[mirror_ubuntu-jammy-kernel.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/debug-monitors.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);
	}

	pr_emerg("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)) {
		current->thread.fault_address = 0;
		current->thread.fault_code = err;
		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);

	/* check for AArch32 breakpoint instructions */
	if (!aarch32_break_handler(regs))
		return;

	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)
{
	pr_crit("%s:%d: bad pte %016lx.\n", file, line, val);
}

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

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

void __pgd_error(const char *file, int line, unsigned long val)
{
	pr_crit("%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>
1442b6ed	35	#include <asm/debug-monitors.h>
60ffc30d CM	36	#include <asm/traps.h>
	37	#include <asm/stacktrace.h>
	38	#include <asm/exception.h>
	39	#include <asm/system_misc.h>
	40
	41	static const char *handler[]= {
	42	"Synchronous Abort",
	43	"IRQ",
	44	"FIQ",
	45	"Error"
	46	};
	47
	48	int show_unhandled_signals = 1;
	49
	50	/*
	51	* Dump out the contents of some memory nicely...
	52	*/
	53	static void dump_mem(const char lvl, const char str, unsigned long bottom,
	54	unsigned long top)
	55	{
	56	unsigned long first;
	57	mm_segment_t fs;
	58	int i;
	59
	60	/*
	61	* We need to switch to kernel mode so that we can use __get_user
	62	* to safely read from kernel space. Note that we now dump the
	63	* code first, just in case the backtrace kills us.
	64	*/
	65	fs = get_fs();
	66	set_fs(KERNEL_DS);
	67
	68	printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);
	69
	70	for (first = bottom & ~31; first < top; first += 32) {
	71	unsigned long p;
	72	char str[sizeof(" 12345678") * 8 + 1];
	73
	74	memset(str, ' ', sizeof(str));
	75	str[sizeof(str) - 1] = '\0';
	76
	77	for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
	78	if (p >= bottom && p < top) {
	79	unsigned int val;
	80	if (__get_user(val, (unsigned int *)p) == 0)
	81	sprintf(str + i * 9, " %08x", val);
	82	else
	83	sprintf(str + i * 9, " ????????");
	84	}
	85	}
	86	printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
	87	}
	88
	89	set_fs(fs);
	90	}
	91
	92	static void dump_backtrace_entry(unsigned long where, unsigned long stack)
	93	{
	94	print_ip_sym(where);
	95	if (in_exception_text(where))
	96	dump_mem("", "Exception stack", stack,
	97	stack + sizeof(struct pt_regs));
	98	}
	99
100	static void dump_instr(const char lvl, struct pt_regs regs)
101	{
102	unsigned long addr = instruction_pointer(regs);
103	mm_segment_t fs;
104	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
105	int i;
106
107	/*
108	* We need to switch to kernel mode so that we can use __get_user
109	* to safely read from kernel space. Note that we now dump the
110	* code first, just in case the backtrace kills us.
111	*/
112	fs = get_fs();
113	set_fs(KERNEL_DS);
114
115	for (i = -4; i < 1; i++) {
116	unsigned int val, bad;
117
118	bad = __get_user(val, &((u32 *)addr)[i]);
119
120	if (!bad)
121	p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
122	else {
123	p += sprintf(p, "bad PC value");
124	break;
125	}
126	}
127	printk("%sCode: %s\n", lvl, str);
128
129	set_fs(fs);
130	}
131
132	static void dump_backtrace(struct pt_regs regs, struct task_struct tsk)
133	{
134	struct stackframe frame;
135	const register unsigned long current_sp asm ("sp");
136
137	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
138
139	if (!tsk)
140	tsk = current;
141
142	if (regs) {
143	frame.fp = regs->regs[29];
144	frame.sp = regs->sp;
145	frame.pc = regs->pc;
146	} else if (tsk == current) {
147	frame.fp = (unsigned long)__builtin_frame_address(0);
148	frame.sp = current_sp;
149	frame.pc = (unsigned long)dump_backtrace;
150	} else {
151	/*
152	* task blocked in __switch_to
153	*/
154	frame.fp = thread_saved_fp(tsk);
155	frame.sp = thread_saved_sp(tsk);
156	frame.pc = thread_saved_pc(tsk);
157	}
158
ac7b406c	159	pr_emerg("Call trace:\n");
60ffc30d CM	160	while (1) {
	161	unsigned long where = frame.pc;
	162	int ret;
	163
	164	ret = unwind_frame(&frame);
	165	if (ret < 0)
	166	break;
	167	dump_backtrace_entry(where, frame.sp);
	168	}
	169	}
	170
60ffc30d CM	171	void show_stack(struct task_struct tsk, unsigned long sp)
	172	{
	173	dump_backtrace(NULL, tsk);
	174	barrier();
	175	}
	176
	177	#ifdef CONFIG_PREEMPT
	178	#define S_PREEMPT " PREEMPT"
	179	#else
	180	#define S_PREEMPT ""
	181	#endif
	182	#ifdef CONFIG_SMP
	183	#define S_SMP " SMP"
	184	#else
	185	#define S_SMP ""
	186	#endif
	187
	188	static int __die(const char str, int err, struct thread_info thread,
	189	struct pt_regs *regs)
	190	{
	191	struct task_struct *tsk = thread->task;
	192	static int die_counter;
	193	int ret;
	194
	195	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
	196	str, err, ++die_counter);
	197
	198	/* trap and error numbers are mostly meaningless on ARM */
	199	ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
	200	if (ret == NOTIFY_STOP)
	201	return ret;
	202
	203	print_modules();
	204	__show_regs(regs);
	205	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
	206	TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
	207
	208	if (!user_mode(regs) \|\| in_interrupt()) {
	209	dump_mem(KERN_EMERG, "Stack: ", regs->sp,
	210	THREAD_SIZE + (unsigned long)task_stack_page(tsk));
	211	dump_backtrace(regs, tsk);
	212	dump_instr(KERN_EMERG, regs);
	213	}
	214
	215	return ret;
	216	}
	217
	218	static DEFINE_RAW_SPINLOCK(die_lock);
	219
	220	/*
	221	* This function is protected against re-entrancy.
	222	*/
	223	void die(const char str, struct pt_regs regs, int err)
	224	{
	225	struct thread_info *thread = current_thread_info();
	226	int ret;
	227
	228	oops_enter();
	229
	230	raw_spin_lock_irq(&die_lock);
	231	console_verbose();
	232	bust_spinlocks(1);
	233	ret = __die(str, err, thread, regs);
	234
235	if (regs && kexec_should_crash(thread->task))
236	crash_kexec(regs);
237
238	bust_spinlocks(0);
373d4d09	239	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
60ffc30d CM	240	raw_spin_unlock_irq(&die_lock);
	241	oops_exit();
	242
	243	if (in_interrupt())
	244	panic("Fatal exception in interrupt");
	245	if (panic_on_oops)
	246	panic("Fatal exception");
	247	if (ret != NOTIFY_STOP)
	248	do_exit(SIGSEGV);
	249	}
	250
	251	void arm64_notify_die(const char str, struct pt_regs regs,
	252	struct siginfo *info, int err)
	253	{
9141300a CM	254	if (user_mode(regs)) {
	255	current->thread.fault_address = 0;
	256	current->thread.fault_code = err;
60ffc30d	257	force_sig_info(info->si_signo, info, current);
9141300a	258	} else {
60ffc30d	259	die(str, regs, err);
9141300a	260	}
60ffc30d CM	261	}
	262
	263	asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
	264	{
	265	siginfo_t info;
	266	void __user pc = (void __user )instruction_pointer(regs);
	267
60ffc30d	268	/* check for AArch32 breakpoint instructions */
1442b6ed	269	if (!aarch32_break_handler(regs))
60ffc30d	270	return;
60ffc30d	271
953dbbed CM	272	if (show_unhandled_signals && unhandled_signal(current, SIGILL) &&
953dbbed CM	273	printk_ratelimit()) {
60ffc30d CM	274	pr_info("%s[%d]: undefined instruction: pc=%p\n",
	275	current->comm, task_pid_nr(current), pc);
	276	dump_instr(KERN_INFO, regs);
	277	}
	278
	279	info.si_signo = SIGILL;
	280	info.si_errno = 0;
	281	info.si_code = ILL_ILLOPC;
	282	info.si_addr = pc;
	283
	284	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
	285	}
	286
	287	long compat_arm_syscall(struct pt_regs *regs);
	288
	289	asmlinkage long do_ni_syscall(struct pt_regs *regs)
	290	{
	291	#ifdef CONFIG_COMPAT
	292	long ret;
	293	if (is_compat_task()) {
	294	ret = compat_arm_syscall(regs);
	295	if (ret != -ENOSYS)
	296	return ret;
	297	}
	298	#endif
	299
953dbbed	300	if (show_unhandled_signals && printk_ratelimit()) {
60ffc30d CM	301	pr_info("%s[%d]: syscall %d\n", current->comm,
	302	task_pid_nr(current), (int)regs->syscallno);
	303	dump_instr("", regs);
	304	if (user_mode(regs))
	305	__show_regs(regs);
	306	}
	307
	308	return sys_ni_syscall();
	309	}
	310
	311	/*
	312	* bad_mode handles the impossible case in the exception vector.
	313	*/
	314	asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
	315	{
9955ac47 MR	316	siginfo_t info;
9955ac47 MR	317	void __user pc = (void __user )instruction_pointer(regs);
60ffc30d CM	318	console_verbose();
	319
	320	pr_crit("Bad mode in %s handler detected, code 0x%08x\n",
	321	handler[reason], esr);
9955ac47 MR	322	__show_regs(regs);
	323
	324	info.si_signo = SIGILL;
	325	info.si_errno = 0;
	326	info.si_code = ILL_ILLOPC;
	327	info.si_addr = pc;
60ffc30d	328
9955ac47	329	arm64_notify_die("Oops - bad mode", regs, &info, 0);
60ffc30d CM	330	}
	331
	332	void __pte_error(const char *file, int line, unsigned long val)
	333	{
ac7b406c	334	pr_crit("%s:%d: bad pte %016lx.\n", file, line, val);
60ffc30d CM	335	}
	336
	337	void __pmd_error(const char *file, int line, unsigned long val)
	338	{
ac7b406c	339	pr_crit("%s:%d: bad pmd %016lx.\n", file, line, val);
60ffc30d CM	340	}
60ffc30d CM	341
c79b954b JL	342	void __pud_error(const char *file, int line, unsigned long val)
	343	{
	344	pr_crit("%s:%d: bad pud %016lx.\n", file, line, val);
	345	}
	346
60ffc30d CM	347	void __pgd_error(const char *file, int line, unsigned long val)
60ffc30d CM	348	{
ac7b406c	349	pr_crit("%s:%d: bad pgd %016lx.\n", file, line, val);
60ffc30d CM	350	}
	351
	352	void __init trap_init(void)
	353	{
	354	return;
	355	}