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