[linux.git] / arch / arm64 / kernel / traps.c

/*
 * Based on arch/arm/kernel/traps.c
 *
 * Copyright (C) 1995-2009 Russell King
 * Copyright (C) 2012 ARM Ltd.
 *
 * 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.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/signal.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/syscalls.h>

#include <asm/atomic.h>
#include <asm/traps.h>
#include <asm/stacktrace.h>
#include <asm/exception.h>
#include <asm/system_misc.h>

static const char *handler[]= {
	"Synchronous Abort",
	"IRQ",
	"FIQ",
	"Error"
};

int show_unhandled_signals = 1;

/*
 * Dump out the contents of some memory nicely...
 */
static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
		     unsigned long top)
{
	unsigned long first;
	mm_segment_t fs;
	int i;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);

	for (first = bottom & ~31; first < top; first += 32) {
		unsigned long p;
		char str[sizeof(" 12345678") * 8 + 1];

		memset(str, ' ', sizeof(str));
		str[sizeof(str) - 1] = '\0';

		for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
			if (p >= bottom && p < top) {
				unsigned int val;
				if (__get_user(val, (unsigned int *)p) == 0)
					sprintf(str + i * 9, " %08x", val);
				else
					sprintf(str + i * 9, " ????????");
			}
		}
		printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
	}

	set_fs(fs);
}

static void dump_backtrace_entry(unsigned long where, unsigned long stack)
{
	print_ip_sym(where);
	if (in_exception_text(where))
		dump_mem("", "Exception stack", stack,
			 stack + sizeof(struct pt_regs));
}

static void dump_instr(const char *lvl, struct pt_regs *regs)
{
	unsigned long addr = instruction_pointer(regs);
	mm_segment_t fs;
	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
	int i;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	for (i = -4; i < 1; i++) {
		unsigned int val, bad;

		bad = __get_user(val, &((u32 *)addr)[i]);

		if (!bad)
			p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
		else {
			p += sprintf(p, "bad PC value");
			break;
		}
	}
	printk("%sCode: %s\n", lvl, str);

	set_fs(fs);
}

static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
	struct stackframe frame;
	const register unsigned long current_sp asm ("sp");

	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);

	if (!tsk)
		tsk = current;

	if (regs) {
		frame.fp = regs->regs[29];
		frame.sp = regs->sp;
		frame.pc = regs->pc;
	} else if (tsk == current) {
		frame.fp = (unsigned long)__builtin_frame_address(0);
		frame.sp = current_sp;
		frame.pc = (unsigned long)dump_backtrace;
	} else {
		/*
		 * task blocked in __switch_to
		 */
		frame.fp = thread_saved_fp(tsk);
		frame.sp = thread_saved_sp(tsk);
		frame.pc = thread_saved_pc(tsk);
	}

	printk("Call trace:\n");
	while (1) {
		unsigned long where = frame.pc;
		int ret;

		ret = unwind_frame(&frame);
		if (ret < 0)
			break;
		dump_backtrace_entry(where, frame.sp);
	}
}

void show_stack(struct task_struct *tsk, unsigned long *sp)
{
	dump_backtrace(NULL, tsk);
	barrier();
}

#ifdef CONFIG_PREEMPT
#define S_PREEMPT " PREEMPT"
#else
#define S_PREEMPT ""
#endif
#ifdef CONFIG_SMP
#define S_SMP " SMP"
#else
#define S_SMP ""
#endif

static int __die(const char *str, int err, struct thread_info *thread,
		 struct pt_regs *regs)
{
	struct task_struct *tsk = thread->task;
	static int die_counter;
	int ret;

	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
		 str, err, ++die_counter);

	/* trap and error numbers are mostly meaningless on ARM */
	ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
	if (ret == NOTIFY_STOP)
		return ret;

	print_modules();
	__show_regs(regs);
	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);

	if (!user_mode(regs) || in_interrupt()) {
		dump_mem(KERN_EMERG, "Stack: ", regs->sp,
			 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
		dump_backtrace(regs, tsk);
		dump_instr(KERN_EMERG, regs);
	}

	return ret;
}

static DEFINE_RAW_SPINLOCK(die_lock);

/*
 * This function is protected against re-entrancy.
 */
void die(const char *str, struct pt_regs *regs, int err)
{
	struct thread_info *thread = current_thread_info();
	int ret;

	oops_enter();

	raw_spin_lock_irq(&die_lock);
	console_verbose();
	bust_spinlocks(1);
	ret = __die(str, err, thread, regs);

	if (regs && kexec_should_crash(thread->task))
		crash_kexec(regs);

	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	raw_spin_unlock_irq(&die_lock);
	oops_exit();

	if (in_interrupt())
		panic("Fatal exception in interrupt");
	if (panic_on_oops)
		panic("Fatal exception");
	if (ret != NOTIFY_STOP)
		do_exit(SIGSEGV);
}

void arm64_notify_die(const char *str, struct pt_regs *regs,
		      struct siginfo *info, int err)
{
	if (user_mode(regs))
		force_sig_info(info->si_signo, info, current);
	else
		die(str, regs, err);
}

asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
	siginfo_t info;
	void __user *pc = (void __user *)instruction_pointer(regs);

#ifdef CONFIG_COMPAT
	/* check for AArch32 breakpoint instructions */
	if (compat_user_mode(regs) && aarch32_break_trap(regs) == 0)
		return;
#endif

	if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
	    printk_ratelimit()) {
		pr_info("%s[%d]: undefined instruction: pc=%p\n",
			current->comm, task_pid_nr(current), pc);
		dump_instr(KERN_INFO, regs);
	}

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code  = ILL_ILLOPC;
	info.si_addr  = pc;

	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
}

long compat_arm_syscall(struct pt_regs *regs);

asmlinkage long do_ni_syscall(struct pt_regs *regs)
{
#ifdef CONFIG_COMPAT
	long ret;
	if (is_compat_task()) {
		ret = compat_arm_syscall(regs);
		if (ret != -ENOSYS)
			return ret;
	}
#endif

	if (show_unhandled_signals && printk_ratelimit()) {
		pr_info("%s[%d]: syscall %d\n", current->comm,
			task_pid_nr(current), (int)regs->syscallno);
		dump_instr("", regs);
		if (user_mode(regs))
			__show_regs(regs);
	}

	return sys_ni_syscall();
}

/*
 * bad_mode handles the impossible case in the exception vector.
 */
asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
{
	siginfo_t info;
	void __user *pc = (void __user *)instruction_pointer(regs);
	console_verbose();

	pr_crit("Bad mode in %s handler detected, code 0x%08x\n",
		handler[reason], esr);
	__show_regs(regs);

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code  = ILL_ILLOPC;
	info.si_addr  = pc;

	arm64_notify_die("Oops - bad mode", regs, &info, 0);
}

void __pte_error(const char *file, int line, unsigned long val)
{
	printk("%s:%d: bad pte %016lx.\n", file, line, val);
}

void __pmd_error(const char *file, int line, unsigned long val)
{
	printk("%s:%d: bad pmd %016lx.\n", file, line, val);
}

void __pgd_error(const char *file, int line, unsigned long val)
{
	printk("%s:%d: bad pgd %016lx.\n", file, line, val);
}

void __init trap_init(void)
{
	return;
}
Commit	Line	Data
60ffc30d CM	1	/*
	2	* Based on arch/arm/kernel/traps.c
	3	*
	4	* Copyright (C) 1995-2009 Russell King
	5	* Copyright (C) 2012 ARM Ltd.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
	20	#include <linux/signal.h>
	21	#include <linux/personality.h>
	22	#include <linux/kallsyms.h>
	23	#include <linux/spinlock.h>
	24	#include <linux/uaccess.h>
	25	#include <linux/hardirq.h>
	26	#include <linux/kdebug.h>
	27	#include <linux/module.h>
	28	#include <linux/kexec.h>
	29	#include <linux/delay.h>
	30	#include <linux/init.h>
	31	#include <linux/sched.h>
	32	#include <linux/syscalls.h>
	33
	34	#include <asm/atomic.h>
	35	#include <asm/traps.h>
	36	#include <asm/stacktrace.h>
	37	#include <asm/exception.h>
	38	#include <asm/system_misc.h>
	39
	40	static const char *handler[]= {
	41	"Synchronous Abort",
	42	"IRQ",
	43	"FIQ",
	44	"Error"
	45	};
	46
	47	int show_unhandled_signals = 1;
	48
	49	/*
	50	* Dump out the contents of some memory nicely...
	51	*/
	52	static void dump_mem(const char lvl, const char str, unsigned long bottom,
	53	unsigned long top)
	54	{
	55	unsigned long first;
	56	mm_segment_t fs;
	57	int i;
	58
	59	/*
	60	* We need to switch to kernel mode so that we can use __get_user
	61	* to safely read from kernel space. Note that we now dump the
	62	* code first, just in case the backtrace kills us.
	63	*/
	64	fs = get_fs();
65	set_fs(KERNEL_DS);
66
67	printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);
68
69	for (first = bottom & ~31; first < top; first += 32) {
70	unsigned long p;
71	char str[sizeof(" 12345678") * 8 + 1];
72
73	memset(str, ' ', sizeof(str));
74	str[sizeof(str) - 1] = '\0';
75
76	for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
77	if (p >= bottom && p < top) {
78	unsigned int val;
79	if (__get_user(val, (unsigned int *)p) == 0)
80	sprintf(str + i * 9, " %08x", val);
81	else
82	sprintf(str + i * 9, " ????????");
83	}
84	}
85	printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
86	}
87
88	set_fs(fs);
89	}
90
91	static void dump_backtrace_entry(unsigned long where, unsigned long stack)
92	{
93	print_ip_sym(where);
94	if (in_exception_text(where))
95	dump_mem("", "Exception stack", stack,
96	stack + sizeof(struct pt_regs));
97	}
98
99	static void dump_instr(const char lvl, struct pt_regs regs)
100	{
101	unsigned long addr = instruction_pointer(regs);
102	mm_segment_t fs;
103	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
104	int i;
105
106	/*
107	* We need to switch to kernel mode so that we can use __get_user
108	* to safely read from kernel space. Note that we now dump the
109	* code first, just in case the backtrace kills us.
110	*/
111	fs = get_fs();
112	set_fs(KERNEL_DS);
113
114	for (i = -4; i < 1; i++) {
115	unsigned int val, bad;
116
117	bad = __get_user(val, &((u32 *)addr)[i]);
118
119	if (!bad)
120	p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
121	else {
122	p += sprintf(p, "bad PC value");
123	break;
124	}
125	}
126	printk("%sCode: %s\n", lvl, str);
127
128	set_fs(fs);
129	}
130
131	static void dump_backtrace(struct pt_regs regs, struct task_struct tsk)
132	{
133	struct stackframe frame;
134	const register unsigned long current_sp asm ("sp");
135
136	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
137
138	if (!tsk)
139	tsk = current;
140
141	if (regs) {
142	frame.fp = regs->regs[29];
143	frame.sp = regs->sp;
144	frame.pc = regs->pc;
145	} else if (tsk == current) {
146	frame.fp = (unsigned long)__builtin_frame_address(0);
147	frame.sp = current_sp;
148	frame.pc = (unsigned long)dump_backtrace;
149	} else {
150	/*
151	* task blocked in __switch_to
152	*/
153	frame.fp = thread_saved_fp(tsk);
154	frame.sp = thread_saved_sp(tsk);
155	frame.pc = thread_saved_pc(tsk);
156	}
157
158	printk("Call trace:\n");
159	while (1) {
160	unsigned long where = frame.pc;
161	int ret;
162
163	ret = unwind_frame(&frame);
164	if (ret < 0)
165	break;
166	dump_backtrace_entry(where, frame.sp);
167	}
168	}
169
60ffc30d CM	170	void show_stack(struct task_struct tsk, unsigned long sp)
	171	{
	172	dump_backtrace(NULL, tsk);
	173	barrier();
	174	}
	175
	176	#ifdef CONFIG_PREEMPT
	177	#define S_PREEMPT " PREEMPT"
	178	#else
	179	#define S_PREEMPT ""
	180	#endif
	181	#ifdef CONFIG_SMP
	182	#define S_SMP " SMP"
	183	#else
	184	#define S_SMP ""
	185	#endif
	186
	187	static int __die(const char str, int err, struct thread_info thread,
	188	struct pt_regs *regs)
	189	{
	190	struct task_struct *tsk = thread->task;
	191	static int die_counter;
	192	int ret;
	193
	194	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
	195	str, err, ++die_counter);
	196
	197	/* trap and error numbers are mostly meaningless on ARM */
	198	ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
	199	if (ret == NOTIFY_STOP)
	200	return ret;
	201
	202	print_modules();
	203	__show_regs(regs);
	204	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
	205	TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
	206
	207	if (!user_mode(regs) \|\| in_interrupt()) {
	208	dump_mem(KERN_EMERG, "Stack: ", regs->sp,
	209	THREAD_SIZE + (unsigned long)task_stack_page(tsk));
	210	dump_backtrace(regs, tsk);
	211	dump_instr(KERN_EMERG, regs);
	212	}
	213
	214	return ret;
	215	}
	216
	217	static DEFINE_RAW_SPINLOCK(die_lock);
	218
	219	/*
	220	* This function is protected against re-entrancy.
	221	*/
	222	void die(const char str, struct pt_regs regs, int err)
	223	{
	224	struct thread_info *thread = current_thread_info();
	225	int ret;
	226
	227	oops_enter();
	228
	229	raw_spin_lock_irq(&die_lock);
	230	console_verbose();
	231	bust_spinlocks(1);
	232	ret = __die(str, err, thread, regs);
	233
234	if (regs && kexec_should_crash(thread->task))
235	crash_kexec(regs);
236
237	bust_spinlocks(0);
373d4d09	238	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
60ffc30d CM	239	raw_spin_unlock_irq(&die_lock);
	240	oops_exit();
	241
	242	if (in_interrupt())
	243	panic("Fatal exception in interrupt");
	244	if (panic_on_oops)
	245	panic("Fatal exception");
	246	if (ret != NOTIFY_STOP)
	247	do_exit(SIGSEGV);
	248	}
	249
	250	void arm64_notify_die(const char str, struct pt_regs regs,
	251	struct siginfo *info, int err)
	252	{
	253	if (user_mode(regs))
	254	force_sig_info(info->si_signo, info, current);
	255	else
	256	die(str, regs, err);
	257	}
	258
	259	asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
	260	{
	261	siginfo_t info;
	262	void __user pc = (void __user )instruction_pointer(regs);
	263
	264	#ifdef CONFIG_COMPAT
	265	/* check for AArch32 breakpoint instructions */
	266	if (compat_user_mode(regs) && aarch32_break_trap(regs) == 0)
	267	return;
	268	#endif
	269
953dbbed CM	270	if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
953dbbed CM	271	printk_ratelimit()) {
60ffc30d CM	272	pr_info("%s[%d]: undefined instruction: pc=%p\n",
	273	current->comm, task_pid_nr(current), pc);
	274	dump_instr(KERN_INFO, regs);
	275	}
	276
	277	info.si_signo = SIGILL;
	278	info.si_errno = 0;
	279	info.si_code = ILL_ILLOPC;
	280	info.si_addr = pc;
	281
	282	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
	283	}
	284
	285	long compat_arm_syscall(struct pt_regs *regs);
	286
	287	asmlinkage long do_ni_syscall(struct pt_regs *regs)
	288	{
	289	#ifdef CONFIG_COMPAT
	290	long ret;
	291	if (is_compat_task()) {
	292	ret = compat_arm_syscall(regs);
	293	if (ret != -ENOSYS)
	294	return ret;
	295	}
	296	#endif
	297
953dbbed	298	if (show_unhandled_signals && printk_ratelimit()) {
60ffc30d CM	299	pr_info("%s[%d]: syscall %d\n", current->comm,
	300	task_pid_nr(current), (int)regs->syscallno);
	301	dump_instr("", regs);
	302	if (user_mode(regs))
	303	__show_regs(regs);
	304	}
	305
	306	return sys_ni_syscall();
	307	}
	308
	309	/*
	310	* bad_mode handles the impossible case in the exception vector.
	311	*/
	312	asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
	313	{
9955ac47 MR	314	siginfo_t info;
9955ac47 MR	315	void __user pc = (void __user )instruction_pointer(regs);
60ffc30d CM	316	console_verbose();
	317
	318	pr_crit("Bad mode in %s handler detected, code 0x%08x\n",
	319	handler[reason], esr);
9955ac47 MR	320	__show_regs(regs);
	321
	322	info.si_signo = SIGILL;
	323	info.si_errno = 0;
	324	info.si_code = ILL_ILLOPC;
	325	info.si_addr = pc;
60ffc30d	326
9955ac47	327	arm64_notify_die("Oops - bad mode", regs, &info, 0);
60ffc30d CM	328	}
	329
	330	void __pte_error(const char *file, int line, unsigned long val)
	331	{
	332	printk("%s:%d: bad pte %016lx.\n", file, line, val);
	333	}
	334
	335	void __pmd_error(const char *file, int line, unsigned long val)
	336	{
	337	printk("%s:%d: bad pmd %016lx.\n", file, line, val);
	338	}
	339
	340	void __pgd_error(const char *file, int line, unsigned long val)
	341	{
	342	printk("%s:%d: bad pgd %016lx.\n", file, line, val);
	343	}
	344
	345	void __init trap_init(void)
	346	{
	347	return;
	348	}