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 __user *) (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 = task_pt_regs(child);
 130                 ret = 0;  /* Default return value. */
 131
 132                 switch (addr) {
 133                 case 0 ... 31:
 134                         tmp = regs->regs[addr];
 135                         break;
 136                 case FPR_BASE ... FPR_BASE + 31:
 137                         if (tsk_used_math(child)) {
 138                                 fpureg_t *fregs = get_fpu_regs(child);
 139
 140                                 /*
 141                                  * The odd registers are actually the high
 142                                  * order bits of the values stored in the even
 143                                  * registers - unless we're using r2k_switch.S.
 144                                  */
 145                                 if (addr & 1)
 146                                         tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
 147                                 else
 148                                         tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
 149                         } else {
 150                                 tmp = -1;       /* FP not yet used  */
 151                         }
 152                         break;
 153                 case PC:
 154                         tmp = regs->cp0_epc;
 155                         break;
 156                 case CAUSE:
 157                         tmp = regs->cp0_cause;
 158                         break;
 159                 case BADVADDR:
 160                         tmp = regs->cp0_badvaddr;
 161                         break;
 162                 case MMHI:
 163                         tmp = regs->hi;
 164                         break;
 165                 case MMLO:
 166                         tmp = regs->lo;
 167                         break;
 168                 case FPC_CSR:
 169                         tmp = child->thread.fpu.fcr31;
 170                         break;
 171                 case FPC_EIR: { /* implementation / version register */
 172                         unsigned int flags;
 173 #ifdef CONFIG_MIPS_MT_SMTC
 174                         unsigned int irqflags;
 175                         unsigned int mtflags;
 176 #endif /* CONFIG_MIPS_MT_SMTC */
 177
 178                         if (!cpu_has_fpu) {
 179                                 tmp = 0;
 180                                 break;
 181                         }
 182
 183 #ifdef CONFIG_MIPS_MT_SMTC
 184                         /* Read-modify-write of Status must be atomic */
 185                         local_irq_save(irqflags);
 186                         mtflags = dmt();
 187 #endif /* CONFIG_MIPS_MT_SMTC */
 188
 189                         preempt_disable();
 190                         if (cpu_has_mipsmt) {
 191                                 unsigned int vpflags = dvpe();
 192                                 flags = read_c0_status();
 193                                 __enable_fpu();
 194                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 195                                 write_c0_status(flags);
 196                                 evpe(vpflags);
 197                         } else {
 198                                 flags = read_c0_status();
 199                                 __enable_fpu();
 200                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 201                                 write_c0_status(flags);
 202                         }
 203 #ifdef CONFIG_MIPS_MT_SMTC
 204                         emt(mtflags);
 205                         local_irq_restore(irqflags);
 206 #endif /* CONFIG_MIPS_MT_SMTC */
 207                         preempt_enable();
 208                         break;
 209                 }
 210                 case DSP_BASE ... DSP_BASE + 5: {
 211                         dspreg_t *dregs;
 212
 213                         if (!cpu_has_dsp) {
 214                                 tmp = 0;
 215                                 ret = -EIO;
 216                                 goto out_tsk;
 217                         }
 218                         dregs = __get_dsp_regs(child);
 219                         tmp = (unsigned long) (dregs[addr - DSP_BASE]);
 220                         break;
 221                 }
 222                 case DSP_CONTROL:
 223                         if (!cpu_has_dsp) {
 224                                 tmp = 0;
 225                                 ret = -EIO;
 226                                 goto out_tsk;
 227                         }
 228                         tmp = child->thread.dsp.dspcontrol;
 229                         break;
 230                 default:
 231                         tmp = 0;
 232                         ret = -EIO;
 233                         goto out_tsk;
 234                 }
 235                 ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
 236                 break;
 237         }
 238
 239         /* when I and D space are separate, this will have to be fixed. */
 240         case PTRACE_POKETEXT: /* write the word at location addr. */
 241         case PTRACE_POKEDATA:
 242                 ret = 0;
 243                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
 244                     == sizeof(data))
 245                         break;
 246                 ret = -EIO;
 247                 break;
 248
 249         /*
 250          * Write 4 bytes into the other process' storage
 251          *  data is the 4 bytes that the user wants written
 252          *  addr is a pointer in the user's storage that contains an
 253          *      8 byte address in the other process where the 4 bytes
 254          *      that is to be written
 255          * (this is run in a 32-bit process looking at a 64-bit process)
 256          * when I and D space are separate, these will need to be fixed.
 257          */
 258         case PTRACE_POKETEXT_3264:
 259         case PTRACE_POKEDATA_3264: {
 260                 u32 __user * addrOthers;
 261
 262                 /* Get the addr in the other process that we want to write into */
 263                 ret = -EIO;
 264                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 265                         break;
 266                 ret = 0;
 267                 if (access_process_vm(child, (u64)addrOthers, &data,
 268                                         sizeof(data), 1) == sizeof(data))
 269                         break;
 270                 ret = -EIO;
 271                 break;
 272         }
 273
 274         case PTRACE_POKEUSR: {
 275                 struct pt_regs *regs;
 276                 ret = 0;
 277                 regs = task_pt_regs(child);
 278
 279                 switch (addr) {
 280                 case 0 ... 31:
 281                         regs->regs[addr] = data;
 282                         break;
 283                 case FPR_BASE ... FPR_BASE + 31: {
 284                         fpureg_t *fregs = get_fpu_regs(child);
 285
 286                         if (!tsk_used_math(child)) {
 287                                 /* FP not yet used  */
 288                                 memset(&child->thread.fpu, ~0,
 289                                        sizeof(child->thread.fpu));
 290                                 child->thread.fpu.fcr31 = 0;
 291                         }
 292                         /*
 293                          * The odd registers are actually the high order bits
 294                          * of the values stored in the even registers - unless
 295                          * we're using r2k_switch.S.
 296                          */
 297                         if (addr & 1) {
 298                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
 299                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
 300                         } else {
 301                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
 302                                 /* Must cast, lest sign extension fill upper
 303                                    bits!  */
 304                                 fregs[addr - FPR_BASE] |= (unsigned int)data;
 305                         }
 306                         break;
 307                 }
 308                 case PC:
 309                         regs->cp0_epc = data;
 310                         break;
 311                 case MMHI:
 312                         regs->hi = data;
 313                         break;
 314                 case MMLO:
 315                         regs->lo = data;
 316                         break;
 317                 case FPC_CSR:
 318                         child->thread.fpu.fcr31 = data;
 319                         break;
 320                 case DSP_BASE ... DSP_BASE + 5: {
 321                         dspreg_t *dregs;
 322
 323                         if (!cpu_has_dsp) {
 324                                 ret = -EIO;
 325                                 break;
 326                         }
 327
 328                         dregs = __get_dsp_regs(child);
 329                         dregs[addr - DSP_BASE] = data;
 330                         break;
 331                 }
 332                 case DSP_CONTROL:
 333                         if (!cpu_has_dsp) {
 334                                 ret = -EIO;
 335                                 break;
 336                         }
 337                         child->thread.dsp.dspcontrol = data;
 338                         break;
 339                 default:
 340                         /* The rest are not allowed. */
 341                         ret = -EIO;
 342                         break;
 343                 }
 344                 break;
 345                 }
 346
 347         case PTRACE_GETREGS:
 348                 ret = ptrace_getregs (child, (__u64 __user *) (__u64) data);
 349                 break;
 350
 351         case PTRACE_SETREGS:
 352                 ret = ptrace_setregs (child, (__u64 __user *) (__u64) data);
 353                 break;
 354
 355         case PTRACE_GETFPREGS:
 356                 ret = ptrace_getfpregs (child, (__u32 __user *) (__u64) data);
 357                 break;
 358
 359         case PTRACE_SETFPREGS:
 360                 ret = ptrace_setfpregs (child, (__u32 __user *) (__u64) data);
 361                 break;
 362
 363         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 364         case PTRACE_CONT: { /* restart after signal. */
 365                 ret = -EIO;
 366                 if (!valid_signal(data))
 367                         break;
 368                 if (request == PTRACE_SYSCALL) {
 369                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 370                 }
 371                 else {
 372                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 373                 }
 374                 child->exit_code = data;
 375                 wake_up_process(child);
 376                 ret = 0;
 377                 break;
 378         }
 379
 380         /*
 381          * make the child exit.  Best I can do is send it a sigkill.
 382          * perhaps it should be put in the status that it wants to
 383          * exit.
 384          */
 385         case PTRACE_KILL:
 386                 ret = 0;
 387                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 388                         break;
 389                 child->exit_code = SIGKILL;
 390                 wake_up_process(child);
 391                 break;
 392
 393         case PTRACE_GET_THREAD_AREA:
 394                 ret = put_user(task_thread_info(child)->tp_value,
 395                                 (unsigned int __user *) (unsigned long) data);
 396                 break;
 397
 398         case PTRACE_DETACH: /* detach a process that was attached. */
 399                 ret = ptrace_detach(child, data);
 400                 break;
 401
 402         case PTRACE_GETEVENTMSG:
 403                 ret = put_user(child->ptrace_message,
 404                                (unsigned int __user *) (unsigned long) data);
 405                 break;
 406
 407         case PTRACE_GET_THREAD_AREA_3264:
 408                 ret = put_user(task_thread_info(child)->tp_value,
 409                                 (unsigned long __user *) (unsigned long) data);
 410                 break;
 411
 412         default:
 413                 ret = ptrace_request(child, request, addr, data);
 414                 break;
 415         }
 416
 417 out_tsk:
 418         put_task_struct(child);
 419 out:
 420         unlock_kernel();
 421         return ret;
 422 }