* sysdeps/i386/stackinfo.h (stackinfo_get_sp): Define.

(stackinfo_sub_sp): Define.

ChangeLog

@@ -1,3 +1,8 @@
+2009-01-29  Ulrich Drepper  <drepper@redhat.com>
+
+	* sysdeps/i386/stackinfo.h (stackinfo_get_sp): Define.
+	(stackinfo_sub_sp): Define.
+
 2009-01-28  Ulrich Drepper  <drepper@redhat.com>
 
 	[BZ #9750]

include/alloca.h

@@ -55,8 +55,8 @@ extern int __libc_alloca_cutoff (size_t size) __attribute__ ((const));
 #else
 # define alloca_account(size, avar) \
   ({ size_t s__ = (size);		    \
-     avar += size__;			    \
-     __alloca (size__); })
+     avar += s__;			    \
+     __alloca (s__); })
 #endif
 
 #endif

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 */