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/kgdb.h> 14 #include <asm/traps.h> 15 16 /* Make a local copy of the registers passed into the handler (bletch) */ 17 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs) 18 { 19 int regno; 20 21 /* Initialize all to zero. */ 22 for (regno = 0; regno < GDB_MAX_REGS; regno++) 23 gdb_regs[regno] = 0; 24 25 gdb_regs[_R0] = kernel_regs->ARM_r0; 26 gdb_regs[_R1] = kernel_regs->ARM_r1; 27 gdb_regs[_R2] = kernel_regs->ARM_r2; 28 gdb_regs[_R3] = kernel_regs->ARM_r3; 29 gdb_regs[_R4] = kernel_regs->ARM_r4; 30 gdb_regs[_R5] = kernel_regs->ARM_r5; 31 gdb_regs[_R6] = kernel_regs->ARM_r6; 32 gdb_regs[_R7] = kernel_regs->ARM_r7; 33 gdb_regs[_R8] = kernel_regs->ARM_r8; 34 gdb_regs[_R9] = kernel_regs->ARM_r9; 35 gdb_regs[_R10] = kernel_regs->ARM_r10; 36 gdb_regs[_FP] = kernel_regs->ARM_fp; 37 gdb_regs[_IP] = kernel_regs->ARM_ip; 38 gdb_regs[_SPT] = kernel_regs->ARM_sp; 39 gdb_regs[_LR] = kernel_regs->ARM_lr; 40 gdb_regs[_PC] = kernel_regs->ARM_pc; 41 gdb_regs[_CPSR] = kernel_regs->ARM_cpsr; 42 } 43 44 /* Copy local gdb registers back to kgdb regs, for later copy to kernel */ 45 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs) 46 { 47 kernel_regs->ARM_r0 = gdb_regs[_R0]; 48 kernel_regs->ARM_r1 = gdb_regs[_R1]; 49 kernel_regs->ARM_r2 = gdb_regs[_R2]; 50 kernel_regs->ARM_r3 = gdb_regs[_R3]; 51 kernel_regs->ARM_r4 = gdb_regs[_R4]; 52 kernel_regs->ARM_r5 = gdb_regs[_R5]; 53 kernel_regs->ARM_r6 = gdb_regs[_R6]; 54 kernel_regs->ARM_r7 = gdb_regs[_R7]; 55 kernel_regs->ARM_r8 = gdb_regs[_R8]; 56 kernel_regs->ARM_r9 = gdb_regs[_R9]; 57 kernel_regs->ARM_r10 = gdb_regs[_R10]; 58 kernel_regs->ARM_fp = gdb_regs[_FP]; 59 kernel_regs->ARM_ip = gdb_regs[_IP]; 60 kernel_regs->ARM_sp = gdb_regs[_SPT]; 61 kernel_regs->ARM_lr = gdb_regs[_LR]; 62 kernel_regs->ARM_pc = gdb_regs[_PC]; 63 kernel_regs->ARM_cpsr = gdb_regs[_CPSR]; 64 } 65 66 void 67 sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task) 68 { 69 struct pt_regs *thread_regs; 70 int regno; 71 72 /* Just making sure... */ 73 if (task == NULL) 74 return; 75 76 /* Initialize to zero */ 77 for (regno = 0; regno < GDB_MAX_REGS; regno++) 78 gdb_regs[regno] = 0; 79 80 /* Otherwise, we have only some registers from switch_to() */ 81 thread_regs = task_pt_regs(task); 82 gdb_regs[_R0] = thread_regs->ARM_r0; 83 gdb_regs[_R1] = thread_regs->ARM_r1; 84 gdb_regs[_R2] = thread_regs->ARM_r2; 85 gdb_regs[_R3] = thread_regs->ARM_r3; 86 gdb_regs[_R4] = thread_regs->ARM_r4; 87 gdb_regs[_R5] = thread_regs->ARM_r5; 88 gdb_regs[_R6] = thread_regs->ARM_r6; 89 gdb_regs[_R7] = thread_regs->ARM_r7; 90 gdb_regs[_R8] = thread_regs->ARM_r8; 91 gdb_regs[_R9] = thread_regs->ARM_r9; 92 gdb_regs[_R10] = thread_regs->ARM_r10; 93 gdb_regs[_FP] = thread_regs->ARM_fp; 94 gdb_regs[_IP] = thread_regs->ARM_ip; 95 gdb_regs[_SPT] = thread_regs->ARM_sp; 96 gdb_regs[_LR] = thread_regs->ARM_lr; 97 gdb_regs[_PC] = thread_regs->ARM_pc; 98 gdb_regs[_CPSR] = thread_regs->ARM_cpsr; 99 } 100 101 static int compiled_break; 102 103 int kgdb_arch_handle_exception(int exception_vector, int signo, 104 int err_code, char *remcom_in_buffer, 105 char *remcom_out_buffer, 106 struct pt_regs *linux_regs) 107 { 108 unsigned long addr; 109 char *ptr; 110 111 switch (remcom_in_buffer[0]) { 112 case 'D': 113 case 'k': 114 case 'c': 115 /* 116 * Try to read optional parameter, pc unchanged if no parm. 117 * If this was a compiled breakpoint, we need to move 118 * to the next instruction or we will just breakpoint 119 * over and over again. 120 */ 121 ptr = &remcom_in_buffer[1]; 122 if (kgdb_hex2long(&ptr, &addr)) 123 linux_regs->ARM_pc = addr; 124 else if (compiled_break == 1) 125 linux_regs->ARM_pc += 4; 126 127 compiled_break = 0; 128 129 return 0; 130 } 131 132 return -1; 133 } 134 135 static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr) 136 { 137 kgdb_handle_exception(1, SIGTRAP, 0, regs); 138 139 return 0; 140 } 141 142 static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr) 143 { 144 compiled_break = 1; 145 kgdb_handle_exception(1, SIGTRAP, 0, regs); 146 147 return 0; 148 } 149 150 static struct undef_hook kgdb_brkpt_hook = { 151 .instr_mask = 0xffffffff, 152 .instr_val = KGDB_BREAKINST, 153 .fn = kgdb_brk_fn 154 }; 155 156 static struct undef_hook kgdb_compiled_brkpt_hook = { 157 .instr_mask = 0xffffffff, 158 .instr_val = KGDB_COMPILED_BREAK, 159 .fn = kgdb_compiled_brk_fn 160 }; 161 162 static void kgdb_call_nmi_hook(void *ignored) 163 { 164 kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); 165 } 166 167 void kgdb_roundup_cpus(unsigned long flags) 168 { 169 local_irq_enable(); 170 smp_call_function(kgdb_call_nmi_hook, NULL, 0); 171 local_irq_disable(); 172 } 173 174 /** 175 * kgdb_arch_init - Perform any architecture specific initalization. 176 * 177 * This function will handle the initalization of any architecture 178 * specific callbacks. 179 */ 180 int kgdb_arch_init(void) 181 { 182 register_undef_hook(&kgdb_brkpt_hook); 183 register_undef_hook(&kgdb_compiled_brkpt_hook); 184 185 return 0; 186 } 187 188 /** 189 * kgdb_arch_exit - Perform any architecture specific uninitalization. 190 * 191 * This function will handle the uninitalization of any architecture 192 * specific callbacks, for dynamic registration and unregistration. 193 */ 194 void kgdb_arch_exit(void) 195 { 196 unregister_undef_hook(&kgdb_brkpt_hook); 197 unregister_undef_hook(&kgdb_compiled_brkpt_hook); 198 } 199 200 /* 201 * Register our undef instruction hooks with ARM undef core. 202 * We regsiter a hook specifically looking for the KGB break inst 203 * and we handle the normal undef case within the do_undefinstr 204 * handler. 205 */ 206 struct kgdb_arch arch_kgdb_ops = { 207 #ifndef __ARMEB__ 208 .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7} 209 #else /* ! __ARMEB__ */ 210 .gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe} 211 #endif 212 }; 213