[PATCH] fs/compat.c: fix 'if (a |= b )' typo

[PATCH] fs/compat.c: fix 'if (a |= b )' typo

[Alexey Dobriyan]

Mentioned by Mark Armbrust somewhere on Usenet.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1913,7 +1913,7 @@ asmlinkage long compat_sys_ppoll(struct
 	}
 
 	if (sigmask) {
-		if (sigsetsize |= sizeof(compat_sigset_t))
+		if (sigsetsize != sizeof(compat_sigset_t))
 			return -EINVAL;
 		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
 			return -EFAULT;

Re: [PATCH] fs/compat.c: fix 'if (a |= b )' typo

[Andrew Morton]

Alexey Dobriyan <adobriyan@gmail.com> wrote:
>
> Mentioned by Mark Armbrust somewhere on Usenet.
> 
> Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
> ---
> 
> --- a/fs/compat.c
> +++ b/fs/compat.c
> @@ -1913,7 +1913,7 @@ asmlinkage long compat_sys_ppoll(struct
>  	}
>  
>  	if (sigmask) {
> -		if (sigsetsize |= sizeof(compat_sigset_t))
> +		if (sigsetsize != sizeof(compat_sigset_t))
>  			return -EINVAL;
>  		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
>  			return -EFAULT;

Oh wow.  I can only assume that this code leg hasn't been exercised at all.

(I'm a bit surprised that the compiler doesn't warn and demand another set
of parentheses, actually.  I guess they decided not to do that for some
reason).

I'll tag this for a 2.6.16 backport, but I'm worried that what we have here
is a pretty significant codepath which just hasn't been executed.