1 /* 2 * SuperH process tracing 3 * 4 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka 5 * Copyright (C) 2002 - 2008 Paul Mundt 6 * 7 * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp> 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file "COPYING" in the main directory of this archive 11 * for more details. 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/slab.h> 21 #include <linux/security.h> 22 #include <linux/signal.h> 23 #include <linux/io.h> 24 #include <linux/audit.h> 25 #include <linux/seccomp.h> 26 #include <linux/tracehook.h> 27 #include <linux/elf.h> 28 #include <linux/regset.h> 29 #include <asm/uaccess.h> 30 #include <asm/pgtable.h> 31 #include <asm/system.h> 32 #include <asm/processor.h> 33 #include <asm/mmu_context.h> 34 #include <asm/syscalls.h> 35 #include <asm/fpu.h> 36 37 #include <trace/syscall.h> 38 39 /* 40 * This routine will get a word off of the process kernel stack. 41 */ 42 static inline int get_stack_long(struct task_struct *task, int offset) 43 { 44 unsigned char *stack; 45 46 stack = (unsigned char *)task_pt_regs(task); 47 stack += offset; 48 return (*((int *)stack)); 49 } 50 51 /* 52 * This routine will put a word on the process kernel stack. 53 */ 54 static inline int put_stack_long(struct task_struct *task, int offset, 55 unsigned long data) 56 { 57 unsigned char *stack; 58 59 stack = (unsigned char *)task_pt_regs(task); 60 stack += offset; 61 *(unsigned long *) stack = data; 62 return 0; 63 } 64 65 void user_enable_single_step(struct task_struct *child) 66 { 67 /* Next scheduling will set up UBC */ 68 if (child->thread.ubc_pc == 0) 69 ubc_usercnt += 1; 70 71 child->thread.ubc_pc = get_stack_long(child, 72 offsetof(struct pt_regs, pc)); 73 74 set_tsk_thread_flag(child, TIF_SINGLESTEP); 75 } 76 77 void user_disable_single_step(struct task_struct *child) 78 { 79 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 80 81 /* 82 * Ensure the UBC is not programmed at the next context switch. 83 * 84 * Normally this is not needed but there are sequences such as 85 * singlestep, signal delivery, and continue that leave the 86 * ubc_pc non-zero leading to spurious SIGTRAPs. 87 */ 88 if (child->thread.ubc_pc != 0) { 89 ubc_usercnt -= 1; 90 child->thread.ubc_pc = 0; 91 } 92 } 93 94 /* 95 * Called by kernel/ptrace.c when detaching.. 96 * 97 * Make sure single step bits etc are not set. 98 */ 99 void ptrace_disable(struct task_struct *child) 100 { 101 user_disable_single_step(child); 102 } 103 104 static int genregs_get(struct task_struct *target, 105 const struct user_regset *regset, 106 unsigned int pos, unsigned int count, 107 void *kbuf, void __user *ubuf) 108 { 109 const struct pt_regs *regs = task_pt_regs(target); 110 int ret; 111 112 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 113 regs->regs, 114 0, 16 * sizeof(unsigned long)); 115 if (!ret) 116 /* PC, PR, SR, GBR, MACH, MACL, TRA */ 117 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 118 ®s->pc, 119 offsetof(struct pt_regs, pc), 120 sizeof(struct pt_regs)); 121 if (!ret) 122 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 123 sizeof(struct pt_regs), -1); 124 125 return ret; 126 } 127 128 static int genregs_set(struct task_struct *target, 129 const struct user_regset *regset, 130 unsigned int pos, unsigned int count, 131 const void *kbuf, const void __user *ubuf) 132 { 133 struct pt_regs *regs = task_pt_regs(target); 134 int ret; 135 136 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 137 regs->regs, 138 0, 16 * sizeof(unsigned long)); 139 if (!ret && count > 0) 140 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 141 ®s->pc, 142 offsetof(struct pt_regs, pc), 143 sizeof(struct pt_regs)); 144 if (!ret) 145 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 146 sizeof(struct pt_regs), -1); 147 148 return ret; 149 } 150 151 #ifdef CONFIG_SH_FPU 152 int fpregs_get(struct task_struct *target, 153 const struct user_regset *regset, 154 unsigned int pos, unsigned int count, 155 void *kbuf, void __user *ubuf) 156 { 157 int ret; 158 159 ret = init_fpu(target); 160 if (ret) 161 return ret; 162 163 if ((boot_cpu_data.flags & CPU_HAS_FPU)) 164 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 165 &target->thread.fpu.hard, 0, -1); 166 167 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 168 &target->thread.fpu.soft, 0, -1); 169 } 170 171 static int fpregs_set(struct task_struct *target, 172 const struct user_regset *regset, 173 unsigned int pos, unsigned int count, 174 const void *kbuf, const void __user *ubuf) 175 { 176 int ret; 177 178 ret = init_fpu(target); 179 if (ret) 180 return ret; 181 182 set_stopped_child_used_math(target); 183 184 if ((boot_cpu_data.flags & CPU_HAS_FPU)) 185 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 186 &target->thread.fpu.hard, 0, -1); 187 188 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 189 &target->thread.fpu.soft, 0, -1); 190 } 191 192 static int fpregs_active(struct task_struct *target, 193 const struct user_regset *regset) 194 { 195 return tsk_used_math(target) ? regset->n : 0; 196 } 197 #endif 198 199 #ifdef CONFIG_SH_DSP 200 static int dspregs_get(struct task_struct *target, 201 const struct user_regset *regset, 202 unsigned int pos, unsigned int count, 203 void *kbuf, void __user *ubuf) 204 { 205 const struct pt_dspregs *regs = 206 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; 207 int ret; 208 209 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 210 0, sizeof(struct pt_dspregs)); 211 if (!ret) 212 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 213 sizeof(struct pt_dspregs), -1); 214 215 return ret; 216 } 217 218 static int dspregs_set(struct task_struct *target, 219 const struct user_regset *regset, 220 unsigned int pos, unsigned int count, 221 const void *kbuf, const void __user *ubuf) 222 { 223 struct pt_dspregs *regs = 224 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; 225 int ret; 226 227 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 228 0, sizeof(struct pt_dspregs)); 229 if (!ret) 230 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 231 sizeof(struct pt_dspregs), -1); 232 233 return ret; 234 } 235 236 static int dspregs_active(struct task_struct *target, 237 const struct user_regset *regset) 238 { 239 struct pt_regs *regs = task_pt_regs(target); 240 241 return regs->sr & SR_DSP ? regset->n : 0; 242 } 243 #endif 244 245 /* 246 * These are our native regset flavours. 247 */ 248 enum sh_regset { 249 REGSET_GENERAL, 250 #ifdef CONFIG_SH_FPU 251 REGSET_FPU, 252 #endif 253 #ifdef CONFIG_SH_DSP 254 REGSET_DSP, 255 #endif 256 }; 257 258 static const struct user_regset sh_regsets[] = { 259 /* 260 * Format is: 261 * R0 --> R15 262 * PC, PR, SR, GBR, MACH, MACL, TRA 263 */ 264 [REGSET_GENERAL] = { 265 .core_note_type = NT_PRSTATUS, 266 .n = ELF_NGREG, 267 .size = sizeof(long), 268 .align = sizeof(long), 269 .get = genregs_get, 270 .set = genregs_set, 271 }, 272 273 #ifdef CONFIG_SH_FPU 274 [REGSET_FPU] = { 275 .core_note_type = NT_PRFPREG, 276 .n = sizeof(struct user_fpu_struct) / sizeof(long), 277 .size = sizeof(long), 278 .align = sizeof(long), 279 .get = fpregs_get, 280 .set = fpregs_set, 281 .active = fpregs_active, 282 }, 283 #endif 284 285 #ifdef CONFIG_SH_DSP 286 [REGSET_DSP] = { 287 .n = sizeof(struct pt_dspregs) / sizeof(long), 288 .size = sizeof(long), 289 .align = sizeof(long), 290 .get = dspregs_get, 291 .set = dspregs_set, 292 .active = dspregs_active, 293 }, 294 #endif 295 }; 296 297 static const struct user_regset_view user_sh_native_view = { 298 .name = "sh", 299 .e_machine = EM_SH, 300 .regsets = sh_regsets, 301 .n = ARRAY_SIZE(sh_regsets), 302 }; 303 304 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 305 { 306 return &user_sh_native_view; 307 } 308 309 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 310 { 311 struct user * dummy = NULL; 312 unsigned long __user *datap = (unsigned long __user *)data; 313 int ret; 314 315 switch (request) { 316 /* read the word at location addr in the USER area. */ 317 case PTRACE_PEEKUSR: { 318 unsigned long tmp; 319 320 ret = -EIO; 321 if ((addr & 3) || addr < 0 || 322 addr > sizeof(struct user) - 3) 323 break; 324 325 if (addr < sizeof(struct pt_regs)) 326 tmp = get_stack_long(child, addr); 327 else if (addr >= (long) &dummy->fpu && 328 addr < (long) &dummy->u_fpvalid) { 329 if (!tsk_used_math(child)) { 330 if (addr == (long)&dummy->fpu.fpscr) 331 tmp = FPSCR_INIT; 332 else 333 tmp = 0; 334 } else 335 tmp = ((long *)&child->thread.fpu) 336 [(addr - (long)&dummy->fpu) >> 2]; 337 } else if (addr == (long) &dummy->u_fpvalid) 338 tmp = !!tsk_used_math(child); 339 else if (addr == PT_TEXT_ADDR) 340 tmp = child->mm->start_code; 341 else if (addr == PT_DATA_ADDR) 342 tmp = child->mm->start_data; 343 else if (addr == PT_TEXT_END_ADDR) 344 tmp = child->mm->end_code; 345 else if (addr == PT_TEXT_LEN) 346 tmp = child->mm->end_code - child->mm->start_code; 347 else 348 tmp = 0; 349 ret = put_user(tmp, datap); 350 break; 351 } 352 353 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 354 ret = -EIO; 355 if ((addr & 3) || addr < 0 || 356 addr > sizeof(struct user) - 3) 357 break; 358 359 if (addr < sizeof(struct pt_regs)) 360 ret = put_stack_long(child, addr, data); 361 else if (addr >= (long) &dummy->fpu && 362 addr < (long) &dummy->u_fpvalid) { 363 set_stopped_child_used_math(child); 364 ((long *)&child->thread.fpu) 365 [(addr - (long)&dummy->fpu) >> 2] = data; 366 ret = 0; 367 } else if (addr == (long) &dummy->u_fpvalid) { 368 conditional_stopped_child_used_math(data, child); 369 ret = 0; 370 } 371 break; 372 373 case PTRACE_GETREGS: 374 return copy_regset_to_user(child, &user_sh_native_view, 375 REGSET_GENERAL, 376 0, sizeof(struct pt_regs), 377 (void __user *)data); 378 case PTRACE_SETREGS: 379 return copy_regset_from_user(child, &user_sh_native_view, 380 REGSET_GENERAL, 381 0, sizeof(struct pt_regs), 382 (const void __user *)data); 383 #ifdef CONFIG_SH_FPU 384 case PTRACE_GETFPREGS: 385 return copy_regset_to_user(child, &user_sh_native_view, 386 REGSET_FPU, 387 0, sizeof(struct user_fpu_struct), 388 (void __user *)data); 389 case PTRACE_SETFPREGS: 390 return copy_regset_from_user(child, &user_sh_native_view, 391 REGSET_FPU, 392 0, sizeof(struct user_fpu_struct), 393 (const void __user *)data); 394 #endif 395 #ifdef CONFIG_SH_DSP 396 case PTRACE_GETDSPREGS: 397 return copy_regset_to_user(child, &user_sh_native_view, 398 REGSET_DSP, 399 0, sizeof(struct pt_dspregs), 400 (void __user *)data); 401 case PTRACE_SETDSPREGS: 402 return copy_regset_from_user(child, &user_sh_native_view, 403 REGSET_DSP, 404 0, sizeof(struct pt_dspregs), 405 (const void __user *)data); 406 #endif 407 #ifdef CONFIG_BINFMT_ELF_FDPIC 408 case PTRACE_GETFDPIC: { 409 unsigned long tmp = 0; 410 411 switch (addr) { 412 case PTRACE_GETFDPIC_EXEC: 413 tmp = child->mm->context.exec_fdpic_loadmap; 414 break; 415 case PTRACE_GETFDPIC_INTERP: 416 tmp = child->mm->context.interp_fdpic_loadmap; 417 break; 418 default: 419 break; 420 } 421 422 ret = 0; 423 if (put_user(tmp, datap)) { 424 ret = -EFAULT; 425 break; 426 } 427 break; 428 } 429 #endif 430 default: 431 ret = ptrace_request(child, request, addr, data); 432 break; 433 } 434 435 return ret; 436 } 437 438 static inline int audit_arch(void) 439 { 440 int arch = EM_SH; 441 442 #ifdef CONFIG_CPU_LITTLE_ENDIAN 443 arch |= __AUDIT_ARCH_LE; 444 #endif 445 446 return arch; 447 } 448 449 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 450 { 451 long ret = 0; 452 453 secure_computing(regs->regs[0]); 454 455 if (test_thread_flag(TIF_SYSCALL_TRACE) && 456 tracehook_report_syscall_entry(regs)) 457 /* 458 * Tracing decided this syscall should not happen. 459 * We'll return a bogus call number to get an ENOSYS 460 * error, but leave the original number in regs->regs[0]. 461 */ 462 ret = -1L; 463 464 if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE))) 465 ftrace_syscall_enter(regs); 466 467 if (unlikely(current->audit_context)) 468 audit_syscall_entry(audit_arch(), regs->regs[3], 469 regs->regs[4], regs->regs[5], 470 regs->regs[6], regs->regs[7]); 471 472 return ret ?: regs->regs[0]; 473 } 474 475 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 476 { 477 int step; 478 479 if (unlikely(current->audit_context)) 480 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]), 481 regs->regs[0]); 482 483 if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE))) 484 ftrace_syscall_exit(regs); 485 486 step = test_thread_flag(TIF_SINGLESTEP); 487 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 488 tracehook_report_syscall_exit(regs, step); 489 } 490