Re: [PATCH v7 05/19] iov_iter: Introduce fault_in_iov_iter_writeable

From: Thomas Gleixner
Date: Sun Aug 29 2021 - 15:51:35 EST


On Sun, Aug 29 2021 at 19:46, Al Viro wrote:

> On Sun, Aug 29, 2021 at 08:44:04PM +0200, Thomas Gleixner wrote:
>> On Sat, Aug 28 2021 at 22:51, Al Viro wrote:
>> > @@ -345,7 +346,7 @@ static inline int xsave_to_user_sigframe(struct xregs_state __user *buf)
>> > */
>> > err = __clear_user(&buf->header, sizeof(buf->header));
>> > if (unlikely(err))
>> > - return -EFAULT;
>> > + return -X86_TRAP_PF;
>>
>> This clear_user can be lifted into copy_fpstate_to_sigframe(). Something
>> like the below.
>
> Hmm... This mixing of -X86_TRAP_... with -E... looks like it's asking for
> trouble in general. Might be worth making e.g. fpu__restore_sig() (and
> its callers) return bool, seeing that we only check for 0/non-zero in
> there.

Let me fix that.