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). */ 47static 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 */ 72static 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 */ 88static 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 */ 106static 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 */ 116void ptrace_disable(struct task_struct *child) 117{ 118 singlestep_disable(child); 119 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 120} 121 122long arch_ptrace(struct task_struct *child, long request, long addr, long data) 123{ 124 unsigned long tmp; 125 int i, ret = 0; 126 127 switch (request) { 128 /* when I and D space are separate, these will need to be fixed. */ 129 case PTRACE_PEEKTEXT: /* read word at location addr. */ 130 case PTRACE_PEEKDATA: 131 i = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); 132 if (i != sizeof(tmp)) 133 goto out_eio; 134 ret = put_user(tmp, (unsigned long *)data); 135 break; 136 137 /* read the word at location addr in the USER area. */ 138 case PTRACE_PEEKUSR: 139 if (addr & 3) 140 goto out_eio; 141 addr >>= 2; /* temporary hack. */ 142 143 if (addr >= 0 && addr < 19) { 144 tmp = get_reg(child, addr); 145 if (addr == PT_SR) 146 tmp >>= 16; 147 } else if (addr >= 21 && addr < 49) { 148 tmp = child->thread.fp[addr - 21]; 149 /* Convert internal fpu reg representation 150 * into long double format 151 */ 152 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) 153 tmp = ((tmp & 0xffff0000) << 15) | 154 ((tmp & 0x0000ffff) << 16); 155 } else 156 break; 157 ret = put_user(tmp, (unsigned long *)data); 158 break; 159 160 /* when I and D space are separate, this will have to be fixed. */ 161 case PTRACE_POKETEXT: /* write the word at location addr. */ 162 case PTRACE_POKEDATA: 163 if (access_process_vm(child, addr, &data, sizeof(data), 1) != sizeof(data)) 164 goto out_eio; 165 break; 166 167 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 168 if (addr & 3) 169 goto out_eio; 170 addr >>= 2; /* temporary hack. */ 171 172 if (addr == PT_SR) { 173 data &= SR_MASK; 174 data <<= 16; 175 data |= get_reg(child, PT_SR) & ~(SR_MASK << 16); 176 } else if (addr >= 0 && addr < 19) { 177 if (put_reg(child, addr, data)) 178 goto out_eio; 179 } else if (addr >= 21 && addr < 48) { 180 /* Convert long double format 181 * into internal fpu reg representation 182 */ 183 if (FPU_IS_EMU && (addr < 45) && !(addr % 3)) { 184 data = (unsigned long)data << 15; 185 data = (data & 0xffff0000) | 186 ((data & 0x0000ffff) >> 1); 187 } 188 child->thread.fp[addr - 21] = data; 189 } else 190 goto out_eio; 191 break; 192 193 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 194 case PTRACE_CONT: /* restart after signal. */ 195 if (!valid_signal(data)) 196 goto out_eio; 197 198 if (request == PTRACE_SYSCALL) 199 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 200 else 201 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 202 child->exit_code = data; 203 singlestep_disable(child); 204 wake_up_process(child); 205 break; 206 207 /* 208 * make the child exit. Best I can do is send it a sigkill. 209 * perhaps it should be put in the status that it wants to 210 * exit. 211 */ 212 case PTRACE_KILL: 213 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 214 break; 215 child->exit_code = SIGKILL; 216 singlestep_disable(child); 217 wake_up_process(child); 218 break; 219 220 case PTRACE_SINGLESTEP: /* set the trap flag. */ 221 if (!valid_signal(data)) 222 goto out_eio; 223 224 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 225 tmp = get_reg(child, PT_SR) | (TRACE_BITS << 16); 226 put_reg(child, PT_SR, tmp); 227 set_tsk_thread_flag(child, TIF_DELAYED_TRACE); 228 229 child->exit_code = data; 230 /* give it a chance to run. */ 231 wake_up_process(child); 232 break; 233 234 case PTRACE_DETACH: /* detach a process that was attached. */ 235 ret = ptrace_detach(child, data); 236 break; 237 238 case PTRACE_GETREGS: /* Get all gp regs from the child. */ 239 for (i = 0; i < 19; i++) { 240 tmp = get_reg(child, i); 241 if (i == PT_SR) 242 tmp >>= 16; 243 ret = put_user(tmp, (unsigned long *)data); 244 if (ret) 245 break; 246 data += sizeof(long); 247 } 248 break; 249 250 case PTRACE_SETREGS: /* Set all gp regs in the child. */ 251 for (i = 0; i < 19; i++) { 252 ret = get_user(tmp, (unsigned long *)data); 253 if (ret) 254 break; 255 if (i == PT_SR) { 256 tmp &= SR_MASK; 257 tmp <<= 16; 258 tmp |= get_reg(child, PT_SR) & ~(SR_MASK << 16); 259 } 260 put_reg(child, i, tmp); 261 data += sizeof(long); 262 } 263 break; 264 265 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 266 if (copy_to_user((void *)data, &child->thread.fp, 267 sizeof(struct user_m68kfp_struct))) 268 ret = -EFAULT; 269 break; 270 271 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 272 if (copy_from_user(&child->thread.fp, (void *)data, 273 sizeof(struct user_m68kfp_struct))) 274 ret = -EFAULT; 275 break; 276 277 default: 278 ret = ptrace_request(child, request, addr, data); 279 break; 280 } 281 282 return ret; 283out_eio: 284 return -EIO; 285} 286 287asmlinkage void syscall_trace(void) 288{ 289 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) 290 ? 0x80 : 0)); 291 /* 292 * this isn't the same as continuing with a signal, but it will do 293 * for normal use. strace only continues with a signal if the 294 * stopping signal is not SIGTRAP. -brl 295 */ 296 if (current->exit_code) { 297 send_sig(current->exit_code, current, 1); 298 current->exit_code = 0; 299 } 300} 301