/* * Traps/Non-MMU Exception handling for ARC * * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * vineetg: May 2011 *  -user-space unaligned access emulation * * Rahul Trivedi: Codito Technologies 2004 */ #include <linux/sched.h>#include <linux/kdebug.h>#include <linux/uaccess.h>#include <linux/ptrace.h>#include <linux/kprobes.h>#include <linux/kgdb.h>#include <asm/setup.h>#include <asm/unaligned.h>#include <asm/kprobes.h> void __init trap_init(void){	return;} void die(const char *str, struct pt_regs *regs, unsigned long address){	show_kernel_fault_diag(str, regs, address); 	/* DEAD END */	__asm__("flag 1");} /* * Helper called for bulk of exceptions NOT needing specific handling *  -for user faults enqueues requested signal *  -for kernel, chk if due to copy_(to|from)_user, otherwise die() */static noinline inthandle_exception(const char *str, struct pt_regs *regs, siginfo_t *info){	if (user_mode(regs)) {		struct task_struct *tsk = current; 		tsk->thread.fault_address = (__force unsigned int)info->si_addr; 		force_sig_info(info->si_signo, info, tsk); 	} else {		/* If not due to copy_(to|from)_user, we are doomed */		if (fixup_exception(regs))			return 0; 		die(str, regs, (unsigned long)info->si_addr);	} 	return 1;} #define DO_ERROR_INFO(signr, str, name, sicode) \int name(unsigned long address, struct pt_regs *regs) \{						\	siginfo_t info = {			\		.si_signo = signr,		\		.si_errno = 0,			\		.si_code  = sicode,		\		.si_addr = (void __user *)address,	\	};					\	return handle_exception(str, regs, &info);\} /* * Entry points for exceptions NOT needing specific handling */DO_ERROR_INFO(SIGILL, "Priv Op/Disabled Extn", do_privilege_fault, ILL_PRVOPC)DO_ERROR_INFO(SIGILL, "Invalid Extn Insn", do_extension_fault, ILL_ILLOPC)DO_ERROR_INFO(SIGILL, "Illegal Insn (or Seq)", insterror_is_error, ILL_ILLOPC)DO_ERROR_INFO(SIGBUS, "Invalid Mem Access", do_memory_error, BUS_ADRERR)DO_ERROR_INFO(SIGTRAP, "Breakpoint Set", trap_is_brkpt, TRAP_BRKPT)DO_ERROR_INFO(SIGBUS, "Misaligned Access", do_misaligned_error, BUS_ADRALN) /* * Entry Point for Misaligned Data access Exception, for emulating in software */int do_misaligned_access(unsigned long address, struct pt_regs *regs,			 struct callee_regs *cregs){	/* If emulation not enabled, or failed, kill the task */	if (misaligned_fixup(address, regs, cregs) != 0)		return do_misaligned_error(address, regs); 	return 0;} /* * Entry point for miscll errors such as Nested Exceptions *  -Duplicate TLB entry is handled seperately though */void do_machine_check_fault(unsigned long address, struct pt_regs *regs){	die("Machine Check Exception", regs, address);}  /* * Entry point for traps induced by ARCompact TRAP_S <n> insn * This is same family as TRAP0/SWI insn (use the same vector). * The only difference being SWI insn take no operand, while TRAP_S does * which reflects in ECR Reg as 8 bit param. * Thus TRAP_S <n> can be used for specific purpose *  -1 used for software breakpointing (gdb) *  -2 used by kprobes */void do_non_swi_trap(unsigned long address, struct pt_regs *regs){	unsigned int param = regs->ecr_param; 	switch (param) {	case 1:		trap_is_brkpt(address, regs);		break; 	case 2:		trap_is_kprobe(address, regs);		break; 	case 3:	case 4:		kgdb_trap(regs);		break; 	default:		break;	}} /* * Entry point for Instruction Error Exception *  -For a corner case, ARC kprobes implementation resorts to using *   this exception, hence the check */void do_insterror_or_kprobe(unsigned long address, struct pt_regs *regs){	int rc; 	/* Check if this exception is caused by kprobes */	rc = notify_die(DIE_IERR, "kprobe_ierr", regs, address, 0, SIGILL);	if (rc == NOTIFY_STOP)		return; 	insterror_is_error(address, regs);}