1 /* 2 * linux/arch/m68k/kernel/ptrace.c 3 * 4 * Copyright (C) 1994 by Hamish Macdonald 5 * Taken from linux/kernel/ptrace.c and modified for M680x0. 6 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds 7 * 8 * This file is subject to the terms and conditions of the GNU General 9 * Public License. See the file COPYING in the main directory of 10 * this archive for more details. 11 */ 12 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/mm.h> 16 #include <linux/smp.h> 17 #include <linux/errno.h> 18 #include <linux/ptrace.h> 19 #include <linux/user.h> 20 #include <linux/signal.h> 21 22 #include <asm/uaccess.h> 23 #include <asm/page.h> 24 #include <asm/pgtable.h> 25 #include <asm/system.h> 26 #include <asm/processor.h> 27 28 /* 29 * does not yet catch signals sent when the child dies. 30 * in exit.c or in signal.c. 31 */ 32 33 /* determines which bits in the SR the user has access to. */ 34 /* 1 = access 0 = no access */ 35 #define SR_MASK 0x001f 36 37 /* sets the trace bits. */ 38 #define TRACE_BITS 0x8000 39 40 /* Find the stack offset for a register, relative to thread.esp0. */ 41 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) 42 #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \ 43 - sizeof(struct switch_stack)) 44 /* Mapping from PT_xxx to the stack offset at which the register is 45 saved. Notice that usp has no stack-slot and needs to be treated 46 specially (see get_reg/put_reg below). */ 47 static int regoff[] = { 48 [0] = PT_REG(d1), 49 [1] = PT_REG(d2), 50 [2] = PT_REG(d3), 51 [3] = PT_REG(d4), 52 [4] = PT_REG(d5), 53 [5] = SW_REG(d6), 54 [6] = SW_REG(d7), 55 [7] = PT_REG(a0), 56 [8] = PT_REG(a1), 57 [9] = PT_REG(a2), 58 [10] = SW_REG(a3), 59 [11] = SW_REG(a4), 60 [12] = SW_REG(a5), 61 [13] = SW_REG(a6), 62 [14] = PT_REG(d0), 63 [15] = -1, 64 [16] = PT_REG(orig_d0), 65 [17] = PT_REG(sr), 66 [18] = PT_REG(pc), 67 }; 68 69 /* 70 * Get contents of register REGNO in task TASK. 71 */ 72 static inline long get_reg(struct task_struct *task, int regno) 73 { 74 unsigned long *addr; 75 76 if (regno == PT_USP) 77 addr = &task->thread.usp; 78 else if (regno < ARRAY_SIZE(regoff)) 79 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 80 else 81 return 0; 82 return *addr; 83 } 84 85 /* 86 * Write contents of register REGNO in task TASK. 87 */ 88 static inline int put_reg(struct task_struct *task, int regno, 89 unsigned long data) 90 { 91 unsigned long *addr; 92 93 if (regno == PT_USP) 94 addr = &task->thread.usp; 95 else if (regno < ARRAY_SIZE(regoff)) 96 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 97 else 98 return -1; 99 *addr = data; 100 return 0; 101 } 102 103 /* 104 * Make sure the single step bit is not set. 105 */ 106 static inline void singlestep_disable(struct task_struct *child) 107 { 108 unsigned long tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); 109 put_reg(child, PT_SR, tmp); 110 clear_tsk_thread_flag(child, TIF_DELAYED_TRACE); 111 } 112 113 /* 114 * Called by kernel/ptrace.c when detaching.. 115 */ 116 void ptrace_disable(struct task_struct *child) 117 { 118 singlestep_disable(child); 119 } 120 121 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 122 { 123 unsigned long tmp; 124 int i, ret = 0; 125 126 switch (request) { 127 /* when I and D space are separate, these will need to be fixed. */ 128 case PTRACE_PEEKTEXT: /* read word at location addr. */ 129 case PTRACE_PEEKDATA: 130 ret = generic_ptrace_peekdata(child, addr, data); 131 break; 132 133 /* read the word at location addr in the USER area. */ 134 case PTRACE_PEEKUSR: 135 if (addr & 3) 136 goto out_eio; 137 addr >>= 2; /* temporary hack. */ 138 139 if (addr >= 0 && addr < 19) { 140 tmp = get_reg(child, addr); 141 if (addr == PT_SR) 142 tmp >>= 16; 143 } else if (addr >= 21 && addr < 49) { 144 tmp = child->thread.fp[addr - 21]; 145 /* Convert internal fpu reg representation 146 * into long double format 147 */ 148 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) 149 tmp = ((tmp & 0xffff0000) << 15) | 150 ((tmp & 0x0000ffff) << 16); 151 } else 152 break; 153 ret = put_user(tmp, (unsigned long *)data); 154 break; 155 156 /* when I and D space are separate, this will have to be fixed. */ 157 case PTRACE_POKETEXT: /* write the word at location addr. */ 158 case PTRACE_POKEDATA: 159 ret = generic_ptrace_pokedata(child, addr, data); 160 break; 161 162 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 163 if (addr & 3) 164 goto out_eio; 165 addr >>= 2; /* temporary hack. */ 166 167 if (addr == PT_SR) { 168 data &= SR_MASK; 169 data <<= 16; 170 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16); 171 } else if (addr >= 0 && addr < 19) { 172 if (put_reg(child, addr, data)) 173 goto out_eio; 174 } else if (addr >= 21 && addr < 48) { 175 /* Convert long double format 176 * into internal fpu reg representation 177 */ 178 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) { 179 data = (unsigned long)data << 15; 180 data = (data & 0xffff0000) | 181 ((data & 0x0000ffff) >> 1); 182 } 183 child->thread.fp[addr - 21] = data; 184 } else 185 goto out_eio; 186 break; 187 188 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 189 case PTRACE_CONT: /* restart after signal. */ 190 if (!valid_signal(data)) 191 goto out_eio; 192 193 if (request == PTRACE_SYSCALL) 194 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 195 else 196 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 197 child->exit_code = data; 198 singlestep_disable(child); 199 wake_up_process(child); 200 break; 201 202 /* 203 * make the child exit. Best I can do is send it a sigkill. 204 * perhaps it should be put in the status that it wants to 205 * exit. 206 */ 207 case PTRACE_KILL: 208 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 209 break; 210 child->exit_code = SIGKILL; 211 singlestep_disable(child); 212 wake_up_process(child); 213 break; 214 215 case PTRACE_SINGLESTEP: /* set the trap flag. */ 216 if (!valid_signal(data)) 217 goto out_eio; 218 219 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 220 tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16); 221 put_reg(child, PT_SR, tmp); 222 set_tsk_thread_flag(child, TIF_DELAYED_TRACE); 223 224 child->exit_code = data; 225 /* give it a chance to run. */ 226 wake_up_process(child); 227 break; 228 229 case PTRACE_GETREGS: /* Get all gp regs from the child. */ 230 for (i = 0; i < 19; i++) { 231 tmp = get_reg(child, i); 232 if (i == PT_SR) 233 tmp >>= 16; 234 ret = put_user(tmp, (unsigned long *)data); 235 if (ret) 236 break; 237 data += sizeof(long); 238 } 239 break; 240 241 case PTRACE_SETREGS: /* Set all gp regs in the child. */ 242 for (i = 0; i < 19; i++) { 243 ret = get_user(tmp, (unsigned long *)data); 244 if (ret) 245 break; 246 if (i == PT_SR) { 247 tmp &= SR_MASK; 248 tmp <<= 16; 249 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16); 250 } 251 put_reg(child, i, tmp); 252 data += sizeof(long); 253 } 254 break; 255 256 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 257 if (copy_to_user((void *)data, &child->thread.fp, 258 sizeof(struct user_m68kfp_struct))) 259 ret = -EFAULT; 260 break; 261 262 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 263 if (copy_from_user(&child->thread.fp, (void *)data, 264 sizeof(struct user_m68kfp_struct))) 265 ret = -EFAULT; 266 break; 267 268 default: 269 ret = ptrace_request(child, request, addr, data); 270 break; 271 } 272 273 return ret; 274 out_eio: 275 return -EIO; 276 } 277 278 asmlinkage void syscall_trace(void) 279 { 280 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) 281 ? 0x80 : 0)); 282 /* 283 * this isn't the same as continuing with a signal, but it will do 284 * for normal use. strace only continues with a signal if the 285 * stopping signal is not SIGTRAP. -brl 286 */ 287 if (current->exit_code) { 288 send_sig(current->exit_code, current, 1); 289 current->exit_code = 0; 290 } 291 } 292