about summary refs log tree commit diff
path: root/sysdeps/i386/stackinfo.h
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/i386/stackinfo.h')
-rw-r--r--sysdeps/i386/stackinfo.h12
1 files changed, 11 insertions, 1 deletions
diff --git a/sysdeps/i386/stackinfo.h b/sysdeps/i386/stackinfo.h
index a9a6745aaf..2530ea7234 100644
--- a/sysdeps/i386/stackinfo.h
+++ b/sysdeps/i386/stackinfo.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2009 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -25,4 +25,14 @@
 /* On x86 the stack grows down.  */
 #define _STACK_GROWS_DOWN	1
 
+/* Access to the stack pointer.  The macros are used in alloca_account
+   for which they need to act as barriers as well, hence the additional
+   (unnecessary) parameters.  */
+#define stackinfo_get_sp() \
+  ({ void *p__; asm volatile ("mov %%esp, %0" : "=r" (p__)); p__; })
+#define stackinfo_sub_sp(ptr) \
+  ({ ptrdiff_t d__;                                             \
+     asm volatile ("sub %%esp, %0" : "=r" (d__) : "0" (ptr));   \
+     d__; })
+
 #endif	/* stackinfo.h */