This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH] Fix PR56990


On Mon, Apr 22, 2013 at 06:11:26PM +0200, Marek Polacek wrote:
> We're getting SIGFPE, because one simply does not divide by zero.
> Fixed by doing the modulo only when size != 0.
> 
> Regtested/bootstrapped on x86_64-linux, ok for trunk and 4.8?
> 
> 2013-04-22  Marek Polacek  <polacek@redhat.com>
> 
> 	PR sanitizer/56990
> 	* tsan.c (instrument_expr): Don't count modulo if the size
> 	is zero.
> 
> 	* gcc.dg/pr56990.c: New test.
> 
> --- gcc/tsan.c.mp	2013-04-19 15:39:46.416450528 +0200
> +++ gcc/tsan.c	2013-04-22 17:23:54.115647673 +0200
> @@ -131,7 +131,8 @@ instrument_expr (gimple_stmt_iterator gs
>    if (TREE_READONLY (base))
>      return false;
>  
> -  if (bitpos % (size * BITS_PER_UNIT)
> +  if ((size != 0

IMHO for size == 0 we should return false too, there is no store or read to
be instrumented.  So
    if (size == 0
	|| bitpos % (size * BITS_PER_UNIT)
	|| bitsize != size * BITS_PER_UNIT)
      return false;
?


	Jakub


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]