[mirror_ubuntu-bionic-kernel.git] / arch / hexagon / kernel / traps.c

/*
 * Kernel traps/events for Hexagon processor
 *
 * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#include <linux/init.h>
#include <linux/sched/signal.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/kdebug.h>
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/tracehook.h>
#include <asm/traps.h>
#include <asm/vm_fault.h>
#include <asm/syscall.h>
#include <asm/registers.h>
#include <asm/unistd.h>
#include <asm/sections.h>
#ifdef CONFIG_KGDB
# include <linux/kgdb.h>
#endif

#define TRAP_SYSCALL	1
#define TRAP_DEBUG	0xdb

void __init trap_init(void)
{
}

#ifdef CONFIG_GENERIC_BUG
/* Maybe should resemble arch/sh/kernel/traps.c ?? */
int is_valid_bugaddr(unsigned long addr)
{
	return 1;
}
#endif /* CONFIG_GENERIC_BUG */

static const char *ex_name(int ex)
{
	switch (ex) {
	case HVM_GE_C_XPROT:
	case HVM_GE_C_XUSER:
		return "Execute protection fault";
	case HVM_GE_C_RPROT:
	case HVM_GE_C_RUSER:
		return "Read protection fault";
	case HVM_GE_C_WPROT:
	case HVM_GE_C_WUSER:
		return "Write protection fault";
	case HVM_GE_C_XMAL:
		return "Misaligned instruction";
	case HVM_GE_C_WREG:
		return "Multiple writes to same register in packet";
	case HVM_GE_C_PCAL:
		return "Program counter values that are not properly aligned";
	case HVM_GE_C_RMAL:
		return "Misaligned data load";
	case HVM_GE_C_WMAL:
		return "Misaligned data store";
	case HVM_GE_C_INVI:
	case HVM_GE_C_PRIVI:
		return "Illegal instruction";
	case HVM_GE_C_BUS:
		return "Precise bus error";
	case HVM_GE_C_CACHE:
		return "Cache error";

	case 0xdb:
		return "Debugger trap";

	default:
		return "Unrecognized exception";
	}
}

static void do_show_stack(struct task_struct *task, unsigned long *fp,
			  unsigned long ip)
{
	int kstack_depth_to_print = 24;
	unsigned long offset, size;
	const char *name = NULL;
	unsigned long *newfp;
	unsigned long low, high;
	char tmpstr[128];
	char *modname;
	int i;

	if (task == NULL)
		task = current;

	printk(KERN_INFO "CPU#%d, %s/%d, Call Trace:\n",
	       raw_smp_processor_id(), task->comm,
	       task_pid_nr(task));

	if (fp == NULL) {
		if (task == current) {
			asm("%0 = r30" : "=r" (fp));
		} else {
			fp = (unsigned long *)
			     ((struct hexagon_switch_stack *)
			     task->thread.switch_sp)->fp;
		}
	}

	if ((((unsigned long) fp) & 0x3) || ((unsigned long) fp < 0x1000)) {
		printk(KERN_INFO "-- Corrupt frame pointer %p\n", fp);
		return;
	}

	/* Saved link reg is one word above FP */
	if (!ip)
		ip = *(fp+1);

	/* Expect kernel stack to be in-bounds */
	low = (unsigned long)task_stack_page(task);
	high = low + THREAD_SIZE - 8;
	low += sizeof(struct thread_info);

	for (i = 0; i < kstack_depth_to_print; i++) {

		name = kallsyms_lookup(ip, &size, &offset, &modname, tmpstr);

		printk(KERN_INFO "[%p] 0x%lx: %s + 0x%lx", fp, ip, name,
			offset);
		if (((unsigned long) fp < low) || (high < (unsigned long) fp))
			printk(KERN_CONT " (FP out of bounds!)");
		if (modname)
			printk(KERN_CONT " [%s] ", modname);
		printk(KERN_CONT "\n");

		newfp = (unsigned long *) *fp;

		if (((unsigned long) newfp) & 0x3) {
			printk(KERN_INFO "-- Corrupt frame pointer %p\n",
				newfp);
			break;
		}

		/* Attempt to continue past exception. */
		if (0 == newfp) {
			struct pt_regs *regs = (struct pt_regs *) (((void *)fp)
						+ 8);

			if (regs->syscall_nr != -1) {
				printk(KERN_INFO "-- trap0 -- syscall_nr: %ld",
					regs->syscall_nr);
				printk(KERN_CONT "  psp: %lx  elr: %lx\n",
					 pt_psp(regs), pt_elr(regs));
				break;
			} else {
				/* really want to see more ... */
				kstack_depth_to_print += 6;
				printk(KERN_INFO "-- %s (0x%lx)  badva: %lx\n",
					ex_name(pt_cause(regs)), pt_cause(regs),
					pt_badva(regs));
			}

			newfp = (unsigned long *) regs->r30;
			ip = pt_elr(regs);
		} else {
			ip = *(newfp + 1);
		}

		/* If link reg is null, we are done. */
		if (ip == 0x0)
			break;

		/* If newfp isn't larger, we're tracing garbage. */
		if (newfp > fp)
			fp = newfp;
		else
			break;
	}
}

void show_stack(struct task_struct *task, unsigned long *fp)
{
	/* Saved link reg is one word above FP */
	do_show_stack(task, fp, 0);
}

int die(const char *str, struct pt_regs *regs, long err)
{
	static struct {
		spinlock_t lock;
		int counter;
	} die = {
		.lock = __SPIN_LOCK_UNLOCKED(die.lock),
		.counter = 0
	};

	console_verbose();
	oops_enter();

	spin_lock_irq(&die.lock);
	bust_spinlocks(1);
	printk(KERN_EMERG "Oops: %s[#%d]:\n", str, ++die.counter);

	if (notify_die(DIE_OOPS, str, regs, err, pt_cause(regs), SIGSEGV) ==
	    NOTIFY_STOP)
		return 1;

	print_modules();
	show_regs(regs);
	do_show_stack(current, &regs->r30, pt_elr(regs));

	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);

	spin_unlock_irq(&die.lock);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops)
		panic("Fatal exception");

	oops_exit();
	do_exit(err);
	return 0;
}

int die_if_kernel(char *str, struct pt_regs *regs, long err)
{
	if (!user_mode(regs))
		return die(str, regs, err);
	else
		return 0;
}

/*
 * It's not clear that misaligned fetches are ever recoverable.
 */
static void misaligned_instruction(struct pt_regs *regs)
{
	die_if_kernel("Misaligned Instruction", regs, 0);
	force_sig(SIGBUS, current);
}

/*
 * Misaligned loads and stores, on the other hand, can be
 * emulated, and probably should be, some day.  But for now
 * they will be considered fatal.
 */
static void misaligned_data_load(struct pt_regs *regs)
{
	die_if_kernel("Misaligned Data Load", regs, 0);
	force_sig(SIGBUS, current);
}

static void misaligned_data_store(struct pt_regs *regs)
{
	die_if_kernel("Misaligned Data Store", regs, 0);
	force_sig(SIGBUS, current);
}

static void illegal_instruction(struct pt_regs *regs)
{
	die_if_kernel("Illegal Instruction", regs, 0);
	force_sig(SIGILL, current);
}

/*
 * Precise bus errors may be recoverable with a a retry,
 * but for now, treat them as irrecoverable.
 */
static void precise_bus_error(struct pt_regs *regs)
{
	die_if_kernel("Precise Bus Error", regs, 0);
	force_sig(SIGBUS, current);
}

/*
 * If anything is to be done here other than panic,
 * it will probably be complex and migrate to another
 * source module.  For now, just die.
 */
static void cache_error(struct pt_regs *regs)
{
	die("Cache Error", regs, 0);
}

/*
 * General exception handler
 */
void do_genex(struct pt_regs *regs)
{
	/*
	 * Decode Cause and Dispatch
	 */
	switch (pt_cause(regs)) {
	case HVM_GE_C_XPROT:
	case HVM_GE_C_XUSER:
		execute_protection_fault(regs);
		break;
	case HVM_GE_C_RPROT:
	case HVM_GE_C_RUSER:
		read_protection_fault(regs);
		break;
	case HVM_GE_C_WPROT:
	case HVM_GE_C_WUSER:
		write_protection_fault(regs);
		break;
	case HVM_GE_C_XMAL:
		misaligned_instruction(regs);
		break;
	case HVM_GE_C_WREG:
		illegal_instruction(regs);
		break;
	case HVM_GE_C_PCAL:
		misaligned_instruction(regs);
		break;
	case HVM_GE_C_RMAL:
		misaligned_data_load(regs);
		break;
	case HVM_GE_C_WMAL:
		misaligned_data_store(regs);
		break;
	case HVM_GE_C_INVI:
	case HVM_GE_C_PRIVI:
		illegal_instruction(regs);
		break;
	case HVM_GE_C_BUS:
		precise_bus_error(regs);
		break;
	case HVM_GE_C_CACHE:
		cache_error(regs);
		break;
	default:
		/* Halt and catch fire */
		panic("Unrecognized exception 0x%lx\n", pt_cause(regs));
		break;
	}
}

/* Indirect system call dispatch */
long sys_syscall(void)
{
	printk(KERN_ERR "sys_syscall invoked!\n");
	return -ENOSYS;
}

void do_trap0(struct pt_regs *regs)
{
	syscall_fn syscall;

	switch (pt_cause(regs)) {
	case TRAP_SYSCALL:
		/* System call is trap0 #1 */

		/* allow strace to catch syscall args  */
		if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) &&
			tracehook_report_syscall_entry(regs)))
			return;  /*  return -ENOSYS somewhere?  */

		/* Interrupts should be re-enabled for syscall processing */
		__vmsetie(VM_INT_ENABLE);

		/*
		 * System call number is in r6, arguments in r0..r5.
		 * Fortunately, no Linux syscall has more than 6 arguments,
		 * and Hexagon ABI passes first 6 arguments in registers.
		 * 64-bit arguments are passed in odd/even register pairs.
		 * Fortunately, we have no system calls that take more
		 * than three arguments with more than one 64-bit value.
		 * Should that change, we'd need to redesign to copy
		 * between user and kernel stacks.
		 */
		regs->syscall_nr = regs->r06;

		/*
		 * GPR R0 carries the first parameter, and is also used
		 * to report the return value.  We need a backup of
		 * the user's value in case we need to do a late restart
		 * of the system call.
		 */
		regs->restart_r0 = regs->r00;

		if ((unsigned long) regs->syscall_nr >= __NR_syscalls) {
			regs->r00 = -1;
		} else {
			syscall = (syscall_fn)
				  (sys_call_table[regs->syscall_nr]);
			regs->r00 = syscall(regs->r00, regs->r01,
				   regs->r02, regs->r03,
				   regs->r04, regs->r05);
		}

		/* allow strace to get the syscall return state  */
		if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE)))
			tracehook_report_syscall_exit(regs, 0);

		break;
	case TRAP_DEBUG:
		/* Trap0 0xdb is debug breakpoint */
		if (user_mode(regs)) {
			struct siginfo info;

			info.si_signo = SIGTRAP;
			info.si_errno = 0;
			/*
			 * Some architecures add some per-thread state
			 * to distinguish between breakpoint traps and
			 * trace traps.  We may want to do that, and
			 * set the si_code value appropriately, or we
			 * may want to use a different trap0 flavor.
			 */
			info.si_code = TRAP_BRKPT;
			info.si_addr = (void __user *) pt_elr(regs);
			force_sig_info(SIGTRAP, &info, current);
		} else {
#ifdef CONFIG_KGDB
			kgdb_handle_exception(pt_cause(regs), SIGTRAP,
					      TRAP_BRKPT, regs);
#endif
		}
		break;
	}
	/* Ignore other trap0 codes for now, especially 0 (Angel calls) */
}

/*
 * Machine check exception handler
 */
void do_machcheck(struct pt_regs *regs)
{
	/* Halt and catch fire */
	__vmstop();
}

/*
 * Treat this like the old 0xdb trap.
 */

void do_debug_exception(struct pt_regs *regs)
{
	regs->hvmer.vmest &= ~HVM_VMEST_CAUSE_MSK;
	regs->hvmer.vmest |= (TRAP_DEBUG << HVM_VMEST_CAUSE_SFT);
	do_trap0(regs);
}
Commit	Line	Data
cf9750ba RK	1	/*
	2	* Kernel traps/events for Hexagon processor
	3	*
8914d7e8	4	* Copyright (c) 2010-2014, The Linux Foundation. All rights reserved.
cf9750ba RK	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 and
	8	* only version 2 as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
	18	* 02110-1301, USA.
	19	*/
	20
	21	#include <linux/init.h>
3f07c014	22	#include <linux/sched/signal.h>
b17b0153	23	#include <linux/sched/debug.h>
68db0cf1	24	#include <linux/sched/task_stack.h>
cf9750ba RK	25	#include <linux/module.h>
	26	#include <linux/kallsyms.h>
	27	#include <linux/kdebug.h>
	28	#include <linux/syscalls.h>
	29	#include <linux/signal.h>
	30	#include <linux/tracehook.h>
	31	#include <asm/traps.h>
	32	#include <asm/vm_fault.h>
	33	#include <asm/syscall.h>
	34	#include <asm/registers.h>
	35	#include <asm/unistd.h>
	36	#include <asm/sections.h>
	37	#ifdef CONFIG_KGDB
	38	# include <linux/kgdb.h>
	39	#endif
	40
	41	#define TRAP_SYSCALL 1
	42	#define TRAP_DEBUG 0xdb
	43
	44	void __init trap_init(void)
	45	{
	46	}
	47
	48	#ifdef CONFIG_GENERIC_BUG
	49	/* Maybe should resemble arch/sh/kernel/traps.c ?? */
	50	int is_valid_bugaddr(unsigned long addr)
	51	{
	52	return 1;
	53	}
	54	#endif /* CONFIG_GENERIC_BUG */
	55
	56	static const char *ex_name(int ex)
	57	{
	58	switch (ex) {
	59	case HVM_GE_C_XPROT:
	60	case HVM_GE_C_XUSER:
	61	return "Execute protection fault";
	62	case HVM_GE_C_RPROT:
	63	case HVM_GE_C_RUSER:
	64	return "Read protection fault";
	65	case HVM_GE_C_WPROT:
	66	case HVM_GE_C_WUSER:
	67	return "Write protection fault";
	68	case HVM_GE_C_XMAL:
	69	return "Misaligned instruction";
db0fe532 RK	70	case HVM_GE_C_WREG:
	71	return "Multiple writes to same register in packet";
	72	case HVM_GE_C_PCAL:
	73	return "Program counter values that are not properly aligned";
cf9750ba RK	74	case HVM_GE_C_RMAL:
	75	return "Misaligned data load";
	76	case HVM_GE_C_WMAL:
	77	return "Misaligned data store";
	78	case HVM_GE_C_INVI:
	79	case HVM_GE_C_PRIVI:
	80	return "Illegal instruction";
	81	case HVM_GE_C_BUS:
	82	return "Precise bus error";
	83	case HVM_GE_C_CACHE:
	84	return "Cache error";
	85
	86	case 0xdb:
	87	return "Debugger trap";
	88
	89	default:
	90	return "Unrecognized exception";
	91	}
	92	}
	93
	94	static void do_show_stack(struct task_struct task, unsigned long fp,
	95	unsigned long ip)
	96	{
	97	int kstack_depth_to_print = 24;
	98	unsigned long offset, size;
	99	const char *name = NULL;
	100	unsigned long *newfp;
	101	unsigned long low, high;
	102	char tmpstr[128];
	103	char *modname;
	104	int i;
	105
	106	if (task == NULL)
	107	task = current;
	108
	109	printk(KERN_INFO "CPU#%d, %s/%d, Call Trace:\n",
	110	raw_smp_processor_id(), task->comm,
	111	task_pid_nr(task));
	112
	113	if (fp == NULL) {
	114	if (task == current) {
	115	asm("%0 = r30" : "=r" (fp));
	116	} else {
	117	fp = (unsigned long *)
	118	((struct hexagon_switch_stack *)
	119	task->thread.switch_sp)->fp;
	120	}
	121	}
	122
	123	if ((((unsigned long) fp) & 0x3) \|\| ((unsigned long) fp < 0x1000)) {
	124	printk(KERN_INFO "-- Corrupt frame pointer %p\n", fp);
	125	return;
	126	}
	127
	128	/* Saved link reg is one word above FP */
	129	if (!ip)
	130	ip = *(fp+1);
	131
	132	/* Expect kernel stack to be in-bounds */
	133	low = (unsigned long)task_stack_page(task);
	134	high = low + THREAD_SIZE - 8;
	135	low += sizeof(struct thread_info);
	136
	137	for (i = 0; i < kstack_depth_to_print; i++) {
138
139	name = kallsyms_lookup(ip, &size, &offset, &modname, tmpstr);
140
141	printk(KERN_INFO "[%p] 0x%lx: %s + 0x%lx", fp, ip, name,
142	offset);
143	if (((unsigned long) fp < low) \|\| (high < (unsigned long) fp))
144	printk(KERN_CONT " (FP out of bounds!)");
145	if (modname)
146	printk(KERN_CONT " [%s] ", modname);
147	printk(KERN_CONT "\n");
148
149	newfp = (unsigned long ) fp;
150
151	if (((unsigned long) newfp) & 0x3) {
152	printk(KERN_INFO "-- Corrupt frame pointer %p\n",
153	newfp);
154	break;
155	}
156
157	/* Attempt to continue past exception. */
158	if (0 == newfp) {
159	struct pt_regs regs = (struct pt_regs ) (((void *)fp)
160	+ 8);
161
162	if (regs->syscall_nr != -1) {
163	printk(KERN_INFO "-- trap0 -- syscall_nr: %ld",
164	regs->syscall_nr);
165	printk(KERN_CONT " psp: %lx elr: %lx\n",
166	pt_psp(regs), pt_elr(regs));
167	break;
168	} else {
169	/* really want to see more ... */
170	kstack_depth_to_print += 6;
171	printk(KERN_INFO "-- %s (0x%lx) badva: %lx\n",
172	ex_name(pt_cause(regs)), pt_cause(regs),
173	pt_badva(regs));
174	}
175
176	newfp = (unsigned long *) regs->r30;
177	ip = pt_elr(regs);
178	} else {
179	ip = *(newfp + 1);
180	}
181
182	/* If link reg is null, we are done. */
183	if (ip == 0x0)
184	break;
185
186	/* If newfp isn't larger, we're tracing garbage. */
187	if (newfp > fp)
188	fp = newfp;
189	else
190	break;
191	}
192	}
193
194	void show_stack(struct task_struct task, unsigned long fp)
195	{
196	/* Saved link reg is one word above FP */
197	do_show_stack(task, fp, 0);
198	}
199
cf9750ba RK	200	int die(const char str, struct pt_regs regs, long err)
	201	{
	202	static struct {
	203	spinlock_t lock;
	204	int counter;
	205	} die = {
	206	.lock = __SPIN_LOCK_UNLOCKED(die.lock),
	207	.counter = 0
	208	};
	209
	210	console_verbose();
	211	oops_enter();
	212
	213	spin_lock_irq(&die.lock);
	214	bust_spinlocks(1);
	215	printk(KERN_EMERG "Oops: %s[#%d]:\n", str, ++die.counter);
	216
	217	if (notify_die(DIE_OOPS, str, regs, err, pt_cause(regs), SIGSEGV) ==
	218	NOTIFY_STOP)
	219	return 1;
	220
	221	print_modules();
	222	show_regs(regs);
	223	do_show_stack(current, &regs->r30, pt_elr(regs));
	224
	225	bust_spinlocks(0);
373d4d09	226	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
cf9750ba RK	227
	228	spin_unlock_irq(&die.lock);
	229
	230	if (in_interrupt())
	231	panic("Fatal exception in interrupt");
	232
	233	if (panic_on_oops)
	234	panic("Fatal exception");
	235
	236	oops_exit();
	237	do_exit(err);
	238	return 0;
	239	}
	240
	241	int die_if_kernel(char str, struct pt_regs regs, long err)
	242	{
	243	if (!user_mode(regs))
	244	return die(str, regs, err);
	245	else
	246	return 0;
	247	}
	248
	249	/*
	250	* It's not clear that misaligned fetches are ever recoverable.
	251	*/
	252	static void misaligned_instruction(struct pt_regs *regs)
	253	{
	254	die_if_kernel("Misaligned Instruction", regs, 0);
	255	force_sig(SIGBUS, current);
	256	}
	257
	258	/*
	259	* Misaligned loads and stores, on the other hand, can be
	260	* emulated, and probably should be, some day. But for now
	261	* they will be considered fatal.
	262	*/
	263	static void misaligned_data_load(struct pt_regs *regs)
	264	{
	265	die_if_kernel("Misaligned Data Load", regs, 0);
	266	force_sig(SIGBUS, current);
	267	}
	268
	269	static void misaligned_data_store(struct pt_regs *regs)
	270	{
	271	die_if_kernel("Misaligned Data Store", regs, 0);
	272	force_sig(SIGBUS, current);
	273	}
	274
	275	static void illegal_instruction(struct pt_regs *regs)
	276	{
	277	die_if_kernel("Illegal Instruction", regs, 0);
	278	force_sig(SIGILL, current);
	279	}
	280
	281	/*
	282	* Precise bus errors may be recoverable with a a retry,
	283	* but for now, treat them as irrecoverable.
	284	*/
	285	static void precise_bus_error(struct pt_regs *regs)
	286	{
	287	die_if_kernel("Precise Bus Error", regs, 0);
	288	force_sig(SIGBUS, current);
	289	}
	290
291	/*
292	* If anything is to be done here other than panic,
293	* it will probably be complex and migrate to another
294	* source module. For now, just die.
295	*/
296	static void cache_error(struct pt_regs *regs)
297	{
298	die("Cache Error", regs, 0);
299	}
300
301	/*
302	* General exception handler
303	*/
304	void do_genex(struct pt_regs *regs)
305	{
306	/*
307	* Decode Cause and Dispatch
308	*/
309	switch (pt_cause(regs)) {
310	case HVM_GE_C_XPROT:
311	case HVM_GE_C_XUSER:
312	execute_protection_fault(regs);
313	break;
314	case HVM_GE_C_RPROT:
315	case HVM_GE_C_RUSER:
316	read_protection_fault(regs);
317	break;
318	case HVM_GE_C_WPROT:
319	case HVM_GE_C_WUSER:
320	write_protection_fault(regs);
321	break;
322	case HVM_GE_C_XMAL:
323	misaligned_instruction(regs);
324	break;
db0fe532 RK	325	case HVM_GE_C_WREG:
	326	illegal_instruction(regs);
	327	break;
	328	case HVM_GE_C_PCAL:
	329	misaligned_instruction(regs);
	330	break;
cf9750ba RK	331	case HVM_GE_C_RMAL:
	332	misaligned_data_load(regs);
	333	break;
	334	case HVM_GE_C_WMAL:
	335	misaligned_data_store(regs);
	336	break;
	337	case HVM_GE_C_INVI:
	338	case HVM_GE_C_PRIVI:
	339	illegal_instruction(regs);
	340	break;
	341	case HVM_GE_C_BUS:
	342	precise_bus_error(regs);
	343	break;
	344	case HVM_GE_C_CACHE:
	345	cache_error(regs);
	346	break;
	347	default:
	348	/* Halt and catch fire */
	349	panic("Unrecognized exception 0x%lx\n", pt_cause(regs));
	350	break;
	351	}
	352	}
	353
	354	/* Indirect system call dispatch */
	355	long sys_syscall(void)
	356	{
	357	printk(KERN_ERR "sys_syscall invoked!\n");
	358	return -ENOSYS;
	359	}
	360
	361	void do_trap0(struct pt_regs *regs)
	362	{
cf9750ba RK	363	syscall_fn syscall;
	364
	365	switch (pt_cause(regs)) {
	366	case TRAP_SYSCALL:
	367	/* System call is trap0 #1 */
	368
	369	/* allow strace to catch syscall args */
	370	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE) &&
	371	tracehook_report_syscall_entry(regs)))
	372	return; /* return -ENOSYS somewhere? */
	373
	374	/* Interrupts should be re-enabled for syscall processing */
	375	__vmsetie(VM_INT_ENABLE);
	376
	377	/*
	378	* System call number is in r6, arguments in r0..r5.
	379	* Fortunately, no Linux syscall has more than 6 arguments,
	380	* and Hexagon ABI passes first 6 arguments in registers.
	381	* 64-bit arguments are passed in odd/even register pairs.
	382	* Fortunately, we have no system calls that take more
	383	* than three arguments with more than one 64-bit value.
	384	* Should that change, we'd need to redesign to copy
	385	* between user and kernel stacks.
	386	*/
	387	regs->syscall_nr = regs->r06;
	388
	389	/*
	390	* GPR R0 carries the first parameter, and is also used
	391	* to report the return value. We need a backup of
	392	* the user's value in case we need to do a late restart
	393	* of the system call.
	394	*/
	395	regs->restart_r0 = regs->r00;
	396
	397	if ((unsigned long) regs->syscall_nr >= __NR_syscalls) {
	398	regs->r00 = -1;
	399	} else {
	400	syscall = (syscall_fn)
	401	(sys_call_table[regs->syscall_nr]);
a11e67c2	402	regs->r00 = syscall(regs->r00, regs->r01,
cf9750ba RK	403	regs->r02, regs->r03,
	404	regs->r04, regs->r05);
	405	}
	406
cf9750ba RK	407	/* allow strace to get the syscall return state */
	408	if (unlikely(test_thread_flag(TIF_SYSCALL_TRACE)))
	409	tracehook_report_syscall_exit(regs, 0);
	410
	411	break;
	412	case TRAP_DEBUG:
	413	/* Trap0 0xdb is debug breakpoint */
	414	if (user_mode(regs)) {
	415	struct siginfo info;
	416
	417	info.si_signo = SIGTRAP;
	418	info.si_errno = 0;
	419	/*
	420	* Some architecures add some per-thread state
	421	* to distinguish between breakpoint traps and
	422	* trace traps. We may want to do that, and
	423	* set the si_code value appropriately, or we
	424	* may want to use a different trap0 flavor.
	425	*/
	426	info.si_code = TRAP_BRKPT;
	427	info.si_addr = (void __user *) pt_elr(regs);
8914d7e8	428	force_sig_info(SIGTRAP, &info, current);
cf9750ba RK	429	} else {
	430	#ifdef CONFIG_KGDB
	431	kgdb_handle_exception(pt_cause(regs), SIGTRAP,
	432	TRAP_BRKPT, regs);
	433	#endif
	434	}
	435	break;
	436	}
	437	/* Ignore other trap0 codes for now, especially 0 (Angel calls) */
	438	}
	439
	440	/*
	441	* Machine check exception handler
	442	*/
	443	void do_machcheck(struct pt_regs *regs)
	444	{
	445	/* Halt and catch fire */
	446	__vmstop();
	447	}
7777746c RK	448
	449	/*
	450	* Treat this like the old 0xdb trap.
	451	*/
	452
	453	void do_debug_exception(struct pt_regs *regs)
	454	{
	455	regs->hvmer.vmest &= ~HVM_VMEST_CAUSE_MSK;
	456	regs->hvmer.vmest \|= (TRAP_DEBUG << HVM_VMEST_CAUSE_SFT);
	457	do_trap0(regs);
	458	}