SH: ____longjmp_chk for GNU/Linux with sigaltstack support.

debug/tst-longjmp_chk2 now passes.

sysdeps/unix/sysv/linux/sh/Makefile

@@ -6,6 +6,10 @@ ifeq ($(subdir),stdlib)
 gen-as-const-headers += ucontext_i.sym
 endif
 
+ifeq ($(subdir),misc)
+gen-as-const-headers += sigaltstack-offsets.sym
+endif
+
 ifeq ($(subdir),math)
 # The libm.so link can't find __fpscr_values
 libm.so-no-z-defs = yes

sysdeps/unix/sysv/linux/sh/____longjmp_chk.S

@@ -0,0 +1,113 @@
+/* Copyright (C) 2009-2012 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 <sigaltstack-offsets.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
+	.text
+
+#define __longjmp ____longjmp_chk
+
+#ifdef PIC
+# define CALL_FAIL \
+	mov.l	.Lfail, r1;				\
+	mov.l	.Lstr, r4;				\
+	mova	.Lgot, r0;				\
+	mov.l	.Lgot, r12;				\
+	add	r0, r12;				\
+	bsrf	r1;					\
+	 add	r12, r4;				\
+.Lfail0:						\
+	bra	0f;					\
+	 nop;						\
+	.align	2;					\
+.Lgot:							\
+	.long	_GLOBAL_OFFSET_TABLE_;			\
+.Lstr:							\
+	.long	longjmp_msg@GOTOFF;			\
+.Lfail:							\
+	.long	__GI___fortify_fail@PLT-(.Lfail0-.);	\
+0:
+#else
+# define CALL_FAIL \
+	mov.l	.Lfail, r1;				\
+	mov.l	.Lstr, r4;				\
+	jsr	@r1;					\
+	 nop;						\
+	bra	0f;					\
+	 nop;						\
+	.align	2;					\
+.Lstr:							\
+	.long	longjmp_msg;				\
+.Lfail:							\
+	.long	__fortify_fail;				\
+0:
+#endif
+
+#define CHECK_SP(reg) \
+	/* Jumping to a higher-address frame is always allowed.	 */	\
+	cmp/hs	r15, reg;						\
+	bt	.Lok;							\
+									\
+	mov.l	r0, @-r15; /* The return value is already in here.  */	\
+	cfi_adjust_cfa_offset (4);					\
+	mov.l	r1, @-r15; /* PTR_DEMANGLE helper.  */			\
+	cfi_adjust_cfa_offset (4);					\
+	mov.l	r2, @-r15; /* The new SP value is already in here.  */	\
+	cfi_adjust_cfa_offset (4);					\
+	mov.l	r4, @-r15; /* We'll still need this one.  */		\
+	cfi_adjust_cfa_offset (4);					\
+	add	#-sizeSS, r15;						\
+	cfi_adjust_cfa_offset (sizeSS);					\
+	mov	#0, r4;							\
+	mov	r15, r5;						\
+	DO_CALL (sigaltstack, 2);					\
+	/* Without working sigaltstack we cannot perform the test.  */	\
+	tst	r0, r0;							\
+	bf	.Lok2;							\
+	mov.l	@(oSS_FLAGS, r15), r0;					\
+	tst	#SS_ONSTACK, r0;					\
+	bt	.Lcall_fail;						\
+	mov.l	@(oSS_SIZE, r15), r2;					\
+	mov.l	@(oSS_SP, r15), r1;					\
+	add	r2, r1;							\
+	sub	r8, r1;							\
+	cmp/hi	r1, r2;							\
+	bf	.Lok2;							\
+.Lcall_fail:								\
+	CALL_FAIL							\
+									\
+.Lok2:									\
+	add	#sizeSS, r15;						\
+	cfi_adjust_cfa_offset (-sizeSS);				\
+	mov.l	@r15+, r4;						\
+	cfi_adjust_cfa_offset (-4);					\
+	mov.l	@r15+, r2;						\
+	cfi_adjust_cfa_offset (-4);					\
+	mov.l	@r15+, r1;						\
+	cfi_adjust_cfa_offset (-4);					\
+	mov.l	@r15+, r0;						\
+	cfi_adjust_cfa_offset (-4);					\
+.Lok:
+
+#include <__longjmp.S>

sysdeps/unix/sysv/linux/sh/sigaltstack-offsets.sym

@@ -0,0 +1,13 @@
+#include <stddef.h>
+#include <signal.h>
+
+--
+
+#define sigaltstack(member)	offsetof (stack_t, member)
+
+sizeSS				sizeof (stack_t)
+oSS_SP				sigaltstack (ss_sp)
+oSS_FLAGS			sigaltstack (ss_flags)
+oSS_SIZE			sigaltstack (ss_size)
+
+SS_ONSTACK