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/sched/task_stack.h> 16 #include <linux/mm.h> 17 #include <linux/smp.h> 18 #include <linux/errno.h> 19 #include <linux/ptrace.h> 20 #include <linux/user.h> 21 #include <linux/signal.h> 22 23 #include <linux/uaccess.h> 24 #include <asm/page.h> 25 #include <asm/processor.h> 26 27 /* 28 * does not yet catch signals sent when the child dies. 29 * in exit.c or in signal.c. 30 */ 31 32 /* determines which bits in the SR the user has access to. */ 33 /* 1 = access 0 = no access */ 34 #define SR_MASK 0x001f 35 36 /* sets the trace bits. */ 37 #define TRACE_BITS 0xC000 38 #define T1_BIT 0x8000 39 #define T0_BIT 0x4000 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 const 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 < ARRAY_SIZE(regoff)) 80 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 81 else 82 return 0; 83 /* Need to take stkadj into account. */ 84 if (regno == PT_SR || regno == PT_PC) { 85 long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj)); 86 addr = (unsigned long *) ((unsigned long)addr + stkadj); 87 /* The sr is actually a 16 bit register. */ 88 if (regno == PT_SR) 89 return *(unsigned short *)addr; 90 } 91 return *addr; 92 } 93 94 /* 95 * Write contents of register REGNO in task TASK. 96 */ 97 static inline int put_reg(struct task_struct *task, int regno, 98 unsigned long data) 99 { 100 unsigned long *addr; 101 102 if (regno == PT_USP) 103 addr = &task->thread.usp; 104 else if (regno < ARRAY_SIZE(regoff)) 105 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 106 else 107 return -1; 108 /* Need to take stkadj into account. */ 109 if (regno == PT_SR || regno == PT_PC) { 110 long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj)); 111 addr = (unsigned long *) ((unsigned long)addr + stkadj); 112 /* The sr is actually a 16 bit register. */ 113 if (regno == PT_SR) { 114 *(unsigned short *)addr = data; 115 return 0; 116 } 117 } 118 *addr = data; 119 return 0; 120 } 121 122 /* 123 * Make sure the single step bit is not set. 124 */ 125 static inline void singlestep_disable(struct task_struct *child) 126 { 127 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS; 128 put_reg(child, PT_SR, tmp); 129 clear_tsk_thread_flag(child, TIF_DELAYED_TRACE); 130 } 131 132 /* 133 * Called by kernel/ptrace.c when detaching.. 134 */ 135 void ptrace_disable(struct task_struct *child) 136 { 137 singlestep_disable(child); 138 } 139 140 void user_enable_single_step(struct task_struct *child) 141 { 142 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS; 143 put_reg(child, PT_SR, tmp | T1_BIT); 144 set_tsk_thread_flag(child, TIF_DELAYED_TRACE); 145 } 146 147 #ifdef CONFIG_MMU 148 void user_enable_block_step(struct task_struct *child) 149 { 150 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS; 151 put_reg(child, PT_SR, tmp | T0_BIT); 152 } 153 #endif 154 155 void user_disable_single_step(struct task_struct *child) 156 { 157 singlestep_disable(child); 158 } 159 160 long arch_ptrace(struct task_struct *child, long request, 161 unsigned long addr, unsigned long data) 162 { 163 unsigned long tmp; 164 int i, ret = 0; 165 int regno = addr >> 2; /* temporary hack. */ 166 unsigned long __user *datap = (unsigned long __user *) data; 167 168 switch (request) { 169 /* read the word at location addr in the USER area. */ 170 case PTRACE_PEEKUSR: 171 if (addr & 3) 172 goto out_eio; 173 174 if (regno >= 0 && regno < 19) { 175 tmp = get_reg(child, regno); 176 } else if (regno >= 21 && regno < 49) { 177 tmp = child->thread.fp[regno - 21]; 178 /* Convert internal fpu reg representation 179 * into long double format 180 */ 181 if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) 182 tmp = ((tmp & 0xffff0000) << 15) | 183 ((tmp & 0x0000ffff) << 16); 184 #ifndef CONFIG_MMU 185 } else if (regno == 49) { 186 tmp = child->mm->start_code; 187 } else if (regno == 50) { 188 tmp = child->mm->start_data; 189 } else if (regno == 51) { 190 tmp = child->mm->end_code; 191 #endif 192 } else 193 goto out_eio; 194 ret = put_user(tmp, datap); 195 break; 196 197 case PTRACE_POKEUSR: 198 /* write the word at location addr in the USER area */ 199 if (addr & 3) 200 goto out_eio; 201 202 if (regno == PT_SR) { 203 data &= SR_MASK; 204 data |= get_reg(child, PT_SR) & ~SR_MASK; 205 } 206 if (regno >= 0 && regno < 19) { 207 if (put_reg(child, regno, data)) 208 goto out_eio; 209 } else if (regno >= 21 && regno < 48) { 210 /* Convert long double format 211 * into internal fpu reg representation 212 */ 213 if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) { 214 data <<= 15; 215 data = (data & 0xffff0000) | 216 ((data & 0x0000ffff) >> 1); 217 } 218 child->thread.fp[regno - 21] = data; 219 } else 220 goto out_eio; 221 break; 222 223 case PTRACE_GETREGS: /* Get all gp regs from the child. */ 224 for (i = 0; i < 19; i++) { 225 tmp = get_reg(child, i); 226 ret = put_user(tmp, datap); 227 if (ret) 228 break; 229 datap++; 230 } 231 break; 232 233 case PTRACE_SETREGS: /* Set all gp regs in the child. */ 234 for (i = 0; i < 19; i++) { 235 ret = get_user(tmp, datap); 236 if (ret) 237 break; 238 if (i == PT_SR) { 239 tmp &= SR_MASK; 240 tmp |= get_reg(child, PT_SR) & ~SR_MASK; 241 } 242 put_reg(child, i, tmp); 243 datap++; 244 } 245 break; 246 247 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 248 if (copy_to_user(datap, &child->thread.fp, 249 sizeof(struct user_m68kfp_struct))) 250 ret = -EFAULT; 251 break; 252 253 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 254 if (copy_from_user(&child->thread.fp, datap, 255 sizeof(struct user_m68kfp_struct))) 256 ret = -EFAULT; 257 break; 258 259 case PTRACE_GET_THREAD_AREA: 260 ret = put_user(task_thread_info(child)->tp_value, datap); 261 break; 262 263 default: 264 ret = ptrace_request(child, request, addr, data); 265 break; 266 } 267 268 return ret; 269 out_eio: 270 return -EIO; 271 } 272 273 asmlinkage void syscall_trace(void) 274 { 275 ptrace_report_syscall(0); 276 } 277 278 #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU) 279 asmlinkage int syscall_trace_enter(void) 280 { 281 int ret = 0; 282 283 if (test_thread_flag(TIF_SYSCALL_TRACE)) 284 ret = ptrace_report_syscall_entry(task_pt_regs(current)); 285 return ret; 286 } 287 288 asmlinkage void syscall_trace_leave(void) 289 { 290 if (test_thread_flag(TIF_SYSCALL_TRACE)) 291 ptrace_report_syscall_exit(task_pt_regs(current), 0); 292 } 293 #endif /* CONFIG_COLDFIRE */ 294