Commit | Line | Data |
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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> |
16 | ||
fca08f32 | 17 | #include <asm/patch.h> |
5cbad0eb JW |
18 | #include <asm/traps.h> |
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 | } |
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 | } |
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, |
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, |
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 | } |
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 */ |
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 | }; |