[PATCH] fix bz #16169 - CFI directives missing from AArch64 clone.S

[Marcus Shawcroft]

Hi

On 16 January 2014 20:31, Tom Tromey <tromey@redhat.com> wrote:

>        svc     0x0
> +       cfi_endproc

The cfi_endproc placement looks sensible to me.

> +       cfi_startproc
> +       cfi_undefined lr

The cfi_undefined is missing () and the convenience name 'lr' is not
known to GAS, therefore this line should be:

  cfi_undefined (x30)

In the ticket Tom points out that the implementation does not honour
the AAPCS, the fix is to insert:

   mov x29, 0

>  #ifdef RESET_PID
>         tbnz    x5, #CLONE_THREAD_BIT, 3f
>         mov     x0, #-1
> @@ -93,7 +96,9 @@ ENTRY(__clone)
>
>         /* We are done, pass the return value through x0.  */
>         b       HIDDEN_JUMPTARGET(_exit)
> +       cfi_endproc
>
> +       cfi_startproc

This part looks fine.

Attached is a revised version of your patch including the two changes
listed above. If there are no further comments in the next 24hrs or so
I'll commit this and address Joseph's comment w.r.t ChangeLog and
NEWS.

Cheers
/Marcus
-------------- next part --------------
diff --git a/ports/sysdeps/unix/sysv/linux/aarch64/clone.S b/ports/sysdeps/unix/sysv/linux/aarch64/clone.S
index 2ca8021..f2964f4 100644
--- a/ports/sysdeps/unix/sysv/linux/aarch64/clone.S
+++ b/ports/sysdeps/unix/sysv/linux/aarch64/clone.S
@@ -63,6 +63,7 @@ ENTRY(__clone)
 	mov	x8, #SYS_ify(clone)
 	/* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid.  */
 	svc	0x0
+	cfi_endproc
 	cmp	x0, #0
 	beq	2f
 	blt	3f
@@ -72,6 +73,9 @@ ENTRY(__clone)
 	b	syscall_error
 
 2:
+	cfi_startproc
+	cfi_undefined (x30)
+	mov	x29, 0
 #ifdef RESET_PID
 	tbnz	x5, #CLONE_THREAD_BIT, 3f
 	mov	x0, #-1
@@ -93,7 +97,8 @@ ENTRY(__clone)
 
 	/* We are done, pass the return value through x0.  */
 	b	HIDDEN_JUMPTARGET(_exit)
-
+	cfi_endproc
+	cfi_startproc
 PSEUDO_END (__clone)
 
 weak_alias (__clone, clone)