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/smp_lock.h> 18 #include <linux/errno.h> 19 #include <linux/ptrace.h> 20 #include <linux/user.h> 21 #include <linux/config.h> 22 #include <linux/signal.h> 23 24 #include <asm/uaccess.h> 25 #include <asm/page.h> 26 #include <asm/pgtable.h> 27 #include <asm/system.h> 28 #include <asm/processor.h> 29 30 /* 31 * does not yet catch signals sent when the child dies. 32 * in exit.c or in signal.c. 33 */ 34 35 /* determines which bits in the SR the user has access to. */ 36 /* 1 = access 0 = no access */ 37 #define SR_MASK 0x001f 38 39 /* sets the trace bits. */ 40 #define TRACE_BITS 0x8000 41 42 /* Find the stack offset for a register, relative to thread.esp0. */ 43 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) 44 #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \ 45 - sizeof(struct switch_stack)) 46 /* Mapping from PT_xxx to the stack offset at which the register is 47 saved. Notice that usp has no stack-slot and needs to be treated 48 specially (see get_reg/put_reg below). */ 49 static int regoff[] = { 50 [0] = PT_REG(d1), 51 [1] = PT_REG(d2), 52 [2] = PT_REG(d3), 53 [3] = PT_REG(d4), 54 [4] = PT_REG(d5), 55 [5] = SW_REG(d6), 56 [6] = SW_REG(d7), 57 [7] = PT_REG(a0), 58 [8] = PT_REG(a1), 59 [9] = PT_REG(a2), 60 [10] = SW_REG(a3), 61 [11] = SW_REG(a4), 62 [12] = SW_REG(a5), 63 [13] = SW_REG(a6), 64 [14] = PT_REG(d0), 65 [15] = -1, 66 [16] = PT_REG(orig_d0), 67 [17] = PT_REG(sr), 68 [18] = PT_REG(pc), 69 }; 70 71 /* 72 * Get contents of register REGNO in task TASK. 73 */ 74 static inline long get_reg(struct task_struct *task, int regno) 75 { 76 unsigned long *addr; 77 78 if (regno == PT_USP) 79 addr = &task->thread.usp; 80 else if (regno < sizeof(regoff)/sizeof(regoff[0])) 81 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 82 else 83 return 0; 84 return *addr; 85 } 86 87 /* 88 * Write contents of register REGNO in task TASK. 89 */ 90 static inline int put_reg(struct task_struct *task, int regno, 91 unsigned long data) 92 { 93 unsigned long *addr; 94 95 if (regno == PT_USP) 96 addr = &task->thread.usp; 97 else if (regno < sizeof(regoff)/sizeof(regoff[0])) 98 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 99 else 100 return -1; 101 *addr = data; 102 return 0; 103 } 104 105 /* 106 * Make sure the single step bit is not set. 107 */ 108 static inline void singlestep_disable(struct task_struct *child) 109 { 110 unsigned long tmp = get_reg(child, PT_SR) & ~(TRACE_BITS << 16); 111 put_reg(child, PT_SR, tmp); 112 clear_tsk_thread_flag(child, TIF_DELAYED_TRACE); 113 } 114 115 /* 116 * Called by kernel/ptrace.c when detaching.. 117 */ 118 void ptrace_disable(struct task_struct *child) 119 { 120 singlestep_disable(child); 121 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 122 } 123 124 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 125 { 126 unsigned long tmp; 127 int i, ret = 0; 128 129 switch (request) { 130 /* when I and D space are separate, these will need to be fixed. */ 131 case PTRACE_PEEKTEXT: /* read word at location addr. */ 132 case PTRACE_PEEKDATA: 133 i = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); 134 if (i != sizeof(tmp)) 135 goto out_eio; 136 ret = put_user(tmp, (unsigned long *)data); 137 break; 138 139 /* read the word at location addr in the USER area. */ 140 case PTRACE_PEEKUSR: 141 if (addr & 3) 142 goto out_eio; 143 addr >>= 2; /* temporary hack. */ 144 145 if (addr >= 0 && addr < 19) { 146 tmp = get_reg(child, addr); 147 if (addr == PT_SR) 148 tmp >>= 16; 149 } else if (addr >= 21 && addr < 49) { 150 tmp = child->thread.fp[addr - 21]; 151 /* Convert internal fpu reg representation 152 * into long double format 153 */ 154 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) 155 tmp = ((tmp & 0xffff0000) << 15) | 156 ((tmp & 0x0000ffff) << 16); 157 } else 158 break; 159 ret = put_user(tmp, (unsigned long *)data); 160 break; 161 162 /* when I and D space are separate, this will have to be fixed. */ 163 case PTRACE_POKETEXT: /* write the word at location addr. */ 164 case PTRACE_POKEDATA: 165 if (access_process_vm(child, addr, &data, sizeof(data), 1) != sizeof(data)) 166 goto out_eio; 167 break; 168 169 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 170 if (addr & 3) 171 goto out_eio; 172 addr >>= 2; /* temporary hack. */ 173 174 if (addr == PT_SR) { 175 data &= SR_MASK; 176 data <<= 16; 177 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16); 178 } else if (addr >= 0 && addr < 19) { 179 if (put_reg(child, addr, data)) 180 goto out_eio; 181 } else if (addr >= 21 && addr < 48) { 182 /* Convert long double format 183 * into internal fpu reg representation 184 */ 185 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) { 186 data = (unsigned long)data << 15; 187 data = (data & 0xffff0000) | 188 ((data & 0x0000ffff) >> 1); 189 } 190 child->thread.fp[addr - 21] = data; 191 } else 192 goto out_eio; 193 break; 194 195 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 196 case PTRACE_CONT: /* restart after signal. */ 197 if (!valid_signal(data)) 198 goto out_eio; 199 200 if (request == PTRACE_SYSCALL) 201 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 202 else 203 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 204 child->exit_code = data; 205 singlestep_disable(child); 206 wake_up_process(child); 207 break; 208 209 /* 210 * make the child exit. Best I can do is send it a sigkill. 211 * perhaps it should be put in the status that it wants to 212 * exit. 213 */ 214 case PTRACE_KILL: 215 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 216 break; 217 child->exit_code = SIGKILL; 218 singlestep_disable(child); 219 wake_up_process(child); 220 break; 221 222 case PTRACE_SINGLESTEP: /* set the trap flag. */ 223 if (!valid_signal(data)) 224 goto out_eio; 225 226 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 227 tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16); 228 put_reg(child, PT_SR, tmp); 229 set_tsk_thread_flag(child, TIF_DELAYED_TRACE); 230 231 child->exit_code = data; 232 /* give it a chance to run. */ 233 wake_up_process(child); 234 break; 235 236 case PTRACE_DETACH: /* detach a process that was attached. */ 237 ret = ptrace_detach(child, data); 238 break; 239 240 case PTRACE_GETREGS: /* Get all gp regs from the child. */ 241 for (i = 0; i < 19; i++) { 242 tmp = get_reg(child, i); 243 if (i == PT_SR) 244 tmp >>= 16; 245 ret = put_user(tmp, (unsigned long *)data); 246 if (ret) 247 break; 248 data += sizeof(long); 249 } 250 break; 251 252 case PTRACE_SETREGS: /* Set all gp regs in the child. */ 253 for (i = 0; i < 19; i++) { 254 ret = get_user(tmp, (unsigned long *)data); 255 if (ret) 256 break; 257 if (i == PT_SR) { 258 tmp &= SR_MASK; 259 tmp <<= 16; 260 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16); 261 } 262 put_reg(child, i, tmp); 263 data += sizeof(long); 264 } 265 break; 266 267 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 268 if (copy_to_user((void *)data, &child->thread.fp, 269 sizeof(struct user_m68kfp_struct))) 270 ret = -EFAULT; 271 break; 272 273 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 274 if (copy_from_user(&child->thread.fp, (void *)data, 275 sizeof(struct user_m68kfp_struct))) 276 ret = -EFAULT; 277 break; 278 279 default: 280 ret = ptrace_request(child, request, addr, data); 281 break; 282 } 283 284 return ret; 285 out_eio: 286 return -EIO; 287 } 288 289 asmlinkage void syscall_trace(void) 290 { 291 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) 292 ? 0x80 : 0)); 293 /* 294 * this isn't the same as continuing with a signal, but it will do 295 * for normal use. strace only continues with a signal if the 296 * stopping signal is not SIGTRAP. -brl 297 */ 298 if (current->exit_code) { 299 send_sig(current->exit_code, current, 1); 300 current->exit_code = 0; 301 } 302 } 303