arch/sh/kernel/ptrace_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SuperH process tracing
   4  *
   5  * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
   6  * Copyright (C) 2002 - 2009  Paul Mundt
   7  *
   8  * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
   9  */
  10 #include <linux/kernel.h>
  11 #include <linux/sched.h>
  12 #include <linux/sched/task_stack.h>
  13 #include <linux/mm.h>
  14 #include <linux/smp.h>
  15 #include <linux/errno.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/user.h>
  18 #include <linux/security.h>
  19 #include <linux/signal.h>
  20 #include <linux/io.h>
  21 #include <linux/audit.h>
  22 #include <linux/seccomp.h>
  23 #include <linux/tracehook.h>
  24 #include <linux/elf.h>
  25 #include <linux/regset.h>
  26 #include <linux/hw_breakpoint.h>
  27 #include <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <asm/mmu_context.h>
  30 #include <asm/syscalls.h>
  31 #include <asm/fpu.h>
  32
  33 #define CREATE_TRACE_POINTS
  34 #include <trace/events/syscalls.h>
  35
  36 /*
  37  * This routine will get a word off of the process kernel stack.
  38  */
  39 static inline int get_stack_long(struct task_struct *task, int offset)
  40 {
  41         unsigned char *stack;
  42
  43         stack = (unsigned char *)task_pt_regs(task);
  44         stack += offset;
  45         return (*((int *)stack));
  46 }
  47
  48 /*
  49  * This routine will put a word on the process kernel stack.
  50  */
  51 static inline int put_stack_long(struct task_struct *task, int offset,
  52                                  unsigned long data)
  53 {
  54         unsigned char *stack;
  55
  56         stack = (unsigned char *)task_pt_regs(task);
  57         stack += offset;
  58         *(unsigned long *) stack = data;
  59         return 0;
  60 }
  61
  62 void ptrace_triggered(struct perf_event *bp,
  63                       struct perf_sample_data *data, struct pt_regs *regs)
  64 {
  65         struct perf_event_attr attr;
  66
  67         /*
  68          * Disable the breakpoint request here since ptrace has defined a
  69          * one-shot behaviour for breakpoint exceptions.
  70          */
  71         attr = bp->attr;
  72         attr.disabled = true;
  73         modify_user_hw_breakpoint(bp, &attr);
  74 }
  75
  76 static int set_single_step(struct task_struct *tsk, unsigned long addr)
  77 {
  78         struct thread_struct *thread = &tsk->thread;
  79         struct perf_event *bp;
  80         struct perf_event_attr attr;
  81
  82         bp = thread->ptrace_bps[0];
  83         if (!bp) {
  84                 ptrace_breakpoint_init(&attr);
  85
  86                 attr.bp_addr = addr;
  87                 attr.bp_len = HW_BREAKPOINT_LEN_2;
  88                 attr.bp_type = HW_BREAKPOINT_R;
  89
  90                 bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
  91                                                  NULL, tsk);
  92                 if (IS_ERR(bp))
  93                         return PTR_ERR(bp);
  94
  95                 thread->ptrace_bps[0] = bp;
  96         } else {
  97                 int err;
  98
  99                 attr = bp->attr;
 100                 attr.bp_addr = addr;
 101                 /* reenable breakpoint */
 102                 attr.disabled = false;
 103                 err = modify_user_hw_breakpoint(bp, &attr);
 104                 if (unlikely(err))
 105                         return err;
 106         }
 107
 108         return 0;
 109 }
 110
 111 void user_enable_single_step(struct task_struct *child)
 112 {
 113         unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
 114
 115         set_tsk_thread_flag(child, TIF_SINGLESTEP);
 116
 117         set_single_step(child, pc);
 118 }
 119
 120 void user_disable_single_step(struct task_struct *child)
 121 {
 122         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
 123 }
 124
 125 /*
 126  * Called by kernel/ptrace.c when detaching..
 127  *
 128  * Make sure single step bits etc are not set.
 129  */
 130 void ptrace_disable(struct task_struct *child)
 131 {
 132         user_disable_single_step(child);
 133 }
 134
 135 static int genregs_get(struct task_struct *target,
 136                        const struct user_regset *regset,
 137                        unsigned int pos, unsigned int count,
 138                        void *kbuf, void __user *ubuf)
 139 {
 140         const struct pt_regs *regs = task_pt_regs(target);
 141         int ret;
 142
 143         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 144                                   regs->regs,
 145                                   0, 16 * sizeof(unsigned long));
 146         if (!ret)
 147                 /* PC, PR, SR, GBR, MACH, MACL, TRA */
 148                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 149                                           &regs->pc,
 150                                           offsetof(struct pt_regs, pc),
 151                                           sizeof(struct pt_regs));
 152         if (!ret)
 153                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 154                                                sizeof(struct pt_regs), -1);
 155
 156         return ret;
 157 }
 158
 159 static int genregs_set(struct task_struct *target,
 160                        const struct user_regset *regset,
 161                        unsigned int pos, unsigned int count,
 162                        const void *kbuf, const void __user *ubuf)
 163 {
 164         struct pt_regs *regs = task_pt_regs(target);
 165         int ret;
 166
 167         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 168                                  regs->regs,
 169                                  0, 16 * sizeof(unsigned long));
 170         if (!ret && count > 0)
 171                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 172                                          &regs->pc,
 173                                          offsetof(struct pt_regs, pc),
 174                                          sizeof(struct pt_regs));
 175         if (!ret)
 176                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 177                                                 sizeof(struct pt_regs), -1);
 178
 179         return ret;
 180 }
 181
 182 #ifdef CONFIG_SH_FPU
 183 int fpregs_get(struct task_struct *target,
 184                const struct user_regset *regset,
 185                unsigned int pos, unsigned int count,
 186                void *kbuf, void __user *ubuf)
 187 {
 188         int ret;
 189
 190         ret = init_fpu(target);
 191         if (ret)
 192                 return ret;
 193
 194         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 195                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 196                                            &target->thread.xstate->hardfpu, 0, -1);
 197
 198         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 199                                    &target->thread.xstate->softfpu, 0, -1);
 200 }
 201
 202 static int fpregs_set(struct task_struct *target,
 203                        const struct user_regset *regset,
 204                        unsigned int pos, unsigned int count,
 205                        const void *kbuf, const void __user *ubuf)
 206 {
 207         int ret;
 208
 209         ret = init_fpu(target);
 210         if (ret)
 211                 return ret;
 212
 213         set_stopped_child_used_math(target);
 214
 215         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 216                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 217                                           &target->thread.xstate->hardfpu, 0, -1);
 218
 219         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 220                                   &target->thread.xstate->softfpu, 0, -1);
 221 }
 222
 223 static int fpregs_active(struct task_struct *target,
 224                          const struct user_regset *regset)
 225 {
 226         return tsk_used_math(target) ? regset->n : 0;
 227 }
 228 #endif
 229
 230 #ifdef CONFIG_SH_DSP
 231 static int dspregs_get(struct task_struct *target,
 232                        const struct user_regset *regset,
 233                        unsigned int pos, unsigned int count,
 234                        void *kbuf, void __user *ubuf)
 235 {
 236         const struct pt_dspregs *regs =
 237                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 238         int ret;
 239
 240         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
 241                                   0, sizeof(struct pt_dspregs));
 242         if (!ret)
 243                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 244                                                sizeof(struct pt_dspregs), -1);
 245
 246         return ret;
 247 }
 248
 249 static int dspregs_set(struct task_struct *target,
 250                        const struct user_regset *regset,
 251                        unsigned int pos, unsigned int count,
 252                        const void *kbuf, const void __user *ubuf)
 253 {
 254         struct pt_dspregs *regs =
 255                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 256         int ret;
 257
 258         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
 259                                  0, sizeof(struct pt_dspregs));
 260         if (!ret)
 261                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 262                                                 sizeof(struct pt_dspregs), -1);
 263
 264         return ret;
 265 }
 266
 267 static int dspregs_active(struct task_struct *target,
 268                           const struct user_regset *regset)
 269 {
 270         struct pt_regs *regs = task_pt_regs(target);
 271
 272         return regs->sr & SR_DSP ? regset->n : 0;
 273 }
 274 #endif
 275
 276 const struct pt_regs_offset regoffset_table[] = {
 277         REGS_OFFSET_NAME(0),
 278         REGS_OFFSET_NAME(1),
 279         REGS_OFFSET_NAME(2),
 280         REGS_OFFSET_NAME(3),
 281         REGS_OFFSET_NAME(4),
 282         REGS_OFFSET_NAME(5),
 283         REGS_OFFSET_NAME(6),
 284         REGS_OFFSET_NAME(7),
 285         REGS_OFFSET_NAME(8),
 286         REGS_OFFSET_NAME(9),
 287         REGS_OFFSET_NAME(10),
 288         REGS_OFFSET_NAME(11),
 289         REGS_OFFSET_NAME(12),
 290         REGS_OFFSET_NAME(13),
 291         REGS_OFFSET_NAME(14),
 292         REGS_OFFSET_NAME(15),
 293         REG_OFFSET_NAME(pc),
 294         REG_OFFSET_NAME(pr),
 295         REG_OFFSET_NAME(sr),
 296         REG_OFFSET_NAME(gbr),
 297         REG_OFFSET_NAME(mach),
 298         REG_OFFSET_NAME(macl),
 299         REG_OFFSET_NAME(tra),
 300         REG_OFFSET_END,
 301 };
 302
 303 /*
 304  * These are our native regset flavours.
 305  */
 306 enum sh_regset {
 307         REGSET_GENERAL,
 308 #ifdef CONFIG_SH_FPU
 309         REGSET_FPU,
 310 #endif
 311 #ifdef CONFIG_SH_DSP
 312         REGSET_DSP,
 313 #endif
 314 };
 315
 316 static const struct user_regset sh_regsets[] = {
 317         /*
 318          * Format is:
 319          *      R0 --> R15
 320          *      PC, PR, SR, GBR, MACH, MACL, TRA
 321          */
 322         [REGSET_GENERAL] = {
 323                 .core_note_type = NT_PRSTATUS,
 324                 .n              = ELF_NGREG,
 325                 .size           = sizeof(long),
 326                 .align          = sizeof(long),
 327                 .get            = genregs_get,
 328                 .set            = genregs_set,
 329         },
 330
 331 #ifdef CONFIG_SH_FPU
 332         [REGSET_FPU] = {
 333                 .core_note_type = NT_PRFPREG,
 334                 .n              = sizeof(struct user_fpu_struct) / sizeof(long),
 335                 .size           = sizeof(long),
 336                 .align          = sizeof(long),
 337                 .get            = fpregs_get,
 338                 .set            = fpregs_set,
 339                 .active         = fpregs_active,
 340         },
 341 #endif
 342
 343 #ifdef CONFIG_SH_DSP
 344         [REGSET_DSP] = {
 345                 .n              = sizeof(struct pt_dspregs) / sizeof(long),
 346                 .size           = sizeof(long),
 347                 .align          = sizeof(long),
 348                 .get            = dspregs_get,
 349                 .set            = dspregs_set,
 350                 .active         = dspregs_active,
 351         },
 352 #endif
 353 };
 354
 355 static const struct user_regset_view user_sh_native_view = {
 356         .name           = "sh",
 357         .e_machine      = EM_SH,
 358         .regsets        = sh_regsets,
 359         .n              = ARRAY_SIZE(sh_regsets),
 360 };
 361
 362 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 363 {
 364         return &user_sh_native_view;
 365 }
 366
 367 long arch_ptrace(struct task_struct *child, long request,
 368                  unsigned long addr, unsigned long data)
 369 {
 370         unsigned long __user *datap = (unsigned long __user *)data;
 371         int ret;
 372
 373         switch (request) {
 374         /* read the word at location addr in the USER area. */
 375         case PTRACE_PEEKUSR: {
 376                 unsigned long tmp;
 377
 378                 ret = -EIO;
 379                 if ((addr & 3) || addr < 0 ||
 380                     addr > sizeof(struct user) - 3)
 381                         break;
 382
 383                 if (addr < sizeof(struct pt_regs))
 384                         tmp = get_stack_long(child, addr);
 385                 else if (addr >= offsetof(struct user, fpu) &&
 386                          addr < offsetof(struct user, u_fpvalid)) {
 387                         if (!tsk_used_math(child)) {
 388                                 if (addr == offsetof(struct user, fpu.fpscr))
 389                                         tmp = FPSCR_INIT;
 390                                 else
 391                                         tmp = 0;
 392                         } else {
 393                                 unsigned long index;
 394                                 ret = init_fpu(child);
 395                                 if (ret)
 396                                         break;
 397                                 index = addr - offsetof(struct user, fpu);
 398                                 tmp = ((unsigned long *)child->thread.xstate)
 399                                         [index >> 2];
 400                         }
 401                 } else if (addr == offsetof(struct user, u_fpvalid))
 402                         tmp = !!tsk_used_math(child);
 403                 else if (addr == PT_TEXT_ADDR)
 404                         tmp = child->mm->start_code;
 405                 else if (addr == PT_DATA_ADDR)
 406                         tmp = child->mm->start_data;
 407                 else if (addr == PT_TEXT_END_ADDR)
 408                         tmp = child->mm->end_code;
 409                 else if (addr == PT_TEXT_LEN)
 410                         tmp = child->mm->end_code - child->mm->start_code;
 411                 else
 412                         tmp = 0;
 413                 ret = put_user(tmp, datap);
 414                 break;
 415         }
 416
 417         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 418                 ret = -EIO;
 419                 if ((addr & 3) || addr < 0 ||
 420                     addr > sizeof(struct user) - 3)
 421                         break;
 422
 423                 if (addr < sizeof(struct pt_regs))
 424                         ret = put_stack_long(child, addr, data);
 425                 else if (addr >= offsetof(struct user, fpu) &&
 426                          addr < offsetof(struct user, u_fpvalid)) {
 427                         unsigned long index;
 428                         ret = init_fpu(child);
 429                         if (ret)
 430                                 break;
 431                         index = addr - offsetof(struct user, fpu);
 432                         set_stopped_child_used_math(child);
 433                         ((unsigned long *)child->thread.xstate)
 434                                 [index >> 2] = data;
 435                         ret = 0;
 436                 } else if (addr == offsetof(struct user, u_fpvalid)) {
 437                         conditional_stopped_child_used_math(data, child);
 438                         ret = 0;
 439                 }
 440                 break;
 441
 442         case PTRACE_GETREGS:
 443                 return copy_regset_to_user(child, &user_sh_native_view,
 444                                            REGSET_GENERAL,
 445                                            0, sizeof(struct pt_regs),
 446                                            datap);
 447         case PTRACE_SETREGS:
 448                 return copy_regset_from_user(child, &user_sh_native_view,
 449                                              REGSET_GENERAL,
 450                                              0, sizeof(struct pt_regs),
 451                                              datap);
 452 #ifdef CONFIG_SH_FPU
 453         case PTRACE_GETFPREGS:
 454                 return copy_regset_to_user(child, &user_sh_native_view,
 455                                            REGSET_FPU,
 456                                            0, sizeof(struct user_fpu_struct),
 457                                            datap);
 458         case PTRACE_SETFPREGS:
 459                 return copy_regset_from_user(child, &user_sh_native_view,
 460                                              REGSET_FPU,
 461                                              0, sizeof(struct user_fpu_struct),
 462                                              datap);
 463 #endif
 464 #ifdef CONFIG_SH_DSP
 465         case PTRACE_GETDSPREGS:
 466                 return copy_regset_to_user(child, &user_sh_native_view,
 467                                            REGSET_DSP,
 468                                            0, sizeof(struct pt_dspregs),
 469                                            datap);
 470         case PTRACE_SETDSPREGS:
 471                 return copy_regset_from_user(child, &user_sh_native_view,
 472                                              REGSET_DSP,
 473                                              0, sizeof(struct pt_dspregs),
 474                                              datap);
 475 #endif
 476         default:
 477                 ret = ptrace_request(child, request, addr, data);
 478                 break;
 479         }
 480
 481         return ret;
 482 }
 483
 484 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 485 {
 486         long ret = 0;
 487
 488         secure_computing_strict(regs->regs[0]);
 489
 490         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 491             tracehook_report_syscall_entry(regs))
 492                 /*
 493                  * Tracing decided this syscall should not happen.
 494                  * We'll return a bogus call number to get an ENOSYS
 495                  * error, but leave the original number in regs->regs[0].
 496                  */
 497                 ret = -1L;
 498
 499         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 500                 trace_sys_enter(regs, regs->regs[0]);
 501
 502         audit_syscall_entry(regs->regs[3], regs->regs[4], regs->regs[5],
 503                             regs->regs[6], regs->regs[7]);
 504
 505         return ret ?: regs->regs[0];
 506 }
 507
 508 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 509 {
 510         int step;
 511
 512         audit_syscall_exit(regs);
 513
 514         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 515                 trace_sys_exit(regs, regs->regs[0]);
 516
 517         step = test_thread_flag(TIF_SINGLESTEP);
 518         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 519                 tracehook_report_syscall_exit(regs, step);
 520 }