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}; 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