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