[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 thread_info *ti;
	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() */
	ti			= task_thread_info(task);
	gdb_regs[_R4]		= ti->cpu_context.r4;
	gdb_regs[_R5]		= ti->cpu_context.r5;
	gdb_regs[_R6]		= ti->cpu_context.r6;
	gdb_regs[_R7]		= ti->cpu_context.r7;
	gdb_regs[_R8]		= ti->cpu_context.r8;
	gdb_regs[_R9]		= ti->cpu_context.r9;
	gdb_regs[_R10]		= ti->cpu_context.sl;
	gdb_regs[_FP]		= ti->cpu_context.fp;
	gdb_regs[_SPT]		= ti->cpu_context.sp;
	gdb_regs[_PC]		= ti->cpu_context.pc;
}

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;

	/* Machine is already stopped, so we can use __patch_text() directly */
	__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)
{
	/* Machine is already stopped, so we can use __patch_text() directly */
	__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	{
001bf455	77	struct thread_info *ti;
5cbad0eb JW	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() */
001bf455 DA	89	ti = task_thread_info(task);
	90	gdb_regs[_R4] = ti->cpu_context.r4;
	91	gdb_regs[_R5] = ti->cpu_context.r5;
	92	gdb_regs[_R6] = ti->cpu_context.r6;
	93	gdb_regs[_R7] = ti->cpu_context.r7;
	94	gdb_regs[_R8] = ti->cpu_context.r8;
	95	gdb_regs[_R9] = ti->cpu_context.r9;
	96	gdb_regs[_R10] = ti->cpu_context.sl;
	97	gdb_regs[_FP] = ti->cpu_context.fp;
	98	gdb_regs[_SPT] = ti->cpu_context.sp;
	99	gdb_regs[_PC] = ti->cpu_context.pc;
5cbad0eb JW	100	}
5cbad0eb JW	101
dcc78711 JW	102	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	103	{
	104	regs->ARM_pc = pc;
	105	}
	106
5cbad0eb JW	107	static int compiled_break;
	108
	109	int kgdb_arch_handle_exception(int exception_vector, int signo,
	110	int err_code, char *remcom_in_buffer,
	111	char *remcom_out_buffer,
	112	struct pt_regs *linux_regs)
	113	{
	114	unsigned long addr;
	115	char *ptr;
	116
	117	switch (remcom_in_buffer[0]) {
	118	case 'D':
	119	case 'k':
	120	case 'c':
5cbad0eb JW	121	/*
	122	* Try to read optional parameter, pc unchanged if no parm.
	123	* If this was a compiled breakpoint, we need to move
	124	* to the next instruction or we will just breakpoint
	125	* over and over again.
	126	*/
	127	ptr = &remcom_in_buffer[1];
	128	if (kgdb_hex2long(&ptr, &addr))
	129	linux_regs->ARM_pc = addr;
	130	else if (compiled_break == 1)
	131	linux_regs->ARM_pc += 4;
	132
	133	compiled_break = 0;
	134
	135	return 0;
	136	}
	137
	138	return -1;
	139	}
	140
	141	static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
	142	{
	143	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	144
	145	return 0;
	146	}
	147
	148	static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
	149	{
	150	compiled_break = 1;
	151	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	152
	153	return 0;
	154	}
	155
	156	static struct undef_hook kgdb_brkpt_hook = {
	157	.instr_mask = 0xffffffff,
	158	.instr_val = KGDB_BREAKINST,
6bf755db OS	159	.cpsr_mask = MODE_MASK,
6bf755db OS	160	.cpsr_val = SVC_MODE,
5cbad0eb JW	161	.fn = kgdb_brk_fn
	162	};
	163
	164	static struct undef_hook kgdb_compiled_brkpt_hook = {
	165	.instr_mask = 0xffffffff,
	166	.instr_val = KGDB_COMPILED_BREAK,
6bf755db OS	167	.cpsr_mask = MODE_MASK,
6bf755db OS	168	.cpsr_val = SVC_MODE,
5cbad0eb JW	169	.fn = kgdb_compiled_brk_fn
	170	};
	171
5d8614cc WD	172	static void kgdb_call_nmi_hook(void *ignored)
	173	{
	174	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
	175	}
	176
	177	void kgdb_roundup_cpus(unsigned long flags)
	178	{
	179	local_irq_enable();
	180	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
	181	local_irq_disable();
	182	}
	183
62a0309c JW	184	static int __kgdb_notify(struct die_args *args, unsigned long cmd)
	185	{
	186	struct pt_regs *regs = args->regs;
	187
	188	if (kgdb_handle_exception(1, args->signr, cmd, regs))
	189	return NOTIFY_DONE;
	190	return NOTIFY_STOP;
	191	}
	192	static int
	193	kgdb_notify(struct notifier_block self, unsigned long cmd, void ptr)
	194	{
	195	unsigned long flags;
	196	int ret;
	197
	198	local_irq_save(flags);
	199	ret = __kgdb_notify(ptr, cmd);
	200	local_irq_restore(flags);
	201
	202	return ret;
	203	}
	204
	205	static struct notifier_block kgdb_notifier = {
	206	.notifier_call = kgdb_notify,
	207	.priority = -INT_MAX,
	208	};
	209
	210
5cbad0eb JW	211	/**
	212	* kgdb_arch_init - Perform any architecture specific initalization.
	213	*
	214	* This function will handle the initalization of any architecture
	215	* specific callbacks.
	216	*/
	217	int kgdb_arch_init(void)
	218	{
62a0309c JW	219	int ret = register_die_notifier(&kgdb_notifier);
	220
	221	if (ret != 0)
	222	return ret;
	223
5cbad0eb JW	224	register_undef_hook(&kgdb_brkpt_hook);
	225	register_undef_hook(&kgdb_compiled_brkpt_hook);
	226
	227	return 0;
	228	}
	229
	230	/**
	231	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	232	*
	233	* This function will handle the uninitalization of any architecture
	234	* specific callbacks, for dynamic registration and unregistration.
	235	*/
	236	void kgdb_arch_exit(void)
	237	{
	238	unregister_undef_hook(&kgdb_brkpt_hook);
	239	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
62a0309c	240	unregister_die_notifier(&kgdb_notifier);
5cbad0eb JW	241	}
5cbad0eb JW	242
23a4e405 DA	243	int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
	244	{
	245	int err;
	246
	247	/* patch_text() only supports int-sized breakpoints */
	248	BUILD_BUG_ON(sizeof(int) != BREAK_INSTR_SIZE);
	249
	250	err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
	251	BREAK_INSTR_SIZE);
	252	if (err)
	253	return err;
	254
7ae85dc7 DA	255	/* Machine is already stopped, so we can use __patch_text() directly */
	256	__patch_text((void *)bpt->bpt_addr,
	257	(unsigned int )arch_kgdb_ops.gdb_bpt_instr);
23a4e405 DA	258
	259	return err;
	260	}
	261
	262	int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
	263	{
7ae85dc7 DA	264	/* Machine is already stopped, so we can use __patch_text() directly */
7ae85dc7 DA	265	__patch_text((void )bpt->bpt_addr, (unsigned int *)bpt->saved_instr);
23a4e405 DA	266
	267	return 0;
	268	}
	269
5cbad0eb JW	270	/*
	271	* Register our undef instruction hooks with ARM undef core.
	272	* We regsiter a hook specifically looking for the KGB break inst
	273	* and we handle the normal undef case within the do_undefinstr
	274	* handler.
	275	*/
	276	struct kgdb_arch arch_kgdb_ops = {
	277	#ifndef __ARMEB__
	278	.gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
	279	#else /* ! __ARMEB__ */
	280	.gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
	281	#endif
	282	};