| 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/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/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 <linux/hw_breakpoint.h> |
| 30 | #include <linux/uaccess.h> |
| 31 | #include <asm/pgtable.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 | set_single_step(child, pc); |
| 122 | } |
| 123 | |
| 124 | void user_disable_single_step(struct task_struct *child) |
| 125 | { |
| 126 | clear_tsk_thread_flag(child, TIF_SINGLESTEP); |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Called by kernel/ptrace.c when detaching.. |
| 131 | * |
| 132 | * Make sure single step bits etc are not set. |
| 133 | */ |
| 134 | void ptrace_disable(struct task_struct *child) |
| 135 | { |
| 136 | user_disable_single_step(child); |
| 137 | } |
| 138 | |
| 139 | static int genregs_get(struct task_struct *target, |
| 140 | const struct user_regset *regset, |
| 141 | unsigned int pos, unsigned int count, |
| 142 | void *kbuf, void __user *ubuf) |
| 143 | { |
| 144 | const struct pt_regs *regs = task_pt_regs(target); |
| 145 | int ret; |
| 146 | |
| 147 | ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, |
| 148 | regs->regs, |
| 149 | 0, 16 * sizeof(unsigned long)); |
| 150 | if (!ret) |
| 151 | /* PC, PR, SR, GBR, MACH, MACL, TRA */ |
| 152 | ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, |
| 153 | ®s->pc, |
| 154 | offsetof(struct pt_regs, pc), |
| 155 | sizeof(struct pt_regs)); |
| 156 | if (!ret) |
| 157 | ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, |
| 158 | sizeof(struct pt_regs), -1); |
| 159 | |
| 160 | return ret; |
| 161 | } |
| 162 | |
| 163 | static int genregs_set(struct task_struct *target, |
| 164 | const struct user_regset *regset, |
| 165 | unsigned int pos, unsigned int count, |
| 166 | const void *kbuf, const void __user *ubuf) |
| 167 | { |
| 168 | struct pt_regs *regs = task_pt_regs(target); |
| 169 | int ret; |
| 170 | |
| 171 | ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, |
| 172 | regs->regs, |
| 173 | 0, 16 * sizeof(unsigned long)); |
| 174 | if (!ret && count > 0) |
| 175 | ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, |
| 176 | ®s->pc, |
| 177 | offsetof(struct pt_regs, pc), |
| 178 | sizeof(struct pt_regs)); |
| 179 | if (!ret) |
| 180 | ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, |
| 181 | sizeof(struct pt_regs), -1); |
| 182 | |
| 183 | return ret; |
| 184 | } |
| 185 | |
| 186 | #ifdef CONFIG_SH_FPU |
| 187 | int fpregs_get(struct task_struct *target, |
| 188 | const struct user_regset *regset, |
| 189 | unsigned int pos, unsigned int count, |
| 190 | void *kbuf, void __user *ubuf) |
| 191 | { |
| 192 | int ret; |
| 193 | |
| 194 | ret = init_fpu(target); |
| 195 | if (ret) |
| 196 | return ret; |
| 197 | |
| 198 | if ((boot_cpu_data.flags & CPU_HAS_FPU)) |
| 199 | return user_regset_copyout(&pos, &count, &kbuf, &ubuf, |
| 200 | &target->thread.xstate->hardfpu, 0, -1); |
| 201 | |
| 202 | return user_regset_copyout(&pos, &count, &kbuf, &ubuf, |
| 203 | &target->thread.xstate->softfpu, 0, -1); |
| 204 | } |
| 205 | |
| 206 | static int fpregs_set(struct task_struct *target, |
| 207 | const struct user_regset *regset, |
| 208 | unsigned int pos, unsigned int count, |
| 209 | const void *kbuf, const void __user *ubuf) |
| 210 | { |
| 211 | int ret; |
| 212 | |
| 213 | ret = init_fpu(target); |
| 214 | if (ret) |
| 215 | return ret; |
| 216 | |
| 217 | set_stopped_child_used_math(target); |
| 218 | |
| 219 | if ((boot_cpu_data.flags & CPU_HAS_FPU)) |
| 220 | return user_regset_copyin(&pos, &count, &kbuf, &ubuf, |
| 221 | &target->thread.xstate->hardfpu, 0, -1); |
| 222 | |
| 223 | return user_regset_copyin(&pos, &count, &kbuf, &ubuf, |
| 224 | &target->thread.xstate->softfpu, 0, -1); |
| 225 | } |
| 226 | |
| 227 | static int fpregs_active(struct task_struct *target, |
| 228 | const struct user_regset *regset) |
| 229 | { |
| 230 | return tsk_used_math(target) ? regset->n : 0; |
| 231 | } |
| 232 | #endif |
| 233 | |
| 234 | #ifdef CONFIG_SH_DSP |
| 235 | static int dspregs_get(struct task_struct *target, |
| 236 | const struct user_regset *regset, |
| 237 | unsigned int pos, unsigned int count, |
| 238 | void *kbuf, void __user *ubuf) |
| 239 | { |
| 240 | const struct pt_dspregs *regs = |
| 241 | (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; |
| 242 | int ret; |
| 243 | |
| 244 | ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, |
| 245 | 0, sizeof(struct pt_dspregs)); |
| 246 | if (!ret) |
| 247 | ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, |
| 248 | sizeof(struct pt_dspregs), -1); |
| 249 | |
| 250 | return ret; |
| 251 | } |
| 252 | |
| 253 | static int dspregs_set(struct task_struct *target, |
| 254 | const struct user_regset *regset, |
| 255 | unsigned int pos, unsigned int count, |
| 256 | const void *kbuf, const void __user *ubuf) |
| 257 | { |
| 258 | struct pt_dspregs *regs = |
| 259 | (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; |
| 260 | int ret; |
| 261 | |
| 262 | ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, |
| 263 | 0, sizeof(struct pt_dspregs)); |
| 264 | if (!ret) |
| 265 | ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, |
| 266 | sizeof(struct pt_dspregs), -1); |
| 267 | |
| 268 | return ret; |
| 269 | } |
| 270 | |
| 271 | static int dspregs_active(struct task_struct *target, |
| 272 | const struct user_regset *regset) |
| 273 | { |
| 274 | struct pt_regs *regs = task_pt_regs(target); |
| 275 | |
| 276 | return regs->sr & SR_DSP ? regset->n : 0; |
| 277 | } |
| 278 | #endif |
| 279 | |
| 280 | const struct pt_regs_offset regoffset_table[] = { |
| 281 | REGS_OFFSET_NAME(0), |
| 282 | REGS_OFFSET_NAME(1), |
| 283 | REGS_OFFSET_NAME(2), |
| 284 | REGS_OFFSET_NAME(3), |
| 285 | REGS_OFFSET_NAME(4), |
| 286 | REGS_OFFSET_NAME(5), |
| 287 | REGS_OFFSET_NAME(6), |
| 288 | REGS_OFFSET_NAME(7), |
| 289 | REGS_OFFSET_NAME(8), |
| 290 | REGS_OFFSET_NAME(9), |
| 291 | REGS_OFFSET_NAME(10), |
| 292 | REGS_OFFSET_NAME(11), |
| 293 | REGS_OFFSET_NAME(12), |
| 294 | REGS_OFFSET_NAME(13), |
| 295 | REGS_OFFSET_NAME(14), |
| 296 | REGS_OFFSET_NAME(15), |
| 297 | REG_OFFSET_NAME(pc), |
| 298 | REG_OFFSET_NAME(pr), |
| 299 | REG_OFFSET_NAME(sr), |
| 300 | REG_OFFSET_NAME(gbr), |
| 301 | REG_OFFSET_NAME(mach), |
| 302 | REG_OFFSET_NAME(macl), |
| 303 | REG_OFFSET_NAME(tra), |
| 304 | REG_OFFSET_END, |
| 305 | }; |
| 306 | |
| 307 | /* |
| 308 | * These are our native regset flavours. |
| 309 | */ |
| 310 | enum sh_regset { |
| 311 | REGSET_GENERAL, |
| 312 | #ifdef CONFIG_SH_FPU |
| 313 | REGSET_FPU, |
| 314 | #endif |
| 315 | #ifdef CONFIG_SH_DSP |
| 316 | REGSET_DSP, |
| 317 | #endif |
| 318 | }; |
| 319 | |
| 320 | static const struct user_regset sh_regsets[] = { |
| 321 | /* |
| 322 | * Format is: |
| 323 | * R0 --> R15 |
| 324 | * PC, PR, SR, GBR, MACH, MACL, TRA |
| 325 | */ |
| 326 | [REGSET_GENERAL] = { |
| 327 | .core_note_type = NT_PRSTATUS, |
| 328 | .n = ELF_NGREG, |
| 329 | .size = sizeof(long), |
| 330 | .align = sizeof(long), |
| 331 | .get = genregs_get, |
| 332 | .set = genregs_set, |
| 333 | }, |
| 334 | |
| 335 | #ifdef CONFIG_SH_FPU |
| 336 | [REGSET_FPU] = { |
| 337 | .core_note_type = NT_PRFPREG, |
| 338 | .n = sizeof(struct user_fpu_struct) / sizeof(long), |
| 339 | .size = sizeof(long), |
| 340 | .align = sizeof(long), |
| 341 | .get = fpregs_get, |
| 342 | .set = fpregs_set, |
| 343 | .active = fpregs_active, |
| 344 | }, |
| 345 | #endif |
| 346 | |
| 347 | #ifdef CONFIG_SH_DSP |
| 348 | [REGSET_DSP] = { |
| 349 | .n = sizeof(struct pt_dspregs) / sizeof(long), |
| 350 | .size = sizeof(long), |
| 351 | .align = sizeof(long), |
| 352 | .get = dspregs_get, |
| 353 | .set = dspregs_set, |
| 354 | .active = dspregs_active, |
| 355 | }, |
| 356 | #endif |
| 357 | }; |
| 358 | |
| 359 | static const struct user_regset_view user_sh_native_view = { |
| 360 | .name = "sh", |
| 361 | .e_machine = EM_SH, |
| 362 | .regsets = sh_regsets, |
| 363 | .n = ARRAY_SIZE(sh_regsets), |
| 364 | }; |
| 365 | |
| 366 | const struct user_regset_view *task_user_regset_view(struct task_struct *task) |
| 367 | { |
| 368 | return &user_sh_native_view; |
| 369 | } |
| 370 | |
| 371 | long arch_ptrace(struct task_struct *child, long request, |
| 372 | unsigned long addr, unsigned long data) |
| 373 | { |
| 374 | unsigned long __user *datap = (unsigned long __user *)data; |
| 375 | int ret; |
| 376 | |
| 377 | switch (request) { |
| 378 | /* read the word at location addr in the USER area. */ |
| 379 | case PTRACE_PEEKUSR: { |
| 380 | unsigned long tmp; |
| 381 | |
| 382 | ret = -EIO; |
| 383 | if ((addr & 3) || addr < 0 || |
| 384 | addr > sizeof(struct user) - 3) |
| 385 | break; |
| 386 | |
| 387 | if (addr < sizeof(struct pt_regs)) |
| 388 | tmp = get_stack_long(child, addr); |
| 389 | else if (addr >= offsetof(struct user, fpu) && |
| 390 | addr < offsetof(struct user, u_fpvalid)) { |
| 391 | if (!tsk_used_math(child)) { |
| 392 | if (addr == offsetof(struct user, fpu.fpscr)) |
| 393 | tmp = FPSCR_INIT; |
| 394 | else |
| 395 | tmp = 0; |
| 396 | } else { |
| 397 | unsigned long index; |
| 398 | ret = init_fpu(child); |
| 399 | if (ret) |
| 400 | break; |
| 401 | index = addr - offsetof(struct user, fpu); |
| 402 | tmp = ((unsigned long *)child->thread.xstate) |
| 403 | [index >> 2]; |
| 404 | } |
| 405 | } else if (addr == offsetof(struct user, u_fpvalid)) |
| 406 | tmp = !!tsk_used_math(child); |
| 407 | else if (addr == PT_TEXT_ADDR) |
| 408 | tmp = child->mm->start_code; |
| 409 | else if (addr == PT_DATA_ADDR) |
| 410 | tmp = child->mm->start_data; |
| 411 | else if (addr == PT_TEXT_END_ADDR) |
| 412 | tmp = child->mm->end_code; |
| 413 | else if (addr == PT_TEXT_LEN) |
| 414 | tmp = child->mm->end_code - child->mm->start_code; |
| 415 | else |
| 416 | tmp = 0; |
| 417 | ret = put_user(tmp, datap); |
| 418 | break; |
| 419 | } |
| 420 | |
| 421 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| 422 | ret = -EIO; |
| 423 | if ((addr & 3) || addr < 0 || |
| 424 | addr > sizeof(struct user) - 3) |
| 425 | break; |
| 426 | |
| 427 | if (addr < sizeof(struct pt_regs)) |
| 428 | ret = put_stack_long(child, addr, data); |
| 429 | else if (addr >= offsetof(struct user, fpu) && |
| 430 | addr < offsetof(struct user, u_fpvalid)) { |
| 431 | unsigned long index; |
| 432 | ret = init_fpu(child); |
| 433 | if (ret) |
| 434 | break; |
| 435 | index = addr - offsetof(struct user, fpu); |
| 436 | set_stopped_child_used_math(child); |
| 437 | ((unsigned long *)child->thread.xstate) |
| 438 | [index >> 2] = data; |
| 439 | ret = 0; |
| 440 | } else if (addr == offsetof(struct user, u_fpvalid)) { |
| 441 | conditional_stopped_child_used_math(data, child); |
| 442 | ret = 0; |
| 443 | } |
| 444 | break; |
| 445 | |
| 446 | case PTRACE_GETREGS: |
| 447 | return copy_regset_to_user(child, &user_sh_native_view, |
| 448 | REGSET_GENERAL, |
| 449 | 0, sizeof(struct pt_regs), |
| 450 | datap); |
| 451 | case PTRACE_SETREGS: |
| 452 | return copy_regset_from_user(child, &user_sh_native_view, |
| 453 | REGSET_GENERAL, |
| 454 | 0, sizeof(struct pt_regs), |
| 455 | datap); |
| 456 | #ifdef CONFIG_SH_FPU |
| 457 | case PTRACE_GETFPREGS: |
| 458 | return copy_regset_to_user(child, &user_sh_native_view, |
| 459 | REGSET_FPU, |
| 460 | 0, sizeof(struct user_fpu_struct), |
| 461 | datap); |
| 462 | case PTRACE_SETFPREGS: |
| 463 | return copy_regset_from_user(child, &user_sh_native_view, |
| 464 | REGSET_FPU, |
| 465 | 0, sizeof(struct user_fpu_struct), |
| 466 | datap); |
| 467 | #endif |
| 468 | #ifdef CONFIG_SH_DSP |
| 469 | case PTRACE_GETDSPREGS: |
| 470 | return copy_regset_to_user(child, &user_sh_native_view, |
| 471 | REGSET_DSP, |
| 472 | 0, sizeof(struct pt_dspregs), |
| 473 | datap); |
| 474 | case PTRACE_SETDSPREGS: |
| 475 | return copy_regset_from_user(child, &user_sh_native_view, |
| 476 | REGSET_DSP, |
| 477 | 0, sizeof(struct pt_dspregs), |
| 478 | datap); |
| 479 | #endif |
| 480 | default: |
| 481 | ret = ptrace_request(child, request, addr, data); |
| 482 | break; |
| 483 | } |
| 484 | |
| 485 | return ret; |
| 486 | } |
| 487 | |
| 488 | asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) |
| 489 | { |
| 490 | long ret = 0; |
| 491 | |
| 492 | secure_computing_strict(regs->regs[0]); |
| 493 | |
| 494 | if (test_thread_flag(TIF_SYSCALL_TRACE) && |
| 495 | tracehook_report_syscall_entry(regs)) |
| 496 | /* |
| 497 | * Tracing decided this syscall should not happen. |
| 498 | * We'll return a bogus call number to get an ENOSYS |
| 499 | * error, but leave the original number in regs->regs[0]. |
| 500 | */ |
| 501 | ret = -1L; |
| 502 | |
| 503 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) |
| 504 | trace_sys_enter(regs, regs->regs[0]); |
| 505 | |
| 506 | audit_syscall_entry(regs->regs[3], regs->regs[4], regs->regs[5], |
| 507 | regs->regs[6], regs->regs[7]); |
| 508 | |
| 509 | return ret ?: regs->regs[0]; |
| 510 | } |
| 511 | |
| 512 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) |
| 513 | { |
| 514 | int step; |
| 515 | |
| 516 | audit_syscall_exit(regs); |
| 517 | |
| 518 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) |
| 519 | trace_sys_exit(regs, regs->regs[0]); |
| 520 | |
| 521 | step = test_thread_flag(TIF_SINGLESTEP); |
| 522 | if (step || test_thread_flag(TIF_SYSCALL_TRACE)) |
| 523 | tracehook_report_syscall_exit(regs, step); |
| 524 | } |