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