On 17/10/2025 11:09 am, Thomas Gleixner wrote:
> @@ -86,21 +79,19 @@ static inline int futex_atomic_cmpxchg_i
> {
> int ret = 0;
>
> - if (can_do_masked_user_access())
> - uaddr = masked_user_access_begin(uaddr);
> - else if (!user_access_begin(uaddr, sizeof(u32)))
> - return -EFAULT;
> - asm volatile("\n"
> - "1:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"
> - "2:\n"
> - _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %0) \
> - : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
> - : "r" (newval), "1" (oldval)
> - : "memory"
> - );
> - user_access_end();
> - *uval = oldval;
> + scoped_masked_user_rw_access(uaddr, Efault) {
> + asm volatile("\n"
> + "1:\t" LOCK_PREFIX "cmpxchgl %3, %2\n"
> + "2:\n"
> + _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG,
> %0) \
> + : "+r" (ret), "=a" (oldval), "+m" (*uaddr)
> + : "r" (newval), "1" (oldval)
> + : "memory");
Minor points, but as you're rewriting this, it wants to be asm_inline
volatile.
There's also a useless line continuation on the end of the ASM_EXTABLE
which can be dropped.
~Andrew
