summaryrefslogtreecommitdiff
path: root/arch/arm/kernel/kgdb.c
blob: ba8ccfede964d93a81c061633bd969916d85ebd5 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
/*
 * 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/kgdb.h>
#include <asm/traps.h>

/* Make a local copy of the registers passed into the handler (bletch) */
void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
{
	int regno;

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

	gdb_regs[_R0]		= kernel_regs->ARM_r0;
	gdb_regs[_R1]		= kernel_regs->ARM_r1;
	gdb_regs[_R2]		= kernel_regs->ARM_r2;
	gdb_regs[_R3]		= kernel_regs->ARM_r3;
	gdb_regs[_R4]		= kernel_regs->ARM_r4;
	gdb_regs[_R5]		= kernel_regs->ARM_r5;
	gdb_regs[_R6]		= kernel_regs->ARM_r6;
	gdb_regs[_R7]		= kernel_regs->ARM_r7;
	gdb_regs[_R8]		= kernel_regs->ARM_r8;
	gdb_regs[_R9]		= kernel_regs->ARM_r9;
	gdb_regs[_R10]		= kernel_regs->ARM_r10;
	gdb_regs[_FP]		= kernel_regs->ARM_fp;
	gdb_regs[_IP]		= kernel_regs->ARM_ip;
	gdb_regs[_SPT]		= kernel_regs->ARM_sp;
	gdb_regs[_LR]		= kernel_regs->ARM_lr;
	gdb_regs[_PC]		= kernel_regs->ARM_pc;
	gdb_regs[_CPSR]		= kernel_regs->ARM_cpsr;
}

/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
{
	kernel_regs->ARM_r0	= gdb_regs[_R0];
	kernel_regs->ARM_r1	= gdb_regs[_R1];
	kernel_regs->ARM_r2	= gdb_regs[_R2];
	kernel_regs->ARM_r3	= gdb_regs[_R3];
	kernel_regs->ARM_r4	= gdb_regs[_R4];
	kernel_regs->ARM_r5	= gdb_regs[_R5];
	kernel_regs->ARM_r6	= gdb_regs[_R6];
	kernel_regs->ARM_r7	= gdb_regs[_R7];
	kernel_regs->ARM_r8	= gdb_regs[_R8];
	kernel_regs->ARM_r9	= gdb_regs[_R9];
	kernel_regs->ARM_r10	= gdb_regs[_R10];
	kernel_regs->ARM_fp	= gdb_regs[_FP];
	kernel_regs->ARM_ip	= gdb_regs[_IP];
	kernel_regs->ARM_sp	= gdb_regs[_SPT];
	kernel_regs->ARM_lr	= gdb_regs[_LR];
	kernel_regs->ARM_pc	= gdb_regs[_PC];
	kernel_regs->ARM_cpsr	= gdb_regs[_CPSR];
}

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;
}

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,
	.fn			= kgdb_brk_fn
};

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

/**
 *	kgdb_arch_init - Perform any architecture specific initalization.
 *
 *	This function will handle the initalization of any architecture
 *	specific callbacks.
 */
int kgdb_arch_init(void)
{
	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);
}

/*
 * 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
};