SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/pgtable.h>
  33 #include <asm/page.h>
  34 #include <asm/system.h>
  35 #include <asm/uaccess.h>
  36 #include <asm/bootinfo.h>
  37
  38 int ptrace_getregs (struct task_struct *child, __s64 __user *data);
  39 int ptrace_setregs (struct task_struct *child, __s64 __user *data);
  40
  41 int ptrace_getfpregs (struct task_struct *child, __u32 __user *data);
  42 int ptrace_setfpregs (struct task_struct *child, __u32 __user *data);
  43
  44 /*
  45  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
  46  * work.  I don't know how to fix this.
  47  */
  48 asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
  49 {
  50         struct task_struct *child;
  51         int ret;
  52
  53 #if 0
  54         printk("ptrace(r=%d,pid=%d,addr=%08lx,data=%08lx)\n",
  55                (int) request, (int) pid, (unsigned long) addr,
  56                (unsigned long) data);
  57 #endif
  58         lock_kernel();
  59         ret = -EPERM;
  60         if (request == PTRACE_TRACEME) {
  61                 /* are we already being traced? */
  62                 if (current->ptrace & PT_PTRACED)
  63                         goto out;
  64                 if ((ret = security_ptrace(current->parent, current)))
  65                         goto out;
  66                 /* set the ptrace bit in the process flags. */
  67                 current->ptrace |= PT_PTRACED;
  68                 ret = 0;
  69                 goto out;
  70         }
  71         ret = -ESRCH;
  72         read_lock(&tasklist_lock);
  73         child = find_task_by_pid(pid);
  74         if (child)
  75                 get_task_struct(child);
  76         read_unlock(&tasklist_lock);
  77         if (!child)
  78                 goto out;
  79
  80         ret = -EPERM;
  81         if (pid == 1)           /* you may not mess with init */
  82                 goto out_tsk;
  83
  84         if (request == PTRACE_ATTACH) {
  85                 ret = ptrace_attach(child);
  86                 goto out_tsk;
  87         }
  88
  89         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  90         if (ret < 0)
  91                 goto out_tsk;
  92
  93         switch (request) {
  94         /* when I and D space are separate, these will need to be fixed. */
  95         case PTRACE_PEEKTEXT: /* read word at location addr. */
  96         case PTRACE_PEEKDATA: {
  97                 unsigned int tmp;
  98                 int copied;
  99
 100                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
 101                 ret = -EIO;
 102                 if (copied != sizeof(tmp))
 103                         break;
 104                 ret = put_user(tmp, (unsigned int *) (unsigned long) data);
 105                 break;
 106         }
 107
 108         /*
 109          * Read 4 bytes of the other process' storage
 110          *  data is a pointer specifying where the user wants the
 111          *      4 bytes copied into
 112          *  addr is a pointer in the user's storage that contains an 8 byte
 113          *      address in the other process of the 4 bytes that is to be read
 114          * (this is run in a 32-bit process looking at a 64-bit process)
 115          * when I and D space are separate, these will need to be fixed.
 116          */
 117         case PTRACE_PEEKTEXT_3264:
 118         case PTRACE_PEEKDATA_3264: {
 119                 u32 tmp;
 120                 int copied;
 121                 u32 __user * addrOthers;
 122
 123                 ret = -EIO;
 124
 125                 /* Get the addr in the other process that we want to read */
 126                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 127                         break;
 128
 129                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 130                                 sizeof(tmp), 0);
 131                 if (copied != sizeof(tmp))
 132                         break;
 133                 ret = put_user(tmp, (u32 __user *) (unsigned long) data);
 134                 break;
 135         }
 136
 137         /* Read the word at location addr in the USER area. */
 138         case PTRACE_PEEKUSR: {
 139                 struct pt_regs *regs;
 140                 unsigned int tmp;
 141
 142                 regs = (struct pt_regs *) ((unsigned long) child->thread_info +
 143                        THREAD_SIZE - 32 - sizeof(struct pt_regs));
 144                 ret = 0;  /* Default return value. */
 145
 146                 switch (addr) {
 147                 case 0 ... 31:
 148                         tmp = regs->regs[addr];
 149                         break;
 150                 case FPR_BASE ... FPR_BASE + 31:
 151                         if (tsk_used_math(child)) {
 152                                 fpureg_t *fregs = get_fpu_regs(child);
 153
 154                                 /*
 155                                  * The odd registers are actually the high
 156                                  * order bits of the values stored in the even
 157                                  * registers - unless we're using r2k_switch.S.
 158                                  */
 159                                 if (addr & 1)
 160                                         tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
 161                                 else
 162                                         tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
 163                         } else {
 164                                 tmp = -1;       /* FP not yet used  */
 165                         }
 166                         break;
 167                 case PC:
 168                         tmp = regs->cp0_epc;
 169                         break;
 170                 case CAUSE:
 171                         tmp = regs->cp0_cause;
 172                         break;
 173                 case BADVADDR:
 174                         tmp = regs->cp0_badvaddr;
 175                         break;
 176                 case MMHI:
 177                         tmp = regs->hi;
 178                         break;
 179                 case MMLO:
 180                         tmp = regs->lo;
 181                         break;
 182                 case FPC_CSR:
 183                         if (cpu_has_fpu)
 184                                 tmp = child->thread.fpu.hard.fcr31;
 185                         else
 186                                 tmp = child->thread.fpu.soft.fcr31;
 187                         break;
 188                 case FPC_EIR: { /* implementation / version register */
 189                         unsigned int flags;
 190
 191                         if (!cpu_has_fpu)
 192                                 break;
 193
 194                         flags = read_c0_status();
 195                         __enable_fpu();
 196                         __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 197                         write_c0_status(flags);
 198                         break;
 199                 }
 200                 case DSP_BASE ... DSP_BASE + 5:
 201                         if (!cpu_has_dsp) {
 202                                 tmp = 0;
 203                                 ret = -EIO;
 204                                 goto out_tsk;
 205                         }
 206                         if (child->thread.dsp.used_dsp) {
 207                                 dspreg_t *dregs = __get_dsp_regs(child);
 208                                 tmp = (unsigned long) (dregs[addr - DSP_BASE]);
 209                         } else {
 210                                 tmp = -1;       /* DSP registers yet used  */
 211                         }
 212                         break;
 213                 case DSP_CONTROL:
 214                         if (!cpu_has_dsp) {
 215                                 tmp = 0;
 216                                 ret = -EIO;
 217                                 goto out_tsk;
 218                         }
 219                         tmp = child->thread.dsp.dspcontrol;
 220                         break;
 221                 default:
 222                         tmp = 0;
 223                         ret = -EIO;
 224                         goto out_tsk;
 225                 }
 226                 ret = put_user(tmp, (unsigned *) (unsigned long) data);
 227                 break;
 228         }
 229
 230         /* when I and D space are separate, this will have to be fixed. */
 231         case PTRACE_POKETEXT: /* write the word at location addr. */
 232         case PTRACE_POKEDATA:
 233                 ret = 0;
 234                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
 235                     == sizeof(data))
 236                         break;
 237                 ret = -EIO;
 238                 break;
 239
 240         /*
 241          * Write 4 bytes into the other process' storage
 242          *  data is the 4 bytes that the user wants written
 243          *  addr is a pointer in the user's storage that contains an
 244          *      8 byte address in the other process where the 4 bytes
 245          *      that is to be written
 246          * (this is run in a 32-bit process looking at a 64-bit process)
 247          * when I and D space are separate, these will need to be fixed.
 248          */
 249         case PTRACE_POKETEXT_3264:
 250         case PTRACE_POKEDATA_3264: {
 251                 u32 __user * addrOthers;
 252
 253                 /* Get the addr in the other process that we want to write into */
 254                 ret = -EIO;
 255                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 256                         break;
 257                 ret = 0;
 258                 if (access_process_vm(child, (u64)addrOthers, &data,
 259                                         sizeof(data), 1) == sizeof(data))
 260                         break;
 261                 ret = -EIO;
 262                 break;
 263         }
 264
 265         case PTRACE_POKEUSR: {
 266                 struct pt_regs *regs;
 267                 ret = 0;
 268                 regs = (struct pt_regs *) ((unsigned long) child->thread_info +
 269                        THREAD_SIZE - 32 - sizeof(struct pt_regs));
 270
 271                 switch (addr) {
 272                 case 0 ... 31:
 273                         regs->regs[addr] = data;
 274                         break;
 275                 case FPR_BASE ... FPR_BASE + 31: {
 276                         fpureg_t *fregs = get_fpu_regs(child);
 277
 278                         if (!tsk_used_math(child)) {
 279                                 /* FP not yet used  */
 280                                 memset(&child->thread.fpu.hard, ~0,
 281                                        sizeof(child->thread.fpu.hard));
 282                                 child->thread.fpu.hard.fcr31 = 0;
 283                         }
 284                         /*
 285                          * The odd registers are actually the high order bits
 286                          * of the values stored in the even registers - unless
 287                          * we're using r2k_switch.S.
 288                          */
 289                         if (addr & 1) {
 290                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
 291                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
 292                         } else {
 293                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
 294                                 /* Must cast, lest sign extension fill upper
 295                                    bits!  */
 296                                 fregs[addr - FPR_BASE] |= (unsigned int)data;
 297                         }
 298                         break;
 299                 }
 300                 case PC:
 301                         regs->cp0_epc = data;
 302                         break;
 303                 case MMHI:
 304                         regs->hi = data;
 305                         break;
 306                 case MMLO:
 307                         regs->lo = data;
 308                         break;
 309                 case FPC_CSR:
 310                         if (cpu_has_fpu)
 311                                 child->thread.fpu.hard.fcr31 = data;
 312                         else
 313                                 child->thread.fpu.soft.fcr31 = data;
 314                         break;
 315                 case DSP_BASE ... DSP_BASE + 5:
 316                         if (!cpu_has_dsp) {
 317                                 ret = -EIO;
 318                                 break;
 319                         }
 320
 321                         dspreg_t *dregs = __get_dsp_regs(child);
 322                         dregs[addr - DSP_BASE] = data;
 323                         break;
 324                 case DSP_CONTROL:
 325                         if (!cpu_has_dsp) {
 326                                 ret = -EIO;
 327                                 break;
 328                         }
 329                         child->thread.dsp.dspcontrol = data;
 330                         break;
 331                 default:
 332                         /* The rest are not allowed. */
 333                         ret = -EIO;
 334                         break;
 335                 }
 336                 break;
 337                 }
 338
 339         case PTRACE_GETREGS:
 340                 ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
 341                 break;
 342
 343         case PTRACE_SETREGS:
 344                 ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
 345                 break;
 346
 347         case PTRACE_GETFPREGS:
 348                 ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
 349                 break;
 350
 351         case PTRACE_SETFPREGS:
 352                 ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
 353                 break;
 354
 355         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 356         case PTRACE_CONT: { /* restart after signal. */
 357                 ret = -EIO;
 358                 if (!valid_signal(data))
 359                         break;
 360                 if (request == PTRACE_SYSCALL) {
 361                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 362                 }
 363                 else {
 364                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 365                 }
 366                 child->exit_code = data;
 367                 wake_up_process(child);
 368                 ret = 0;
 369                 break;
 370         }
 371
 372         /*
 373          * make the child exit.  Best I can do is send it a sigkill.
 374          * perhaps it should be put in the status that it wants to
 375          * exit.
 376          */
 377         case PTRACE_KILL:
 378                 ret = 0;
 379                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 380                         break;
 381                 child->exit_code = SIGKILL;
 382                 wake_up_process(child);
 383                 break;
 384
 385         case PTRACE_GET_THREAD_AREA:
 386                 ret = put_user(child->thread_info->tp_value,
 387                                 (unsigned int __user *) (unsigned long) data);
 388                 break;
 389
 390         case PTRACE_DETACH: /* detach a process that was attached. */
 391                 ret = ptrace_detach(child, data);
 392                 break;
 393
 394         case PTRACE_GETEVENTMSG:
 395                 ret = put_user(child->ptrace_message,
 396                                (unsigned int __user *) (unsigned long) data);
 397                 break;
 398
 399         case PTRACE_GET_THREAD_AREA_3264:
 400                 ret = put_user(child->thread_info->tp_value,
 401                                 (unsigned long __user *) (unsigned long) data);
 402                 break;
 403
 404         default:
 405                 ret = ptrace_request(child, request, addr, data);
 406                 break;
 407         }
 408
 409 out_tsk:
 410         put_task_struct(child);
 411 out:
 412         unlock_kernel();
 413         return ret;
 414 }