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 #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 user_enable_single_step(struct task_struct *child)
  67 {
  68         /* Next scheduling will set up UBC */
  69         if (child->thread.ubc_pc == 0)
  70                 ubc_usercnt += 1;
  71
  72         child->thread.ubc_pc = get_stack_long(child,
  73                                 offsetof(struct pt_regs, pc));
  74
  75         set_tsk_thread_flag(child, TIF_SINGLESTEP);
  76 }
  77
  78 void user_disable_single_step(struct task_struct *child)
  79 {
  80         clear_tsk_thread_flag(child, TIF_SINGLESTEP);
  81
  82         /*
  83          * Ensure the UBC is not programmed at the next context switch.
  84          *
  85          * Normally this is not needed but there are sequences such as
  86          * singlestep, signal delivery, and continue that leave the
  87          * ubc_pc non-zero leading to spurious SIGTRAPs.
  88          */
  89         if (child->thread.ubc_pc != 0) {
  90                 ubc_usercnt -= 1;
  91                 child->thread.ubc_pc = 0;
  92         }
  93 }
  94
  95 /*
  96  * Called by kernel/ptrace.c when detaching..
  97  *
  98  * Make sure single step bits etc are not set.
  99  */
 100 void ptrace_disable(struct task_struct *child)
 101 {
 102         user_disable_single_step(child);
 103 }
 104
 105 static int genregs_get(struct task_struct *target,
 106                        const struct user_regset *regset,
 107                        unsigned int pos, unsigned int count,
 108                        void *kbuf, void __user *ubuf)
 109 {
 110         const struct pt_regs *regs = task_pt_regs(target);
 111         int ret;
 112
 113         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 114                                   regs->regs,
 115                                   0, 16 * sizeof(unsigned long));
 116         if (!ret)
 117                 /* PC, PR, SR, GBR, MACH, MACL, TRA */
 118                 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 119                                           &regs->pc,
 120                                           offsetof(struct pt_regs, pc),
 121                                           sizeof(struct pt_regs));
 122         if (!ret)
 123                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 124                                                sizeof(struct pt_regs), -1);
 125
 126         return ret;
 127 }
 128
 129 static int genregs_set(struct task_struct *target,
 130                        const struct user_regset *regset,
 131                        unsigned int pos, unsigned int count,
 132                        const void *kbuf, const void __user *ubuf)
 133 {
 134         struct pt_regs *regs = task_pt_regs(target);
 135         int ret;
 136
 137         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 138                                  regs->regs,
 139                                  0, 16 * sizeof(unsigned long));
 140         if (!ret && count > 0)
 141                 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 142                                          &regs->pc,
 143                                          offsetof(struct pt_regs, pc),
 144                                          sizeof(struct pt_regs));
 145         if (!ret)
 146                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 147                                                 sizeof(struct pt_regs), -1);
 148
 149         return ret;
 150 }
 151
 152 #ifdef CONFIG_SH_FPU
 153 int fpregs_get(struct task_struct *target,
 154                const struct user_regset *regset,
 155                unsigned int pos, unsigned int count,
 156                void *kbuf, void __user *ubuf)
 157 {
 158         int ret;
 159
 160         ret = init_fpu(target);
 161         if (ret)
 162                 return ret;
 163
 164         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 165                 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 166                                            &target->thread.fpu.hard, 0, -1);
 167
 168         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
 169                                    &target->thread.fpu.soft, 0, -1);
 170 }
 171
 172 static int fpregs_set(struct task_struct *target,
 173                        const struct user_regset *regset,
 174                        unsigned int pos, unsigned int count,
 175                        const void *kbuf, const void __user *ubuf)
 176 {
 177         int ret;
 178
 179         ret = init_fpu(target);
 180         if (ret)
 181                 return ret;
 182
 183         set_stopped_child_used_math(target);
 184
 185         if ((boot_cpu_data.flags & CPU_HAS_FPU))
 186                 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 187                                           &target->thread.fpu.hard, 0, -1);
 188
 189         return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
 190                                   &target->thread.fpu.soft, 0, -1);
 191 }
 192
 193 static int fpregs_active(struct task_struct *target,
 194                          const struct user_regset *regset)
 195 {
 196         return tsk_used_math(target) ? regset->n : 0;
 197 }
 198 #endif
 199
 200 #ifdef CONFIG_SH_DSP
 201 static int dspregs_get(struct task_struct *target,
 202                        const struct user_regset *regset,
 203                        unsigned int pos, unsigned int count,
 204                        void *kbuf, void __user *ubuf)
 205 {
 206         const struct pt_dspregs *regs =
 207                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 208         int ret;
 209
 210         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
 211                                   0, sizeof(struct pt_dspregs));
 212         if (!ret)
 213                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 214                                                sizeof(struct pt_dspregs), -1);
 215
 216         return ret;
 217 }
 218
 219 static int dspregs_set(struct task_struct *target,
 220                        const struct user_regset *regset,
 221                        unsigned int pos, unsigned int count,
 222                        const void *kbuf, const void __user *ubuf)
 223 {
 224         struct pt_dspregs *regs =
 225                 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
 226         int ret;
 227
 228         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
 229                                  0, sizeof(struct pt_dspregs));
 230         if (!ret)
 231                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 232                                                 sizeof(struct pt_dspregs), -1);
 233
 234         return ret;
 235 }
 236
 237 static int dspregs_active(struct task_struct *target,
 238                           const struct user_regset *regset)
 239 {
 240         struct pt_regs *regs = task_pt_regs(target);
 241
 242         return regs->sr & SR_DSP ? regset->n : 0;
 243 }
 244 #endif
 245
 246 /*
 247  * These are our native regset flavours.
 248  */
 249 enum sh_regset {
 250         REGSET_GENERAL,
 251 #ifdef CONFIG_SH_FPU
 252         REGSET_FPU,
 253 #endif
 254 #ifdef CONFIG_SH_DSP
 255         REGSET_DSP,
 256 #endif
 257 };
 258
 259 static const struct user_regset sh_regsets[] = {
 260         /*
 261          * Format is:
 262          *      R0 --> R15
 263          *      PC, PR, SR, GBR, MACH, MACL, TRA
 264          */
 265         [REGSET_GENERAL] = {
 266                 .core_note_type = NT_PRSTATUS,
 267                 .n              = ELF_NGREG,
 268                 .size           = sizeof(long),
 269                 .align          = sizeof(long),
 270                 .get            = genregs_get,
 271                 .set            = genregs_set,
 272         },
 273
 274 #ifdef CONFIG_SH_FPU
 275         [REGSET_FPU] = {
 276                 .core_note_type = NT_PRFPREG,
 277                 .n              = sizeof(struct user_fpu_struct) / sizeof(long),
 278                 .size           = sizeof(long),
 279                 .align          = sizeof(long),
 280                 .get            = fpregs_get,
 281                 .set            = fpregs_set,
 282                 .active         = fpregs_active,
 283         },
 284 #endif
 285
 286 #ifdef CONFIG_SH_DSP
 287         [REGSET_DSP] = {
 288                 .n              = sizeof(struct pt_dspregs) / sizeof(long),
 289                 .size           = sizeof(long),
 290                 .align          = sizeof(long),
 291                 .get            = dspregs_get,
 292                 .set            = dspregs_set,
 293                 .active         = dspregs_active,
 294         },
 295 #endif
 296 };
 297
 298 static const struct user_regset_view user_sh_native_view = {
 299         .name           = "sh",
 300         .e_machine      = EM_SH,
 301         .regsets        = sh_regsets,
 302         .n              = ARRAY_SIZE(sh_regsets),
 303 };
 304
 305 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 306 {
 307         return &user_sh_native_view;
 308 }
 309
 310 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 311 {
 312         struct user * dummy = NULL;
 313         unsigned long __user *datap = (unsigned long __user *)data;
 314         int ret;
 315
 316         switch (request) {
 317         /* read the word at location addr in the USER area. */
 318         case PTRACE_PEEKUSR: {
 319                 unsigned long tmp;
 320
 321                 ret = -EIO;
 322                 if ((addr & 3) || addr < 0 ||
 323                     addr > sizeof(struct user) - 3)
 324                         break;
 325
 326                 if (addr < sizeof(struct pt_regs))
 327                         tmp = get_stack_long(child, addr);
 328                 else if (addr >= (long) &dummy->fpu &&
 329                          addr < (long) &dummy->u_fpvalid) {
 330                         if (!tsk_used_math(child)) {
 331                                 if (addr == (long)&dummy->fpu.fpscr)
 332                                         tmp = FPSCR_INIT;
 333                                 else
 334                                         tmp = 0;
 335                         } else
 336                                 tmp = ((long *)&child->thread.fpu)
 337                                         [(addr - (long)&dummy->fpu) >> 2];
 338                 } else if (addr == (long) &dummy->u_fpvalid)
 339                         tmp = !!tsk_used_math(child);
 340                 else if (addr == PT_TEXT_ADDR)
 341                         tmp = child->mm->start_code;
 342                 else if (addr == PT_DATA_ADDR)
 343                         tmp = child->mm->start_data;
 344                 else if (addr == PT_TEXT_END_ADDR)
 345                         tmp = child->mm->end_code;
 346                 else if (addr == PT_TEXT_LEN)
 347                         tmp = child->mm->end_code - child->mm->start_code;
 348                 else
 349                         tmp = 0;
 350                 ret = put_user(tmp, datap);
 351                 break;
 352         }
 353
 354         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 355                 ret = -EIO;
 356                 if ((addr & 3) || addr < 0 ||
 357                     addr > sizeof(struct user) - 3)
 358                         break;
 359
 360                 if (addr < sizeof(struct pt_regs))
 361                         ret = put_stack_long(child, addr, data);
 362                 else if (addr >= (long) &dummy->fpu &&
 363                          addr < (long) &dummy->u_fpvalid) {
 364                         set_stopped_child_used_math(child);
 365                         ((long *)&child->thread.fpu)
 366                                 [(addr - (long)&dummy->fpu) >> 2] = data;
 367                         ret = 0;
 368                 } else if (addr == (long) &dummy->u_fpvalid) {
 369                         conditional_stopped_child_used_math(data, child);
 370                         ret = 0;
 371                 }
 372                 break;
 373
 374         case PTRACE_GETREGS:
 375                 return copy_regset_to_user(child, &user_sh_native_view,
 376                                            REGSET_GENERAL,
 377                                            0, sizeof(struct pt_regs),
 378                                            (void __user *)data);
 379         case PTRACE_SETREGS:
 380                 return copy_regset_from_user(child, &user_sh_native_view,
 381                                              REGSET_GENERAL,
 382                                              0, sizeof(struct pt_regs),
 383                                              (const void __user *)data);
 384 #ifdef CONFIG_SH_FPU
 385         case PTRACE_GETFPREGS:
 386                 return copy_regset_to_user(child, &user_sh_native_view,
 387                                            REGSET_FPU,
 388                                            0, sizeof(struct user_fpu_struct),
 389                                            (void __user *)data);
 390         case PTRACE_SETFPREGS:
 391                 return copy_regset_from_user(child, &user_sh_native_view,
 392                                              REGSET_FPU,
 393                                              0, sizeof(struct user_fpu_struct),
 394                                              (const void __user *)data);
 395 #endif
 396 #ifdef CONFIG_SH_DSP
 397         case PTRACE_GETDSPREGS:
 398                 return copy_regset_to_user(child, &user_sh_native_view,
 399                                            REGSET_DSP,
 400                                            0, sizeof(struct pt_dspregs),
 401                                            (void __user *)data);
 402         case PTRACE_SETDSPREGS:
 403                 return copy_regset_from_user(child, &user_sh_native_view,
 404                                              REGSET_DSP,
 405                                              0, sizeof(struct pt_dspregs),
 406                                              (const void __user *)data);
 407 #endif
 408 #ifdef CONFIG_BINFMT_ELF_FDPIC
 409         case PTRACE_GETFDPIC: {
 410                 unsigned long tmp = 0;
 411
 412                 switch (addr) {
 413                 case PTRACE_GETFDPIC_EXEC:
 414                         tmp = child->mm->context.exec_fdpic_loadmap;
 415                         break;
 416                 case PTRACE_GETFDPIC_INTERP:
 417                         tmp = child->mm->context.interp_fdpic_loadmap;
 418                         break;
 419                 default:
 420                         break;
 421                 }
 422
 423                 ret = 0;
 424                 if (put_user(tmp, datap)) {
 425                         ret = -EFAULT;
 426                         break;
 427                 }
 428                 break;
 429         }
 430 #endif
 431         default:
 432                 ret = ptrace_request(child, request, addr, data);
 433                 break;
 434         }
 435
 436         return ret;
 437 }
 438
 439 static inline int audit_arch(void)
 440 {
 441         int arch = EM_SH;
 442
 443 #ifdef CONFIG_CPU_LITTLE_ENDIAN
 444         arch |= __AUDIT_ARCH_LE;
 445 #endif
 446
 447         return arch;
 448 }
 449
 450 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 451 {
 452         long ret = 0;
 453
 454         secure_computing(regs->regs[0]);
 455
 456         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 457             tracehook_report_syscall_entry(regs))
 458                 /*
 459                  * Tracing decided this syscall should not happen.
 460                  * We'll return a bogus call number to get an ENOSYS
 461                  * error, but leave the original number in regs->regs[0].
 462                  */
 463                 ret = -1L;
 464
 465         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 466                 trace_sys_enter(regs, regs->regs[0]);
 467
 468         if (unlikely(current->audit_context))
 469                 audit_syscall_entry(audit_arch(), regs->regs[3],
 470                                     regs->regs[4], regs->regs[5],
 471                                     regs->regs[6], regs->regs[7]);
 472
 473         return ret ?: regs->regs[0];
 474 }
 475
 476 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 477 {
 478         int step;
 479
 480         if (unlikely(current->audit_context))
 481                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
 482                                    regs->regs[0]);
 483
 484         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
 485                 trace_sys_exit(regs, regs->regs[0]);
 486
 487         step = test_thread_flag(TIF_SINGLESTEP);
 488         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 489                 tracehook_report_syscall_exit(regs, step);
 490 }