2 * arch/arm/kernel/kgdb.c
6 * Copyright (c) 2002-2004 MontaVista Software, Inc
7 * Copyright (c) 2008 Wind River Systems, Inc.
9 * Authors: George Davis <davis_g@mvista.com>
10 * Deepak Saxena <dsaxena@plexity.net>
12 #include <linux/irq.h>
13 #include <linux/kdebug.h>
14 #include <linux/kgdb.h>
15 #include <linux/uaccess.h>
17 #include <asm/traps.h>
21 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
23 { "r0", 4, offsetof(struct pt_regs, ARM_r0)},
24 { "r1", 4, offsetof(struct pt_regs, ARM_r1)},
25 { "r2", 4, offsetof(struct pt_regs, ARM_r2)},
26 { "r3", 4, offsetof(struct pt_regs, ARM_r3)},
27 { "r4", 4, offsetof(struct pt_regs, ARM_r4)},
28 { "r5", 4, offsetof(struct pt_regs, ARM_r5)},
29 { "r6", 4, offsetof(struct pt_regs, ARM_r6)},
30 { "r7", 4, offsetof(struct pt_regs, ARM_r7)},
31 { "r8", 4, offsetof(struct pt_regs, ARM_r8)},
32 { "r9", 4, offsetof(struct pt_regs, ARM_r9)},
33 { "r10", 4, offsetof(struct pt_regs, ARM_r10)},
34 { "fp", 4, offsetof(struct pt_regs, ARM_fp)},
35 { "ip", 4, offsetof(struct pt_regs, ARM_ip)},
36 { "sp", 4, offsetof(struct pt_regs, ARM_sp)},
37 { "lr", 4, offsetof(struct pt_regs, ARM_lr)},
38 { "pc", 4, offsetof(struct pt_regs, ARM_pc)},
48 { "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
51 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
53 if (regno >= DBG_MAX_REG_NUM || regno < 0)
56 if (dbg_reg_def[regno].offset != -1)
57 memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
58 dbg_reg_def[regno].size);
60 memset(mem, 0, dbg_reg_def[regno].size);
61 return dbg_reg_def[regno].name;
64 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
66 if (regno >= DBG_MAX_REG_NUM || regno < 0)
69 if (dbg_reg_def[regno].offset != -1)
70 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
71 dbg_reg_def[regno].size);
76 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
78 struct pt_regs *thread_regs;
81 /* Just making sure... */
85 /* Initialize to zero */
86 for (regno = 0; regno < GDB_MAX_REGS; regno++)
89 /* Otherwise, we have only some registers from switch_to() */
90 thread_regs = task_pt_regs(task);
91 gdb_regs[_R0] = thread_regs->ARM_r0;
92 gdb_regs[_R1] = thread_regs->ARM_r1;
93 gdb_regs[_R2] = thread_regs->ARM_r2;
94 gdb_regs[_R3] = thread_regs->ARM_r3;
95 gdb_regs[_R4] = thread_regs->ARM_r4;
96 gdb_regs[_R5] = thread_regs->ARM_r5;
97 gdb_regs[_R6] = thread_regs->ARM_r6;
98 gdb_regs[_R7] = thread_regs->ARM_r7;
99 gdb_regs[_R8] = thread_regs->ARM_r8;
100 gdb_regs[_R9] = thread_regs->ARM_r9;
101 gdb_regs[_R10] = thread_regs->ARM_r10;
102 gdb_regs[_FP] = thread_regs->ARM_fp;
103 gdb_regs[_IP] = thread_regs->ARM_ip;
104 gdb_regs[_SPT] = thread_regs->ARM_sp;
105 gdb_regs[_LR] = thread_regs->ARM_lr;
106 gdb_regs[_PC] = thread_regs->ARM_pc;
107 gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
110 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
115 static int compiled_break;
117 int kgdb_arch_handle_exception(int exception_vector, int signo,
118 int err_code, char *remcom_in_buffer,
119 char *remcom_out_buffer,
120 struct pt_regs *linux_regs)
125 switch (remcom_in_buffer[0]) {
130 * Try to read optional parameter, pc unchanged if no parm.
131 * If this was a compiled breakpoint, we need to move
132 * to the next instruction or we will just breakpoint
133 * over and over again.
135 ptr = &remcom_in_buffer[1];
136 if (kgdb_hex2long(&ptr, &addr))
137 linux_regs->ARM_pc = addr;
138 else if (compiled_break == 1)
139 linux_regs->ARM_pc += 4;
149 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
151 kgdb_handle_exception(1, SIGTRAP, 0, regs);
156 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
159 kgdb_handle_exception(1, SIGTRAP, 0, regs);
164 static struct undef_hook kgdb_brkpt_hook = {
165 .instr_mask = 0xffffffff,
166 .instr_val = KGDB_BREAKINST,
167 .cpsr_mask = MODE_MASK,
168 .cpsr_val = SVC_MODE,
172 static struct undef_hook kgdb_compiled_brkpt_hook = {
173 .instr_mask = 0xffffffff,
174 .instr_val = KGDB_COMPILED_BREAK,
175 .cpsr_mask = MODE_MASK,
176 .cpsr_val = SVC_MODE,
177 .fn = kgdb_compiled_brk_fn
180 static void kgdb_call_nmi_hook(void *ignored)
182 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
185 void kgdb_roundup_cpus(unsigned long flags)
188 smp_call_function(kgdb_call_nmi_hook, NULL, 0);
192 static int __kgdb_notify(struct die_args *args, unsigned long cmd)
194 struct pt_regs *regs = args->regs;
196 if (kgdb_handle_exception(1, args->signr, cmd, regs))
201 kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
206 local_irq_save(flags);
207 ret = __kgdb_notify(ptr, cmd);
208 local_irq_restore(flags);
213 static struct notifier_block kgdb_notifier = {
214 .notifier_call = kgdb_notify,
215 .priority = -INT_MAX,
220 * kgdb_arch_init - Perform any architecture specific initalization.
222 * This function will handle the initalization of any architecture
223 * specific callbacks.
225 int kgdb_arch_init(void)
227 int ret = register_die_notifier(&kgdb_notifier);
232 register_undef_hook(&kgdb_brkpt_hook);
233 register_undef_hook(&kgdb_compiled_brkpt_hook);
239 * kgdb_arch_exit - Perform any architecture specific uninitalization.
241 * This function will handle the uninitalization of any architecture
242 * specific callbacks, for dynamic registration and unregistration.
244 void kgdb_arch_exit(void)
246 unregister_undef_hook(&kgdb_brkpt_hook);
247 unregister_undef_hook(&kgdb_compiled_brkpt_hook);
248 unregister_die_notifier(&kgdb_notifier);
251 int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
255 /* patch_text() only supports int-sized breakpoints */
256 BUILD_BUG_ON(sizeof(int) != BREAK_INSTR_SIZE);
258 err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
263 patch_text((void *)bpt->bpt_addr,
264 *(unsigned int *)arch_kgdb_ops.gdb_bpt_instr);
269 int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
271 patch_text((void *)bpt->bpt_addr, *(unsigned int *)bpt->saved_instr);
277 * Register our undef instruction hooks with ARM undef core.
278 * We regsiter a hook specifically looking for the KGB break inst
279 * and we handle the normal undef case within the do_undefinstr
282 struct kgdb_arch arch_kgdb_ops = {
284 .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
285 #else /* ! __ARMEB__ */
286 .gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}