arch/sh/kernel/ptrace_32.c

   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                                           &regs->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                                          &regs->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 }