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/mm.h>
  16 #include <linux/smp.h>
  17 #include <linux/errno.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/user.h>
  20 #include <linux/slab.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 <asm/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/system.h>
  33 #include <asm/processor.h>
  34 #include <asm/mmu_context.h>
  35 #include <asm/syscalls.h>
  36 #include <asm/fpu.h>
  37
  38 #define CREATE_TRACE_POINTS
  39 #include <trace/events/syscalls.h>
  40
  41 /*
  42  * This routine will get a word off of the process kernel stack.
  43  */
  44 static inline int get_stack_long(struct task_struct *task, int offset)
  45 {
  46         unsigned char *stack;
  47
  48         stack = (unsigned char *)task_pt_regs(task);
  49         stack += offset;
  50         return (*((int *)stack));
  51 }
  52
  53 /*
  54  * This routine will put a word on the process kernel stack.
  55  */
  56 static inline int put_stack_long(struct task_struct *task, int offset,
  57                                  unsigned long data)
  58 {
  59         unsigned char *stack;
  60
  61         stack = (unsigned char *)task_pt_regs(task);
  62         stack += offset;
  63         *(unsigned long *) stack = data;
  64         return 0;
  65 }
  66
  67 void ptrace_triggered(struct perf_event *bp, int nmi,
  68                       struct perf_sample_data *data, struct pt_regs *regs)
  69 {
  70         struct perf_event_attr attr;
  71
  72         /*
  73          * Disable the breakpoint request here since ptrace has defined a
  74          * one-shot behaviour for breakpoint exceptions.
  75          */
  76         attr = bp->attr;
  77         attr.disabled = true;
  78         modify_user_hw_breakpoint(bp, &attr);
  79 }
  80
  81 static int set_single_step(struct task_struct *tsk, unsigned long addr)
  82 {
  83         struct thread_struct *thread = &tsk->thread;
  84         struct perf_event *bp;
  85         struct perf_event_attr attr;
  86
  87         bp = thread->ptrace_bps[0];
  88         if (!bp) {
  89                 hw_breakpoint_init(&attr);
  90
  91                 attr.bp_addr = addr;
  92                 attr.bp_len = HW_BREAKPOINT_LEN_2;
  93                 attr.bp_type = HW_BREAKPOINT_R;
  94
  95                 bp = register_user_hw_breakpoint(&attr, ptrace_triggered, 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                 err = modify_user_hw_breakpoint(bp, &attr);
 106                 if (unlikely(err))
 107                         return err;
 108         }
 109
 110         return 0;
 111 }
 112
 113 void user_enable_single_step(struct task_struct *child)
 114 {
 115         unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
 116
 117         set_tsk_thread_flag(child, TIF_SINGLESTEP);
 118
 119         set_single_step(child, pc);
 120 }
 121
 122 void user_disable_single_step(struct task_struct *child)
 123 {
 124         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
 125 }
 126
 127 /*
 128  * Called by kernel/ptrace.c when detaching..
 129  *
 130  * Make sure single step bits etc are not set.
 131  */
 132 void ptrace_disable(struct task_struct *child)
 133 {
 134         user_disable_single_step(child);
 135 }
 136
 137 static int genregs_get(struct task_struct *target,
 138                        const struct user_regset *regset,
 139                        unsigned int pos, unsigned int count,
 140                        void *kbuf, void __user *ubuf)
 141 {
 142         const struct pt_regs *regs = task_pt_regs(target);
 143         int ret;
 144
 145         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 146                                   regs->regs,
 147                                   0, 16 * sizeof(unsigned long));
 148         if (!ret)
 149                 /* PC, PR, SR, GBR, MACH, MACL, TRA */
 150                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 151                                           &regs->pc,
 152                                           offsetof(struct pt_regs, pc),
 153                                           sizeof(struct pt_regs));
 154         if (!ret)
 155                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 156                                                sizeof(struct pt_regs), -1);
 157
 158         return ret;
 159 }
 160
 161 static int genregs_set(struct task_struct *target,
 162                        const struct user_regset *regset,
 163                        unsigned int pos, unsigned int count,
 164                        const void *kbuf, const void __user *ubuf)
 165 {
 166         struct pt_regs *regs = task_pt_regs(target);
 167         int ret;
 168
 169         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 170                                  regs->regs,
 171                                  0, 16 * sizeof(unsigned long));
 172         if (!ret && count > 0)
 173                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 174                                          &regs->pc,
 175                                          offsetof(struct pt_regs, pc),
 176                                          sizeof(struct pt_regs));
 177         if (!ret)
 178                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 179                                                 sizeof(struct pt_regs), -1);
 180
 181         return ret;
 182 }
 183
 184 #ifdef CONFIG_SH_FPU
 185 int fpregs_get(struct task_struct *target,
 186                const struct user_regset *regset,
 187                unsigned int pos, unsigned int count,
 188                void *kbuf, void __user *ubuf)
 189 {
 190         int ret;
 191
 192         ret = init_fpu(target);
 193         if (ret)
 194                 return ret;
 195
 196         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 197                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 198                                            &target->thread.xstate->hardfpu, 0, -1);
 199
 200         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 201                                    &target->thread.xstate->softfpu, 0, -1);
 202 }
 203
 204 static int fpregs_set(struct task_struct *target,
 205                        const struct user_regset *regset,
 206                        unsigned int pos, unsigned int count,
 207                        const void *kbuf, const void __user *ubuf)
 208 {
 209         int ret;
 210
 211         ret = init_fpu(target);
 212         if (ret)
 213                 return ret;
 214
 215         set_stopped_child_used_math(target);
 216
 217         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 218                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 219                                           &target->thread.xstate->hardfpu, 0, -1);
 220
 221         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 222                                   &target->thread.xstate->softfpu, 0, -1);
 223 }
 224
 225 static int fpregs_active(struct task_struct *target,
 226                          const struct user_regset *regset)
 227 {
 228         return tsk_used_math(target) ? regset->n : 0;
 229 }
 230 #endif
 231
 232 #ifdef CONFIG_SH_DSP
 233 static int dspregs_get(struct task_struct *target,
 234                        const struct user_regset *regset,
 235                        unsigned int pos, unsigned int count,
 236                        void *kbuf, void __user *ubuf)
 237 {
 238         const struct pt_dspregs *regs =
 239                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 240         int ret;
 241
 242         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
 243                                   0, sizeof(struct pt_dspregs));
 244         if (!ret)
 245                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 246                                                sizeof(struct pt_dspregs), -1);
 247
 248         return ret;
 249 }
 250
 251 static int dspregs_set(struct task_struct *target,
 252                        const struct user_regset *regset,
 253                        unsigned int pos, unsigned int count,
 254                        const void *kbuf, const void __user *ubuf)
 255 {
 256         struct pt_dspregs *regs =
 257                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 258         int ret;
 259
 260         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
 261                                  0, sizeof(struct pt_dspregs));
 262         if (!ret)
 263                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 264                                                 sizeof(struct pt_dspregs), -1);
 265
 266         return ret;
 267 }
 268
 269 static int dspregs_active(struct task_struct *target,
 270                           const struct user_regset *regset)
 271 {
 272         struct pt_regs *regs = task_pt_regs(target);
 273
 274         return regs->sr & SR_DSP ? regset->n : 0;
 275 }
 276 #endif
 277
 278 /*
 279  * These are our native regset flavours.
 280  */
 281 enum sh_regset {
 282         REGSET_GENERAL,
 283 #ifdef CONFIG_SH_FPU
 284         REGSET_FPU,
 285 #endif
 286 #ifdef CONFIG_SH_DSP
 287         REGSET_DSP,
 288 #endif
 289 };
 290
 291 static const struct user_regset sh_regsets[] = {
 292         /*
 293          * Format is:
 294          *      R0 --> R15
 295          *      PC, PR, SR, GBR, MACH, MACL, TRA
 296          */
 297         [REGSET_GENERAL] = {
 298                 .core_note_type = NT_PRSTATUS,
 299                 .n              = ELF_NGREG,
 300                 .size           = sizeof(long),
 301                 .align          = sizeof(long),
 302                 .get            = genregs_get,
 303                 .set            = genregs_set,
 304         },
 305
 306 #ifdef CONFIG_SH_FPU
 307         [REGSET_FPU] = {
 308                 .core_note_type = NT_PRFPREG,
 309                 .n              = sizeof(struct user_fpu_struct) / sizeof(long),
 310                 .size           = sizeof(long),
 311                 .align          = sizeof(long),
 312                 .get            = fpregs_get,
 313                 .set            = fpregs_set,
 314                 .active         = fpregs_active,
 315         },
 316 #endif
 317
 318 #ifdef CONFIG_SH_DSP
 319         [REGSET_DSP] = {
 320                 .n              = sizeof(struct pt_dspregs) / sizeof(long),
 321                 .size           = sizeof(long),
 322                 .align          = sizeof(long),
 323                 .get            = dspregs_get,
 324                 .set            = dspregs_set,
 325                 .active         = dspregs_active,
 326         },
 327 #endif
 328 };
 329
 330 static const struct user_regset_view user_sh_native_view = {
 331         .name           = "sh",
 332         .e_machine      = EM_SH,
 333         .regsets        = sh_regsets,
 334         .n              = ARRAY_SIZE(sh_regsets),
 335 };
 336
 337 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 338 {
 339         return &user_sh_native_view;
 340 }
 341
 342 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 343 {
 344         struct user * dummy = NULL;
 345         unsigned long __user *datap = (unsigned long __user *)data;
 346         int ret;
 347
 348         switch (request) {
 349         /* read the word at location addr in the USER area. */
 350         case PTRACE_PEEKUSR: {
 351                 unsigned long tmp;
 352
 353                 ret = -EIO;
 354                 if ((addr & 3) || addr < 0 ||
 355                     addr > sizeof(struct user) - 3)
 356                         break;
 357
 358                 if (addr < sizeof(struct pt_regs))
 359                         tmp = get_stack_long(child, addr);
 360                 else if (addr >= (long) &dummy->fpu &&
 361                          addr < (long) &dummy->u_fpvalid) {
 362                         if (!tsk_used_math(child)) {
 363                                 if (addr == (long)&dummy->fpu.fpscr)
 364                                         tmp = FPSCR_INIT;
 365                                 else
 366                                         tmp = 0;
 367                         } else
 368                                 tmp = ((long *)child->thread.xstate)
 369                                         [(addr - (long)&dummy->fpu) >> 2];
 370                 } else if (addr == (long) &dummy->u_fpvalid)
 371                         tmp = !!tsk_used_math(child);
 372                 else if (addr == PT_TEXT_ADDR)
 373                         tmp = child->mm->start_code;
 374                 else if (addr == PT_DATA_ADDR)
 375                         tmp = child->mm->start_data;
 376                 else if (addr == PT_TEXT_END_ADDR)
 377                         tmp = child->mm->end_code;
 378                 else if (addr == PT_TEXT_LEN)
 379                         tmp = child->mm->end_code - child->mm->start_code;
 380                 else
 381                         tmp = 0;
 382                 ret = put_user(tmp, datap);
 383                 break;
 384         }
 385
 386         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 387                 ret = -EIO;
 388                 if ((addr & 3) || addr < 0 ||
 389                     addr > sizeof(struct user) - 3)
 390                         break;
 391
 392                 if (addr < sizeof(struct pt_regs))
 393                         ret = put_stack_long(child, addr, data);
 394                 else if (addr >= (long) &dummy->fpu &&
 395                          addr < (long) &dummy->u_fpvalid) {
 396                         set_stopped_child_used_math(child);
 397                         ((long *)child->thread.xstate)
 398                                 [(addr - (long)&dummy->fpu) >> 2] = data;
 399                         ret = 0;
 400                 } else if (addr == (long) &dummy->u_fpvalid) {
 401                         conditional_stopped_child_used_math(data, child);
 402                         ret = 0;
 403                 }
 404                 break;
 405
 406         case PTRACE_GETREGS:
 407                 return copy_regset_to_user(child, &user_sh_native_view,
 408                                            REGSET_GENERAL,
 409                                            0, sizeof(struct pt_regs),
 410                                            (void __user *)data);
 411         case PTRACE_SETREGS:
 412                 return copy_regset_from_user(child, &user_sh_native_view,
 413                                              REGSET_GENERAL,
 414                                              0, sizeof(struct pt_regs),
 415                                              (const void __user *)data);
 416 #ifdef CONFIG_SH_FPU
 417         case PTRACE_GETFPREGS:
 418                 return copy_regset_to_user(child, &user_sh_native_view,
 419                                            REGSET_FPU,
 420                                            0, sizeof(struct user_fpu_struct),
 421                                            (void __user *)data);
 422         case PTRACE_SETFPREGS:
 423                 return copy_regset_from_user(child, &user_sh_native_view,
 424                                              REGSET_FPU,
 425                                              0, sizeof(struct user_fpu_struct),
 426                                              (const void __user *)data);
 427 #endif
 428 #ifdef CONFIG_SH_DSP
 429         case PTRACE_GETDSPREGS:
 430                 return copy_regset_to_user(child, &user_sh_native_view,
 431                                            REGSET_DSP,
 432                                            0, sizeof(struct pt_dspregs),
 433                                            (void __user *)data);
 434         case PTRACE_SETDSPREGS:
 435                 return copy_regset_from_user(child, &user_sh_native_view,
 436                                              REGSET_DSP,
 437                                              0, sizeof(struct pt_dspregs),
 438                                              (const void __user *)data);
 439 #endif
 440 #ifdef CONFIG_BINFMT_ELF_FDPIC
 441         case PTRACE_GETFDPIC: {
 442                 unsigned long tmp = 0;
 443
 444                 switch (addr) {
 445                 case PTRACE_GETFDPIC_EXEC:
 446                         tmp = child->mm->context.exec_fdpic_loadmap;
 447                         break;
 448                 case PTRACE_GETFDPIC_INTERP:
 449                         tmp = child->mm->context.interp_fdpic_loadmap;
 450                         break;
 451                 default:
 452                         break;
 453                 }
 454
 455                 ret = 0;
 456                 if (put_user(tmp, datap)) {
 457                         ret = -EFAULT;
 458                         break;
 459                 }
 460                 break;
 461         }
 462 #endif
 463         default:
 464                 ret = ptrace_request(child, request, addr, data);
 465                 break;
 466         }
 467
 468         return ret;
 469 }
 470
 471 static inline int audit_arch(void)
 472 {
 473         int arch = EM_SH;
 474
 475 #ifdef CONFIG_CPU_LITTLE_ENDIAN
 476         arch |= __AUDIT_ARCH_LE;
 477 #endif
 478
 479         return arch;
 480 }
 481
 482 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 483 {
 484         long ret = 0;
 485
 486         secure_computing(regs->regs[0]);
 487
 488         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 489             tracehook_report_syscall_entry(regs))
 490                 /*
 491                  * Tracing decided this syscall should not happen.
 492                  * We'll return a bogus call number to get an ENOSYS
 493                  * error, but leave the original number in regs->regs[0].
 494                  */
 495                 ret = -1L;
 496
 497         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 498                 trace_sys_enter(regs, regs->regs[0]);
 499
 500         if (unlikely(current->audit_context))
 501                 audit_syscall_entry(audit_arch(), regs->regs[3],
 502                                     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         if (unlikely(current->audit_context))
 513                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
 514                                    regs->regs[0]);
 515
 516         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 517                 trace_sys_exit(regs, regs->regs[0]);
 518
 519         step = test_thread_flag(TIF_SINGLESTEP);
 520         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 521                 tracehook_report_syscall_exit(regs, step);
 522 }