1 /* 2 * SuperH process tracing 3 * 4 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka 5 * Copyright (C) 2002 - 2009 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/security.h> 21 #include <linux/signal.h> 22 #include <linux/io.h> 23 #include <linux/audit.h> 24 #include <linux/seccomp.h> 25 #include <linux/tracehook.h> 26 #include <linux/elf.h> 27 #include <linux/regset.h> 28 #include <linux/hw_breakpoint.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 #define CREATE_TRACE_POINTS 38 #include <trace/events/syscalls.h> 39 40 /* 41 * This routine will get a word off of the process kernel stack. 42 */ 43 static inline int get_stack_long(struct task_struct *task, int offset) 44 { 45 unsigned char *stack; 46 47 stack = (unsigned char *)task_pt_regs(task); 48 stack += offset; 49 return (*((int *)stack)); 50 } 51 52 /* 53 * This routine will put a word on the process kernel stack. 54 */ 55 static inline int put_stack_long(struct task_struct *task, int offset, 56 unsigned long data) 57 { 58 unsigned char *stack; 59 60 stack = (unsigned char *)task_pt_regs(task); 61 stack += offset; 62 *(unsigned long *) stack = data; 63 return 0; 64 } 65 66 void ptrace_triggered(struct perf_event *bp, 67 struct perf_sample_data *data, struct pt_regs *regs) 68 { 69 struct perf_event_attr attr; 70 71 /* 72 * Disable the breakpoint request here since ptrace has defined a 73 * one-shot behaviour for breakpoint exceptions. 74 */ 75 attr = bp->attr; 76 attr.disabled = true; 77 modify_user_hw_breakpoint(bp, &attr); 78 } 79 80 static int set_single_step(struct task_struct *tsk, unsigned long addr) 81 { 82 struct thread_struct *thread = &tsk->thread; 83 struct perf_event *bp; 84 struct perf_event_attr attr; 85 86 bp = thread->ptrace_bps[0]; 87 if (!bp) { 88 ptrace_breakpoint_init(&attr); 89 90 attr.bp_addr = addr; 91 attr.bp_len = HW_BREAKPOINT_LEN_2; 92 attr.bp_type = HW_BREAKPOINT_R; 93 94 bp = register_user_hw_breakpoint(&attr, ptrace_triggered, 95 NULL, tsk); 96 if (IS_ERR(bp)) 97 return PTR_ERR(bp); 98 99 thread->ptrace_bps[0] = bp; 100 } else { 101 int err; 102 103 attr = bp->attr; 104 attr.bp_addr = addr; 105 /* reenable breakpoint */ 106 attr.disabled = false; 107 err = modify_user_hw_breakpoint(bp, &attr); 108 if (unlikely(err)) 109 return err; 110 } 111 112 return 0; 113 } 114 115 void user_enable_single_step(struct task_struct *child) 116 { 117 unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc)); 118 119 set_tsk_thread_flag(child, TIF_SINGLESTEP); 120 121 if (ptrace_get_breakpoints(child) < 0) 122 return; 123 124 set_single_step(child, pc); 125 ptrace_put_breakpoints(child); 126 } 127 128 void user_disable_single_step(struct task_struct *child) 129 { 130 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 131 } 132 133 /* 134 * Called by kernel/ptrace.c when detaching.. 135 * 136 * Make sure single step bits etc are not set. 137 */ 138 void ptrace_disable(struct task_struct *child) 139 { 140 user_disable_single_step(child); 141 } 142 143 static int genregs_get(struct task_struct *target, 144 const struct user_regset *regset, 145 unsigned int pos, unsigned int count, 146 void *kbuf, void __user *ubuf) 147 { 148 const struct pt_regs *regs = task_pt_regs(target); 149 int ret; 150 151 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 152 regs->regs, 153 0, 16 * sizeof(unsigned long)); 154 if (!ret) 155 /* PC, PR, SR, GBR, MACH, MACL, TRA */ 156 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 157 ®s->pc, 158 offsetof(struct pt_regs, pc), 159 sizeof(struct pt_regs)); 160 if (!ret) 161 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 162 sizeof(struct pt_regs), -1); 163 164 return ret; 165 } 166 167 static int genregs_set(struct task_struct *target, 168 const struct user_regset *regset, 169 unsigned int pos, unsigned int count, 170 const void *kbuf, const void __user *ubuf) 171 { 172 struct pt_regs *regs = task_pt_regs(target); 173 int ret; 174 175 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 176 regs->regs, 177 0, 16 * sizeof(unsigned long)); 178 if (!ret && count > 0) 179 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 180 ®s->pc, 181 offsetof(struct pt_regs, pc), 182 sizeof(struct pt_regs)); 183 if (!ret) 184 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 185 sizeof(struct pt_regs), -1); 186 187 return ret; 188 } 189 190 #ifdef CONFIG_SH_FPU 191 int fpregs_get(struct task_struct *target, 192 const struct user_regset *regset, 193 unsigned int pos, unsigned int count, 194 void *kbuf, void __user *ubuf) 195 { 196 int ret; 197 198 ret = init_fpu(target); 199 if (ret) 200 return ret; 201 202 if ((boot_cpu_data.flags & CPU_HAS_FPU)) 203 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 204 &target->thread.xstate->hardfpu, 0, -1); 205 206 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 207 &target->thread.xstate->softfpu, 0, -1); 208 } 209 210 static int fpregs_set(struct task_struct *target, 211 const struct user_regset *regset, 212 unsigned int pos, unsigned int count, 213 const void *kbuf, const void __user *ubuf) 214 { 215 int ret; 216 217 ret = init_fpu(target); 218 if (ret) 219 return ret; 220 221 set_stopped_child_used_math(target); 222 223 if ((boot_cpu_data.flags & CPU_HAS_FPU)) 224 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 225 &target->thread.xstate->hardfpu, 0, -1); 226 227 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 228 &target->thread.xstate->softfpu, 0, -1); 229 } 230 231 static int fpregs_active(struct task_struct *target, 232 const struct user_regset *regset) 233 { 234 return tsk_used_math(target) ? regset->n : 0; 235 } 236 #endif 237 238 #ifdef CONFIG_SH_DSP 239 static int dspregs_get(struct task_struct *target, 240 const struct user_regset *regset, 241 unsigned int pos, unsigned int count, 242 void *kbuf, void __user *ubuf) 243 { 244 const struct pt_dspregs *regs = 245 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; 246 int ret; 247 248 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 249 0, sizeof(struct pt_dspregs)); 250 if (!ret) 251 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 252 sizeof(struct pt_dspregs), -1); 253 254 return ret; 255 } 256 257 static int dspregs_set(struct task_struct *target, 258 const struct user_regset *regset, 259 unsigned int pos, unsigned int count, 260 const void *kbuf, const void __user *ubuf) 261 { 262 struct pt_dspregs *regs = 263 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; 264 int ret; 265 266 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 267 0, sizeof(struct pt_dspregs)); 268 if (!ret) 269 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 270 sizeof(struct pt_dspregs), -1); 271 272 return ret; 273 } 274 275 static int dspregs_active(struct task_struct *target, 276 const struct user_regset *regset) 277 { 278 struct pt_regs *regs = task_pt_regs(target); 279 280 return regs->sr & SR_DSP ? regset->n : 0; 281 } 282 #endif 283 284 const struct pt_regs_offset regoffset_table[] = { 285 REGS_OFFSET_NAME(0), 286 REGS_OFFSET_NAME(1), 287 REGS_OFFSET_NAME(2), 288 REGS_OFFSET_NAME(3), 289 REGS_OFFSET_NAME(4), 290 REGS_OFFSET_NAME(5), 291 REGS_OFFSET_NAME(6), 292 REGS_OFFSET_NAME(7), 293 REGS_OFFSET_NAME(8), 294 REGS_OFFSET_NAME(9), 295 REGS_OFFSET_NAME(10), 296 REGS_OFFSET_NAME(11), 297 REGS_OFFSET_NAME(12), 298 REGS_OFFSET_NAME(13), 299 REGS_OFFSET_NAME(14), 300 REGS_OFFSET_NAME(15), 301 REG_OFFSET_NAME(pc), 302 REG_OFFSET_NAME(pr), 303 REG_OFFSET_NAME(sr), 304 REG_OFFSET_NAME(gbr), 305 REG_OFFSET_NAME(mach), 306 REG_OFFSET_NAME(macl), 307 REG_OFFSET_NAME(tra), 308 REG_OFFSET_END, 309 }; 310 311 /* 312 * These are our native regset flavours. 313 */ 314 enum sh_regset { 315 REGSET_GENERAL, 316 #ifdef CONFIG_SH_FPU 317 REGSET_FPU, 318 #endif 319 #ifdef CONFIG_SH_DSP 320 REGSET_DSP, 321 #endif 322 }; 323 324 static const struct user_regset sh_regsets[] = { 325 /* 326 * Format is: 327 * R0 --> R15 328 * PC, PR, SR, GBR, MACH, MACL, TRA 329 */ 330 [REGSET_GENERAL] = { 331 .core_note_type = NT_PRSTATUS, 332 .n = ELF_NGREG, 333 .size = sizeof(long), 334 .align = sizeof(long), 335 .get = genregs_get, 336 .set = genregs_set, 337 }, 338 339 #ifdef CONFIG_SH_FPU 340 [REGSET_FPU] = { 341 .core_note_type = NT_PRFPREG, 342 .n = sizeof(struct user_fpu_struct) / sizeof(long), 343 .size = sizeof(long), 344 .align = sizeof(long), 345 .get = fpregs_get, 346 .set = fpregs_set, 347 .active = fpregs_active, 348 }, 349 #endif 350 351 #ifdef CONFIG_SH_DSP 352 [REGSET_DSP] = { 353 .n = sizeof(struct pt_dspregs) / sizeof(long), 354 .size = sizeof(long), 355 .align = sizeof(long), 356 .get = dspregs_get, 357 .set = dspregs_set, 358 .active = dspregs_active, 359 }, 360 #endif 361 }; 362 363 static const struct user_regset_view user_sh_native_view = { 364 .name = "sh", 365 .e_machine = EM_SH, 366 .regsets = sh_regsets, 367 .n = ARRAY_SIZE(sh_regsets), 368 }; 369 370 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 371 { 372 return &user_sh_native_view; 373 } 374 375 long arch_ptrace(struct task_struct *child, long request, 376 unsigned long addr, unsigned long data) 377 { 378 unsigned long __user *datap = (unsigned long __user *)data; 379 int ret; 380 381 switch (request) { 382 /* read the word at location addr in the USER area. */ 383 case PTRACE_PEEKUSR: { 384 unsigned long tmp; 385 386 ret = -EIO; 387 if ((addr & 3) || addr < 0 || 388 addr > sizeof(struct user) - 3) 389 break; 390 391 if (addr < sizeof(struct pt_regs)) 392 tmp = get_stack_long(child, addr); 393 else if (addr >= offsetof(struct user, fpu) && 394 addr < offsetof(struct user, u_fpvalid)) { 395 if (!tsk_used_math(child)) { 396 if (addr == offsetof(struct user, fpu.fpscr)) 397 tmp = FPSCR_INIT; 398 else 399 tmp = 0; 400 } else { 401 unsigned long index; 402 ret = init_fpu(child); 403 if (ret) 404 break; 405 index = addr - offsetof(struct user, fpu); 406 tmp = ((unsigned long *)child->thread.xstate) 407 [index >> 2]; 408 } 409 } else if (addr == offsetof(struct user, u_fpvalid)) 410 tmp = !!tsk_used_math(child); 411 else if (addr == PT_TEXT_ADDR) 412 tmp = child->mm->start_code; 413 else if (addr == PT_DATA_ADDR) 414 tmp = child->mm->start_data; 415 else if (addr == PT_TEXT_END_ADDR) 416 tmp = child->mm->end_code; 417 else if (addr == PT_TEXT_LEN) 418 tmp = child->mm->end_code - child->mm->start_code; 419 else 420 tmp = 0; 421 ret = put_user(tmp, datap); 422 break; 423 } 424 425 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 426 ret = -EIO; 427 if ((addr & 3) || addr < 0 || 428 addr > sizeof(struct user) - 3) 429 break; 430 431 if (addr < sizeof(struct pt_regs)) 432 ret = put_stack_long(child, addr, data); 433 else if (addr >= offsetof(struct user, fpu) && 434 addr < offsetof(struct user, u_fpvalid)) { 435 unsigned long index; 436 ret = init_fpu(child); 437 if (ret) 438 break; 439 index = addr - offsetof(struct user, fpu); 440 set_stopped_child_used_math(child); 441 ((unsigned long *)child->thread.xstate) 442 [index >> 2] = data; 443 ret = 0; 444 } else if (addr == offsetof(struct user, u_fpvalid)) { 445 conditional_stopped_child_used_math(data, child); 446 ret = 0; 447 } 448 break; 449 450 case PTRACE_GETREGS: 451 return copy_regset_to_user(child, &user_sh_native_view, 452 REGSET_GENERAL, 453 0, sizeof(struct pt_regs), 454 datap); 455 case PTRACE_SETREGS: 456 return copy_regset_from_user(child, &user_sh_native_view, 457 REGSET_GENERAL, 458 0, sizeof(struct pt_regs), 459 datap); 460 #ifdef CONFIG_SH_FPU 461 case PTRACE_GETFPREGS: 462 return copy_regset_to_user(child, &user_sh_native_view, 463 REGSET_FPU, 464 0, sizeof(struct user_fpu_struct), 465 datap); 466 case PTRACE_SETFPREGS: 467 return copy_regset_from_user(child, &user_sh_native_view, 468 REGSET_FPU, 469 0, sizeof(struct user_fpu_struct), 470 datap); 471 #endif 472 #ifdef CONFIG_SH_DSP 473 case PTRACE_GETDSPREGS: 474 return copy_regset_to_user(child, &user_sh_native_view, 475 REGSET_DSP, 476 0, sizeof(struct pt_dspregs), 477 datap); 478 case PTRACE_SETDSPREGS: 479 return copy_regset_from_user(child, &user_sh_native_view, 480 REGSET_DSP, 481 0, sizeof(struct pt_dspregs), 482 datap); 483 #endif 484 default: 485 ret = ptrace_request(child, request, addr, data); 486 break; 487 } 488 489 return ret; 490 } 491 492 static inline int audit_arch(void) 493 { 494 int arch = EM_SH; 495 496 #ifdef CONFIG_CPU_LITTLE_ENDIAN 497 arch |= __AUDIT_ARCH_LE; 498 #endif 499 500 return arch; 501 } 502 503 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 504 { 505 long ret = 0; 506 507 secure_computing(regs->regs[0]); 508 509 if (test_thread_flag(TIF_SYSCALL_TRACE) && 510 tracehook_report_syscall_entry(regs)) 511 /* 512 * Tracing decided this syscall should not happen. 513 * We'll return a bogus call number to get an ENOSYS 514 * error, but leave the original number in regs->regs[0]. 515 */ 516 ret = -1L; 517 518 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 519 trace_sys_enter(regs, regs->regs[0]); 520 521 audit_syscall_entry(audit_arch(), regs->regs[3], 522 regs->regs[4], regs->regs[5], 523 regs->regs[6], regs->regs[7]); 524 525 return ret ?: regs->regs[0]; 526 } 527 528 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 529 { 530 int step; 531 532 audit_syscall_exit(regs); 533 534 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 535 trace_sys_exit(regs, regs->regs[0]); 536 537 step = test_thread_flag(TIF_SINGLESTEP); 538 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 539 tracehook_report_syscall_exit(regs, step); 540 } 541