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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 */
12#include <linux/irq.h>
13#include <linux/kdebug.h>
14#include <linux/kgdb.h>
15#include <asm/traps.h>
16
17struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
18{
19 { "r0", 4, offsetof(struct pt_regs, ARM_r0)},
20 { "r1", 4, offsetof(struct pt_regs, ARM_r1)},
21 { "r2", 4, offsetof(struct pt_regs, ARM_r2)},
22 { "r3", 4, offsetof(struct pt_regs, ARM_r3)},
23 { "r4", 4, offsetof(struct pt_regs, ARM_r4)},
24 { "r5", 4, offsetof(struct pt_regs, ARM_r5)},
25 { "r6", 4, offsetof(struct pt_regs, ARM_r6)},
26 { "r7", 4, offsetof(struct pt_regs, ARM_r7)},
27 { "r8", 4, offsetof(struct pt_regs, ARM_r8)},
28 { "r9", 4, offsetof(struct pt_regs, ARM_r9)},
29 { "r10", 4, offsetof(struct pt_regs, ARM_r10)},
30 { "fp", 4, offsetof(struct pt_regs, ARM_fp)},
31 { "ip", 4, offsetof(struct pt_regs, ARM_ip)},
32 { "sp", 4, offsetof(struct pt_regs, ARM_sp)},
33 { "lr", 4, offsetof(struct pt_regs, ARM_lr)},
34 { "pc", 4, offsetof(struct pt_regs, ARM_pc)},
35 { "f0", 12, -1 },
36 { "f1", 12, -1 },
37 { "f2", 12, -1 },
38 { "f3", 12, -1 },
39 { "f4", 12, -1 },
40 { "f5", 12, -1 },
41 { "f6", 12, -1 },
42 { "f7", 12, -1 },
43 { "fps", 4, -1 },
44 { "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
45};
46
47char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
48{
49 if (regno >= DBG_MAX_REG_NUM || regno < 0)
50 return NULL;
51
52 if (dbg_reg_def[regno].offset != -1)
53 memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
54 dbg_reg_def[regno].size);
55 else
56 memset(mem, 0, dbg_reg_def[regno].size);
57 return dbg_reg_def[regno].name;
58}
59
60int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
61{
62 if (regno >= DBG_MAX_REG_NUM || regno < 0)
63 return -EINVAL;
64
65 if (dbg_reg_def[regno].offset != -1)
66 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
67 dbg_reg_def[regno].size);
68 return 0;
69}
70
71void
72sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
73{
74 struct pt_regs *thread_regs;
75 int regno;
76
77 /* Just making sure... */
78 if (task == NULL)
79 return;
80
81 /* Initialize to zero */
82 for (regno = 0; regno < GDB_MAX_REGS; regno++)
83 gdb_regs[regno] = 0;
84
85 /* Otherwise, we have only some registers from switch_to() */
86 thread_regs = task_pt_regs(task);
87 gdb_regs[_R0] = thread_regs->ARM_r0;
88 gdb_regs[_R1] = thread_regs->ARM_r1;
89 gdb_regs[_R2] = thread_regs->ARM_r2;
90 gdb_regs[_R3] = thread_regs->ARM_r3;
91 gdb_regs[_R4] = thread_regs->ARM_r4;
92 gdb_regs[_R5] = thread_regs->ARM_r5;
93 gdb_regs[_R6] = thread_regs->ARM_r6;
94 gdb_regs[_R7] = thread_regs->ARM_r7;
95 gdb_regs[_R8] = thread_regs->ARM_r8;
96 gdb_regs[_R9] = thread_regs->ARM_r9;
97 gdb_regs[_R10] = thread_regs->ARM_r10;
98 gdb_regs[_FP] = thread_regs->ARM_fp;
99 gdb_regs[_IP] = thread_regs->ARM_ip;
100 gdb_regs[_SPT] = thread_regs->ARM_sp;
101 gdb_regs[_LR] = thread_regs->ARM_lr;
102 gdb_regs[_PC] = thread_regs->ARM_pc;
103 gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
104}
105
106void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
107{
108 regs->ARM_pc = pc;
109}
110
111static int compiled_break;
112
113int kgdb_arch_handle_exception(int exception_vector, int signo,
114 int err_code, char *remcom_in_buffer,
115 char *remcom_out_buffer,
116 struct pt_regs *linux_regs)
117{
118 unsigned long addr;
119 char *ptr;
120
121 switch (remcom_in_buffer[0]) {
122 case 'D':
123 case 'k':
124 case 'c':
125 /*
126 * Try to read optional parameter, pc unchanged if no parm.
127 * If this was a compiled breakpoint, we need to move
128 * to the next instruction or we will just breakpoint
129 * over and over again.
130 */
131 ptr = &remcom_in_buffer[1];
132 if (kgdb_hex2long(&ptr, &addr))
133 linux_regs->ARM_pc = addr;
134 else if (compiled_break == 1)
135 linux_regs->ARM_pc += 4;
136
137 compiled_break = 0;
138
139 return 0;
140 }
141
142 return -1;
143}
144
145static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
146{
147 kgdb_handle_exception(1, SIGTRAP, 0, regs);
148
149 return 0;
150}
151
152static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
153{
154 compiled_break = 1;
155 kgdb_handle_exception(1, SIGTRAP, 0, regs);
156
157 return 0;
158}
159
160static struct undef_hook kgdb_brkpt_hook = {
161 .instr_mask = 0xffffffff,
162 .instr_val = KGDB_BREAKINST,
163 .fn = kgdb_brk_fn
164};
165
166static struct undef_hook kgdb_compiled_brkpt_hook = {
167 .instr_mask = 0xffffffff,
168 .instr_val = KGDB_COMPILED_BREAK,
169 .fn = kgdb_compiled_brk_fn
170};
171
172static void kgdb_call_nmi_hook(void *ignored)
173{
174 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
175}
176
177void 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
184static 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}
192static int
193kgdb_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
205static struct notifier_block kgdb_notifier = {
206 .notifier_call = kgdb_notify,
207 .priority = -INT_MAX,
208};
209
210
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 */
217int kgdb_arch_init(void)
218{
219 int ret = register_die_notifier(&kgdb_notifier);
220
221 if (ret != 0)
222 return ret;
223
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 */
236void kgdb_arch_exit(void)
237{
238 unregister_undef_hook(&kgdb_brkpt_hook);
239 unregister_undef_hook(&kgdb_compiled_brkpt_hook);
240 unregister_die_notifier(&kgdb_notifier);
241}
242
243/*
244 * Register our undef instruction hooks with ARM undef core.
245 * We regsiter a hook specifically looking for the KGB break inst
246 * and we handle the normal undef case within the do_undefinstr
247 * handler.
248 */
249struct kgdb_arch arch_kgdb_ops = {
250#ifndef __ARMEB__
251 .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
252#else /* ! __ARMEB__ */
253 .gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
254#endif
255};
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 */
12#include <linux/irq.h>
13#include <linux/kdebug.h>
14#include <linux/kgdb.h>
15#include <linux/uaccess.h>
16
17#include <asm/patch.h>
18#include <asm/traps.h>
19
20struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
21{
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};
49
50char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
51{
52 if (regno >= DBG_MAX_REG_NUM || regno < 0)
53 return NULL;
54
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;
61}
62
63int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
64{
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;
72}
73
74void
75sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
76{
77 struct thread_info *ti;
78 int regno;
79
80 /* Just making sure... */
81 if (task == NULL)
82 return;
83
84 /* Initialize to zero */
85 for (regno = 0; regno < GDB_MAX_REGS; regno++)
86 gdb_regs[regno] = 0;
87
88 /* Otherwise, we have only some registers from switch_to() */
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;
100}
101
102void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
103{
104 regs->ARM_pc = pc;
105}
106
107static int compiled_break;
108
109int 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':
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
141static 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
148static 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
156static struct undef_hook kgdb_brkpt_hook = {
157 .instr_mask = 0xffffffff,
158 .instr_val = KGDB_BREAKINST,
159 .cpsr_mask = MODE_MASK,
160 .cpsr_val = SVC_MODE,
161 .fn = kgdb_brk_fn
162};
163
164static struct undef_hook kgdb_compiled_brkpt_hook = {
165 .instr_mask = 0xffffffff,
166 .instr_val = KGDB_COMPILED_BREAK,
167 .cpsr_mask = MODE_MASK,
168 .cpsr_val = SVC_MODE,
169 .fn = kgdb_compiled_brk_fn
170};
171
172static void kgdb_call_nmi_hook(void *ignored)
173{
174 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
175}
176
177void 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
184static 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}
192static int
193kgdb_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
205static struct notifier_block kgdb_notifier = {
206 .notifier_call = kgdb_notify,
207 .priority = -INT_MAX,
208};
209
210
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 */
217int kgdb_arch_init(void)
218{
219 int ret = register_die_notifier(&kgdb_notifier);
220
221 if (ret != 0)
222 return ret;
223
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 */
236void kgdb_arch_exit(void)
237{
238 unregister_undef_hook(&kgdb_brkpt_hook);
239 unregister_undef_hook(&kgdb_compiled_brkpt_hook);
240 unregister_die_notifier(&kgdb_notifier);
241}
242
243int 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
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);
258
259 return err;
260}
261
262int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
263{
264 /* Machine is already stopped, so we can use __patch_text() directly */
265 __patch_text((void *)bpt->bpt_addr, *(unsigned int *)bpt->saved_instr);
266
267 return 0;
268}
269
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 */
276struct 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};