tile: make the prolog of clone() more conformant

With this change we properly set up the frame first, and tear
it down last, doing argument checking only when the frame is set up.

diff --git a/ChangeLog b/ChangeLog
index 7dd6029..0ab15a2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2014-10-02  Chris Metcalf  <cmetcalf@tilera.com>
 
+       * sysdeps/unix/sysv/linux/tile/clone.S (__clone): Fix code
+       to set up frame more cleanly.
+
        * sysdeps/tile/memcmp.c: New file.
 
        * sysdeps/unix/sysv/linux/tile/sysconf.c: New file.

diff --git a/sysdeps/unix/sysv/linux/tile/clone.S b/sysdeps/unix/sysv/linux/tile/clone.S
index f48dba5..0e109f8 100644 (file)
--- a/sysdeps/unix/sysv/linux/tile/clone.S
+++ b/sysdeps/unix/sysv/linux/tile/clone.S
@@ -41,10 +41,6 @@
 
        .text
 ENTRY (__clone)
-       /* sanity check arguments */
-       BEQZ r0, .Linvalid
-       BEQZ r1, .Linvalid
-
        /* Create a stack frame so we can pass callee-saves to new task. */
        {
         move r10, sp
@@ -71,6 +67,10 @@ ENTRY (__clone)
        ST r11, r32
        cfi_offset (r32, FRAME_R32 - FRAME_SIZE)
 
+       /* sanity check arguments */
+       BEQZ r0, .Linvalid
+       BEQZ r1, .Linvalid
+
        /* Make sure child stack is properly aligned, and set up the
           top frame so that we can call out of it immediately in the
           child.  Setting it up here means we fault in the parent if
@@ -120,6 +120,7 @@ ENTRY (__clone)
        swint1
        BEQZ r0, .Lthread_start  /* If in child task.  */
 
+.Ldone:
        /* Restore the callee-saved registers and return. */
        ADDLI_PTR lr, sp, FRAME_SIZE
        {
@@ -149,7 +150,7 @@ ENTRY (__clone)
 .Linvalid:
        {
         movei r1, EINVAL
-        j SYSCALL_ERROR_NAME
+        j .Ldone
        }
 
 /* This function expects to receive: