alloc_hist(sym, evlist->nr_entries)
>
> And proceed, only complaining on ENOMEM, like we do in parse_source in
> builtin-top.c.
>
> I.e. if the user asked to go to a function without hits, no problem,
> allocate the data structures needed for doing the annotation and show 0
> hits on all lines.
>
> - Arnaldo
>
>> Signed-off-by: David Ahern <dsahern@xxxxxxxxx>
>> ---
>> tools/perf/util/annotate.c | 3 +++
>> tools/perf/util/ui/browsers/annotate.c | 2 ++
>> 2 files changed, 5 insertions(+), 0 deletions(-)
>>
>> diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
>> index bc8f477..26652b1 100644
>> --- a/tools/perf/util/annotate.c
>> +++ b/tools/perf/util/annotate.c
>> @@ -205,6 +205,9 @@ static int symbol__parse_objdump_line(struct symbol *sym, struct map *map,
>> size_t line_len;
>> s64 line_ip, offset = -1;
>>
>> + if (!notes->src)
>> + return -1;
>> +
>> if (getline(&line, &line_len, file) < 0)
>> return -1;
>>
>> diff --git a/tools/perf/util/ui/browsers/annotate.c b/tools/perf/util/ui/browsers/annotate.c
>> index a2c351c..5a67ead 100644
>> --- a/tools/perf/util/ui/browsers/annotate.c
>> +++ b/tools/perf/util/ui/browsers/annotate.c
>> @@ -410,6 +410,8 @@ int symbol__tui_annotate(struct symbol *sym, struct map *map, int evidx,
>> ui_helpline__push("Press <- or ESC to exit");
>>
>> notes = symbol__annotation(sym);
>> + if (!notes->src)
>> + return -1;
>>
>> list_for_each_entry(pos, &notes->src->source, node) {
>> struct objdump_line_rb_node *rbpos;
>> --
>> 1.7.6.4
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