Re: [PATCH] bail out in mathemu if __copy_to_user fails

[Randy Dunlap <randy.dunlap@oracle.com>]

On Thu, 2 Nov 2006 00:03:16 +0100 Jesper Juhl wrote:

> I believe we should check the return value of 
> __copy_to_user in math-emu/fpu_entry.c and bail out of save_i387_soft() if 
> it fails.
> This patch does that.
> 
> This also kills the warning :
>   arch/i386/math-emu/fpu_entry.c:745: warning: ignoring return value of `__copy_to_user', declared with attribute warn_unused_result


http://www.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.19-rc4/2.6.19-rc4-mm1/broken-out/x86_64-mm-i386-mathemu-must-check.patch


> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
> ---
> 
> diff --git a/arch/i386/math-emu/fpu_entry.c b/arch/i386/math-emu/fpu_entry.c
> index d93f16e..ddf8fa3 100644
> --- a/arch/i386/math-emu/fpu_entry.c
> +++ b/arch/i386/math-emu/fpu_entry.c
> @@ -742,7 +742,8 @@ #ifdef PECULIAR_486
>    S387->fcs &= ~0xf8000000;
>    S387->fos |= 0xffff0000;
>  #endif /* PECULIAR_486 */
> -  __copy_to_user(d, &S387->cwd, 7*4);
> +  if (__copy_to_user(d, &S387->cwd, 7*4))
> +    return -1;
>    RE_ENTRANT_CHECK_ON;
>  
>    d += 7*4;


---
~Randy