[PATCH] m68k: fix sigreturn decoding

[Dmitry V. Levin]

On Wed, Mar 11, 2015 at 03:10:34PM +0100, Andreas Schwab wrote:
> * sigreturn.c (sys_sigreturn) [M68K]: Fetch the words of the
> signal mask from the proper place.
> ---
>  sigreturn.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/sigreturn.c b/sigreturn.c
> index 648bd0a..a96257f 100644
> --- a/sigreturn.c
> +++ b/sigreturn.c
> @@ -128,8 +128,20 @@ sys_sigreturn(struct tcb *tcp)
>  		long addr;
>  		if (upeek(tcp->pid, 4*PT_USP, &addr) < 0)
>  			return 0;
> +		/* Fetch pointer to struct sigcontext.  */
> +		if (umove(tcp, addr + 2 * sizeof(int), &addr) < 0)
> +			return 0;
> +		unsigned long mask[NSIG / 8 / sizeof(long)];
> +		/* Fetch first word of signal mask.  */
> +		if (umove(tcp, addr, &mask[0]) < 0)
> +			return 0;
> +		/* Fetch remaining words of signal mask, located
> +		   immediately before.  */
> +		addr -= sizeof (mask) - sizeof(long);
> +		if (umoven(tcp, addr, sizeof (mask) - sizeof(long), (char *) &mask[1]) < 0)
> +			return 0;

You might want to save a syscall here by fetching the whole sizeof(mask)
in a single umoven call.


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