Re: [patch] libmudflap: check for NULL path in dlopen wrapper

[Jakub Jelinek]

On Wed, Jan 16, 2013 at 04:32:25PM +0100, Matthias Klose wrote:
>       PR mudflap/24619
>       * mf-hooks2.c (dlopen wrapper): Check for NULL path.
> 
> Index: b/src/libmudflap/mf-hooks2.c
> ===================================================================
> --- a/libmudflap/mf-hooks2.c
> +++ b/libmudflap/mf-hooks2.c
> @@ -1677,8 +1677,10 @@
>    size_t n;
>    TRACE ("%s\n", __PRETTY_FUNCTION__);
>    n = strlen (path);
> -  MF_VALIDATE_EXTENT (path, CLAMPADD(n, 1), __MF_CHECK_READ, "dlopen path");
> -  p = dlopen (path, flags);
> +  if (NULL != path) {
> +    MF_VALIDATE_EXTENT (path, CLAMPADD(n, 1), __MF_CHECK_READ, "dlopen 
> path");
> +    p = dlopen (path, flags);
> +  }

That can't be the right fix, given you still do strlen (path)
unconditionally.  Thus the compiler can assume path is non-NULL.

        Jakub