[PATCH v5 07/22] powerpc: Fix Race conditions in pthread cancellation [BZ#12683]

[Paul E Murphy]

On 4/10/23 2:58 PM, Adhemerval Zanella via Libc-alpha wrote:
> By adding the required syscall_cancel.S.
> 
> Checked on powerpc64le-linux-gnu, powerpc64-linux-gnu and
> powerpc-linux-gnu.
> ---
Thanks. A couple trivial comments, but otherwise LGTM.

Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>

> +ENTRY (__syscall_cancel_arch)
> +
> +	.globl __syscall_cancel_arch_start
> +__syscall_cancel_arch_start:
> +
> +	/* if (*cancelhandling & CANCELED_BITMASK)
> +	     __syscall_do_cancel()  */
> +	lwz     r0,0(r3)
> +	andi.   r0,r0,TCB_CANCELED_BITMASK
> +	bne-    1f
Really trivial opinion nit, the branch hint should be removed.

> +
> +	/* Issue a 6 argument syscall, the nr [r4] being the syscall
> +	   number.  */
> +	mr      r0,r4
> +	mr      r3,r5
> +	mr      r4,r6
> +	mr      r5,r7
> +	mr      r6,r8
> +	mr      r7,r9
> +	mr      r8,r10
> +	sc
For consistency with the other syscall usage, can this also use the 
appropriate wrappers for using scv?

> +
> +	.globl __syscall_cancel_arch_end
> +__syscall_cancel_arch_end:
> +
> +	bnslr+
> +	neg	r3,r3
> +	blr
> +
> +	/* Although the __syscall_do_cancel do not return, we need to stack
> +	   being set correctly for unwind.  */
> +1:
> +	TAIL_CALL_NO_RETURN (__syscall_do_cancel