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 <linux/kprobes.h>
26 #include <asm/traps.h>
28 struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
29 { "x0", 8, offsetof(struct pt_regs, regs[0])},
30 { "x1", 8, offsetof(struct pt_regs, regs[1])},
31 { "x2", 8, offsetof(struct pt_regs, regs[2])},
32 { "x3", 8, offsetof(struct pt_regs, regs[3])},
33 { "x4", 8, offsetof(struct pt_regs, regs[4])},
34 { "x5", 8, offsetof(struct pt_regs, regs[5])},
35 { "x6", 8, offsetof(struct pt_regs, regs[6])},
36 { "x7", 8, offsetof(struct pt_regs, regs[7])},
37 { "x8", 8, offsetof(struct pt_regs, regs[8])},
38 { "x9", 8, offsetof(struct pt_regs, regs[9])},
39 { "x10", 8, offsetof(struct pt_regs, regs[10])},
40 { "x11", 8, offsetof(struct pt_regs, regs[11])},
41 { "x12", 8, offsetof(struct pt_regs, regs[12])},
42 { "x13", 8, offsetof(struct pt_regs, regs[13])},
43 { "x14", 8, offsetof(struct pt_regs, regs[14])},
44 { "x15", 8, offsetof(struct pt_regs, regs[15])},
45 { "x16", 8, offsetof(struct pt_regs, regs[16])},
46 { "x17", 8, offsetof(struct pt_regs, regs[17])},
47 { "x18", 8, offsetof(struct pt_regs, regs[18])},
48 { "x19", 8, offsetof(struct pt_regs, regs[19])},
49 { "x20", 8, offsetof(struct pt_regs, regs[20])},
50 { "x21", 8, offsetof(struct pt_regs, regs[21])},
51 { "x22", 8, offsetof(struct pt_regs, regs[22])},
52 { "x23", 8, offsetof(struct pt_regs, regs[23])},
53 { "x24", 8, offsetof(struct pt_regs, regs[24])},
54 { "x25", 8, offsetof(struct pt_regs, regs[25])},
55 { "x26", 8, offsetof(struct pt_regs, regs[26])},
56 { "x27", 8, offsetof(struct pt_regs, regs[27])},
57 { "x28", 8, offsetof(struct pt_regs, regs[28])},
58 { "x29", 8, offsetof(struct pt_regs, regs[29])},
59 { "x30", 8, offsetof(struct pt_regs, regs[30])},
60 { "sp", 8, offsetof(struct pt_regs, sp)},
61 { "pc", 8, offsetof(struct pt_regs, pc)},
62 { "pstate", 8, offsetof(struct pt_regs, pstate)},
99 char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
101 if (regno >= DBG_MAX_REG_NUM || regno < 0)
104 if (dbg_reg_def[regno].offset != -1)
105 memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
106 dbg_reg_def[regno].size);
108 memset(mem, 0, dbg_reg_def[regno].size);
109 return dbg_reg_def[regno].name;
112 int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
114 if (regno >= DBG_MAX_REG_NUM || regno < 0)
117 if (dbg_reg_def[regno].offset != -1)
118 memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
119 dbg_reg_def[regno].size);
124 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
126 struct pt_regs *thread_regs;
128 /* Initialize to zero */
129 memset((char *)gdb_regs, 0, NUMREGBYTES);
130 thread_regs = task_pt_regs(task);
131 memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
134 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
139 static int compiled_break;
141 static void kgdb_arch_update_addr(struct pt_regs *regs,
142 char *remcom_in_buffer)
147 ptr = &remcom_in_buffer[1];
148 if (kgdb_hex2long(&ptr, &addr))
149 kgdb_arch_set_pc(regs, addr);
150 else if (compiled_break == 1)
151 kgdb_arch_set_pc(regs, regs->pc + 4);
156 int kgdb_arch_handle_exception(int exception_vector, int signo,
157 int err_code, char *remcom_in_buffer,
158 char *remcom_out_buffer,
159 struct pt_regs *linux_regs)
163 switch (remcom_in_buffer[0]) {
167 * Packet D (Detach), k (kill). No special handling
168 * is required here. Handle same as c packet.
172 * Packet c (Continue) to continue executing.
173 * Set pc to required address.
174 * Try to read optional parameter and set pc.
175 * If this was a compiled breakpoint, we need to move
176 * to the next instruction else we will just breakpoint
177 * over and over again.
179 kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
180 atomic_set(&kgdb_cpu_doing_single_step, -1);
181 kgdb_single_step = 0;
184 * Received continue command, disable single step
186 if (kernel_active_single_step())
187 kernel_disable_single_step();
193 * Update step address value with address passed
195 * On debug exception return PC is copied to ELR
197 * If no step address is passed, resume from the address
198 * pointed by PC. Do not update PC
200 kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
201 atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id());
202 kgdb_single_step = 1;
205 * Enable single step handling
207 if (!kernel_active_single_step())
208 kernel_enable_single_step(linux_regs);
217 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
219 kgdb_handle_exception(1, SIGTRAP, 0, regs);
222 NOKPROBE_SYMBOL(kgdb_brk_fn)
224 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
227 kgdb_handle_exception(1, SIGTRAP, 0, regs);
231 NOKPROBE_SYMBOL(kgdb_compiled_brk_fn);
233 static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
235 kgdb_handle_exception(1, SIGTRAP, 0, regs);
238 NOKPROBE_SYMBOL(kgdb_step_brk_fn);
240 static struct break_hook kgdb_brkpt_hook = {
241 .esr_mask = 0xffffffff,
242 .esr_val = (u32)ESR_ELx_VAL_BRK64(KGDB_DYN_DBG_BRK_IMM),
246 static struct break_hook kgdb_compiled_brkpt_hook = {
247 .esr_mask = 0xffffffff,
248 .esr_val = (u32)ESR_ELx_VAL_BRK64(KGDB_COMPILED_DBG_BRK_IMM),
249 .fn = kgdb_compiled_brk_fn
252 static struct step_hook kgdb_step_hook = {
253 .fn = kgdb_step_brk_fn
256 static void kgdb_call_nmi_hook(void *ignored)
258 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
261 void kgdb_roundup_cpus(unsigned long flags)
264 smp_call_function(kgdb_call_nmi_hook, NULL, 0);
268 static int __kgdb_notify(struct die_args *args, unsigned long cmd)
270 struct pt_regs *regs = args->regs;
272 if (kgdb_handle_exception(1, args->signr, cmd, regs))
278 kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
283 local_irq_save(flags);
284 ret = __kgdb_notify(ptr, cmd);
285 local_irq_restore(flags);
290 static struct notifier_block kgdb_notifier = {
291 .notifier_call = kgdb_notify,
293 * Want to be lowest priority
295 .priority = -INT_MAX,
299 * kgdb_arch_init - Perform any architecture specific initalization.
300 * This function will handle the initalization of any architecture
301 * specific callbacks.
303 int kgdb_arch_init(void)
305 int ret = register_die_notifier(&kgdb_notifier);
310 register_break_hook(&kgdb_brkpt_hook);
311 register_break_hook(&kgdb_compiled_brkpt_hook);
312 register_step_hook(&kgdb_step_hook);
317 * kgdb_arch_exit - Perform any architecture specific uninitalization.
318 * This function will handle the uninitalization of any architecture
319 * specific callbacks, for dynamic registration and unregistration.
321 void kgdb_arch_exit(void)
323 unregister_break_hook(&kgdb_brkpt_hook);
324 unregister_break_hook(&kgdb_compiled_brkpt_hook);
325 unregister_step_hook(&kgdb_step_hook);
326 unregister_die_notifier(&kgdb_notifier);
330 * ARM instructions are always in LE.
331 * Break instruction is encoded in LE format
333 struct kgdb_arch arch_kgdb_ops = {
335 KGDB_DYN_BRK_INS_BYTE(0),
336 KGDB_DYN_BRK_INS_BYTE(1),
337 KGDB_DYN_BRK_INS_BYTE(2),
338 KGDB_DYN_BRK_INS_BYTE(3),