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