Add sigstack handling to Linux ____longjmp_chk on i386.

All other i386 ports need to provide their own versions.

1 files changed, 143 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
new file mode 100644
index 0000000000..02c401c236
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/i386/____longjmp_chk.S
@@ -0,0 +1,143 @@
+/* Copyright (C) 2001,2004,2005,2006,2009 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
+   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 Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <jmpbuf-offsets.h>
+#include <asm-syntax.h>
+
+
+	.section .rodata.str1.1,"aMS",@progbits,1
+	.type	longjmp_msg,@object
+longjmp_msg:
+	.string "longjmp causes uninitialized stack frame"
+	.size	longjmp_msg, .-longjmp_msg
+
+
+#ifdef PIC
+# define CALL_FAIL	movl	%ebx, %ecx;				      \
+			cfi_register(%ebx,%ecx);			      \
+			LOAD_PIC_REG (bx);				      \
+			leal	longjmp_msg@GOTOFF(%ebx), %eax;		      \
+			call	__GI___fortify_fail@PLT
+#else
+# define CALL_FAIL	movl	$longjmp_msg, %eax;			      \
+			call	__fortify_fail
+#endif
+
+#define CHECK_ESP(reg) \
+	cmpl	reg, %esp;						      \
+	jbe	.Lok;							      \
+	CALL_FAIL;							      \
+.Lok:
+
+
+	.text
+ENTRY (____longjmp_chk)
+	movl	4(%esp), %ecx	/* User's jmp_buf in %ecx.  */
+
+	/* Save the return address now.  */
+	movl	(JB_PC*4)(%ecx), %edx
+	/* Get the stack pointer.  */
+	movl	(JB_SP*4)(%ecx), %edi
+	cfi_undefined(%edi)
+	PTR_DEMANGLE (%edx)
+	PTR_DEMANGLE (%edi)
+
+	pushl	$0
+	cfi_adjust_cfa_offset(4)
+	cmpl	%edi, %esp
+	jbe	.Lok
+
+	subl	$12, %esp
+	cfi_adjust_cfa_offset(12)
+	xorl	%ebx, %ebx
+	movl	%esp, %ecx
+	movl	$__NR_sigaltstack, %eax
+	ENTER_KERNEL
+	movl	4(%esp), %ebx
+	addl	$12, %esp
+	cfi_adjust_cfa_offset(-12)
+	movl	8(%esp), %ecx
+	testl	%eax, %eax
+	jne	.Lok
+	andl	$1, %ebx
+	movl	%ebx, (%esp)
+.Lok:
+	cfi_def_cfa(%ecx, 0)
+	cfi_register(%eip, %edx)
+	cfi_register(%esp, %edi)
+	cfi_offset(%ebx, JB_BX*4)
+	cfi_offset(%esi, JB_SI*4)
+	cfi_offset(%edi, JB_DI*4)
+	cfi_offset(%ebp, JB_BP*4)
+
+	movl	12(%esp), %eax	/* Second argument is return value.  */
+	xchgl	%edi, %esp
+	cfi_restore(%edi)
+
+	cmpl	%esp, %edi
+	jnbe	.Lcheck
+
+     	/* Restore registers.  */
+.Lout:	movl	(JB_BX*4)(%ecx), %ebx
+	movl	(JB_SI*4)(%ecx), %esi
+	movl	(JB_DI*4)(%ecx), %edi
+	movl	(JB_BP*4)(%ecx), %ebp
+	cfi_restore(%ebx)
+	cfi_restore(%esi)
+	cfi_restore(%edi)
+	cfi_restore(%ebp)
+
+	/* Jump to saved PC.  */
+     	jmp	*%edx
+
+	cfi_def_cfa(%ecx, 0)
+	cfi_register(%eip, %edx)
+	cfi_offset(%ebx, JB_BX*4)
+	cfi_offset(%esi, JB_SI*4)
+	cfi_offset(%edi, JB_DI*4)
+	cfi_offset(%ebp, JB_BP*4)
+
+.Lcheck:
+	cmpl	$0, (%edi)
+	je	.Lfail
+
+	subl	$12, %esp
+	cfi_adjust_cfa_offset(12)
+	xorl	%ebx, %ebx
+	movl	%esp, %ecx
+	movl	$__NR_sigaltstack, %eax
+	ENTER_KERNEL
+	testl	$1, 4(%esp)
+	leal	12(%esp), %esp
+	movl	8(%edi), %ecx
+	movl	12(%edi), %eax
+	cfi_adjust_cfa_offset(-12)
+	je	.Lout
+
+.Lfail:	xchgl	%edi, %esp
+	cfi_def_cfa(%esp, 8)
+	cfi_restore(%esp)
+	cfi_restore(%ebx)
+	cfi_restore(%esi)
+	cfi_undefined(%edi)
+	cfi_restore(%ebp)
+
+	CALL_FAIL
+	hlt
+END (____longjmp_chk)