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@@ -47,13 +47,13 @@
 /*
  * The original i386 ABI said that the stack pointer need be only 4-byte
  * aligned before a function call (STACK_ALIGN == 4).  The ABI supplement
  * version 1.0 changed the required alignment to 16-byte for the benefit of
  * floating point code compiled using sse2.  The compiler assumes this
- * alignment and maintains it for calls made from that function.  If the
- * stack is initially properly aligned, it will continue to be so aligned.
- * If it is not initially so aligned, it will never become so aligned.
+ * alignment and maintains it for calls it generates.  If the stack is
+ * initially properly aligned, it will continue to be so aligned.  If it is
+ * not initially so aligned, it will never become so aligned.
  *
  * One slightly confusing detail to keep in mind is that the 16-byte
  * alignment (%esp & 0xf == 0) is true just *before* the call instruction.
  * The call instruction will then push a return value, decrementing %esp by
  * 4.  Therefore, if one dumps %esp at the at the very first instruction in

@@ -85,23 +85,28 @@
         size = sizeof (long) * (argc + 1);
 
         tsp = (long *)(((uintptr_t)ucp->uc_stack.ss_sp +
             ucp->uc_stack.ss_size - size) & ~(STACK_ALIGN - 1));
 
+        /*
+         * Since we're emulating the call instruction, we must push the
+         * return address (which involves adjusting the stack pointer to
+         * have the proper 4-byte bias).
+         */
         sp = tsp - 1;
 
-        va_start(ap, argc);
-
-        while (argc-- > 0) {
-                *tsp++ = va_arg(ap, long);
-        }
-
-        va_end(ap);
-
         *sp = (long)resumecontext;              /* return address */
 
         ucp->uc_mcontext.gregs[UESP] = (greg_t)sp;
+
+        /*
+         * "push" all the arguments
+         */
+        va_start(ap, argc);
+        while (argc-- > 0)
+                *tsp++ = va_arg(ap, long);
+        va_end(ap);
 }
 
 
 static void
 resumecontext(void)