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                         preempt_disable();
 179                         if (!cpu_has_fpu) {
 180                                 preempt_enable();
 181                                 tmp = 0;
 182                                 break;
 183                         }
 184
 185 #ifdef CONFIG_MIPS_MT_SMTC
 186                         /* Read-modify-write of Status must be atomic */
 187                         local_irq_save(irqflags);
 188                         mtflags = dmt();
 189 #endif /* CONFIG_MIPS_MT_SMTC */
 190
 191                         if (cpu_has_mipsmt) {
 192                                 unsigned int vpflags = dvpe();
 193                                 flags = read_c0_status();
 194                                 __enable_fpu();
 195                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 196                                 write_c0_status(flags);
 197                                 evpe(vpflags);
 198                         } else {
 199                                 flags = read_c0_status();
 200                                 __enable_fpu();
 201                                 __asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
 202                                 write_c0_status(flags);
 203                         }
 204 #ifdef CONFIG_MIPS_MT_SMTC
 205                         emt(mtflags);
 206                         local_irq_restore(irqflags);
 207 #endif /* CONFIG_MIPS_MT_SMTC */
 208                         preempt_enable();
 209                         break;
 210                 }
 211                 case DSP_BASE ... DSP_BASE + 5: {
 212                         dspreg_t *dregs;
 213
 214                         if (!cpu_has_dsp) {
 215                                 tmp = 0;
 216                                 ret = -EIO;
 217                                 goto out_tsk;
 218                         }
 219                         dregs = __get_dsp_regs(child);
 220                         tmp = (unsigned long) (dregs[addr - DSP_BASE]);
 221                         break;
 222                 }
 223                 case DSP_CONTROL:
 224                         if (!cpu_has_dsp) {
 225                                 tmp = 0;
 226                                 ret = -EIO;
 227                                 goto out_tsk;
 228                         }
 229                         tmp = child->thread.dsp.dspcontrol;
 230                         break;
 231                 default:
 232                         tmp = 0;
 233                         ret = -EIO;
 234                         goto out_tsk;
 235                 }
 236                 ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
 237                 break;
 238         }
 239
 240         /* when I and D space are separate, this will have to be fixed. */
 241         case PTRACE_POKETEXT: /* write the word at location addr. */
 242         case PTRACE_POKEDATA:
 243                 ret = 0;
 244                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
 245                     == sizeof(data))
 246                         break;
 247                 ret = -EIO;
 248                 break;
 249
 250         /*
 251          * Write 4 bytes into the other process' storage
 252          *  data is the 4 bytes that the user wants written
 253          *  addr is a pointer in the user's storage that contains an
 254          *      8 byte address in the other process where the 4 bytes
 255          *      that is to be written
 256          * (this is run in a 32-bit process looking at a 64-bit process)
 257          * when I and D space are separate, these will need to be fixed.
 258          */
 259         case PTRACE_POKETEXT_3264:
 260         case PTRACE_POKEDATA_3264: {
 261                 u32 __user * addrOthers;
 262
 263                 /* Get the addr in the other process that we want to write into */
 264                 ret = -EIO;
 265                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 266                         break;
 267                 ret = 0;
 268                 if (access_process_vm(child, (u64)addrOthers, &data,
 269                                         sizeof(data), 1) == sizeof(data))
 270                         break;
 271                 ret = -EIO;
 272                 break;
 273         }
 274
 275         case PTRACE_POKEUSR: {
 276                 struct pt_regs *regs;
 277                 ret = 0;
 278                 regs = task_pt_regs(child);
 279
 280                 switch (addr) {
 281                 case 0 ... 31:
 282                         regs->regs[addr] = data;
 283                         break;
 284                 case FPR_BASE ... FPR_BASE + 31: {
 285                         fpureg_t *fregs = get_fpu_regs(child);
 286
 287                         if (!tsk_used_math(child)) {
 288                                 /* FP not yet used  */
 289                                 memset(&child->thread.fpu, ~0,
 290                                        sizeof(child->thread.fpu));
 291                                 child->thread.fpu.fcr31 = 0;
 292                         }
 293                         /*
 294                          * The odd registers are actually the high order bits
 295                          * of the values stored in the even registers - unless
 296                          * we're using r2k_switch.S.
 297                          */
 298                         if (addr & 1) {
 299                                 fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
 300                                 fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
 301                         } else {
 302                                 fregs[addr - FPR_BASE] &= ~0xffffffffLL;
 303                                 /* Must cast, lest sign extension fill upper
 304                                    bits!  */
 305                                 fregs[addr - FPR_BASE] |= (unsigned int)data;
 306                         }
 307                         break;
 308                 }
 309                 case PC:
 310                         regs->cp0_epc = data;
 311                         break;
 312                 case MMHI:
 313                         regs->hi = data;
 314                         break;
 315                 case MMLO:
 316                         regs->lo = data;
 317                         break;
 318                 case FPC_CSR:
 319                         child->thread.fpu.fcr31 = data;
 320                         break;
 321                 case DSP_BASE ... DSP_BASE + 5: {
 322                         dspreg_t *dregs;
 323
 324                         if (!cpu_has_dsp) {
 325                                 ret = -EIO;
 326                                 break;
 327                         }
 328
 329                         dregs = __get_dsp_regs(child);
 330                         dregs[addr - DSP_BASE] = data;
 331                         break;
 332                 }
 333                 case DSP_CONTROL:
 334                         if (!cpu_has_dsp) {
 335                                 ret = -EIO;
 336                                 break;
 337                         }
 338                         child->thread.dsp.dspcontrol = data;
 339                         break;
 340                 default:
 341                         /* The rest are not allowed. */
 342                         ret = -EIO;
 343                         break;
 344                 }
 345                 break;
 346                 }
 347
 348         case PTRACE_GETREGS:
 349                 ret = ptrace_getregs(child, (__u64 __user *) (__u64) data);
 350                 break;
 351
 352         case PTRACE_SETREGS:
 353                 ret = ptrace_setregs(child, (__u64 __user *) (__u64) data);
 354                 break;
 355
 356         case PTRACE_GETFPREGS:
 357                 ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
 358                 break;
 359
 360         case PTRACE_SETFPREGS:
 361                 ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
 362                 break;
 363
 364         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 365         case PTRACE_CONT: { /* restart after signal. */
 366                 ret = -EIO;
 367                 if (!valid_signal(data))
 368                         break;
 369                 if (request == PTRACE_SYSCALL) {
 370                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 371                 }
 372                 else {
 373                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 374                 }
 375                 child->exit_code = data;
 376                 wake_up_process(child);
 377                 ret = 0;
 378                 break;
 379         }
 380
 381         /*
 382          * make the child exit.  Best I can do is send it a sigkill.
 383          * perhaps it should be put in the status that it wants to
 384          * exit.
 385          */
 386         case PTRACE_KILL:
 387                 ret = 0;
 388                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 389                         break;
 390                 child->exit_code = SIGKILL;
 391                 wake_up_process(child);
 392                 break;
 393
 394         case PTRACE_GET_THREAD_AREA:
 395                 ret = put_user(task_thread_info(child)->tp_value,
 396                                 (unsigned int __user *) (unsigned long) data);
 397                 break;
 398
 399         case PTRACE_DETACH: /* detach a process that was attached. */
 400                 ret = ptrace_detach(child, data);
 401                 break;
 402
 403         case PTRACE_GETEVENTMSG:
 404                 ret = put_user(child->ptrace_message,
 405                                (unsigned int __user *) (unsigned long) data);
 406                 break;
 407
 408         case PTRACE_GET_THREAD_AREA_3264:
 409                 ret = put_user(task_thread_info(child)->tp_value,
 410                                 (unsigned long __user *) (unsigned long) data);
 411                 break;
 412
 413         default:
 414                 ret = ptrace_request(child, request, addr, data);
 415                 break;
 416         }
 417
 418 out_tsk:
 419         put_task_struct(child);
 420 out:
 421         unlock_kernel();
 422         return ret;
 423 }