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