4 * Based on arch/arm/kernel/kgdb.c
6 * Copyright (C) 2013 Cavium Inc.
7 * Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include <linux/irq.h>
23 #include <linux/kdebug.h>
24 #include <linux/kgdb.h>
25 #include <asm/traps.h>
27 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
28 { "x0", 8, offsetof(struct pt_regs, regs[0])},
29 { "x1", 8, offsetof(struct pt_regs, regs[1])},
30 { "x2", 8, offsetof(struct pt_regs, regs[2])},
31 { "x3", 8, offsetof(struct pt_regs, regs[3])},
32 { "x4", 8, offsetof(struct pt_regs, regs[4])},
33 { "x5", 8, offsetof(struct pt_regs, regs[5])},
34 { "x6", 8, offsetof(struct pt_regs, regs[6])},
35 { "x7", 8, offsetof(struct pt_regs, regs[7])},
36 { "x8", 8, offsetof(struct pt_regs, regs[8])},
37 { "x9", 8, offsetof(struct pt_regs, regs[9])},
38 { "x10", 8, offsetof(struct pt_regs, regs[10])},
39 { "x11", 8, offsetof(struct pt_regs, regs[11])},
40 { "x12", 8, offsetof(struct pt_regs, regs[12])},
41 { "x13", 8, offsetof(struct pt_regs, regs[13])},
42 { "x14", 8, offsetof(struct pt_regs, regs[14])},
43 { "x15", 8, offsetof(struct pt_regs, regs[15])},
44 { "x16", 8, offsetof(struct pt_regs, regs[16])},
45 { "x17", 8, offsetof(struct pt_regs, regs[17])},
46 { "x18", 8, offsetof(struct pt_regs, regs[18])},
47 { "x19", 8, offsetof(struct pt_regs, regs[19])},
48 { "x20", 8, offsetof(struct pt_regs, regs[20])},
49 { "x21", 8, offsetof(struct pt_regs, regs[21])},
50 { "x22", 8, offsetof(struct pt_regs, regs[22])},
51 { "x23", 8, offsetof(struct pt_regs, regs[23])},
52 { "x24", 8, offsetof(struct pt_regs, regs[24])},
53 { "x25", 8, offsetof(struct pt_regs, regs[25])},
54 { "x26", 8, offsetof(struct pt_regs, regs[26])},
55 { "x27", 8, offsetof(struct pt_regs, regs[27])},
56 { "x28", 8, offsetof(struct pt_regs, regs[28])},
57 { "x29", 8, offsetof(struct pt_regs, regs[29])},
58 { "x30", 8, offsetof(struct pt_regs, regs[30])},
59 { "sp", 8, offsetof(struct pt_regs, sp)},
60 { "pc", 8, offsetof(struct pt_regs, pc)},
61 { "pstate", 8, offsetof(struct pt_regs, pstate)},
98 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
100 if (regno >= DBG_MAX_REG_NUM || regno < 0)
103 if (dbg_reg_def[regno].offset != -1)
104 memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
105 dbg_reg_def[regno].size);
107 memset(mem, 0, dbg_reg_def[regno].size);
108 return dbg_reg_def[regno].name;
111 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
113 if (regno >= DBG_MAX_REG_NUM || regno < 0)
116 if (dbg_reg_def[regno].offset != -1)
117 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
118 dbg_reg_def[regno].size);
123 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
125 struct pt_regs *thread_regs;
127 /* Initialize to zero */
128 memset((char *)gdb_regs, 0, NUMREGBYTES);
129 thread_regs = task_pt_regs(task);
130 memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
133 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
138 static int compiled_break;
140 static void kgdb_arch_update_addr(struct pt_regs *regs,
141 char *remcom_in_buffer)
146 ptr = &remcom_in_buffer[1];
147 if (kgdb_hex2long(&ptr, &addr))
148 kgdb_arch_set_pc(regs, addr);
149 else if (compiled_break == 1)
150 kgdb_arch_set_pc(regs, regs->pc + 4);
155 int kgdb_arch_handle_exception(int exception_vector, int signo,
156 int err_code, char *remcom_in_buffer,
157 char *remcom_out_buffer,
158 struct pt_regs *linux_regs)
162 switch (remcom_in_buffer[0]) {
166 * Packet D (Detach), k (kill). No special handling
167 * is required here. Handle same as c packet.
171 * Packet c (Continue) to continue executing.
172 * Set pc to required address.
173 * Try to read optional parameter and set pc.
174 * If this was a compiled breakpoint, we need to move
175 * to the next instruction else we will just breakpoint
176 * over and over again.
178 kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
179 atomic_set(&kgdb_cpu_doing_single_step, -1);
180 kgdb_single_step = 0;
183 * Received continue command, disable single step
185 if (kernel_active_single_step())
186 kernel_disable_single_step();
192 * Update step address value with address passed
194 * On debug exception return PC is copied to ELR
196 * If no step address is passed, resume from the address
197 * pointed by PC. Do not update PC
199 kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
200 atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id());
201 kgdb_single_step = 1;
204 * Enable single step handling
206 if (!kernel_active_single_step())
207 kernel_enable_single_step(linux_regs);
216 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
219 return DBG_HOOK_ERROR;
221 kgdb_handle_exception(1, SIGTRAP, 0, regs);
222 return DBG_HOOK_HANDLED;
225 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
228 return DBG_HOOK_ERROR;
231 kgdb_handle_exception(1, SIGTRAP, 0, regs);
233 return DBG_HOOK_HANDLED;
236 static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
239 return DBG_HOOK_ERROR;
241 kgdb_handle_exception(0, SIGTRAP, 0, regs);
242 return DBG_HOOK_HANDLED;
245 static struct break_hook kgdb_brkpt_hook = {
246 .esr_mask = 0xffffffff,
247 .esr_val = (u32)ESR_ELx_VAL_BRK64(KGDB_DYN_DBG_BRK_IMM),
251 static struct break_hook kgdb_compiled_brkpt_hook = {
252 .esr_mask = 0xffffffff,
253 .esr_val = (u32)ESR_ELx_VAL_BRK64(KGDB_COMPILED_DBG_BRK_IMM),
254 .fn = kgdb_compiled_brk_fn
257 static struct step_hook kgdb_step_hook = {
258 .fn = kgdb_step_brk_fn
261 static void kgdb_call_nmi_hook(void *ignored)
263 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
266 void kgdb_roundup_cpus(unsigned long flags)
269 smp_call_function(kgdb_call_nmi_hook, NULL, 0);
273 static int __kgdb_notify(struct die_args *args, unsigned long cmd)
275 struct pt_regs *regs = args->regs;
277 if (kgdb_handle_exception(1, args->signr, cmd, regs))
283 kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
288 local_irq_save(flags);
289 ret = __kgdb_notify(ptr, cmd);
290 local_irq_restore(flags);
295 static struct notifier_block kgdb_notifier = {
296 .notifier_call = kgdb_notify,
298 * Want to be lowest priority
300 .priority = -INT_MAX,
304 * kgdb_arch_init - Perform any architecture specific initalization.
305 * This function will handle the initalization of any architecture
306 * specific callbacks.
308 int kgdb_arch_init(void)
310 int ret = register_die_notifier(&kgdb_notifier);
315 register_break_hook(&kgdb_brkpt_hook);
316 register_break_hook(&kgdb_compiled_brkpt_hook);
317 register_step_hook(&kgdb_step_hook);
322 * kgdb_arch_exit - Perform any architecture specific uninitalization.
323 * This function will handle the uninitalization of any architecture
324 * specific callbacks, for dynamic registration and unregistration.
326 void kgdb_arch_exit(void)
328 unregister_break_hook(&kgdb_brkpt_hook);
329 unregister_break_hook(&kgdb_compiled_brkpt_hook);
330 unregister_step_hook(&kgdb_step_hook);
331 unregister_die_notifier(&kgdb_notifier);
335 * ARM instructions are always in LE.
336 * Break instruction is encoded in LE format
338 struct kgdb_arch arch_kgdb_ops = {
340 KGDB_DYN_BRK_INS_BYTE(0),
341 KGDB_DYN_BRK_INS_BYTE(1),
342 KGDB_DYN_BRK_INS_BYTE(2),
343 KGDB_DYN_BRK_INS_BYTE(3),