____longjmp_chk for ARM

["Joseph S. Myers" <joseph at codesourcery dot com>]

All targets now need to provide a function ____longjmp_chk (without which 
glibc will fail to build); this is used for _FORTIFY_SOURCE checking for 
attempts to longjmp into a stack frame from which the program has 
returned, by comparing the current and saved stack pointers.  I've applied 
this patch to add an ARM version.

diff --git a/ChangeLog.arm b/ChangeLog.arm
index 420c153..1088fc0 100644
--- a/ChangeLog.arm
+++ b/ChangeLog.arm
@@ -1,5 +1,11 @@
 2009-05-16  Joseph Myers  <joseph@codesourcery.com>
 
+	* sysdeps/arm/____longjmp_chk.S: New file.
+	* sysdeps/arm/__longjmp.S: If CHECK_SP is defined, use it.
+	* sysdeps/arm/eabi/__longjmp.S: Likewise.
+
+2009-05-16  Joseph Myers  <joseph@codesourcery.com>
+
 	* sysdeps/unix/sysv/linux/arm/kernel-features.h (__ASSUME_PREADV,
 	__ASSUME_PWRITEV): Don't undefine.
 
diff --git a/sysdeps/arm/____longjmp_chk.S b/sysdeps/arm/____longjmp_chk.S
new file mode 100644
index 0000000..9b65c36
--- /dev/null
+++ b/sysdeps/arm/____longjmp_chk.S
@@ -0,0 +1,55 @@
+/* Copyright (C) 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
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING.  If not, write to the Free
+   Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+   02110-1301, USA.  */
+
+
+	.section .rodata.str1.1,"aMS",%progbits,1
+	.type	longjmp_msg,%object
+longjmp_msg:
+	.string "longjmp causes uninitialized stack frame"
+	.size	longjmp_msg, .-longjmp_msg
+	.text
+
+#define __longjmp ____longjmp_chk
+
+#ifdef PIC
+# define CALL_FAIL						\
+	ldr	sl, .L_GOT;					\
+.L_GOT_OFF:							\
+	add	sl, pc, sl;					\
+	ldr	r0, .Lstr;					\
+	add	r0, sl, r0;					\
+	B	PLTJMP(HIDDEN_JUMPTARGET(__fortify_fail));	\
+.L_GOT:								\
+	.word	_GLOBAL_OFFSET_TABLE_-(.L_GOT_OFF+8);		\
+.Lstr:								\
+	.word	longjmp_msg(GOTOFF);
+#else
+# define CALL_FAIL					\
+	ldr	r0, .Lstr;				\
+	B	HIDDEN_JUMPTARGET(__fortify_fail);	\
+.Lstr:							\
+	.word	longjmp_msg;
+#endif
+
+#define CHECK_SP(reg)				\
+	cmp	sp, reg;				\
+	ble	.Lok;				\
+	CALL_FAIL				\
+.Lok:
+
+#include <__longjmp.S>
diff --git a/sysdeps/arm/__longjmp.S b/sysdeps/arm/__longjmp.S
index 7b30160..c834e78 100644
--- a/sysdeps/arm/__longjmp.S
+++ b/sysdeps/arm/__longjmp.S
@@ -1,5 +1,5 @@
 /* longjmp for ARM.
-   Copyright (C) 1997, 1998 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 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
@@ -29,5 +29,9 @@ ENTRY (__longjmp)
 	movs	r0, r1		/* get the return value in place */
 	moveq	r0, #1		/* can't let setjmp() return zero! */
 
+#ifdef CHECK_SP
+	ldr	r1, [ip, #32]
+	CHECK_SP (r1)
+#endif
 	LOADREGS(ia, ip, {v1-v6, sl, fp, sp, pc})
 END (__longjmp)
diff --git a/sysdeps/arm/eabi/__longjmp.S b/sysdeps/arm/eabi/__longjmp.S
index fff25cd..1f3f791 100644
--- a/sysdeps/arm/eabi/__longjmp.S
+++ b/sysdeps/arm/eabi/__longjmp.S
@@ -1,5 +1,5 @@
 /* longjmp for ARM.
-   Copyright (C) 1997, 1998, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1998, 2005, 2006, 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
@@ -30,6 +30,10 @@ ENTRY (__longjmp)
 	movs	r0, r1		/* get the return value in place */
 	moveq	r0, #1		/* can't let setjmp() return zero! */
 
+#ifdef CHECK_SP
+	ldr	r1, [ip, #32]
+	CHECK_SP (r1)
+#endif
 	LOADREGS(ia, ip!, {v1-v6, sl, fp, sp, lr})
 
 #ifdef IS_IN_rtld

-- 
Joseph S. Myers
joseph@codesourcery.com