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 = task_pt_dspregs(target);
 204         int ret;
 205
 206         ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs,
 207                                   0, sizeof(struct pt_dspregs));
 208         if (!ret)
 209                 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
 210                                                sizeof(struct pt_dspregs), -1);
 211
 212         return ret;
 213 }
 214
 215 static int dspregs_set(struct task_struct *target,
 216                        const struct user_regset *regset,
 217                        unsigned int pos, unsigned int count,
 218                        const void *kbuf, const void __user *ubuf)
 219 {
 220         struct pt_dspregs *regs = task_pt_dspregs(target);
 221         int ret;
 222
 223         ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
 224                                  0, sizeof(struct pt_dspregs));
 225         if (!ret)
 226                 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 227                                                 sizeof(struct pt_dspregs), -1);
 228
 229         return ret;
 230 }
 231
 232 static int dspregs_active(struct task_struct *target,
 233                           const struct user_regset *regset)
 234 {
 235         struct pt_regs *regs = task_pt_regs(target);
 236
 237         return regs->sr & SR_DSP ? regset->n : 0;
 238 }
 239 #endif
 240
 241 /*
 242  * These are our native regset flavours.
 243  */
 244 enum sh_regset {
 245         REGSET_GENERAL,
 246 #ifdef CONFIG_SH_FPU
 247         REGSET_FPU,
 248 #endif
 249 #ifdef CONFIG_SH_DSP
 250         REGSET_DSP,
 251 #endif
 252 };
 253
 254 static const struct user_regset sh_regsets[] = {
 255         /*
 256          * Format is:
 257          *      R0 --> R15
 258          *      PC, PR, SR, GBR, MACH, MACL, TRA
 259          */
 260         [REGSET_GENERAL] = {
 261                 .core_note_type = NT_PRSTATUS,
 262                 .n              = ELF_NGREG,
 263                 .size           = sizeof(long),
 264                 .align          = sizeof(long),
 265                 .get            = genregs_get,
 266                 .set            = genregs_set,
 267         },
 268
 269 #ifdef CONFIG_SH_FPU
 270         [REGSET_FPU] = {
 271                 .core_note_type = NT_PRFPREG,
 272                 .n              = sizeof(struct user_fpu_struct) / sizeof(long),
 273                 .size           = sizeof(long),
 274                 .align          = sizeof(long),
 275                 .get            = fpregs_get,
 276                 .set            = fpregs_set,
 277                 .active         = fpregs_active,
 278         },
 279 #endif
 280
 281 #ifdef CONFIG_SH_DSP
 282         [REGSET_DSP] = {
 283                 .n              = sizeof(struct pt_dspregs) / sizeof(long),
 284                 .size           = sizeof(long),
 285                 .align          = sizeof(long),
 286                 .get            = dspregs_get,
 287                 .set            = dspregs_set,
 288                 .active         = dspregs_active,
 289         },
 290 #endif
 291 };
 292
 293 static const struct user_regset_view user_sh_native_view = {
 294         .name           = "sh",
 295         .e_machine      = EM_SH,
 296         .regsets        = sh_regsets,
 297         .n              = ARRAY_SIZE(sh_regsets),
 298 };
 299
 300 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 301 {
 302         return &user_sh_native_view;
 303 }
 304
 305 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 306 {
 307         struct user * dummy = NULL;
 308         unsigned long __user *datap = (unsigned long __user *)data;
 309         int ret;
 310
 311         switch (request) {
 312         /* read the word at location addr in the USER area. */
 313         case PTRACE_PEEKUSR: {
 314                 unsigned long tmp;
 315
 316                 ret = -EIO;
 317                 if ((addr & 3) || addr < 0 ||
 318                     addr > sizeof(struct user) - 3)
 319                         break;
 320
 321                 if (addr < sizeof(struct pt_regs))
 322                         tmp = get_stack_long(child, addr);
 323                 else if (addr >= (long) &dummy->fpu &&
 324                          addr < (long) &dummy->u_fpvalid) {
 325                         if (!tsk_used_math(child)) {
 326                                 if (addr == (long)&dummy->fpu.fpscr)
 327                                         tmp = FPSCR_INIT;
 328                                 else
 329                                         tmp = 0;
 330                         } else
 331                                 tmp = ((long *)&child->thread.fpu)
 332                                         [(addr - (long)&dummy->fpu) >> 2];
 333                 } else if (addr == (long) &dummy->u_fpvalid)
 334                         tmp = !!tsk_used_math(child);
 335                 else
 336                         tmp = 0;
 337                 ret = put_user(tmp, datap);
 338                 break;
 339         }
 340
 341         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 342                 ret = -EIO;
 343                 if ((addr & 3) || addr < 0 ||
 344                     addr > sizeof(struct user) - 3)
 345                         break;
 346
 347                 if (addr < sizeof(struct pt_regs))
 348                         ret = put_stack_long(child, addr, data);
 349                 else if (addr >= (long) &dummy->fpu &&
 350                          addr < (long) &dummy->u_fpvalid) {
 351                         set_stopped_child_used_math(child);
 352                         ((long *)&child->thread.fpu)
 353                                 [(addr - (long)&dummy->fpu) >> 2] = data;
 354                         ret = 0;
 355                 } else if (addr == (long) &dummy->u_fpvalid) {
 356                         conditional_stopped_child_used_math(data, child);
 357                         ret = 0;
 358                 }
 359                 break;
 360
 361         case PTRACE_GETREGS:
 362                 return copy_regset_to_user(child, &user_sh_native_view,
 363                                            REGSET_GENERAL,
 364                                            0, sizeof(struct pt_regs),
 365                                            (void __user *)data);
 366         case PTRACE_SETREGS:
 367                 return copy_regset_from_user(child, &user_sh_native_view,
 368                                              REGSET_GENERAL,
 369                                              0, sizeof(struct pt_regs),
 370                                              (const void __user *)data);
 371 #ifdef CONFIG_SH_FPU
 372         case PTRACE_GETFPREGS:
 373                 return copy_regset_to_user(child, &user_sh_native_view,
 374                                            REGSET_FPU,
 375                                            0, sizeof(struct user_fpu_struct),
 376                                            (void __user *)data);
 377         case PTRACE_SETFPREGS:
 378                 return copy_regset_from_user(child, &user_sh_native_view,
 379                                              REGSET_FPU,
 380                                              0, sizeof(struct user_fpu_struct),
 381                                              (const void __user *)data);
 382 #endif
 383 #ifdef CONFIG_SH_DSP
 384         case PTRACE_GETDSPREGS:
 385                 return copy_regset_to_user(child, &user_sh_native_view,
 386                                            REGSET_DSP,
 387                                            0, sizeof(struct pt_dspregs),
 388                                            (void __user *)data);
 389         case PTRACE_SETDSPREGS:
 390                 return copy_regset_from_user(child, &user_sh_native_view,
 391                                              REGSET_DSP,
 392                                              0, sizeof(struct pt_dspregs),
 393                                              (const void __user *)data);
 394 #endif
 395 #ifdef CONFIG_BINFMT_ELF_FDPIC
 396         case PTRACE_GETFDPIC: {
 397                 unsigned long tmp = 0;
 398
 399                 switch (addr) {
 400                 case PTRACE_GETFDPIC_EXEC:
 401                         tmp = child->mm->context.exec_fdpic_loadmap;
 402                         break;
 403                 case PTRACE_GETFDPIC_INTERP:
 404                         tmp = child->mm->context.interp_fdpic_loadmap;
 405                         break;
 406                 default:
 407                         break;
 408                 }
 409
 410                 ret = 0;
 411                 if (put_user(tmp, datap)) {
 412                         ret = -EFAULT;
 413                         break;
 414                 }
 415                 break;
 416         }
 417 #endif
 418         default:
 419                 ret = ptrace_request(child, request, addr, data);
 420                 break;
 421         }
 422
 423         return ret;
 424 }
 425
 426 static inline int audit_arch(void)
 427 {
 428         int arch = EM_SH;
 429
 430 #ifdef CONFIG_CPU_LITTLE_ENDIAN
 431         arch |= __AUDIT_ARCH_LE;
 432 #endif
 433
 434         return arch;
 435 }
 436
 437 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
 438 {
 439         long ret = 0;
 440
 441         secure_computing(regs->regs[0]);
 442
 443         if (test_thread_flag(TIF_SYSCALL_TRACE) &&
 444             tracehook_report_syscall_entry(regs))
 445                 /*
 446                  * Tracing decided this syscall should not happen.
 447                  * We'll return a bogus call number to get an ENOSYS
 448                  * error, but leave the original number in regs->regs[0].
 449                  */
 450                 ret = -1L;
 451
 452         if (unlikely(current->audit_context))
 453                 audit_syscall_entry(audit_arch(), regs->regs[3],
 454                                     regs->regs[4], regs->regs[5],
 455                                     regs->regs[6], regs->regs[7]);
 456
 457         return ret ?: regs->regs[0];
 458 }
 459
 460 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
 461 {
 462         int step;
 463
 464         if (unlikely(current->audit_context))
 465                 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
 466                                    regs->regs[0]);
 467
 468         step = test_thread_flag(TIF_SINGLESTEP);
 469         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
 470                 tracehook_report_syscall_exit(regs, step);
 471 }