Re: [PATCH] sched: Fix sched_getaffinity

[KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>]

> 
> taskset on 2.6.34-rc3 fails on one of my ppc64 test boxes with the following
> error:
> 
> sched_getaffinity(0, 16, 0x10029650030) = -1 EINVAL (Invalid argument)
> 
> This box has 128 threads and 16 bytes is enough to cover it. Commit
> cd3d8031eb4311e516329aee03c79a08333141f1 (sched: sched_getaffinity(): Allow
> less than NR_CPUS length) is comparing this 16 bytes agains nr_cpu_ids.
> 
> Fix it by comparing nr_cpu_ids to the number of bits in the cpumask we pass in.
> 
> Signed-off-by: Anton Blanchard <anton@samba.org>

Oops, yes yes, thanks to correct my moron ;-) 
I'll stop all todays job and will get sleeping soon.
	Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>


> ---
> 
> diff --git a/kernel/sched.c b/kernel/sched.c
> index 49d2fa7..0c1ec87 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -4902,7 +4902,7 @@ SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len,
>  	int ret;
>  	cpumask_var_t mask;
>  
> -	if (len < nr_cpu_ids)
> +	if ((len * BITS_PER_BYTE) < nr_cpu_ids)
>  		return -EINVAL;
>  	if (len & (sizeof(unsigned long)-1))
>  		return -EINVAL;
> --
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