[deliverable/linux.git] / arch / arm / kernel / kgdb.c

/*
 * arch/arm/kernel/kgdb.c
 *
 * ARM KGDB support
 *
 * Copyright (c) 2002-2004 MontaVista Software, Inc
 * Copyright (c) 2008 Wind River Systems, Inc.
 *
 * Authors:  George Davis <davis_g@mvista.com>
 *           Deepak Saxena <dsaxena@plexity.net>
 */
#include <linux/irq.h>
#include <linux/kdebug.h>
#include <linux/kgdb.h>
#include <linux/uaccess.h>

#include <asm/patch.h>
#include <asm/traps.h>

struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
{
	{ "r0", 4, offsetof(struct pt_regs, ARM_r0)},
	{ "r1", 4, offsetof(struct pt_regs, ARM_r1)},
	{ "r2", 4, offsetof(struct pt_regs, ARM_r2)},
	{ "r3", 4, offsetof(struct pt_regs, ARM_r3)},
	{ "r4", 4, offsetof(struct pt_regs, ARM_r4)},
	{ "r5", 4, offsetof(struct pt_regs, ARM_r5)},
	{ "r6", 4, offsetof(struct pt_regs, ARM_r6)},
	{ "r7", 4, offsetof(struct pt_regs, ARM_r7)},
	{ "r8", 4, offsetof(struct pt_regs, ARM_r8)},
	{ "r9", 4, offsetof(struct pt_regs, ARM_r9)},
	{ "r10", 4, offsetof(struct pt_regs, ARM_r10)},
	{ "fp", 4, offsetof(struct pt_regs, ARM_fp)},
	{ "ip", 4, offsetof(struct pt_regs, ARM_ip)},
	{ "sp", 4, offsetof(struct pt_regs, ARM_sp)},
	{ "lr", 4, offsetof(struct pt_regs, ARM_lr)},
	{ "pc", 4, offsetof(struct pt_regs, ARM_pc)},
	{ "f0", 12, -1 },
	{ "f1", 12, -1 },
	{ "f2", 12, -1 },
	{ "f3", 12, -1 },
	{ "f4", 12, -1 },
	{ "f5", 12, -1 },
	{ "f6", 12, -1 },
	{ "f7", 12, -1 },
	{ "fps", 4, -1 },
	{ "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
};

char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
{
	if (regno >= DBG_MAX_REG_NUM || regno < 0)
		return NULL;

	if (dbg_reg_def[regno].offset != -1)
		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
		       dbg_reg_def[regno].size);
	else
		memset(mem, 0, dbg_reg_def[regno].size);
	return dbg_reg_def[regno].name;
}

int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
{
	if (regno >= DBG_MAX_REG_NUM || regno < 0)
		return -EINVAL;

	if (dbg_reg_def[regno].offset != -1)
		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
		       dbg_reg_def[regno].size);
	return 0;
}

void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
{
	struct pt_regs *thread_regs;
	int regno;

	/* Just making sure... */
	if (task == NULL)
		return;

	/* Initialize to zero */
	for (regno = 0; regno < GDB_MAX_REGS; regno++)
		gdb_regs[regno] = 0;

	/* Otherwise, we have only some registers from switch_to() */
	thread_regs		= task_pt_regs(task);
	gdb_regs[_R0]		= thread_regs->ARM_r0;
	gdb_regs[_R1]		= thread_regs->ARM_r1;
	gdb_regs[_R2]		= thread_regs->ARM_r2;
	gdb_regs[_R3]		= thread_regs->ARM_r3;
	gdb_regs[_R4]		= thread_regs->ARM_r4;
	gdb_regs[_R5]		= thread_regs->ARM_r5;
	gdb_regs[_R6]		= thread_regs->ARM_r6;
	gdb_regs[_R7]		= thread_regs->ARM_r7;
	gdb_regs[_R8]		= thread_regs->ARM_r8;
	gdb_regs[_R9]		= thread_regs->ARM_r9;
	gdb_regs[_R10]		= thread_regs->ARM_r10;
	gdb_regs[_FP]		= thread_regs->ARM_fp;
	gdb_regs[_IP]		= thread_regs->ARM_ip;
	gdb_regs[_SPT]		= thread_regs->ARM_sp;
	gdb_regs[_LR]		= thread_regs->ARM_lr;
	gdb_regs[_PC]		= thread_regs->ARM_pc;
	gdb_regs[_CPSR]		= thread_regs->ARM_cpsr;
}

void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
{
	regs->ARM_pc = pc;
}

static int compiled_break;

int kgdb_arch_handle_exception(int exception_vector, int signo,
			       int err_code, char *remcom_in_buffer,
			       char *remcom_out_buffer,
			       struct pt_regs *linux_regs)
{
	unsigned long addr;
	char *ptr;

	switch (remcom_in_buffer[0]) {
	case 'D':
	case 'k':
	case 'c':
		/*
		 * Try to read optional parameter, pc unchanged if no parm.
		 * If this was a compiled breakpoint, we need to move
		 * to the next instruction or we will just breakpoint
		 * over and over again.
		 */
		ptr = &remcom_in_buffer[1];
		if (kgdb_hex2long(&ptr, &addr))
			linux_regs->ARM_pc = addr;
		else if (compiled_break == 1)
			linux_regs->ARM_pc += 4;

		compiled_break = 0;

		return 0;
	}

	return -1;
}

static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
{
	kgdb_handle_exception(1, SIGTRAP, 0, regs);

	return 0;
}

static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
{
	compiled_break = 1;
	kgdb_handle_exception(1, SIGTRAP, 0, regs);

	return 0;
}

static struct undef_hook kgdb_brkpt_hook = {
	.instr_mask		= 0xffffffff,
	.instr_val		= KGDB_BREAKINST,
	.cpsr_mask		= MODE_MASK,
	.cpsr_val		= SVC_MODE,
	.fn			= kgdb_brk_fn
};

static struct undef_hook kgdb_compiled_brkpt_hook = {
	.instr_mask		= 0xffffffff,
	.instr_val		= KGDB_COMPILED_BREAK,
	.cpsr_mask		= MODE_MASK,
	.cpsr_val		= SVC_MODE,
	.fn			= kgdb_compiled_brk_fn
};

static void kgdb_call_nmi_hook(void *ignored)
{
       kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
}

void kgdb_roundup_cpus(unsigned long flags)
{
       local_irq_enable();
       smp_call_function(kgdb_call_nmi_hook, NULL, 0);
       local_irq_disable();
}

static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
	struct pt_regs *regs = args->regs;

	if (kgdb_handle_exception(1, args->signr, cmd, regs))
		return NOTIFY_DONE;
	return NOTIFY_STOP;
}
static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
	unsigned long flags;
	int ret;

	local_irq_save(flags);
	ret = __kgdb_notify(ptr, cmd);
	local_irq_restore(flags);

	return ret;
}

static struct notifier_block kgdb_notifier = {
	.notifier_call	= kgdb_notify,
	.priority	= -INT_MAX,
};


/**
 *	kgdb_arch_init - Perform any architecture specific initalization.
 *
 *	This function will handle the initalization of any architecture
 *	specific callbacks.
 */
int kgdb_arch_init(void)
{
	int ret = register_die_notifier(&kgdb_notifier);

	if (ret != 0)
		return ret;

	register_undef_hook(&kgdb_brkpt_hook);
	register_undef_hook(&kgdb_compiled_brkpt_hook);

	return 0;
}

/**
 *	kgdb_arch_exit - Perform any architecture specific uninitalization.
 *
 *	This function will handle the uninitalization of any architecture
 *	specific callbacks, for dynamic registration and unregistration.
 */
void kgdb_arch_exit(void)
{
	unregister_undef_hook(&kgdb_brkpt_hook);
	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
	unregister_die_notifier(&kgdb_notifier);
}

int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
{
	int err;

	/* patch_text() only supports int-sized breakpoints */
	BUILD_BUG_ON(sizeof(int) != BREAK_INSTR_SIZE);

	err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
				BREAK_INSTR_SIZE);
	if (err)
		return err;

	patch_text((void *)bpt->bpt_addr,
		   *(unsigned int *)arch_kgdb_ops.gdb_bpt_instr);

	return err;
}

int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
{
	patch_text((void *)bpt->bpt_addr, *(unsigned int *)bpt->saved_instr);

	return 0;
}

/*
 * Register our undef instruction hooks with ARM undef core.
 * We regsiter a hook specifically looking for the KGB break inst
 * and we handle the normal undef case within the do_undefinstr
 * handler.
 */
struct kgdb_arch arch_kgdb_ops = {
#ifndef __ARMEB__
	.gdb_bpt_instr		= {0xfe, 0xde, 0xff, 0xe7}
#else /* ! __ARMEB__ */
	.gdb_bpt_instr		= {0xe7, 0xff, 0xde, 0xfe}
#endif
};
Commit	Line	Data
5cbad0eb JW	1	/*
	2	* arch/arm/kernel/kgdb.c
	3	*
	4	* ARM KGDB support
	5	*
	6	* Copyright (c) 2002-2004 MontaVista Software, Inc
	7	* Copyright (c) 2008 Wind River Systems, Inc.
	8	*
	9	* Authors: George Davis <davis_g@mvista.com>
	10	* Deepak Saxena <dsaxena@plexity.net>
	11	*/
5d8614cc	12	#include <linux/irq.h>
62a0309c	13	#include <linux/kdebug.h>
5cbad0eb	14	#include <linux/kgdb.h>
23a4e405 DA	15	#include <linux/uaccess.h>
23a4e405 DA	16
fca08f32	17	#include <asm/patch.h>
5cbad0eb JW	18	#include <asm/traps.h>
5cbad0eb JW	19
22eeef4b	20	struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
5cbad0eb	21	{
22eeef4b JW	22	{ "r0", 4, offsetof(struct pt_regs, ARM_r0)},
	23	{ "r1", 4, offsetof(struct pt_regs, ARM_r1)},
	24	{ "r2", 4, offsetof(struct pt_regs, ARM_r2)},
	25	{ "r3", 4, offsetof(struct pt_regs, ARM_r3)},
	26	{ "r4", 4, offsetof(struct pt_regs, ARM_r4)},
	27	{ "r5", 4, offsetof(struct pt_regs, ARM_r5)},
	28	{ "r6", 4, offsetof(struct pt_regs, ARM_r6)},
	29	{ "r7", 4, offsetof(struct pt_regs, ARM_r7)},
	30	{ "r8", 4, offsetof(struct pt_regs, ARM_r8)},
	31	{ "r9", 4, offsetof(struct pt_regs, ARM_r9)},
	32	{ "r10", 4, offsetof(struct pt_regs, ARM_r10)},
	33	{ "fp", 4, offsetof(struct pt_regs, ARM_fp)},
	34	{ "ip", 4, offsetof(struct pt_regs, ARM_ip)},
	35	{ "sp", 4, offsetof(struct pt_regs, ARM_sp)},
	36	{ "lr", 4, offsetof(struct pt_regs, ARM_lr)},
	37	{ "pc", 4, offsetof(struct pt_regs, ARM_pc)},
	38	{ "f0", 12, -1 },
	39	{ "f1", 12, -1 },
	40	{ "f2", 12, -1 },
	41	{ "f3", 12, -1 },
	42	{ "f4", 12, -1 },
	43	{ "f5", 12, -1 },
	44	{ "f6", 12, -1 },
	45	{ "f7", 12, -1 },
	46	{ "fps", 4, -1 },
	47	{ "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
	48	};
5cbad0eb	49
22eeef4b JW	50	char dbg_get_reg(int regno, void mem, struct pt_regs *regs)
	51	{
	52	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
	53	return NULL;
5cbad0eb	54
22eeef4b JW	55	if (dbg_reg_def[regno].offset != -1)
	56	memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
	57	dbg_reg_def[regno].size);
	58	else
	59	memset(mem, 0, dbg_reg_def[regno].size);
	60	return dbg_reg_def[regno].name;
5cbad0eb JW	61	}
5cbad0eb JW	62
22eeef4b	63	int dbg_set_reg(int regno, void mem, struct pt_regs regs)
5cbad0eb	64	{
22eeef4b JW	65	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
	66	return -EINVAL;
	67
	68	if (dbg_reg_def[regno].offset != -1)
	69	memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
	70	dbg_reg_def[regno].size);
	71	return 0;
5cbad0eb JW	72	}
	73
	74	void
	75	sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct task)
	76	{
	77	struct pt_regs *thread_regs;
	78	int regno;
	79
	80	/* Just making sure... */
	81	if (task == NULL)
	82	return;
	83
	84	/* Initialize to zero */
834b2964	85	for (regno = 0; regno < GDB_MAX_REGS; regno++)
5cbad0eb JW	86	gdb_regs[regno] = 0;
	87
	88	/* Otherwise, we have only some registers from switch_to() */
	89	thread_regs = task_pt_regs(task);
	90	gdb_regs[_R0] = thread_regs->ARM_r0;
	91	gdb_regs[_R1] = thread_regs->ARM_r1;
	92	gdb_regs[_R2] = thread_regs->ARM_r2;
	93	gdb_regs[_R3] = thread_regs->ARM_r3;
	94	gdb_regs[_R4] = thread_regs->ARM_r4;
	95	gdb_regs[_R5] = thread_regs->ARM_r5;
	96	gdb_regs[_R6] = thread_regs->ARM_r6;
	97	gdb_regs[_R7] = thread_regs->ARM_r7;
	98	gdb_regs[_R8] = thread_regs->ARM_r8;
	99	gdb_regs[_R9] = thread_regs->ARM_r9;
	100	gdb_regs[_R10] = thread_regs->ARM_r10;
	101	gdb_regs[_FP] = thread_regs->ARM_fp;
	102	gdb_regs[_IP] = thread_regs->ARM_ip;
	103	gdb_regs[_SPT] = thread_regs->ARM_sp;
	104	gdb_regs[_LR] = thread_regs->ARM_lr;
	105	gdb_regs[_PC] = thread_regs->ARM_pc;
	106	gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
	107	}
	108
dcc78711 JW	109	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	110	{
	111	regs->ARM_pc = pc;
	112	}
	113
5cbad0eb JW	114	static int compiled_break;
	115
	116	int kgdb_arch_handle_exception(int exception_vector, int signo,
	117	int err_code, char *remcom_in_buffer,
	118	char *remcom_out_buffer,
	119	struct pt_regs *linux_regs)
	120	{
	121	unsigned long addr;
	122	char *ptr;
	123
	124	switch (remcom_in_buffer[0]) {
	125	case 'D':
	126	case 'k':
	127	case 'c':
5cbad0eb JW	128	/*
	129	* Try to read optional parameter, pc unchanged if no parm.
	130	* If this was a compiled breakpoint, we need to move
	131	* to the next instruction or we will just breakpoint
	132	* over and over again.
	133	*/
	134	ptr = &remcom_in_buffer[1];
	135	if (kgdb_hex2long(&ptr, &addr))
	136	linux_regs->ARM_pc = addr;
	137	else if (compiled_break == 1)
	138	linux_regs->ARM_pc += 4;
	139
	140	compiled_break = 0;
	141
	142	return 0;
	143	}
	144
	145	return -1;
	146	}
	147
	148	static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
	149	{
	150	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	151
	152	return 0;
	153	}
	154
	155	static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
	156	{
	157	compiled_break = 1;
	158	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	159
	160	return 0;
	161	}
	162
	163	static struct undef_hook kgdb_brkpt_hook = {
	164	.instr_mask = 0xffffffff,
	165	.instr_val = KGDB_BREAKINST,
6bf755db OS	166	.cpsr_mask = MODE_MASK,
6bf755db OS	167	.cpsr_val = SVC_MODE,
5cbad0eb JW	168	.fn = kgdb_brk_fn
	169	};
	170
	171	static struct undef_hook kgdb_compiled_brkpt_hook = {
	172	.instr_mask = 0xffffffff,
	173	.instr_val = KGDB_COMPILED_BREAK,
6bf755db OS	174	.cpsr_mask = MODE_MASK,
6bf755db OS	175	.cpsr_val = SVC_MODE,
5cbad0eb JW	176	.fn = kgdb_compiled_brk_fn
	177	};
	178
5d8614cc WD	179	static void kgdb_call_nmi_hook(void *ignored)
	180	{
	181	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
	182	}
	183
	184	void kgdb_roundup_cpus(unsigned long flags)
	185	{
	186	local_irq_enable();
	187	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
	188	local_irq_disable();
	189	}
	190
62a0309c JW	191	static int __kgdb_notify(struct die_args *args, unsigned long cmd)
	192	{
	193	struct pt_regs *regs = args->regs;
	194
	195	if (kgdb_handle_exception(1, args->signr, cmd, regs))
	196	return NOTIFY_DONE;
	197	return NOTIFY_STOP;
	198	}
	199	static int
	200	kgdb_notify(struct notifier_block self, unsigned long cmd, void ptr)
	201	{
	202	unsigned long flags;
	203	int ret;
	204
	205	local_irq_save(flags);
	206	ret = __kgdb_notify(ptr, cmd);
	207	local_irq_restore(flags);
	208
	209	return ret;
	210	}
	211
	212	static struct notifier_block kgdb_notifier = {
	213	.notifier_call = kgdb_notify,
	214	.priority = -INT_MAX,
	215	};
	216
	217
5cbad0eb JW	218	/**
	219	* kgdb_arch_init - Perform any architecture specific initalization.
	220	*
	221	* This function will handle the initalization of any architecture
	222	* specific callbacks.
	223	*/
	224	int kgdb_arch_init(void)
	225	{
62a0309c JW	226	int ret = register_die_notifier(&kgdb_notifier);
	227
	228	if (ret != 0)
	229	return ret;
	230
5cbad0eb JW	231	register_undef_hook(&kgdb_brkpt_hook);
	232	register_undef_hook(&kgdb_compiled_brkpt_hook);
	233
	234	return 0;
	235	}
	236
	237	/**
	238	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	239	*
	240	* This function will handle the uninitalization of any architecture
	241	* specific callbacks, for dynamic registration and unregistration.
	242	*/
	243	void kgdb_arch_exit(void)
	244	{
	245	unregister_undef_hook(&kgdb_brkpt_hook);
	246	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
62a0309c	247	unregister_die_notifier(&kgdb_notifier);
5cbad0eb JW	248	}
5cbad0eb JW	249
23a4e405 DA	250	int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
	251	{
	252	int err;
	253
	254	/* patch_text() only supports int-sized breakpoints */
	255	BUILD_BUG_ON(sizeof(int) != BREAK_INSTR_SIZE);
	256
	257	err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
	258	BREAK_INSTR_SIZE);
	259	if (err)
	260	return err;
	261
	262	patch_text((void *)bpt->bpt_addr,
	263	(unsigned int )arch_kgdb_ops.gdb_bpt_instr);
	264
	265	return err;
	266	}
	267
	268	int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
	269	{
	270	patch_text((void )bpt->bpt_addr, (unsigned int *)bpt->saved_instr);
	271
	272	return 0;
	273	}
	274
5cbad0eb JW	275	/*
	276	* Register our undef instruction hooks with ARM undef core.
	277	* We regsiter a hook specifically looking for the KGB break inst
	278	* and we handle the normal undef case within the do_undefinstr
	279	* handler.
	280	*/
	281	struct kgdb_arch arch_kgdb_ops = {
	282	#ifndef __ARMEB__
	283	.gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
	284	#else /* ! __ARMEB__ */
	285	.gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
	286	#endif
	287	};