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