summary refs log tree commit diff
path: root/arch/sh/kernel/traps.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/kernel/traps.c')
-rw-r--r--arch/sh/kernel/traps.c949
1 files changed, 35 insertions, 914 deletions
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index cf99111cb33f..a3bdc68ef02c 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -1,947 +1,68 @@
-/*
- * 'traps.c' handles hardware traps and faults after we have saved some
- * state in 'entry.S'.
- *
- *  SuperH version: Copyright (C) 1999 Niibe Yutaka
- *                  Copyright (C) 2000 Philipp Rumpf
- *                  Copyright (C) 2000 David Howells
- *                  Copyright (C) 2002 - 2007 Paul Mundt
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-#include <linux/kernel.h>
-#include <linux/ptrace.h>
-#include <linux/init.h>
-#include <linux/spinlock.h>
-#include <linux/module.h>
-#include <linux/kallsyms.h>
-#include <linux/io.h>
 #include <linux/bug.h>
-#include <linux/debug_locks.h>
+#include <linux/io.h>
+#include <linux/types.h>
 #include <linux/kdebug.h>
-#include <linux/kexec.h>
-#include <linux/limits.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
 #include <asm/system.h>
-#include <asm/uaccess.h>
-
-#ifdef CONFIG_SH_KGDB
-#include <asm/kgdb.h>
-#define CHK_REMOTE_DEBUG(regs)			\
-{						\
-	if (kgdb_debug_hook && !user_mode(regs))\
-		(*kgdb_debug_hook)(regs);       \
-}
-#else
-#define CHK_REMOTE_DEBUG(regs)
-#endif
-
-#ifdef CONFIG_CPU_SH2
-# define TRAP_RESERVED_INST	4
-# define TRAP_ILLEGAL_SLOT_INST	6
-# define TRAP_ADDRESS_ERROR	9
-# ifdef CONFIG_CPU_SH2A
-#  define TRAP_DIVZERO_ERROR	17
-#  define TRAP_DIVOVF_ERROR	18
-# endif
-#else
-#define TRAP_RESERVED_INST	12
-#define TRAP_ILLEGAL_SLOT_INST	13
-#endif
-
-static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
-{
-	unsigned long p;
-	int i;
-
-	printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
-
-	for (p = bottom & ~31; p < top; ) {
-		printk("%04lx: ", p & 0xffff);
-
-		for (i = 0; i < 8; i++, p += 4) {
-			unsigned int val;
-
-			if (p < bottom || p >= top)
-				printk("         ");
-			else {
-				if (__get_user(val, (unsigned int __user *)p)) {
-					printk("\n");
-					return;
-				}
-				printk("%08x ", val);
-			}
-		}
-		printk("\n");
-	}
-}
-
-static DEFINE_SPINLOCK(die_lock);
-
-void die(const char * str, struct pt_regs * regs, long err)
-{
-	static int die_counter;
-
-	oops_enter();
-
-	console_verbose();
-	spin_lock_irq(&die_lock);
-	bust_spinlocks(1);
-
-	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
-
-	CHK_REMOTE_DEBUG(regs);
-	print_modules();
-	show_regs(regs);
-
-	printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
-			task_pid_nr(current), task_stack_page(current) + 1);
-
-	if (!user_mode(regs) || in_interrupt())
-		dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
-			 (unsigned long)task_stack_page(current));
-
-	bust_spinlocks(0);
-	add_taint(TAINT_DIE);
-	spin_unlock_irq(&die_lock);
-
-	if (kexec_should_crash(current))
-		crash_kexec(regs);
-
-	if (in_interrupt())
-		panic("Fatal exception in interrupt");
-
-	if (panic_on_oops)
-		panic("Fatal exception");
-
-	oops_exit();
-	do_exit(SIGSEGV);
-}
-
-static inline void die_if_kernel(const char *str, struct pt_regs *regs,
-				 long err)
-{
-	if (!user_mode(regs))
-		die(str, regs, err);
-}
-
-/*
- * try and fix up kernelspace address errors
- * - userspace errors just cause EFAULT to be returned, resulting in SEGV
- * - kernel/userspace interfaces cause a jump to an appropriate handler
- * - other kernel errors are bad
- * - return 0 if fixed-up, -EFAULT if non-fatal (to the kernel) fault
- */
-static int die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
-{
-	if (!user_mode(regs)) {
-		const struct exception_table_entry *fixup;
-		fixup = search_exception_tables(regs->pc);
-		if (fixup) {
-			regs->pc = fixup->fixup;
-			return 0;
-		}
-		die(str, regs, err);
-	}
-	return -EFAULT;
-}
-
-/*
- * handle an instruction that does an unaligned memory access by emulating the
- * desired behaviour
- * - note that PC _may not_ point to the faulting instruction
- *   (if that instruction is in a branch delay slot)
- * - return 0 if emulation okay, -EFAULT on existential error
- */
-static int handle_unaligned_ins(u16 instruction, struct pt_regs *regs)
-{
-	int ret, index, count;
-	unsigned long *rm, *rn;
-	unsigned char *src, *dst;
-
-	index = (instruction>>8)&15;	/* 0x0F00 */
-	rn = &regs->regs[index];
-
-	index = (instruction>>4)&15;	/* 0x00F0 */
-	rm = &regs->regs[index];
-
-	count = 1<<(instruction&3);
-
-	ret = -EFAULT;
-	switch (instruction>>12) {
-	case 0: /* mov.[bwl] to/from memory via r0+rn */
-		if (instruction & 8) {
-			/* from memory */
-			src = (unsigned char*) *rm;
-			src += regs->regs[0];
-			dst = (unsigned char*) rn;
-			*(unsigned long*)dst = 0;
-
-#ifdef __LITTLE_ENDIAN__
-			if (copy_from_user(dst, src, count))
-				goto fetch_fault;
-
-			if ((count == 2) && dst[1] & 0x80) {
-				dst[2] = 0xff;
-				dst[3] = 0xff;
-			}
-#else
-			dst += 4-count;
-
-			if (__copy_user(dst, src, count))
-				goto fetch_fault;
-
-			if ((count == 2) && dst[2] & 0x80) {
-				dst[0] = 0xff;
-				dst[1] = 0xff;
-			}
-#endif
-		} else {
-			/* to memory */
-			src = (unsigned char*) rm;
-#if !defined(__LITTLE_ENDIAN__)
-			src += 4-count;
-#endif
-			dst = (unsigned char*) *rn;
-			dst += regs->regs[0];
-
-			if (copy_to_user(dst, src, count))
-				goto fetch_fault;
-		}
-		ret = 0;
-		break;
-
-	case 1: /* mov.l Rm,@(disp,Rn) */
-		src = (unsigned char*) rm;
-		dst = (unsigned char*) *rn;
-		dst += (instruction&0x000F)<<2;
-
-		if (copy_to_user(dst,src,4))
-			goto fetch_fault;
-		ret = 0;
-		break;
-
-	case 2: /* mov.[bwl] to memory, possibly with pre-decrement */
-		if (instruction & 4)
-			*rn -= count;
-		src = (unsigned char*) rm;
-		dst = (unsigned char*) *rn;
-#if !defined(__LITTLE_ENDIAN__)
-		src += 4-count;
-#endif
-		if (copy_to_user(dst, src, count))
-			goto fetch_fault;
-		ret = 0;
-		break;
-
-	case 5: /* mov.l @(disp,Rm),Rn */
-		src = (unsigned char*) *rm;
-		src += (instruction&0x000F)<<2;
-		dst = (unsigned char*) rn;
-		*(unsigned long*)dst = 0;
-
-		if (copy_from_user(dst,src,4))
-			goto fetch_fault;
-		ret = 0;
-		break;
 
-	case 6:	/* mov.[bwl] from memory, possibly with post-increment */
-		src = (unsigned char*) *rm;
-		if (instruction & 4)
-			*rm += count;
-		dst = (unsigned char*) rn;
-		*(unsigned long*)dst = 0;
-
-#ifdef __LITTLE_ENDIAN__
-		if (copy_from_user(dst, src, count))
-			goto fetch_fault;
-
-		if ((count == 2) && dst[1] & 0x80) {
-			dst[2] = 0xff;
-			dst[3] = 0xff;
-		}
-#else
-		dst += 4-count;
-
-		if (copy_from_user(dst, src, count))
-			goto fetch_fault;
-
-		if ((count == 2) && dst[2] & 0x80) {
-			dst[0] = 0xff;
-			dst[1] = 0xff;
-		}
-#endif
-		ret = 0;
-		break;
-
-	case 8:
-		switch ((instruction&0xFF00)>>8) {
-		case 0x81: /* mov.w R0,@(disp,Rn) */
-			src = (unsigned char*) &regs->regs[0];
-#if !defined(__LITTLE_ENDIAN__)
-			src += 2;
-#endif
-			dst = (unsigned char*) *rm; /* called Rn in the spec */
-			dst += (instruction&0x000F)<<1;
-
-			if (copy_to_user(dst, src, 2))
-				goto fetch_fault;
-			ret = 0;
-			break;
-
-		case 0x85: /* mov.w @(disp,Rm),R0 */
-			src = (unsigned char*) *rm;
-			src += (instruction&0x000F)<<1;
-			dst = (unsigned char*) &regs->regs[0];
-			*(unsigned long*)dst = 0;
-
-#if !defined(__LITTLE_ENDIAN__)
-			dst += 2;
-#endif
-
-			if (copy_from_user(dst, src, 2))
-				goto fetch_fault;
-
-#ifdef __LITTLE_ENDIAN__
-			if (dst[1] & 0x80) {
-				dst[2] = 0xff;
-				dst[3] = 0xff;
-			}
-#else
-			if (dst[2] & 0x80) {
-				dst[0] = 0xff;
-				dst[1] = 0xff;
-			}
-#endif
-			ret = 0;
-			break;
-		}
-		break;
-	}
-	return ret;
-
- fetch_fault:
-	/* Argh. Address not only misaligned but also non-existent.
-	 * Raise an EFAULT and see if it's trapped
-	 */
-	return die_if_no_fixup("Fault in unaligned fixup", regs, 0);
-}
-
-/*
- * emulate the instruction in the delay slot
- * - fetches the instruction from PC+2
- */
-static inline int handle_unaligned_delayslot(struct pt_regs *regs)
+#ifdef CONFIG_BUG
+static void handle_BUG(struct pt_regs *regs)
 {
-	u16 instruction;
-
-	if (copy_from_user(&instruction, (u16 *)(regs->pc+2), 2)) {
-		/* the instruction-fetch faulted */
-		if (user_mode(regs))
-			return -EFAULT;
-
-		/* kernel */
-		die("delay-slot-insn faulting in handle_unaligned_delayslot",
-		    regs, 0);
+	enum bug_trap_type tt;
+	tt = report_bug(regs->pc, regs);
+	if (tt == BUG_TRAP_TYPE_WARN) {
+		regs->pc += instruction_size(regs->pc);
+		return;
 	}
 
-	return handle_unaligned_ins(instruction,regs);
+	die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
 }
 
-/*
- * handle an instruction that does an unaligned memory access
- * - have to be careful of branch delay-slot instructions that fault
- *  SH3:
- *   - if the branch would be taken PC points to the branch
- *   - if the branch would not be taken, PC points to delay-slot
- *  SH4:
- *   - PC always points to delayed branch
- * - return 0 if handled, -EFAULT if failed (may not return if in kernel)
- */
-
-/* Macros to determine offset from current PC for branch instructions */
-/* Explicit type coercion is used to force sign extension where needed */
-#define SH_PC_8BIT_OFFSET(instr) ((((signed char)(instr))*2) + 4)
-#define SH_PC_12BIT_OFFSET(instr) ((((signed short)(instr<<4))>>3) + 4)
-
-/*
- * XXX: SH-2A needs this too, but it needs an overhaul thanks to mixed 32-bit
- * opcodes..
- */
-#ifndef CONFIG_CPU_SH2A
-static int handle_unaligned_notify_count = 10;
-
-static int handle_unaligned_access(u16 instruction, struct pt_regs *regs)
+int is_valid_bugaddr(unsigned long addr)
 {
-	u_int rm;
-	int ret, index;
-
-	index = (instruction>>8)&15;	/* 0x0F00 */
-	rm = regs->regs[index];
-
-	/* shout about the first ten userspace fixups */
-	if (user_mode(regs) && handle_unaligned_notify_count>0) {
-		handle_unaligned_notify_count--;
-
-		printk(KERN_NOTICE "Fixing up unaligned userspace access "
-		       "in \"%s\" pid=%d pc=0x%p ins=0x%04hx\n",
-		       current->comm, task_pid_nr(current),
-		       (u16 *)regs->pc, instruction);
-	}
-
-	ret = -EFAULT;
-	switch (instruction&0xF000) {
-	case 0x0000:
-		if (instruction==0x000B) {
-			/* rts */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0)
-				regs->pc = regs->pr;
-		}
-		else if ((instruction&0x00FF)==0x0023) {
-			/* braf @Rm */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0)
-				regs->pc += rm + 4;
-		}
-		else if ((instruction&0x00FF)==0x0003) {
-			/* bsrf @Rm */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0) {
-				regs->pr = regs->pc + 4;
-				regs->pc += rm + 4;
-			}
-		}
-		else {
-			/* mov.[bwl] to/from memory via r0+rn */
-			goto simple;
-		}
-		break;
-
-	case 0x1000: /* mov.l Rm,@(disp,Rn) */
-		goto simple;
-
-	case 0x2000: /* mov.[bwl] to memory, possibly with pre-decrement */
-		goto simple;
-
-	case 0x4000:
-		if ((instruction&0x00FF)==0x002B) {
-			/* jmp @Rm */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0)
-				regs->pc = rm;
-		}
-		else if ((instruction&0x00FF)==0x000B) {
-			/* jsr @Rm */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0) {
-				regs->pr = regs->pc + 4;
-				regs->pc = rm;
-			}
-		}
-		else {
-			/* mov.[bwl] to/from memory via r0+rn */
-			goto simple;
-		}
-		break;
-
-	case 0x5000: /* mov.l @(disp,Rm),Rn */
-		goto simple;
-
-	case 0x6000: /* mov.[bwl] from memory, possibly with post-increment */
-		goto simple;
-
-	case 0x8000: /* bf lab, bf/s lab, bt lab, bt/s lab */
-		switch (instruction&0x0F00) {
-		case 0x0100: /* mov.w R0,@(disp,Rm) */
-			goto simple;
-		case 0x0500: /* mov.w @(disp,Rm),R0 */
-			goto simple;
-		case 0x0B00: /* bf   lab - no delayslot*/
-			break;
-		case 0x0F00: /* bf/s lab */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0) {
-#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
-				if ((regs->sr & 0x00000001) != 0)
-					regs->pc += 4; /* next after slot */
-				else
-#endif
-					regs->pc += SH_PC_8BIT_OFFSET(instruction);
-			}
-			break;
-		case 0x0900: /* bt   lab - no delayslot */
-			break;
-		case 0x0D00: /* bt/s lab */
-			ret = handle_unaligned_delayslot(regs);
-			if (ret==0) {
-#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
-				if ((regs->sr & 0x00000001) == 0)
-					regs->pc += 4; /* next after slot */
-				else
-#endif
-					regs->pc += SH_PC_8BIT_OFFSET(instruction);
-			}
-			break;
-		}
-		break;
-
-	case 0xA000: /* bra label */
-		ret = handle_unaligned_delayslot(regs);
-		if (ret==0)
-			regs->pc += SH_PC_12BIT_OFFSET(instruction);
-		break;
-
-	case 0xB000: /* bsr label */
-		ret = handle_unaligned_delayslot(regs);
-		if (ret==0) {
-			regs->pr = regs->pc + 4;
-			regs->pc += SH_PC_12BIT_OFFSET(instruction);
-		}
-		break;
-	}
-	return ret;
-
-	/* handle non-delay-slot instruction */
- simple:
-	ret = handle_unaligned_ins(instruction,regs);
-	if (ret==0)
-		regs->pc += instruction_size(instruction);
-	return ret;
+	return addr >= PAGE_OFFSET;
 }
-#endif /* CONFIG_CPU_SH2A */
-
-#ifdef CONFIG_CPU_HAS_SR_RB
-#define lookup_exception_vector(x)	\
-	__asm__ __volatile__ ("stc r2_bank, %0\n\t" : "=r" ((x)))
-#else
-#define lookup_exception_vector(x)	\
-	__asm__ __volatile__ ("mov r4, %0\n\t" : "=r" ((x)))
 #endif
 
 /*
- * Handle various address error exceptions:
- *  - instruction address error:
- *       misaligned PC
- *       PC >= 0x80000000 in user mode
- *  - data address error (read and write)
- *       misaligned data access
- *       access to >= 0x80000000 is user mode
- * Unfortuntaly we can't distinguish between instruction address error
- * and data address errors caused by read accesses.
+ * Generic trap handler.
  */
-asmlinkage void do_address_error(struct pt_regs *regs,
-				 unsigned long writeaccess,
-				 unsigned long address)
+BUILD_TRAP_HANDLER(debug)
 {
-	unsigned long error_code = 0;
-	mm_segment_t oldfs;
-	siginfo_t info;
-#ifndef CONFIG_CPU_SH2A
-	u16 instruction;
-	int tmp;
-#endif
-
-	/* Intentional ifdef */
-#ifdef CONFIG_CPU_HAS_SR_RB
-	lookup_exception_vector(error_code);
-#endif
-
-	oldfs = get_fs();
-
-	if (user_mode(regs)) {
-		int si_code = BUS_ADRERR;
-
-		local_irq_enable();
+	TRAP_HANDLER_DECL;
 
-		/* bad PC is not something we can fix */
-		if (regs->pc & 1) {
-			si_code = BUS_ADRALN;
-			goto uspace_segv;
-		}
+	/* Rewind */
+	regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
 
-#ifndef CONFIG_CPU_SH2A
-		set_fs(USER_DS);
-		if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) {
-			/* Argh. Fault on the instruction itself.
-			   This should never happen non-SMP
-			*/
-			set_fs(oldfs);
-			goto uspace_segv;
-		}
-
-		tmp = handle_unaligned_access(instruction, regs);
-		set_fs(oldfs);
-
-		if (tmp==0)
-			return; /* sorted */
-#endif
-
-uspace_segv:
-		printk(KERN_NOTICE "Sending SIGBUS to \"%s\" due to unaligned "
-		       "access (PC %lx PR %lx)\n", current->comm, regs->pc,
-		       regs->pr);
-
-		info.si_signo = SIGBUS;
-		info.si_errno = 0;
-		info.si_code = si_code;
-		info.si_addr = (void __user *)address;
-		force_sig_info(SIGBUS, &info, current);
-	} else {
-		if (regs->pc & 1)
-			die("unaligned program counter", regs, error_code);
-
-#ifndef CONFIG_CPU_SH2A
-		set_fs(KERNEL_DS);
-		if (copy_from_user(&instruction, (u16 *)(regs->pc), 2)) {
-			/* Argh. Fault on the instruction itself.
-			   This should never happen non-SMP
-			*/
-			set_fs(oldfs);
-			die("insn faulting in do_address_error", regs, 0);
-		}
-
-		handle_unaligned_access(instruction, regs);
-		set_fs(oldfs);
-#else
-		printk(KERN_NOTICE "Killing process \"%s\" due to unaligned "
-		       "access\n", current->comm);
+	if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
+		       SIGTRAP) == NOTIFY_STOP)
+		return;
 
-		force_sig(SIGSEGV, current);
-#endif
-	}
+	force_sig(SIGTRAP, current);
 }
 
-#ifdef CONFIG_SH_DSP
 /*
- *	SH-DSP support gerg@snapgear.com.
+ * Special handler for BUG() traps.
  */
-int is_dsp_inst(struct pt_regs *regs)
+BUILD_TRAP_HANDLER(bug)
 {
-	unsigned short inst = 0;
-
-	/*
-	 * Safe guard if DSP mode is already enabled or we're lacking
-	 * the DSP altogether.
-	 */
-	if (!(current_cpu_data.flags & CPU_HAS_DSP) || (regs->sr & SR_DSP))
-		return 0;
-
-	get_user(inst, ((unsigned short *) regs->pc));
-
-	inst &= 0xf000;
-
-	/* Check for any type of DSP or support instruction */
-	if ((inst == 0xf000) || (inst == 0x4000))
-		return 1;
-
-	return 0;
-}
-#else
-#define is_dsp_inst(regs)	(0)
-#endif /* CONFIG_SH_DSP */
+	TRAP_HANDLER_DECL;
 
-#ifdef CONFIG_CPU_SH2A
-asmlinkage void do_divide_error(unsigned long r4, unsigned long r5,
-				unsigned long r6, unsigned long r7,
-				struct pt_regs __regs)
-{
-	siginfo_t info;
-
-	switch (r4) {
-	case TRAP_DIVZERO_ERROR:
-		info.si_code = FPE_INTDIV;
-		break;
-	case TRAP_DIVOVF_ERROR:
-		info.si_code = FPE_INTOVF;
-		break;
-	}
-
-	force_sig_info(SIGFPE, &info, current);
-}
-#endif
-
-/* arch/sh/kernel/cpu/sh4/fpu.c */
-extern int do_fpu_inst(unsigned short, struct pt_regs *);
-extern asmlinkage void do_fpu_state_restore(unsigned long r4, unsigned long r5,
-		unsigned long r6, unsigned long r7, struct pt_regs __regs);
-
-asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
-				unsigned long r6, unsigned long r7,
-				struct pt_regs __regs)
-{
-	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
-	unsigned long error_code;
-	struct task_struct *tsk = current;
-
-#ifdef CONFIG_SH_FPU_EMU
-	unsigned short inst = 0;
-	int err;
-
-	get_user(inst, (unsigned short*)regs->pc);
-
-	err = do_fpu_inst(inst, regs);
-	if (!err) {
-		regs->pc += instruction_size(inst);
-		return;
-	}
-	/* not a FPU inst. */
-#endif
+	/* Rewind */
+	regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
 
-#ifdef CONFIG_SH_DSP
-	/* Check if it's a DSP instruction */
-	if (is_dsp_inst(regs)) {
-		/* Enable DSP mode, and restart instruction. */
-		regs->sr |= SR_DSP;
+	if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
+		       SIGTRAP) == NOTIFY_STOP)
 		return;
-	}
-#endif
-
-	lookup_exception_vector(error_code);
-
-	local_irq_enable();
-	CHK_REMOTE_DEBUG(regs);
-	force_sig(SIGILL, tsk);
-	die_if_no_fixup("reserved instruction", regs, error_code);
-}
-
-#ifdef CONFIG_SH_FPU_EMU
-static int emulate_branch(unsigned short inst, struct pt_regs* regs)
-{
-	/*
-	 * bfs: 8fxx: PC+=d*2+4;
-	 * bts: 8dxx: PC+=d*2+4;
-	 * bra: axxx: PC+=D*2+4;
-	 * bsr: bxxx: PC+=D*2+4  after PR=PC+4;
-	 * braf:0x23: PC+=Rn*2+4;
-	 * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4;
-	 * jmp: 4x2b: PC=Rn;
-	 * jsr: 4x0b: PC=Rn      after PR=PC+4;
-	 * rts: 000b: PC=PR;
-	 */
-	if ((inst & 0xfd00) == 0x8d00) {
-		regs->pc += SH_PC_8BIT_OFFSET(inst);
-		return 0;
-	}
-
-	if ((inst & 0xe000) == 0xa000) {
-		regs->pc += SH_PC_12BIT_OFFSET(inst);
-		return 0;
-	}
-
-	if ((inst & 0xf0df) == 0x0003) {
-		regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4;
-		return 0;
-	}
-
-	if ((inst & 0xf0df) == 0x400b) {
-		regs->pc = regs->regs[(inst & 0x0f00) >> 8];
-		return 0;
-	}
-
-	if ((inst & 0xffff) == 0x000b) {
-		regs->pc = regs->pr;
-		return 0;
-	}
-
-	return 1;
-}
-#endif
-
-asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
-				unsigned long r6, unsigned long r7,
-				struct pt_regs __regs)
-{
-	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
-	unsigned long error_code;
-	struct task_struct *tsk = current;
-#ifdef CONFIG_SH_FPU_EMU
-	unsigned short inst = 0;
-
-	get_user(inst, (unsigned short *)regs->pc + 1);
-	if (!do_fpu_inst(inst, regs)) {
-		get_user(inst, (unsigned short *)regs->pc);
-		if (!emulate_branch(inst, regs))
-			return;
-		/* fault in branch.*/
-	}
-	/* not a FPU inst. */
-#endif
-
-	lookup_exception_vector(error_code);
-
-	local_irq_enable();
-	CHK_REMOTE_DEBUG(regs);
-	force_sig(SIGILL, tsk);
-	die_if_no_fixup("illegal slot instruction", regs, error_code);
-}
-
-asmlinkage void do_exception_error(unsigned long r4, unsigned long r5,
-				   unsigned long r6, unsigned long r7,
-				   struct pt_regs __regs)
-{
-	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
-	long ex;
-
-	lookup_exception_vector(ex);
-	die_if_kernel("exception", regs, ex);
-}
-
-#if defined(CONFIG_SH_STANDARD_BIOS)
-void *gdb_vbr_vector;
-
-static inline void __init gdb_vbr_init(void)
-{
-	register unsigned long vbr;
-
-	/*
-	 * Read the old value of the VBR register to initialise
-	 * the vector through which debug and BIOS traps are
-	 * delegated by the Linux trap handler.
-	 */
-	asm volatile("stc vbr, %0" : "=r" (vbr));
-
-	gdb_vbr_vector = (void *)(vbr + 0x100);
-	printk("Setting GDB trap vector to 0x%08lx\n",
-	       (unsigned long)gdb_vbr_vector);
-}
-#endif
-
-void __cpuinit per_cpu_trap_init(void)
-{
-	extern void *vbr_base;
-
-#ifdef CONFIG_SH_STANDARD_BIOS
-	if (raw_smp_processor_id() == 0)
-		gdb_vbr_init();
-#endif
-
-	/* NOTE: The VBR value should be at P1
-	   (or P2, virtural "fixed" address space).
-	   It's definitely should not in physical address.  */
-
-	asm volatile("ldc	%0, vbr"
-		     : /* no output */
-		     : "r" (&vbr_base)
-		     : "memory");
-}
-
-void *set_exception_table_vec(unsigned int vec, void *handler)
-{
-	extern void *exception_handling_table[];
-	void *old_handler;
-
-	old_handler = exception_handling_table[vec];
-	exception_handling_table[vec] = handler;
-	return old_handler;
-}
-
-extern asmlinkage void address_error_handler(unsigned long r4, unsigned long r5,
-					     unsigned long r6, unsigned long r7,
-					     struct pt_regs __regs);
-
-void __init trap_init(void)
-{
-	set_exception_table_vec(TRAP_RESERVED_INST, do_reserved_inst);
-	set_exception_table_vec(TRAP_ILLEGAL_SLOT_INST, do_illegal_slot_inst);
-
-#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
-    defined(CONFIG_SH_FPU_EMU)
-	/*
-	 * For SH-4 lacking an FPU, treat floating point instructions as
-	 * reserved. They'll be handled in the math-emu case, or faulted on
-	 * otherwise.
-	 */
-	set_exception_table_evt(0x800, do_reserved_inst);
-	set_exception_table_evt(0x820, do_illegal_slot_inst);
-#elif defined(CONFIG_SH_FPU)
-#ifdef CONFIG_CPU_SUBTYPE_SHX3
-	set_exception_table_evt(0xd80, do_fpu_state_restore);
-	set_exception_table_evt(0xda0, do_fpu_state_restore);
-#else
-	set_exception_table_evt(0x800, do_fpu_state_restore);
-	set_exception_table_evt(0x820, do_fpu_state_restore);
-#endif
-#endif
-
-#ifdef CONFIG_CPU_SH2
-	set_exception_table_vec(TRAP_ADDRESS_ERROR, address_error_handler);
-#endif
-#ifdef CONFIG_CPU_SH2A
-	set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
-	set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
-#endif
-
-	/* Setup VBR for boot cpu */
-	per_cpu_trap_init();
-}
 
 #ifdef CONFIG_BUG
-void handle_BUG(struct pt_regs *regs)
-{
-	enum bug_trap_type tt;
-	tt = report_bug(regs->pc, regs);
-	if (tt == BUG_TRAP_TYPE_WARN) {
-		regs->pc += 2;
-		return;
+	if (__kernel_text_address(instruction_pointer(regs))) {
+		opcode_t insn = *(opcode_t *)instruction_pointer(regs);
+		if (insn == TRAPA_BUG_OPCODE)
+			handle_BUG(regs);
 	}
-
-	die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
-}
-
-int is_valid_bugaddr(unsigned long addr)
-{
-	return addr >= PAGE_OFFSET;
-}
-#endif
-
-void show_trace(struct task_struct *tsk, unsigned long *sp,
-		struct pt_regs *regs)
-{
-	unsigned long addr;
-
-	if (regs && user_mode(regs))
-		return;
-
-	printk("\nCall trace: ");
-#ifdef CONFIG_KALLSYMS
-	printk("\n");
 #endif
 
-	while (!kstack_end(sp)) {
-		addr = *sp++;
-		if (kernel_text_address(addr))
-			print_ip_sym(addr);
-	}
-
-	printk("\n");
-
-	if (!tsk)
-		tsk = current;
-
-	debug_show_held_locks(tsk);
-}
-
-void show_stack(struct task_struct *tsk, unsigned long *sp)
-{
-	unsigned long stack;
-
-	if (!tsk)
-		tsk = current;
-	if (tsk == current)
-		sp = (unsigned long *)current_stack_pointer;
-	else
-		sp = (unsigned long *)tsk->thread.sp;
-
-	stack = (unsigned long)sp;
-	dump_mem("Stack: ", stack, THREAD_SIZE +
-		 (unsigned long)task_stack_page(tsk));
-	show_trace(tsk, sp, NULL);
-}
-
-void dump_stack(void)
-{
-	show_stack(NULL, NULL);
+	force_sig(SIGTRAP, current);
 }
-EXPORT_SYMBOL(dump_stack);