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// SPDX-License-Identifier: GPL-2.0-or-later/* * OpenRISC traps.c * * Linux architectural port borrowing liberally from similar works of * others.  All original copyrights apply as per the original source * declaration. * * Modifications for the OpenRISC architecture: * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> * *  Here we handle the break vectors not used by the system call *  mechanism, as well as some general stack/register dumping *  things. */ #include <linux/init.h>#include <linux/sched.h>#include <linux/sched/debug.h>#include <linux/sched/task_stack.h>#include <linux/kernel.h>#include <linux/extable.h>#include <linux/kmod.h>#include <linux/string.h>#include <linux/errno.h>#include <linux/ptrace.h>#include <linux/timer.h>#include <linux/mm.h>#include <linux/kallsyms.h>#include <linux/uaccess.h> #include <asm/bug.h>#include <asm/fpu.h>#include <asm/io.h>#include <asm/processor.h>#include <asm/unwinder.h>#include <asm/sections.h> int lwa_flag;static unsigned long __user *lwa_addr; asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector);asmlinkage void do_trap(struct pt_regs *regs, unsigned long address);asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address);asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address);asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address);asmlinkage void do_illegal_instruction(struct pt_regs *regs,				       unsigned long address); static void print_trace(void *data, unsigned long addr, int reliable){	const char *loglvl = data; 	pr_info("%s[<%p>] %s%pS\n", loglvl, (void *) addr, reliable ? "" : "? ",		(void *) addr);} static void print_data(unsigned long base_addr, unsigned long word, int i){	if (i == 0)		pr_info("(%08lx:)\t%08lx", base_addr + (i * 4), word);	else		pr_info(" %08lx:\t%08lx", base_addr + (i * 4), word);} /* displays a short stack trace */void show_stack(struct task_struct *task, unsigned long *esp, const char *loglvl){	if (esp == NULL)		esp = (unsigned long *)&esp; 	pr_info("%sCall trace:\n", loglvl);	unwind_stack((void *)loglvl, esp, print_trace);} void show_registers(struct pt_regs *regs){	int i;	int in_kernel = 1;	unsigned long esp; 	esp = (unsigned long)(regs->sp);	if (user_mode(regs))		in_kernel = 0; 	pr_info("CPU #: %d\n"		"   PC: %08lx    SR: %08lx    SP: %08lx\n",		smp_processor_id(), regs->pc, regs->sr, regs->sp);	pr_info("GPR00: %08lx GPR01: %08lx GPR02: %08lx GPR03: %08lx\n",		0L, regs->gpr[1], regs->gpr[2], regs->gpr[3]);	pr_info("GPR04: %08lx GPR05: %08lx GPR06: %08lx GPR07: %08lx\n",		regs->gpr[4], regs->gpr[5], regs->gpr[6], regs->gpr[7]);	pr_info("GPR08: %08lx GPR09: %08lx GPR10: %08lx GPR11: %08lx\n",		regs->gpr[8], regs->gpr[9], regs->gpr[10], regs->gpr[11]);	pr_info("GPR12: %08lx GPR13: %08lx GPR14: %08lx GPR15: %08lx\n",		regs->gpr[12], regs->gpr[13], regs->gpr[14], regs->gpr[15]);	pr_info("GPR16: %08lx GPR17: %08lx GPR18: %08lx GPR19: %08lx\n",		regs->gpr[16], regs->gpr[17], regs->gpr[18], regs->gpr[19]);	pr_info("GPR20: %08lx GPR21: %08lx GPR22: %08lx GPR23: %08lx\n",		regs->gpr[20], regs->gpr[21], regs->gpr[22], regs->gpr[23]);	pr_info("GPR24: %08lx GPR25: %08lx GPR26: %08lx GPR27: %08lx\n",		regs->gpr[24], regs->gpr[25], regs->gpr[26], regs->gpr[27]);	pr_info("GPR28: %08lx GPR29: %08lx GPR30: %08lx GPR31: %08lx\n",		regs->gpr[28], regs->gpr[29], regs->gpr[30], regs->gpr[31]);	pr_info("  RES: %08lx oGPR11: %08lx\n",		regs->gpr[11], regs->orig_gpr11); 	pr_info("Process %s (pid: %d, stackpage=%08lx)\n",		current->comm, current->pid, (unsigned long)current);	/*	 * When in-kernel, we also print out the stack and code at the	 * time of the fault..	 */	if (in_kernel) { 		pr_info("\nStack: ");		show_stack(NULL, (unsigned long *)esp, KERN_EMERG); 		if (esp < PAGE_OFFSET)			goto bad_stack; 		pr_info("\n");		for (i = -8; i < 24; i += 1) {			unsigned long word; 			if (__get_user(word, &((unsigned long *)esp)[i])) {bad_stack:				pr_info(" Bad Stack value.");				break;			} 			print_data(esp, word, i);		} 		pr_info("\nCode: ");		if (regs->pc < PAGE_OFFSET)			goto bad; 		for (i = -6; i < 6; i += 1) {			unsigned long word; 			if (__get_user(word, &((unsigned long *)regs->pc)[i])) {bad:				pr_info(" Bad PC value.");				break;			} 			print_data(regs->pc, word, i);		}	}	pr_info("\n");} /* This is normally the 'Oops' routine */void __noreturn die(const char *str, struct pt_regs *regs, long err){ 	console_verbose();	pr_emerg("\n%s#: %04lx\n", str, err & 0xffff);	show_registers(regs);#ifdef CONFIG_JUMP_UPON_UNHANDLED_EXCEPTION	pr_emerg("\n\nUNHANDLED_EXCEPTION: entering infinite loop\n"); 	/* shut down interrupts */	local_irq_disable(); 	__asm__ __volatile__("l.nop   1");	do {} while (1);#endif	make_task_dead(SIGSEGV);} asmlinkage void unhandled_exception(struct pt_regs *regs, int ea, int vector){	pr_emerg("Unable to handle exception at EA =0x%x, vector 0x%x",		 ea, vector);	die("Oops", regs, 9);} asmlinkage void do_fpe_trap(struct pt_regs *regs, unsigned long address){	if (user_mode(regs)) {		int code = FPE_FLTUNK;#ifdef CONFIG_FPU		unsigned long fpcsr; 		save_fpu(current);		fpcsr = current->thread.fpcsr; 		if (fpcsr & SPR_FPCSR_IVF)			code = FPE_FLTINV;		else if (fpcsr & SPR_FPCSR_OVF)			code = FPE_FLTOVF;		else if (fpcsr & SPR_FPCSR_UNF)			code = FPE_FLTUND;		else if (fpcsr & SPR_FPCSR_DZF)			code = FPE_FLTDIV;		else if (fpcsr & SPR_FPCSR_IXF)			code = FPE_FLTRES; 		/* Clear all flags */		current->thread.fpcsr &= ~SPR_FPCSR_ALLF;		restore_fpu(current);#endif		force_sig_fault(SIGFPE, code, (void __user *)regs->pc);	} else {		pr_emerg("KERNEL: Illegal fpe exception 0x%.8lx\n", regs->pc);		die("Die:", regs, SIGFPE);	}} asmlinkage void do_trap(struct pt_regs *regs, unsigned long address){	if (user_mode(regs)) {		force_sig_fault(SIGTRAP, TRAP_BRKPT, (void __user *)regs->pc);	} else {		pr_emerg("KERNEL: Illegal trap exception 0x%.8lx\n", regs->pc);		die("Die:", regs, SIGILL);	}} asmlinkage void do_unaligned_access(struct pt_regs *regs, unsigned long address){	if (user_mode(regs)) {		/* Send a SIGBUS */		force_sig_fault(SIGBUS, BUS_ADRALN, (void __user *)address);	} else {		pr_emerg("KERNEL: Unaligned Access 0x%.8lx\n", address);		die("Die:", regs, address);	} } asmlinkage void do_bus_fault(struct pt_regs *regs, unsigned long address){	if (user_mode(regs)) {		/* Send a SIGBUS */		force_sig_fault(SIGBUS, BUS_ADRERR, (void __user *)address);	} else {		/* Kernel mode */		pr_emerg("KERNEL: Bus error (SIGBUS) 0x%.8lx\n", address);		die("Die:", regs, address);	}} static inline int in_delay_slot(struct pt_regs *regs){#ifdef CONFIG_OPENRISC_NO_SPR_SR_DSX	/* No delay slot flag, do the old way */	unsigned int op, insn; 	insn = *((unsigned int *)regs->pc);	op = insn >> 26;	switch (op) {	case 0x00: /* l.j */	case 0x01: /* l.jal */	case 0x03: /* l.bnf */	case 0x04: /* l.bf */	case 0x11: /* l.jr */	case 0x12: /* l.jalr */		return 1;	default:		return 0;	}#else	return mfspr(SPR_SR) & SPR_SR_DSX;#endif} static inline void adjust_pc(struct pt_regs *regs, unsigned long address){	int displacement;	unsigned int rb, op, jmp; 	if (unlikely(in_delay_slot(regs))) {		/* In delay slot, instruction at pc is a branch, simulate it */		jmp = *((unsigned int *)regs->pc); 		displacement = sign_extend32(((jmp) & 0x3ffffff) << 2, 27);		rb = (jmp & 0x0000ffff) >> 11;		op = jmp >> 26; 		switch (op) {		case 0x00: /* l.j */			regs->pc += displacement;			return;		case 0x01: /* l.jal */			regs->pc += displacement;			regs->gpr[9] = regs->pc + 8;			return;		case 0x03: /* l.bnf */			if (regs->sr & SPR_SR_F)				regs->pc += 8;			else				regs->pc += displacement;			return;		case 0x04: /* l.bf */			if (regs->sr & SPR_SR_F)				regs->pc += displacement;			else				regs->pc += 8;			return;		case 0x11: /* l.jr */			regs->pc = regs->gpr[rb];			return;		case 0x12: /* l.jalr */			regs->pc = regs->gpr[rb];			regs->gpr[9] = regs->pc + 8;			return;		default:			break;		}	} else {		regs->pc += 4;	}} static inline void simulate_lwa(struct pt_regs *regs, unsigned long address,				unsigned int insn){	unsigned int ra, rd;	unsigned long value;	unsigned long orig_pc;	long imm; 	const struct exception_table_entry *entry; 	orig_pc = regs->pc;	adjust_pc(regs, address); 	ra = (insn >> 16) & 0x1f;	rd = (insn >> 21) & 0x1f;	imm = (short)insn;	lwa_addr = (unsigned long __user *)(regs->gpr[ra] + imm); 	if ((unsigned long)lwa_addr & 0x3) {		do_unaligned_access(regs, address);		return;	} 	if (get_user(value, lwa_addr)) {		if (user_mode(regs)) {			force_sig(SIGSEGV);			return;		} 		if ((entry = search_exception_tables(orig_pc))) {			regs->pc = entry->fixup;			return;		} 		/* kernel access in kernel space, load it directly */		value = *((unsigned long *)lwa_addr);	} 	lwa_flag = 1;	regs->gpr[rd] = value;} static inline void simulate_swa(struct pt_regs *regs, unsigned long address,				unsigned int insn){	unsigned long __user *vaddr;	unsigned long orig_pc;	unsigned int ra, rb;	long imm; 	const struct exception_table_entry *entry; 	orig_pc = regs->pc;	adjust_pc(regs, address); 	ra = (insn >> 16) & 0x1f;	rb = (insn >> 11) & 0x1f;	imm = (short)(((insn & 0x2200000) >> 10) | (insn & 0x7ff));	vaddr = (unsigned long __user *)(regs->gpr[ra] + imm); 	if (!lwa_flag || vaddr != lwa_addr) {		regs->sr &= ~SPR_SR_F;		return;	} 	if ((unsigned long)vaddr & 0x3) {		do_unaligned_access(regs, address);		return;	} 	if (put_user(regs->gpr[rb], vaddr)) {		if (user_mode(regs)) {			force_sig(SIGSEGV);			return;		} 		if ((entry = search_exception_tables(orig_pc))) {			regs->pc = entry->fixup;			return;		} 		/* kernel access in kernel space, store it directly */		*((unsigned long *)vaddr) = regs->gpr[rb];	} 	lwa_flag = 0;	regs->sr |= SPR_SR_F;} #define INSN_LWA	0x1b#define INSN_SWA	0x33 asmlinkage void do_illegal_instruction(struct pt_regs *regs,				       unsigned long address){	unsigned int op;	unsigned int insn = *((unsigned int *)address); 	op = insn >> 26; 	switch (op) {	case INSN_LWA:		simulate_lwa(regs, address, insn);		return; 	case INSN_SWA:		simulate_swa(regs, address, insn);		return; 	default:		break;	} 	if (user_mode(regs)) {		/* Send a SIGILL */		force_sig_fault(SIGILL, ILL_ILLOPC, (void __user *)address);	} else {		/* Kernel mode */		pr_emerg("KERNEL: Illegal instruction (SIGILL) 0x%.8lx\n",			 address);		die("Die:", regs, address);	}}

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