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 #include <linux/regset.h> 23 #include <linux/elf.h> 24 #include <linux/seccomp.h> 25 #include <linux/uaccess.h> 26 #include <asm/page.h> 27 #include <asm/processor.h> 28 29 #include "ptrace.h" 30 31 /* 32 * does not yet catch signals sent when the child dies. 33 * in exit.c or in signal.c. 34 */ 35 36 /* determines which bits in the SR the user has access to. */ 37 /* 1 = access 0 = no access */ 38 #define SR_MASK 0x001f 39 40 /* sets the trace bits. */ 41 #define TRACE_BITS 0xC000 42 #define T1_BIT 0x8000 43 #define T0_BIT 0x4000 44 45 /* Find the stack offset for a register, relative to thread.esp0. */ 46 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg) 47 #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \ 48 - sizeof(struct switch_stack)) 49 /* Mapping from PT_xxx to the stack offset at which the register is 50 saved. Notice that usp has no stack-slot and needs to be treated 51 specially (see get_reg/put_reg below). */ 52 static const int regoff[] = { 53 [0] = PT_REG(d1), 54 [1] = PT_REG(d2), 55 [2] = PT_REG(d3), 56 [3] = PT_REG(d4), 57 [4] = PT_REG(d5), 58 [5] = SW_REG(d6), 59 [6] = SW_REG(d7), 60 [7] = PT_REG(a0), 61 [8] = PT_REG(a1), 62 [9] = PT_REG(a2), 63 [10] = SW_REG(a3), 64 [11] = SW_REG(a4), 65 [12] = SW_REG(a5), 66 [13] = SW_REG(a6), 67 [14] = PT_REG(d0), 68 [15] = -1, 69 [16] = PT_REG(orig_d0), 70 [17] = PT_REG(sr), 71 [18] = PT_REG(pc), 72 }; 73 74 /* 75 * Get contents of register REGNO in task TASK. 76 */ 77 static inline long get_reg(struct task_struct *task, int regno) 78 { 79 unsigned long *addr; 80 81 if (regno == PT_USP) 82 addr = &task->thread.usp; 83 else if (regno < ARRAY_SIZE(regoff)) 84 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 85 else 86 return 0; 87 /* Need to take stkadj into account. */ 88 if (regno == PT_SR || regno == PT_PC) { 89 long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj)); 90 addr = (unsigned long *) ((unsigned long)addr + stkadj); 91 /* The sr is actually a 16 bit register. */ 92 if (regno == PT_SR) 93 return *(unsigned short *)addr; 94 } 95 return *addr; 96 } 97 98 /* 99 * Write contents of register REGNO in task TASK. 100 */ 101 static inline int put_reg(struct task_struct *task, int regno, 102 unsigned long data) 103 { 104 unsigned long *addr; 105 106 if (regno == PT_USP) 107 addr = &task->thread.usp; 108 else if (regno < ARRAY_SIZE(regoff)) 109 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]); 110 else 111 return -1; 112 /* Need to take stkadj into account. */ 113 if (regno == PT_SR || regno == PT_PC) { 114 long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj)); 115 addr = (unsigned long *) ((unsigned long)addr + stkadj); 116 /* The sr is actually a 16 bit register. */ 117 if (regno == PT_SR) { 118 *(unsigned short *)addr = data; 119 return 0; 120 } 121 } 122 *addr = data; 123 return 0; 124 } 125 126 /* 127 * Make sure the single step bit is not set. 128 */ 129 static inline void singlestep_disable(struct task_struct *child) 130 { 131 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS; 132 put_reg(child, PT_SR, tmp); 133 clear_tsk_thread_flag(child, TIF_DELAYED_TRACE); 134 } 135 136 /* 137 * Called by kernel/ptrace.c when detaching.. 138 */ 139 void ptrace_disable(struct task_struct *child) 140 { 141 singlestep_disable(child); 142 } 143 144 void user_enable_single_step(struct task_struct *child) 145 { 146 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS; 147 put_reg(child, PT_SR, tmp | T1_BIT); 148 set_tsk_thread_flag(child, TIF_DELAYED_TRACE); 149 } 150 151 #ifdef CONFIG_MMU 152 void user_enable_block_step(struct task_struct *child) 153 { 154 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS; 155 put_reg(child, PT_SR, tmp | T0_BIT); 156 } 157 #endif 158 159 void user_disable_single_step(struct task_struct *child) 160 { 161 singlestep_disable(child); 162 } 163 164 long arch_ptrace(struct task_struct *child, long request, 165 unsigned long addr, unsigned long data) 166 { 167 unsigned long tmp; 168 int i, ret = 0; 169 int regno = addr >> 2; /* temporary hack. */ 170 unsigned long __user *datap = (unsigned long __user *) data; 171 172 switch (request) { 173 /* read the word at location addr in the USER area. */ 174 case PTRACE_PEEKUSR: 175 if (addr & 3) 176 goto out_eio; 177 178 if (regno >= 0 && regno < 19) { 179 tmp = get_reg(child, regno); 180 } else if (regno >= 21 && regno < 49) { 181 tmp = child->thread.fp[regno - 21]; 182 /* Convert internal fpu reg representation 183 * into long double format 184 */ 185 if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) 186 tmp = ((tmp & 0xffff0000) << 15) | 187 ((tmp & 0x0000ffff) << 16); 188 #ifndef CONFIG_MMU 189 } else if (regno == 49) { 190 tmp = child->mm->start_code; 191 } else if (regno == 50) { 192 tmp = child->mm->start_data; 193 } else if (regno == 51) { 194 tmp = child->mm->end_code; 195 #endif 196 } else 197 goto out_eio; 198 ret = put_user(tmp, datap); 199 break; 200 201 case PTRACE_POKEUSR: 202 /* write the word at location addr in the USER area */ 203 if (addr & 3) 204 goto out_eio; 205 206 if (regno == PT_SR) { 207 data &= SR_MASK; 208 data |= get_reg(child, PT_SR) & ~SR_MASK; 209 } 210 if (regno >= 0 && regno < 19) { 211 if (put_reg(child, regno, data)) 212 goto out_eio; 213 } else if (regno >= 21 && regno < 48) { 214 /* Convert long double format 215 * into internal fpu reg representation 216 */ 217 if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) { 218 data <<= 15; 219 data = (data & 0xffff0000) | 220 ((data & 0x0000ffff) >> 1); 221 } 222 child->thread.fp[regno - 21] = data; 223 } else 224 goto out_eio; 225 break; 226 227 case PTRACE_GETREGS: /* Get all gp regs from the child. */ 228 for (i = 0; i < 19; i++) { 229 tmp = get_reg(child, i); 230 ret = put_user(tmp, datap); 231 if (ret) 232 break; 233 datap++; 234 } 235 break; 236 237 case PTRACE_SETREGS: /* Set all gp regs in the child. */ 238 for (i = 0; i < 19; i++) { 239 ret = get_user(tmp, datap); 240 if (ret) 241 break; 242 if (i == PT_SR) { 243 tmp &= SR_MASK; 244 tmp |= get_reg(child, PT_SR) & ~SR_MASK; 245 } 246 put_reg(child, i, tmp); 247 datap++; 248 } 249 break; 250 251 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 252 if (copy_to_user(datap, &child->thread.fp, 253 sizeof(struct user_m68kfp_struct))) 254 ret = -EFAULT; 255 break; 256 257 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 258 if (copy_from_user(&child->thread.fp, datap, 259 sizeof(struct user_m68kfp_struct))) 260 ret = -EFAULT; 261 break; 262 263 case PTRACE_GET_THREAD_AREA: 264 ret = put_user(task_thread_info(child)->tp_value, datap); 265 break; 266 267 default: 268 ret = ptrace_request(child, request, addr, data); 269 break; 270 } 271 272 return ret; 273 out_eio: 274 return -EIO; 275 } 276 277 asmlinkage int syscall_trace_enter(void) 278 { 279 int ret = 0; 280 281 if (test_thread_flag(TIF_SYSCALL_TRACE)) 282 ret = ptrace_report_syscall_entry(task_pt_regs(current)); 283 284 if (secure_computing() == -1) 285 return -1; 286 287 return ret; 288 } 289 290 asmlinkage void syscall_trace_leave(void) 291 { 292 if (test_thread_flag(TIF_SYSCALL_TRACE)) 293 ptrace_report_syscall_exit(task_pt_regs(current), 0); 294 } 295 296 #if defined(CONFIG_BINFMT_ELF_FDPIC) && defined(CONFIG_ELF_CORE) 297 /* 298 * Currently the only thing that needs to use regsets for m68k is the 299 * coredump support of the elf_fdpic loader. Implement the minimum 300 * definitions required for that. 301 */ 302 static int m68k_regset_get(struct task_struct *target, 303 const struct user_regset *regset, 304 struct membuf to) 305 { 306 struct pt_regs *ptregs = task_pt_regs(target); 307 u32 uregs[ELF_NGREG]; 308 309 ELF_CORE_COPY_REGS(uregs, ptregs); 310 return membuf_write(&to, uregs, sizeof(uregs)); 311 } 312 313 enum m68k_regset { 314 REGSET_GPR, 315 #ifdef CONFIG_FPU 316 REGSET_FPU, 317 #endif 318 }; 319 320 static const struct user_regset m68k_user_regsets[] = { 321 [REGSET_GPR] = { 322 .core_note_type = NT_PRSTATUS, 323 .n = ELF_NGREG, 324 .size = sizeof(u32), 325 .align = sizeof(u16), 326 .regset_get = m68k_regset_get, 327 }, 328 #ifdef CONFIG_FPU 329 [REGSET_FPU] = { 330 .core_note_type = NT_PRFPREG, 331 .n = sizeof(struct user_m68kfp_struct) / sizeof(u32), 332 .size = sizeof(u32), 333 .align = sizeof(u32), 334 } 335 #endif /* CONFIG_FPU */ 336 }; 337 338 static const struct user_regset_view user_m68k_view = { 339 .name = "m68k", 340 .e_machine = EM_68K, 341 .ei_osabi = ELF_OSABI, 342 .regsets = m68k_user_regsets, 343 .n = ARRAY_SIZE(m68k_user_regsets) 344 }; 345 346 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 347 { 348 return &user_m68k_view; 349 } 350 #endif /* CONFIG_BINFMT_ELF_FDPIC && CONFIG_ELF_CORE */ 351