Fix _exit_with_stack_teardown for x86.
Change-Id: Ife8f9c538c86f7c0017143015d5ee849a99b625b
diff --git a/libc/arch-x86/bionic/_exit_with_stack_teardown.S b/libc/arch-x86/bionic/_exit_with_stack_teardown.S
index 9128f10..03a4be0 100644
--- a/libc/arch-x86/bionic/_exit_with_stack_teardown.S
+++ b/libc/arch-x86/bionic/_exit_with_stack_teardown.S
@@ -3,12 +3,13 @@
// void _exit_with_stack_teardown(void* stackBase, size_t stackSize, int status)
ENTRY(_exit_with_stack_teardown)
- // We can trash %ebx here since this call should never return.
+ // We can trash registers because this function never returns.
// We can also take advantage of the fact that the linux syscall trap
// handler saves all the registers, so we don't need a stack to keep
// the status argument for exit while doing the munmap.
mov 4(%esp), %ebx // stackBase
mov 8(%esp), %ecx // stackSize
+ mov 12(%esp), %edx // Also copy 'status' off the stack we're about to unmap.
mov $__NR_munmap, %eax
int $0x80
// If munmap failed, we ignore the failure and exit anyway.