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