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Message-ID: <20100722163851.GA10307@redhat.com>
Date: Thu, 22 Jul 2010 19:38:51 +0300
From: Gleb Natapov <gleb@...hat.com>
To: Arnaldo Carvalho de Melo <acme@...radead.org>
Cc: linux-kernel@...r.kernel.org, mingo@...e.hu, peterz@...radead.org,
paulus@...ba.org
Subject: Re: [PATCH] Re: perf annotate segfaults when source code has goto
label that looks like hex number
On Thu, Jul 22, 2010 at 11:33:45AM -0300, Arnaldo Carvalho de Melo wrote:
> Em Thu, Jul 22, 2010 at 10:20:44AM +0300, Gleb Natapov escreveu:
> > strtoull() returns valid number when it gets line with label and following
> > test passes too. I can't think of a way to unambiguously distinguish between
> > label and valid rip. May be running objdump with --prefix-addresses will
> > help, but it may make other thing unambiguous.
>
> [root@...lia ~]# objdump --start-address=0x0000000000400474 --stop-address=0x0000000000400496 -dS ./a.out | grep -P ':\t'
> 400474: 55 push %rbp
> 400475: 48 89 e5 mov %rsp,%rbp
> 400478: 89 7d ec mov %edi,-0x14(%rbp)
> 40047b: 48 89 75 e0 mov %rsi,-0x20(%rbp)
> 40047f: eb 01 jmp 400482 <main+0xe>
> 400481: 90 nop
> 400482: 83 45 fc 01 addl $0x1,-0x4(%rbp)
> 400486: 81 7d fc 80 96 98 00 cmpl $0x989680,-0x4(%rbp)
> 40048d: 75 f2 jne 400481 <main+0xd>
> 40048f: 90 nop
> 400490: b8 00 00 00 00 mov $0x0,%eax
> 400495: c9 leaveq
> [root@...lia ~]# objdump --start-address=0x0000000000400474
> --stop-address=0x0000000000400496 -dS ./a.out | grep ':$'
> Disassembly of section .text:
> 0000000000400474 <main>:
> add:
> [root@...lia ~]#
>
> Can you try the attached patch?
>
I can, only later. But if I underhand your patch correctly perf will
still crash if there is a comment after the label on the same line.
> With it we get:
>
>
> [root@...lia ~]# perf annotate
>
> ------------------------------------------------
> Percent | Source code & Disassembly of a.out
> ------------------------------------------------
> :
> :
> :
> : Disassembly of section .text:
> :
> : 0000000000400474 <main>:
> : int main(int argc, char **argv)
> : {
> 0.00 : 400474: 55 push %rbp
> 0.00 : 400475: 48 89 e5 mov %rsp,%rbp
> 0.00 : 400478: 89 7d ec mov %edi,-0x14(%rbp)
> 0.00 : 40047b: 48 89 75 e0 mov %rsi,-0x20(%rbp)
> 0.00 : 40047f: eb 01 jmp 400482 <main+0xe>
> :
> : while(1) {
> : i++;
> : if (i == 10000000)
> : goto add;
> : }
> 21.05 : 400481: 90 nop
> : int main(int argc, char **argv)
> : {
> : int i;
> :
> : while(1) {
> : i++;
> 0.00 : 400482: 83 45 fc 01 addl $0x1,-0x4(%rbp)
> : if (i == 10000000)
> 15.79 : 400486: 81 7d fc 80 96 98 00 cmpl $0x989680,-0x4(%rbp)
> 63.16 : 40048d: 75 f2 jne 400481 <main+0xd>
> : goto add;
> 0.00 : 40048f: 90 nop
> : }
> : add:
> : return 0;
> 0.00 : 400490: b8 00 00 00 00 mov $0x0,%eax
> : }
> 0.00 : 400495: c9 leaveq
> diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
> index 699cf81..e3486d5 100644
> --- a/tools/perf/util/hist.c
> +++ b/tools/perf/util/hist.c
> @@ -976,7 +976,7 @@ static int hist_entry__parse_objdump_line(struct hist_entry *self, FILE *file,
> * Parse hexa addresses followed by ':'
> */
> line_ip = strtoull(tmp, &tmp2, 16);
> - if (*tmp2 != ':' || tmp == tmp2)
> + if (*tmp2 != ':' || tmp == tmp2 || tmp2[1] == '\0')
> line_ip = -1;
> }
>
--
Gleb.
--
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