[PATCH] ARC: align child stack in clone

[Pavel.Kozlov at synopsys.com]

From: Pavel Kozlov <pavel.kozlov at synopsys.com>

The ARCv2 ABI requires 4 byte stack pointer alignment. Don't allow to
use unaligned child stack in clone. As the stack grows down,
align it down.

This was pointed by misc/tst-misalign-clone-internal and
misc/tst-misalign-clone tests. Stack alignmet fixes these tests
fails.
---
 sysdeps/unix/sysv/linux/arc/clone.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sysdeps/unix/sysv/linux/arc/clone.S b/sysdeps/unix/sysv/linux/arc/clone.S
index bd924890844a..f32c83f17a65 100644
--- a/sysdeps/unix/sysv/linux/arc/clone.S
+++ b/sysdeps/unix/sysv/linux/arc/clone.S
@@ -41,6 +41,7 @@
 
 ENTRY (__clone)
 	cmp	r0, 0		/* @fn can't be NULL.  */
+	and	r1,r1,-4	/* @child_stack be 4 bytes aligned per ABI.  */
 	cmp.ne	r1, 0		/* @child_stack can't be NULL.  */
 	bz	L (__sys_err)
 
-- 
2.25.1