[linux-2.6-block.git] / arch / unicore32 / kernel / traps.c

/*
 * linux/arch/unicore32/kernel/traps.c
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * 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.
 *
 *  'traps.c' handles hardware exceptions after we have saved some state.
 *  Mostly a debugging aid, but will probably kill the offending process.
 */
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/spinlock.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/kdebug.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/atomic.h>
#include <linux/unistd.h>

#include <asm/cacheflush.h>
#include <asm/system.h>
#include <asm/traps.h>

#include "setup.h"

static void dump_mem(const char *, const char *, unsigned long, unsigned long);

void dump_backtrace_entry(unsigned long where,
		unsigned long from, unsigned long frame)
{
#ifdef CONFIG_KALLSYMS
	printk(KERN_DEFAULT "[<%08lx>] (%pS) from [<%08lx>] (%pS)\n",
			where, (void *)where, from, (void *)from);
#else
	printk(KERN_DEFAULT "Function entered at [<%08lx>] from [<%08lx>]\n",
			where, from);
#endif
}

/*
 * Stack pointers should always be within the kernels view of
 * physical memory.  If it is not there, then we can't dump
 * out any information relating to the stack.
 */
static int verify_stack(unsigned long sp)
{
	if (sp < PAGE_OFFSET ||
	    (sp > (unsigned long)high_memory && high_memory != NULL))
		return -EFAULT;

	return 0;
}

/*
 * 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(KERN_DEFAULT "%s%s(0x%08lx to 0x%08lx)\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 long val;
				if (__get_user(val, (unsigned long *)p) == 0)
					sprintf(str + i * 9, " %08lx", val);
				else
					sprintf(str + i * 9, " ????????");
			}
		}
		printk(KERN_DEFAULT "%s%04lx:%s\n", lvl, first & 0xffff, str);
	}

	set_fs(fs);
}

static void dump_instr(const char *lvl, struct pt_regs *regs)
{
	unsigned long addr = instruction_pointer(regs);
	const int width = 8;
	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 ? "(%0*x) " : "%0*x ",
					width, val);
		else {
			p += sprintf(p, "bad PC value");
			break;
		}
	}
	printk(KERN_DEFAULT "%sCode: %s\n", lvl, str);

	set_fs(fs);
}

static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
	unsigned int fp, mode;
	int ok = 1;

	printk(KERN_DEFAULT "Backtrace: ");

	if (!tsk)
		tsk = current;

	if (regs) {
		fp = regs->UCreg_fp;
		mode = processor_mode(regs);
	} else if (tsk != current) {
		fp = thread_saved_fp(tsk);
		mode = 0x10;
	} else {
		asm("mov %0, fp" : "=r" (fp) : : "cc");
		mode = 0x10;
	}

	if (!fp) {
		printk("no frame pointer");
		ok = 0;
	} else if (verify_stack(fp)) {
		printk("invalid frame pointer 0x%08x", fp);
		ok = 0;
	} else if (fp < (unsigned long)end_of_stack(tsk))
		printk("frame pointer underflow");
	printk("\n");

	if (ok)
		c_backtrace(fp, mode);
}

void dump_stack(void)
{
	dump_backtrace(NULL, NULL);
}
EXPORT_SYMBOL(dump_stack);

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

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;

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

	/* trap and error numbers are mostly meaningless on UniCore */
	ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, \
			SIGSEGV);
	if (ret == NOTIFY_STOP)
		return ret;

	print_modules();
	__show_regs(regs);
	printk(KERN_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->UCreg_sp,
			 THREAD_SIZE + (unsigned long)task_stack_page(tsk));
		dump_backtrace(regs, tsk);
		dump_instr(KERN_EMERG, regs);
	}

	return ret;
}

DEFINE_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();

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

	bust_spinlocks(0);
	add_taint(TAINT_DIE);
	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 uc32_notify_die(const char *str, struct pt_regs *regs,
		struct siginfo *info, unsigned long err, unsigned long trap)
{
	if (user_mode(regs)) {
		current->thread.error_code = err;
		current->thread.trap_no = trap;

		force_sig_info(info->si_signo, info, current);
	} else
		die(str, regs, err);
}

/*
 * bad_mode handles the impossible case in the vectors.  If you see one of
 * these, then it's extremely serious, and could mean you have buggy hardware.
 * It never returns, and never tries to sync.  We hope that we can at least
 * dump out some state information...
 */
asmlinkage void bad_mode(struct pt_regs *regs, unsigned int reason)
{
	console_verbose();

	printk(KERN_CRIT "Bad mode detected with reason 0x%x\n", reason);

	die("Oops - bad mode", regs, 0);
	local_irq_disable();
	panic("bad mode");
}

void __pte_error(const char *file, int line, unsigned long val)
{
	printk(KERN_DEFAULT "%s:%d: bad pte %08lx.\n", file, line, val);
}

void __pmd_error(const char *file, int line, unsigned long val)
{
	printk(KERN_DEFAULT "%s:%d: bad pmd %08lx.\n", file, line, val);
}

void __pgd_error(const char *file, int line, unsigned long val)
{
	printk(KERN_DEFAULT "%s:%d: bad pgd %08lx.\n", file, line, val);
}

asmlinkage void __div0(void)
{
	printk(KERN_DEFAULT "Division by zero in kernel.\n");
	dump_stack();
}
EXPORT_SYMBOL(__div0);

void abort(void)
{
	BUG();

	/* if that doesn't kill us, halt */
	panic("Oops failed to kill thread");
}
EXPORT_SYMBOL(abort);

void __init trap_init(void)
{
	return;
}

void __init early_trap_init(void)
{
	unsigned long vectors = VECTORS_BASE;

	/*
	 * Copy the vectors, stubs (in entry-unicore.S)
	 * into the vector page, mapped at 0xffff0000, and ensure these
	 * are visible to the instruction stream.
	 */
	memcpy((void *)vectors,
			__vectors_start,
			__vectors_end - __vectors_start);
	memcpy((void *)vectors + 0x200,
			__stubs_start,
			__stubs_end - __stubs_start);

	early_signal_init();

	flush_icache_range(vectors, vectors + PAGE_SIZE);
}
Commit	Line	Data
141c943f G	1	/*
	2	* linux/arch/unicore32/kernel/traps.c
	3	*
	4	* Code specific to PKUnity SoC and UniCore ISA
	5	*
	6	* Copyright (C) 2001-2010 GUAN Xue-tao
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	* 'traps.c' handles hardware exceptions after we have saved some state.
	13	* Mostly a debugging aid, but will probably kill the offending process.
	14	*/
	15	#include <linux/module.h>
	16	#include <linux/signal.h>
	17	#include <linux/spinlock.h>
	18	#include <linux/personality.h>
	19	#include <linux/kallsyms.h>
	20	#include <linux/kdebug.h>
	21	#include <linux/uaccess.h>
	22	#include <linux/delay.h>
	23	#include <linux/hardirq.h>
	24	#include <linux/init.h>
141c943f G	25	#include <linux/atomic.h>
	26	#include <linux/unistd.h>
	27
	28	#include <asm/cacheflush.h>
	29	#include <asm/system.h>
	30	#include <asm/traps.h>
	31
	32	#include "setup.h"
	33
	34	static void dump_mem(const char , const char , unsigned long, unsigned long);
	35
	36	void dump_backtrace_entry(unsigned long where,
	37	unsigned long from, unsigned long frame)
	38	{
	39	#ifdef CONFIG_KALLSYMS
	40	printk(KERN_DEFAULT "[<%08lx>] (%pS) from [<%08lx>] (%pS)\n",
	41	where, (void )where, from, (void )from);
	42	#else
	43	printk(KERN_DEFAULT "Function entered at [<%08lx>] from [<%08lx>]\n",
	44	where, from);
	45	#endif
	46	}
	47
	48	/*
	49	* Stack pointers should always be within the kernels view of
	50	* physical memory. If it is not there, then we can't dump
	51	* out any information relating to the stack.
	52	*/
	53	static int verify_stack(unsigned long sp)
	54	{
	55	if (sp < PAGE_OFFSET \|\|
	56	(sp > (unsigned long)high_memory && high_memory != NULL))
	57	return -EFAULT;
	58
	59	return 0;
	60	}
	61
	62	/*
	63	* Dump out the contents of some memory nicely...
	64	*/
	65	static void dump_mem(const char lvl, const char str, unsigned long bottom,
	66	unsigned long top)
	67	{
	68	unsigned long first;
	69	mm_segment_t fs;
	70	int i;
	71
	72	/*
	73	* We need to switch to kernel mode so that we can use __get_user
	74	* to safely read from kernel space. Note that we now dump the
	75	* code first, just in case the backtrace kills us.
	76	*/
	77	fs = get_fs();
	78	set_fs(KERNEL_DS);
	79
	80	printk(KERN_DEFAULT "%s%s(0x%08lx to 0x%08lx)\n",
	81	lvl, str, bottom, top);
	82
	83	for (first = bottom & ~31; first < top; first += 32) {
	84	unsigned long p;
	85	char str[sizeof(" 12345678") * 8 + 1];
	86
	87	memset(str, ' ', sizeof(str));
	88	str[sizeof(str) - 1] = '\0';
89
90	for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
91	if (p >= bottom && p < top) {
92	unsigned long val;
93	if (__get_user(val, (unsigned long *)p) == 0)
94	sprintf(str + i * 9, " %08lx", val);
95	else
96	sprintf(str + i * 9, " ????????");
97	}
98	}
99	printk(KERN_DEFAULT "%s%04lx:%s\n", lvl, first & 0xffff, str);
100	}
101
102	set_fs(fs);
103	}
104
105	static void dump_instr(const char lvl, struct pt_regs regs)
106	{
107	unsigned long addr = instruction_pointer(regs);
108	const int width = 8;
109	mm_segment_t fs;
110	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
111	int i;
112
113	/*
114	* We need to switch to kernel mode so that we can use __get_user
115	* to safely read from kernel space. Note that we now dump the
116	* code first, just in case the backtrace kills us.
117	*/
118	fs = get_fs();
119	set_fs(KERNEL_DS);
120
121	for (i = -4; i < 1; i++) {
122	unsigned int val, bad;
123
124	bad = __get_user(val, &((u32 *)addr)[i]);
125
126	if (!bad)
127	p += sprintf(p, i == 0 ? "(%0x) " : "%0x ",
128	width, val);
129	else {
130	p += sprintf(p, "bad PC value");
131	break;
132	}
133	}
134	printk(KERN_DEFAULT "%sCode: %s\n", lvl, str);
135
136	set_fs(fs);
137	}
138
139	static void dump_backtrace(struct pt_regs regs, struct task_struct tsk)
140	{
141	unsigned int fp, mode;
142	int ok = 1;
143
144	printk(KERN_DEFAULT "Backtrace: ");
145
146	if (!tsk)
147	tsk = current;
148
149	if (regs) {
150	fp = regs->UCreg_fp;
151	mode = processor_mode(regs);
152	} else if (tsk != current) {
153	fp = thread_saved_fp(tsk);
154	mode = 0x10;
155	} else {
156	asm("mov %0, fp" : "=r" (fp) : : "cc");
157	mode = 0x10;
158	}
159
160	if (!fp) {
161	printk("no frame pointer");
162	ok = 0;
163	} else if (verify_stack(fp)) {
164	printk("invalid frame pointer 0x%08x", fp);
165	ok = 0;
166	} else if (fp < (unsigned long)end_of_stack(tsk))
167	printk("frame pointer underflow");
168	printk("\n");
169
170	if (ok)
171	c_backtrace(fp, mode);
172	}
173
174	void dump_stack(void)
175	{
176	dump_backtrace(NULL, NULL);
177	}
178	EXPORT_SYMBOL(dump_stack);
179
180	void show_stack(struct task_struct tsk, unsigned long sp)
181	{
182	dump_backtrace(NULL, tsk);
183	barrier();
184	}
185
186	static int __die(const char str, int err, struct thread_info thread,
187	struct pt_regs *regs)
188	{
189	struct task_struct *tsk = thread->task;
190	static int die_counter;
191	int ret;
192
193	printk(KERN_EMERG "Internal error: %s: %x [#%d]\n",
194	str, err, ++die_counter);
141c943f G	195
	196	/* trap and error numbers are mostly meaningless on UniCore */
	197	ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, \
	198	SIGSEGV);
	199	if (ret == NOTIFY_STOP)
	200	return ret;
	201
	202	print_modules();
	203	__show_regs(regs);
	204	printk(KERN_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->UCreg_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	DEFINE_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	spin_lock_irq(&die_lock);
	230	console_verbose();
	231	bust_spinlocks(1);
	232	ret = __die(str, err, thread, regs);
	233
	234	bust_spinlocks(0);
	235	add_taint(TAINT_DIE);
	236	spin_unlock_irq(&die_lock);
	237	oops_exit();
	238
	239	if (in_interrupt())
	240	panic("Fatal exception in interrupt");
	241	if (panic_on_oops)
	242	panic("Fatal exception");
	243	if (ret != NOTIFY_STOP)
	244	do_exit(SIGSEGV);
	245	}
	246
	247	void uc32_notify_die(const char str, struct pt_regs regs,
	248	struct siginfo *info, unsigned long err, unsigned long trap)
	249	{
	250	if (user_mode(regs)) {
	251	current->thread.error_code = err;
	252	current->thread.trap_no = trap;
	253
	254	force_sig_info(info->si_signo, info, current);
	255	} else
	256	die(str, regs, err);
	257	}
	258
259	/*
260	* bad_mode handles the impossible case in the vectors. If you see one of
261	* these, then it's extremely serious, and could mean you have buggy hardware.
262	* It never returns, and never tries to sync. We hope that we can at least
263	* dump out some state information...
264	*/
265	asmlinkage void bad_mode(struct pt_regs *regs, unsigned int reason)
266	{
267	console_verbose();
268
269	printk(KERN_CRIT "Bad mode detected with reason 0x%x\n", reason);
270
271	die("Oops - bad mode", regs, 0);
272	local_irq_disable();
273	panic("bad mode");
274	}
275
276	void __pte_error(const char *file, int line, unsigned long val)
277	{
278	printk(KERN_DEFAULT "%s:%d: bad pte %08lx.\n", file, line, val);
279	}
280
281	void __pmd_error(const char *file, int line, unsigned long val)
282	{
283	printk(KERN_DEFAULT "%s:%d: bad pmd %08lx.\n", file, line, val);
284	}
285
286	void __pgd_error(const char *file, int line, unsigned long val)
287	{
288	printk(KERN_DEFAULT "%s:%d: bad pgd %08lx.\n", file, line, val);
289	}
290
291	asmlinkage void __div0(void)
292	{
293	printk(KERN_DEFAULT "Division by zero in kernel.\n");
294	dump_stack();
295	}
296	EXPORT_SYMBOL(__div0);
297
298	void abort(void)
299	{
300	BUG();
301
302	/* if that doesn't kill us, halt */
303	panic("Oops failed to kill thread");
304	}
305	EXPORT_SYMBOL(abort);
306
307	void __init trap_init(void)
308	{
309	return;
310	}
311
312	void __init early_trap_init(void)
313	{
314	unsigned long vectors = VECTORS_BASE;
315
316	/*
317	* Copy the vectors, stubs (in entry-unicore.S)
318	* into the vector page, mapped at 0xffff0000, and ensure these
319	* are visible to the instruction stream.
320	*/
321	memcpy((void *)vectors,
322	__vectors_start,
323	__vectors_end - __vectors_start);
324	memcpy((void *)vectors + 0x200,
325	__stubs_start,
326	__stubs_end - __stubs_start);
327
328	early_signal_init();
329
330	flush_icache_range(vectors, vectors + PAGE_SIZE);
331	}