On Thu, 24 Aug 2017, Will Deacon wrote:
> On Thu, Aug 24, 2017 at 09:31:05AM +0200, Jiri Slaby wrote:
> > +static int futex_atomic_op_inuser(unsigned int encoded_op, u32 __user *uaddr)
> > +{
> > + unsigned int op = (encoded_op & 0x70000000) >> 28;
> > + unsigned int cmp = (encoded_op & 0x0f000000) >> 24;
> > + int oparg = sign_extend32((encoded_op & 0x00fff000) >> 12, 12);
> > + int cmparg = sign_extend32(encoded_op & 0x00000fff, 12);
> > + int oldval, ret;
> > +
> > + if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) {
> > + if (oparg < 0 || oparg > 31)
> > + return -EINVAL;
> > + oparg = 1 << oparg;
> > + }
> > +
> > + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
> > + return -EFAULT;
> > +
> > + ret = arch_futex_atomic_op_inuser(op, oparg, &oldval, uaddr);
> > + if (ret)
> > + return ret;
>
> We could move the pagefault_{disable,enable} calls here, and then remove
> them from the futex_atomic_op_inuser callsites elsewhere in futex.c
Correct, but we can do that after getting this in.
Thanks,
tglx
