linux-kernel - Re: [PATCH] Re: perf annotate segfaults when source code has goto label that looks like hex number

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

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.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/