Hurd: ____longjmp_chk

4 files changed, 128 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 976aa1e92d..9aa8753a48 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2012-05-10  Thomas Schwinge  <thomas@schwinge.name>
+
+	* sysdeps/mach/hurd/i386/____longjmp_chk.S: New file.
+	* sysdeps/mach/hurd/i386/signal-defines.sym: New file.
+	* sysdeps/mach/hurd/i386/Makefile (gen-as-const-headers): Add
+	signal-defines.sym.
+
 2012-05-10  Samuel Thibault  <samuel.thibault@ens-lyon.org>
 
         * bits/in.h (SOL_IP, SOL_IPV6, SOL_ICMPV6): New macros.
diff --git a/sysdeps/mach/hurd/i386/Makefile b/sysdeps/mach/hurd/i386/Makefile
index 0eef17e8f2..5f988097c2 100644
--- a/sysdeps/mach/hurd/i386/Makefile
+++ b/sysdeps/mach/hurd/i386/Makefile
@@ -2,3 +2,7 @@ ifeq ($(subdir),misc)
 sysdep_routines += ioperm
 sysdep_headers += sys/io.h
 endif
+
+ifeq ($(subdir),debug)
+gen-as-const-headers += signal-defines.sym
+endif
diff --git a/sysdeps/mach/hurd/i386/____longjmp_chk.S b/sysdeps/mach/hurd/i386/____longjmp_chk.S
new file mode 100644
index 0000000000..f499fbd1e7
--- /dev/null
+++ b/sysdeps/mach/hurd/i386/____longjmp_chk.S
@@ -0,0 +1,107 @@
+/* Copyright (C) 2001-2012 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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+#include <jmpbuf-offsets.h>
+#include <asm-syntax.h>
+
+#include <signal-defines.h>
+/* #include <signal.h> */
+#define SS_ONSTACK 1
+
+
+	.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; /* TODO: what's this mov good for? */ \
+			cfi_register(%ebx,%ecx);			      \
+			LOAD_PIC_REG (bx);				      \
+			leal	longjmp_msg@GOTOFF(%ebx), %eax;		      \
+			call	HIDDEN_JUMPTARGET(__fortify_fail)
+#else
+# define CALL_FAIL	movl	$longjmp_msg, %eax;			      \
+			call	HIDDEN_JUMPTARGET(__fortify_fail)
+#endif
+
+
+	.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)
+
+	cmpl	%edi, %esp
+	/* Jumping to a higher-address frame is always allowed.  */
+	jbe	.Lok
+
+	/* Passing here, we're either about to do something invalid, or we're
+	executing on an alternative signal stack.  */
+
+	/* TODO: need locking?  */
+	/* struct hurd_sigstate * _hurd_self_sigstate (void) */
+	call	_hurd_self_sigstate
+	/* TODO: %eax and %eax->sigaltstack are always valid?  */
+
+	testl	$SS_ONSTACK, (HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_FLAGS__OFFSET)(%eax)
+	/* Fail if SS_ONSTACK is not set.  */
+	jz	.Lfail
+
+	movl	(HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SP__OFFSET)(%eax), %ebx
+	addl	(HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
+	subl	%edi, %ebx
+	cmpl	(HURD_SIGSTATE__SIGALTSTACK__OFFSET + SIGALTSTACK__SS_SIZE__OFFSET)(%eax), %ebx
+	/* TODO: comment this calculation.  */
+	jae	.Lok
+
+.Lfail:	CALL_FAIL
+
+.Lok:	/* We add unwind information for the target here.  */
+	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	8(%esp), %eax	/* Second argument is return value.  */
+	movl	%edi, %esp
+
+	/* Restore registers.  */
+	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
+END (____longjmp_chk)
diff --git a/sysdeps/mach/hurd/i386/signal-defines.sym b/sysdeps/mach/hurd/i386/signal-defines.sym
new file mode 100644
index 0000000000..9521bd723c
--- /dev/null
+++ b/sysdeps/mach/hurd/i386/signal-defines.sym
@@ -0,0 +1,10 @@
+#include <hurd/signal.h>
+#include <signal.h>
+
+--
+
+HURD_SIGSTATE__SIGALTSTACK__OFFSET	offsetof(struct hurd_sigstate, sigaltstack)
+
+SIGALTSTACK__SS_SP__OFFSET		offsetof(struct sigaltstack, ss_sp)
+SIGALTSTACK__SS_SIZE__OFFSET		offsetof(struct sigaltstack, ss_size)
+SIGALTSTACK__SS_FLAGS__OFFSET		offsetof(struct sigaltstack, ss_flags)