Pileus Git - ~andy/linux/blob - 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 - 2008  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 <asm/uaccess.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/system.h>
  32 #include <asm/processor.h>
  33 #include <asm/mmu_context.h>
  34 #include <asm/syscalls.h>
  35 #include <asm/fpu.h>
  36
  37 #include <trace/syscall.h>
  38
  39 /*
  40  * This routine will get a word off of the process kernel stack.
  41  */
  42 static inline int get_stack_long(struct task_struct *task, int offset)
  43 {
  44         unsigned char *stack;
  45
  46         stack = (unsigned char *)task_pt_regs(task);
  47         stack += offset;
  48         return (*((int *)stack));
  49 }
  50
  51 /*
  52  * This routine will put a word on the process kernel stack.
  53  */
  54 static inline int put_stack_long(struct task_struct *task, int offset,
  55                                  unsigned long data)
  56 {
  57         unsigned char *stack;
  58
  59         stack = (unsigned char *)task_pt_regs(task);
  60         stack += offset;
  61         *(unsigned long *) stack = data;
  62         return 0;
  63 }
  64
  65 void user_enable_single_step(struct task_struct *child)
  66 {
  67         /* Next scheduling will set up UBC */
  68         if (child->thread.ubc_pc == 0)
  69                 ubc_usercnt += 1;
  70
  71         child->thread.ubc_pc = get_stack_long(child,
  72                                 offsetof(struct pt_regs, pc));
  73
  74         set_tsk_thread_flag(child, TIF_SINGLESTEP);
  75 }
  76
  77 void user_disable_single_step(struct task_struct *child)
  78 {
  79         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
  80
  81         /*
  82          * Ensure the UBC is not programmed at the next context switch.
  83          *
  84          * Normally this is not needed but there are sequences such as
  85          * singlestep, signal delivery, and continue that leave the
  86          * ubc_pc non-zero leading to spurious SIGTRAPs.
  87          */
  88         if (child->thread.ubc_pc != 0) {
  89                 ubc_usercnt -= 1;
  90                 child->thread.ubc_pc = 0;
  91         }
  92 }
  93
  94 /*
  95  * Called by kernel/ptrace.c when detaching..
  96  *
  97  * Make sure single step bits etc are not set.
  98  */
  99 void ptrace_disable(struct task_struct *child)
 100 {
 101         user_disable_single_step(child);
 102 }
 103
 104 static int genregs_get(struct task_struct *target,
 105                        const struct user_regset *regset,
 106                        unsigned int pos, unsigned int count,
 107                        void *kbuf, void __user *ubuf)
 108 {
 109         const struct pt_regs *regs = task_pt_regs(target);
 110         int ret;
 111
 112         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 113                                   regs->regs,
 114                                   0, 16 * sizeof(unsigned long));
 115         if (!ret)
 116                 /* PC, PR, SR, GBR, MACH, MACL, TRA */
 117                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 118                                           &regs->pc,
 119                                           offsetof(struct pt_regs, pc),
 120                                           sizeof(struct pt_regs));
 121         if (!ret)
 122                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 123                                                sizeof(struct pt_regs), -1);
 124
 125         return ret;
 126 }
 127
 128 static int genregs_set(struct task_struct *target,
 129                        const struct user_regset *regset,
 130                        unsigned int pos, unsigned int count,
 131                        const void *kbuf, const void __user *ubuf)
 132 {
 133         struct pt_regs *regs = task_pt_regs(target);
 134         int ret;
 135
 136         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 137                                  regs->regs,
 138                                  0, 16 * sizeof(unsigned long));
 139         if (!ret && count > 0)
 140                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 141                                          &regs->pc,
 142                                          offsetof(struct pt_regs, pc),
 143                                          sizeof(struct pt_regs));
 144         if (!ret)
 145                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 146                                                 sizeof(struct pt_regs), -1);
 147
 148         return ret;
 149 }
 150
 151 #ifdef CONFIG_SH_FPU
 152 int fpregs_get(struct task_struct *target,
 153                const struct user_regset *regset,
 154                unsigned int pos, unsigned int count,
 155                void *kbuf, void __user *ubuf)
 156 {
 157         int ret;
 158
 159         ret = init_fpu(target);
 160         if (ret)
 161                 return ret;
 162
 163         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 164                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 165                                            &target->thread.fpu.hard, 0, -1);
 166
 167         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 168                                    &target->thread.fpu.soft, 0, -1);
 169 }
 170
 171 static int fpregs_set(struct task_struct *target,
 172                        const struct user_regset *regset,
 173                        unsigned int pos, unsigned int count,
 174                        const void *kbuf, const void __user *ubuf)
 175 {
 176         int ret;
 177
 178         ret = init_fpu(target);
 179         if (ret)
 180                 return ret;
 181
 182         set_stopped_child_used_math(target);
 183
 184         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 185                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 186                                           &target->thread.fpu.hard, 0, -1);
 187
 188         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 189                                   &target->thread.fpu.soft, 0, -1);
 190 }
 191
 192 static int fpregs_active(struct task_struct *target,
 193                          const struct user_regset *regset)
 194 {
 195         return tsk_used_math(target) ? regset->n : 0;
 196 }
 197 #endif
 198
 199 #ifdef CONFIG_SH_DSP
 200 static int dspregs_get(struct task_struct *target,
 201                        const struct user_regset *regset,
 202                        unsigned int pos, unsigned int count,
 203                        void *kbuf, void __user *ubuf)
 204 {
 205         const struct pt_dspregs *regs =
 206                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 207         int ret;
 208
 209         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
 210                                   0, sizeof(struct pt_dspregs));
 211         if (!ret)
 212                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 213                                                sizeof(struct pt_dspregs), -1);
 214
 215         return ret;
 216 }
 217
 218 static int dspregs_set(struct task_struct *target,
 219                        const struct user_regset *regset,
 220                        unsigned int pos, unsigned int count,
 221                        const void *kbuf, const void __user *ubuf)
 222 {
 223         struct pt_dspregs *regs =
 224                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 225         int ret;
 226
 227         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
 228                                  0, sizeof(struct pt_dspregs));
 229         if (!ret)
 230                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 231                                                 sizeof(struct pt_dspregs), -1);
 232
 233         return ret;
 234 }
 235
 236 static int dspregs_active(struct task_struct *target,
 237                           const struct user_regset *regset)
 238 {
 239         struct pt_regs *regs = task_pt_regs(target);
 240
 241         return regs->sr & SR_DSP ? regset->n : 0;
 242 }
 243 #endif
 244
 245 /*
 246  * These are our native regset flavours.
 247  */
 248 enum sh_regset {
 249         REGSET_GENERAL,
 250 #ifdef CONFIG_SH_FPU
 251         REGSET_FPU,
 252 #endif
 253 #ifdef CONFIG_SH_DSP
 254         REGSET_DSP,
 255 #endif
 256 };
 257
 258 static const struct user_regset sh_regsets[] = {
 259         /*
 260          * Format is:
 261          *      R0 --> R15
 262          *      PC, PR, SR, GBR, MACH, MACL, TRA
 263          */
 264         [REGSET_GENERAL] = {
 265                 .core_note_type = NT_PRSTATUS,
 266                 .n              = ELF_NGREG,
 267                 .size           = sizeof(long),
 268                 .align          = sizeof(long),
 269                 .get            = genregs_get,
 270                 .set            = genregs_set,
 271         },
 272
 273 #ifdef CONFIG_SH_FPU
 274         [REGSET_FPU] = {
 275                 .core_note_type = NT_PRFPREG,
 276                 .n              = sizeof(struct user_fpu_struct) / sizeof(long),
 277                 .size           = sizeof(long),
 278                 .align          = sizeof(long),
 279                 .get            = fpregs_get,
 280                 .set            = fpregs_set,
 281                 .active         = fpregs_active,
 282         },
 283 #endif
 284
 285 #ifdef CONFIG_SH_DSP
 286         [REGSET_DSP] = {
 287                 .n              = sizeof(struct pt_dspregs) / sizeof(long),
 288                 .size           = sizeof(long),
 289                 .align          = sizeof(long),
 290                 .get            = dspregs_get,
 291                 .set            = dspregs_set,
 292                 .active         = dspregs_active,
 293         },
 294 #endif
 295 };
 296
 297 static const struct user_regset_view user_sh_native_view = {
 298         .name           = "sh",
 299         .e_machine      = EM_SH,
 300         .regsets        = sh_regsets,
 301         .n              = ARRAY_SIZE(sh_regsets),
 302 };
 303
 304 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 305 {
 306         return &user_sh_native_view;
 307 }
 308
 309 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 310 {
 311         struct user * dummy = NULL;
 312         unsigned long __user *datap = (unsigned long __user *)data;
 313         int ret;
 314
 315         switch (request) {
 316         /* read the word at location addr in the USER area. */
 317         case PTRACE_PEEKUSR: {
 318                 unsigned long tmp;
 319
 320                 ret = -EIO;
 321                 if ((addr & 3) || addr < 0 ||
 322                     addr > sizeof(struct user) - 3)
 323                         break;
 324
 325                 if (addr < sizeof(struct pt_regs))
 326                         tmp = get_stack_long(child, addr);
 327                 else if (addr >= (long) &dummy->fpu &&
 328                          addr < (long) &dummy->u_fpvalid) {
 329                         if (!tsk_used_math(child)) {
 330                                 if (addr == (long)&dummy->fpu.fpscr)
 331                                         tmp = FPSCR_INIT;
 332                                 else
 333                                         tmp = 0;
 334                         } else
 335                                 tmp = ((long *)&child->thread.fpu)
 336                                         [(addr - (long)&dummy->fpu) >> 2];
 337                 } else if (addr == (long) &dummy->u_fpvalid)
 338                         tmp = !!tsk_used_math(child);
 339                 else if (addr == PT_TEXT_ADDR)
 340                         tmp = child->mm->start_code;
 341                 else if (addr == PT_DATA_ADDR)
 342                         tmp = child->mm->start_data;
 343                 else if (addr == PT_TEXT_END_ADDR)
 344                         tmp = child->mm->end_code;
 345                 else if (addr == PT_TEXT_LEN)
 346                         tmp = child->mm->end_code - child->mm->start_code;
 347                 else
 348                         tmp = 0;
 349                 ret = put_user(tmp, datap);
 350                 break;
 351         }
 352
 353         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 354                 ret = -EIO;
 355                 if ((addr & 3) || addr < 0 ||
 356                     addr > sizeof(struct user) - 3)
 357                         break;
 358
 359                 if (addr < sizeof(struct pt_regs))
 360                         ret = put_stack_long(child, addr, data);
 361                 else if (addr >= (long) &dummy->fpu &&
 362                          addr < (long) &dummy->u_fpvalid) {
 363                         set_stopped_child_used_math(child);
 364                         ((long *)&child->thread.fpu)
 365                                 [(addr - (long)&dummy->fpu) >> 2] = data;
 366                         ret = 0;
 367                 } else if (addr == (long) &dummy->u_fpvalid) {
 368                         conditional_stopped_child_used_math(data, child);
 369                         ret = 0;
 370                 }
 371                 break;
 372
 373         case PTRACE_GETREGS:
 374                 return copy_regset_to_user(child, &user_sh_native_view,
 375                                            REGSET_GENERAL,
 376                                            0, sizeof(struct pt_regs),
 377                                            (void __user *)data);
 378         case PTRACE_SETREGS:
 379                 return copy_regset_from_user(child, &user_sh_native_view,
 380                                              REGSET_GENERAL,
 381                                              0, sizeof(struct pt_regs),
 382                                              (const void __user *)data);
 383 #ifdef CONFIG_SH_FPU
 384         case PTRACE_GETFPREGS:
 385                 return copy_regset_to_user(child, &user_sh_native_view,
 386                                            REGSET_FPU,
 387                                            0, sizeof(struct user_fpu_struct),
 388                                            (void __user *)data);
 389         case PTRACE_SETFPREGS:
 390                 return copy_regset_from_user(child, &user_sh_native_view,
 391                                              REGSET_FPU,
 392                                              0, sizeof(struct user_fpu_struct),
 393                                              (const void __user *)data);
 394 #endif
 395 #ifdef CONFIG_SH_DSP
 396         case PTRACE_GETDSPREGS:
 397                 return copy_regset_to_user(child, &user_sh_native_view,
 398                                            REGSET_DSP,
 399                                            0, sizeof(struct pt_dspregs),
 400                                            (void __user *)data);
 401         case PTRACE_SETDSPREGS:
 402                 return copy_regset_from_user(child, &user_sh_native_view,
 403                                              REGSET_DSP,
 404                                              0, sizeof(struct pt_dspregs),
 405                                              (const void __user *)data);
 406 #endif
 407 #ifdef CONFIG_BINFMT_ELF_FDPIC
 408         case PTRACE_GETFDPIC: {
 409                 unsigned long tmp = 0;
 410
 411                 switch (addr) {
 412                 case PTRACE_GETFDPIC_EXEC:
 413                         tmp = child->mm->context.exec_fdpic_loadmap;
 414                         break;
 415                 case PTRACE_GETFDPIC_INTERP:
 416                         tmp = child->mm->context.interp_fdpic_loadmap;
 417                         break;
 418                 default:
 419                         break;
 420                 }
 421
 422                 ret = 0;
 423                 if (put_user(tmp, datap)) {
 424                         ret = -EFAULT;
 425                         break;
 426                 }
 427                 break;
 428         }
 429 #endif
 430         default:
 431                 ret = ptrace_request(child, request, addr, data);
 432                 break;
 433         }
 434
 435         return ret;
 436 }
 437
 438 static inline int audit_arch(void)
 439 {
 440         int arch = EM_SH;
 441
 442 #ifdef CONFIG_CPU_LITTLE_ENDIAN
 443         arch |= __AUDIT_ARCH_LE;
 444 #endif
 445
 446         return arch;
 447 }
 448
 449 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 450 {
 451         long ret = 0;
 452
 453         secure_computing(regs->regs[0]);
 454
 455         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 456             tracehook_report_syscall_entry(regs))
 457                 /*
 458                  * Tracing decided this syscall should not happen.
 459                  * We'll return a bogus call number to get an ENOSYS
 460                  * error, but leave the original number in regs->regs[0].
 461                  */
 462                 ret = -1L;
 463
 464         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
 465                 ftrace_syscall_enter(regs);
 466
 467         if (unlikely(current->audit_context))
 468                 audit_syscall_entry(audit_arch(), regs->regs[3],
 469                                     regs->regs[4], regs->regs[5],
 470                                     regs->regs[6], regs->regs[7]);
 471
 472         return ret ?: regs->regs[0];
 473 }
 474
 475 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 476 {
 477         int step;
 478
 479         if (unlikely(current->audit_context))
 480                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
 481                                    regs->regs[0]);
 482
 483         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
 484                 ftrace_syscall_exit(regs);
 485
 486         step = test_thread_flag(TIF_SINGLESTEP);
 487         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 488                 tracehook_report_syscall_exit(regs, step);
 489 }