arch/mips/kernel/ptrace32.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1992 Ross Biro
   7  * Copyright (C) Linus Torvalds
   8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
   9  * Copyright (C) 1996 David S. Miller
  10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
  11  * Copyright (C) 1999 MIPS Technologies, Inc.
  12  * Copyright (C) 2000 Ulf Carlsson
  13  *
  14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
  15  * binaries.
  16  */
  17 #include <linux/compiler.h>
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/mm.h>
  21 #include <linux/errno.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/smp.h>
  24 #include <linux/smp_lock.h>
  25 #include <linux/user.h>
  26 #include <linux/security.h>
  27
  28 #include <asm/cpu.h>
  29 #include <asm/dsp.h>
  30 #include <asm/fpu.h>
  31 #include <asm/mipsregs.h>
  32 #include <asm/mipsmtregs.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/page.h>
  35 #include <asm/system.h>
  36 #include <asm/uaccess.h>
  37 #include <asm/bootinfo.h>
  38
  39 int ptrace_getregs (struct task_struct *child, __s64 __user *data);
  40 int ptrace_setregs (struct task_struct *child, __s64 __user *data);
  41
  42 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data);
  43 int ptrace_setfpregs (struct task_struct *child, __u32 __user *data);
  44
  45 /*
  46  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
  47  * work.  I don't know how to fix this.
  48  */
  49 asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
  50 {
  51         struct task_struct *child;
  52         int ret;
  53
  54 #if 0
  55         printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
  56                (int) request, (int) pid, (unsigned long) addr,
  57                (unsigned long) data);
  58 #endif
  59         lock_kernel();
  60         ret = -EPERM;
  61         if (request == PTRACE_TRACEME) {
  62                 /* are we already being traced? */
  63                 if (current->ptrace & PT_PTRACED)
  64                         goto out;
  65                 if ((ret = security_ptrace(current->parent, current)))
  66                         goto out;
  67                 /* set the ptrace bit in the process flags. */
  68                 current->ptrace |= PT_PTRACED;
  69                 ret = 0;
  70                 goto out;
  71         }
  72         ret = -ESRCH;
  73         read_lock(&tasklist_lock);
  74         child = find_task_by_pid(pid);
  75         if (child)
  76                 get_task_struct(child);
  77         read_unlock(&tasklist_lock);
  78         if (!child)
  79                 goto out;
  80
  81         ret = -EPERM;
  82         if (pid == 1)           /* you may not mess with init */
  83                 goto out_tsk;
  84
  85         if (request == PTRACE_ATTACH) {
  86                 ret = ptrace_attach(child);
  87                 goto out_tsk;
  88         }
  89
  90         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  91         if (ret < 0)
  92                 goto out_tsk;
  93
  94         switch (request) {
  95         /* when I and D space are separate, these will need to be fixed. */
  96         case PTRACE_PEEKTEXT: /* read word at location addr. */
  97         case PTRACE_PEEKDATA: {
  98                 unsigned int tmp;
  99                 int copied;
 100
 101                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
 102                 ret = -EIO;
 103                 if (copied != sizeof(tmp))
 104                         break;
 105                 ret = put_user(tmp, (unsigned int *) (unsigned long) data);
 106                 break;
 107         }
 108
 109         /*
 110          * Read 4 bytes of the other process' storage
 111          *  data is a pointer specifying where the user wants the
 112          *      4 bytes copied into
 113          *  addr is a pointer in the user's storage that contains an 8 byte
 114          *      address in the other process of the 4 bytes that is to be read
 115          * (this is run in a 32-bit process looking at a 64-bit process)
 116          * when I and D space are separate, these will need to be fixed.
 117          */
 118         case PTRACE_PEEKTEXT_3264:
 119         case PTRACE_PEEKDATA_3264: {
 120                 u32 tmp;
 121                 int copied;
 122                 u32 __user * addrOthers;
 123
 124                 ret = -EIO;
 125
 126                 /* Get the addr in the other process that we want to read */
 127                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 128                         break;
 129
 130                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 131                                 sizeof(tmp), 0);
 132                 if (copied != sizeof(tmp))
 133                         break;
 134                 ret = put_user(tmp, (u32 __user *) (unsigned long) data);
 135                 break;
 136         }
 137
 138         /* Read the word at location addr in the USER area. */
 139         case PTRACE_PEEKUSR: {
 140                 struct pt_regs *regs;
 141                 unsigned int tmp;
 142
 143                 regs = (struct pt_regs *) ((unsigned long) child->thread_info +
 144                        THREAD_SIZE - 32 - sizeof(struct pt_regs));
 145                 ret = 0;  /* Default return value. */
 146
 147                 switch (addr) {
 148                 case 0 ... 31:
 149                         tmp = regs->regs[addr];
 150                         break;
 151                 case FPR_BASE ... FPR_BASE + 31:
 152                         if (tsk_used_math(child)) {
 153                                 fpureg_t *fregs = get_fpu_regs(child);
 154
 155                                 /*
 156                                  * The odd registers are actually the high
 157                                  * order bits of the values stored in the even
 158                                  * registers - unless we're using r2k_switch.S.
 159                                  */
 160                                 if (addr & 1)
 161                                         tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
 162                                 else
 163                                         tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
 164                         } else {
 165                                 tmp = -1;       /* FP not yet used  */
 166                         }
 167                         break;
 168                 case PC:
 169                         tmp = regs->cp0_epc;
 170                         break;
 171                 case CAUSE:
 172                         tmp = regs->cp0_cause;
 173                         break;
 174                 case BADVADDR:
 175                         tmp = regs->cp0_badvaddr;
 176                         break;
 177                 case MMHI:
 178                         tmp = regs->hi;
 179                         break;
 180                 case MMLO:
 181                         tmp = regs->lo;
 182                         break;
 183                 case FPC_CSR:
 184                         if (cpu_has_fpu)
 185                                 tmp = child->thread.fpu.hard.fcr31;
 186                         else
 187                                 tmp = child->thread.fpu.soft.fcr31;
 188                         break;
 189                 case FPC_EIR: { /* implementation / version register */
 190                         unsigned int flags;
 191
 192                         if (!cpu_has_fpu)
 193                                 break;
 194
 195                         preempt_disable();
 196                         if (cpu_has_mipsmt) {
 197                                 unsigned int vpflags = dvpe();
 198                                 flags = read_c0_status();
 199                                 __enable_fpu();
 200                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 201                                 write_c0_status(flags);
 202                                 evpe(vpflags);
 203                         } else {
 204                                 flags = read_c0_status();
 205                                 __enable_fpu();
 206                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 207                                 write_c0_status(flags);
 208                         }
 209                         preempt_enable();
 210                         break;
 211                 }
 212                 case DSP_BASE ... DSP_BASE + 5:
 213                         if (!cpu_has_dsp) {
 214                                 tmp = 0;
 215                                 ret = -EIO;
 216                                 goto out_tsk;
 217                         }
 218                         if (child->thread.dsp.used_dsp) {
 219                                 dspreg_t *dregs = __get_dsp_regs(child);
 220                                 tmp = (unsigned long) (dregs[addr - DSP_BASE]);
 221                         } else {
 222                                 tmp = -1;       /* DSP registers yet used  */
 223                         }
 224                         break;
 225                 case DSP_CONTROL:
 226                         if (!cpu_has_dsp) {
 227                                 tmp = 0;
 228                                 ret = -EIO;
 229                                 goto out_tsk;
 230                         }
 231                         tmp = child->thread.dsp.dspcontrol;
 232                         break;
 233                 default:
 234                         tmp = 0;
 235                         ret = -EIO;
 236                         goto out_tsk;
 237                 }
 238                 ret = put_user(tmp, (unsigned *) (unsigned long) data);
 239                 break;
 240         }
 241
 242         /* when I and D space are separate, this will have to be fixed. */
 243         case PTRACE_POKETEXT: /* write the word at location addr. */
 244         case PTRACE_POKEDATA:
 245                 ret = 0;
 246                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
 247                     == sizeof(data))
 248                         break;
 249                 ret = -EIO;
 250                 break;
 251
 252         /*
 253          * Write 4 bytes into the other process' storage
 254          *  data is the 4 bytes that the user wants written
 255          *  addr is a pointer in the user's storage that contains an
 256          *      8 byte address in the other process where the 4 bytes
 257          *      that is to be written
 258          * (this is run in a 32-bit process looking at a 64-bit process)
 259          * when I and D space are separate, these will need to be fixed.
 260          */
 261         case PTRACE_POKETEXT_3264:
 262         case PTRACE_POKEDATA_3264: {
 263                 u32 __user * addrOthers;
 264
 265                 /* Get the addr in the other process that we want to write into */
 266                 ret = -EIO;
 267                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 268                         break;
 269                 ret = 0;
 270                 if (access_process_vm(child, (u64)addrOthers, &data,
 271                                         sizeof(data), 1) == sizeof(data))
 272                         break;
 273                 ret = -EIO;
 274                 break;
 275         }
 276
 277         case PTRACE_POKEUSR: {
 278                 struct pt_regs *regs;
 279                 ret = 0;
 280                 regs = (struct pt_regs *) ((unsigned long) child->thread_info +
 281                        THREAD_SIZE - 32 - sizeof(struct pt_regs));
 282
 283                 switch (addr) {
 284                 case 0 ... 31:
 285                         regs->regs[addr] = data;
 286                         break;
 287                 case FPR_BASE ... FPR_BASE + 31: {
 288                         fpureg_t *fregs = get_fpu_regs(child);
 289
 290                         if (!tsk_used_math(child)) {
 291                                 /* FP not yet used  */
 292                                 memset(&child->thread.fpu.hard, ~0,
 293                                        sizeof(child->thread.fpu.hard));
 294                                 child->thread.fpu.hard.fcr31 = 0;
 295                         }
 296                         /*
 297                          * The odd registers are actually the high order bits
 298                          * of the values stored in the even registers - unless
 299                          * we're using r2k_switch.S.
 300                          */
 301                         if (addr & 1) {
 302                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
 303                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
 304                         } else {
 305                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
 306                                 /* Must cast, lest sign extension fill upper
 307                                    bits!  */
 308                                 fregs[addr - FPR_BASE] |= (unsigned int)data;
 309                         }
 310                         break;
 311                 }
 312                 case PC:
 313                         regs->cp0_epc = data;
 314                         break;
 315                 case MMHI:
 316                         regs->hi = data;
 317                         break;
 318                 case MMLO:
 319                         regs->lo = data;
 320                         break;
 321                 case FPC_CSR:
 322                         if (cpu_has_fpu)
 323                                 child->thread.fpu.hard.fcr31 = data;
 324                         else
 325                                 child->thread.fpu.soft.fcr31 = data;
 326                         break;
 327                 case DSP_BASE ... DSP_BASE + 5:
 328                         if (!cpu_has_dsp) {
 329                                 ret = -EIO;
 330                                 break;
 331                         }
 332
 333                         dspreg_t *dregs = __get_dsp_regs(child);
 334                         dregs[addr - DSP_BASE] = data;
 335                         break;
 336                 case DSP_CONTROL:
 337                         if (!cpu_has_dsp) {
 338                                 ret = -EIO;
 339                                 break;
 340                         }
 341                         child->thread.dsp.dspcontrol = data;
 342                         break;
 343                 default:
 344                         /* The rest are not allowed. */
 345                         ret = -EIO;
 346                         break;
 347                 }
 348                 break;
 349                 }
 350
 351         case PTRACE_GETREGS:
 352                 ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
 353                 break;
 354
 355         case PTRACE_SETREGS:
 356                 ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
 357                 break;
 358
 359         case PTRACE_GETFPREGS:
 360                 ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
 361                 break;
 362
 363         case PTRACE_SETFPREGS:
 364                 ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
 365                 break;
 366
 367         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 368         case PTRACE_CONT: { /* restart after signal. */
 369                 ret = -EIO;
 370                 if (!valid_signal(data))
 371                         break;
 372                 if (request == PTRACE_SYSCALL) {
 373                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 374                 }
 375                 else {
 376                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 377                 }
 378                 child->exit_code = data;
 379                 wake_up_process(child);
 380                 ret = 0;
 381                 break;
 382         }
 383
 384         /*
 385          * make the child exit.  Best I can do is send it a sigkill.
 386          * perhaps it should be put in the status that it wants to
 387          * exit.
 388          */
 389         case PTRACE_KILL:
 390                 ret = 0;
 391                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 392                         break;
 393                 child->exit_code = SIGKILL;
 394                 wake_up_process(child);
 395                 break;
 396
 397         case PTRACE_GET_THREAD_AREA:
 398                 ret = put_user(child->thread_info->tp_value,
 399                                 (unsigned int __user *) (unsigned long) data);
 400                 break;
 401
 402         case PTRACE_DETACH: /* detach a process that was attached. */
 403                 ret = ptrace_detach(child, data);
 404                 break;
 405
 406         case PTRACE_GETEVENTMSG:
 407                 ret = put_user(child->ptrace_message,
 408                                (unsigned int __user *) (unsigned long) data);
 409                 break;
 410
 411         case PTRACE_GET_THREAD_AREA_3264:
 412                 ret = put_user(child->thread_info->tp_value,
 413                                 (unsigned long __user *) (unsigned long) data);
 414                 break;
 415
 416         default:
 417                 ret = ptrace_request(child, request, addr, data);
 418                 break;
 419         }
 420
 421 out_tsk:
 422         put_task_struct(child);
 423 out:
 424         unlock_kernel();
 425         return ret;
 426 }