arch/ppc64/kernel/ptrace32.c

   1 /*
   2  *  linux/arch/ppc64/kernel/ptrace32.c
   3  *
   4  *  PowerPC version
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *
   7  *  Derived from "arch/m68k/kernel/ptrace.c"
   8  *  Copyright (C) 1994 by Hamish Macdonald
   9  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
  10  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
  11  *
  12  * Modified by Cort Dougan (cort@hq.fsmlabs.com)
  13  * and Paul Mackerras (paulus@linuxcare.com.au).
  14  *
  15  * This file is subject to the terms and conditions of the GNU General
  16  * Public License.  See the file README.legal in the main directory of
  17  * this archive for more details.
  18  */
  19
  20 #include <linux/config.h>
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/mm.h>
  24 #include <linux/smp.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/errno.h>
  27 #include <linux/ptrace.h>
  28 #include <linux/user.h>
  29 #include <linux/security.h>
  30 #include <linux/signal.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <asm/page.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/system.h>
  36 #include <asm/ptrace-common.h>
  37
  38 /*
  39  * does not yet catch signals sent when the child dies.
  40  * in exit.c or in signal.c.
  41  */
  42
  43 int compat_sys_ptrace(long request, long pid, unsigned long addr, unsigned long data)
  44 {
  45         struct task_struct *child;
  46         int ret = -EPERM;
  47
  48         lock_kernel();
  49         if (request == PTRACE_TRACEME) {
  50                 /* are we already being traced? */
  51                 if (current->ptrace & PT_PTRACED)
  52                         goto out;
  53                 ret = security_ptrace(current->parent, current);
  54                 if (ret)
  55                         goto out;
  56                 /* set the ptrace bit in the process flags. */
  57                 current->ptrace |= PT_PTRACED;
  58                 ret = 0;
  59                 goto out;
  60         }
  61         ret = -ESRCH;
  62         read_lock(&tasklist_lock);
  63         child = find_task_by_pid(pid);
  64         if (child)
  65                 get_task_struct(child);
  66         read_unlock(&tasklist_lock);
  67         if (!child)
  68                 goto out;
  69
  70         ret = -EPERM;
  71         if (pid == 1)           /* you may not mess with init */
  72                 goto out_tsk;
  73
  74         if (request == PTRACE_ATTACH) {
  75                 ret = ptrace_attach(child);
  76                 goto out_tsk;
  77         }
  78
  79         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  80         if (ret < 0)
  81                 goto out_tsk;
  82
  83         switch (request) {
  84         /* when I and D space are separate, these will need to be fixed. */
  85         case PTRACE_PEEKTEXT: /* read word at location addr. */
  86         case PTRACE_PEEKDATA: {
  87                 unsigned int tmp;
  88                 int copied;
  89
  90                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
  91                 ret = -EIO;
  92                 if (copied != sizeof(tmp))
  93                         break;
  94                 ret = put_user(tmp, (u32 __user *)data);
  95                 break;
  96         }
  97
  98         /*
  99          * Read 4 bytes of the other process' storage
 100          *  data is a pointer specifying where the user wants the
 101          *      4 bytes copied into
 102          *  addr is a pointer in the user's storage that contains an 8 byte
 103          *      address in the other process of the 4 bytes that is to be read
 104          * (this is run in a 32-bit process looking at a 64-bit process)
 105          * when I and D space are separate, these will need to be fixed.
 106          */
 107         case PPC_PTRACE_PEEKTEXT_3264:
 108         case PPC_PTRACE_PEEKDATA_3264: {
 109                 u32 tmp;
 110                 int copied;
 111                 u32 __user * addrOthers;
 112
 113                 ret = -EIO;
 114
 115                 /* Get the addr in the other process that we want to read */
 116                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 117                         break;
 118
 119                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 120                                 sizeof(tmp), 0);
 121                 if (copied != sizeof(tmp))
 122                         break;
 123                 ret = put_user(tmp, (u32 __user *)data);
 124                 break;
 125         }
 126
 127         /* Read a register (specified by ADDR) out of the "user area" */
 128         case PTRACE_PEEKUSR: {
 129                 int index;
 130                 unsigned long tmp;
 131
 132                 ret = -EIO;
 133                 /* convert to index and check */
 134                 index = (unsigned long) addr >> 2;
 135                 if ((addr & 3) || (index > PT_FPSCR32))
 136                         break;
 137
 138                 if (index < PT_FPR0) {
 139                         tmp = get_reg(child, index);
 140                 } else {
 141                         flush_fp_to_thread(child);
 142                         /*
 143                          * the user space code considers the floating point
 144                          * to be an array of unsigned int (32 bits) - the
 145                          * index passed in is based on this assumption.
 146                          */
 147                         tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
 148                 }
 149                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 150                 break;
 151         }
 152
 153         /*
 154          * Read 4 bytes out of the other process' pt_regs area
 155          *  data is a pointer specifying where the user wants the
 156          *      4 bytes copied into
 157          *  addr is the offset into the other process' pt_regs structure
 158          *      that is to be read
 159          * (this is run in a 32-bit process looking at a 64-bit process)
 160          */
 161         case PPC_PTRACE_PEEKUSR_3264: {
 162                 u32 index;
 163                 u32 reg32bits;
 164                 u64 tmp;
 165                 u32 numReg;
 166                 u32 part;
 167
 168                 ret = -EIO;
 169                 /* Determine which register the user wants */
 170                 index = (u64)addr >> 2;
 171                 numReg = index / 2;
 172                 /* Determine which part of the register the user wants */
 173                 if (index % 2)
 174                         part = 1;  /* want the 2nd half of the register (right-most). */
 175                 else
 176                         part = 0;  /* want the 1st half of the register (left-most). */
 177
 178                 /* Validate the input - check to see if address is on the wrong boundary or beyond the end of the user area */
 179                 if ((addr & 3) || numReg > PT_FPSCR)
 180                         break;
 181
 182                 if (numReg >= PT_FPR0) {
 183                         flush_fp_to_thread(child);
 184                         tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
 185                 } else { /* register within PT_REGS struct */
 186                         tmp = get_reg(child, numReg);
 187                 }
 188                 reg32bits = ((u32*)&tmp)[part];
 189                 ret = put_user(reg32bits, (u32 __user *)data);
 190                 break;
 191         }
 192
 193         /* If I and D space are separate, this will have to be fixed. */
 194         case PTRACE_POKETEXT: /* write the word at location addr. */
 195         case PTRACE_POKEDATA: {
 196                 unsigned int tmp;
 197                 tmp = data;
 198                 ret = 0;
 199                 if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1)
 200                                 == sizeof(tmp))
 201                         break;
 202                 ret = -EIO;
 203                 break;
 204         }
 205
 206         /*
 207          * Write 4 bytes into the other process' storage
 208          *  data is the 4 bytes that the user wants written
 209          *  addr is a pointer in the user's storage that contains an
 210          *      8 byte address in the other process where the 4 bytes
 211          *      that is to be written
 212          * (this is run in a 32-bit process looking at a 64-bit process)
 213          * when I and D space are separate, these will need to be fixed.
 214          */
 215         case PPC_PTRACE_POKETEXT_3264:
 216         case PPC_PTRACE_POKEDATA_3264: {
 217                 u32 tmp = data;
 218                 u32 __user * addrOthers;
 219
 220                 /* Get the addr in the other process that we want to write into */
 221                 ret = -EIO;
 222                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 223                         break;
 224                 ret = 0;
 225                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 226                                         sizeof(tmp), 1) == sizeof(tmp))
 227                         break;
 228                 ret = -EIO;
 229                 break;
 230         }
 231
 232         /* write the word at location addr in the USER area */
 233         case PTRACE_POKEUSR: {
 234                 unsigned long index;
 235
 236                 ret = -EIO;
 237                 /* convert to index and check */
 238                 index = (unsigned long) addr >> 2;
 239                 if ((addr & 3) || (index > PT_FPSCR32))
 240                         break;
 241
 242                 if (index == PT_ORIG_R3)
 243                         break;
 244                 if (index < PT_FPR0) {
 245                         ret = put_reg(child, index, data);
 246                 } else {
 247                         flush_fp_to_thread(child);
 248                         /*
 249                          * the user space code considers the floating point
 250                          * to be an array of unsigned int (32 bits) - the
 251                          * index passed in is based on this assumption.
 252                          */
 253                         ((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
 254                         ret = 0;
 255                 }
 256                 break;
 257         }
 258
 259         /*
 260          * Write 4 bytes into the other process' pt_regs area
 261          *  data is the 4 bytes that the user wants written
 262          *  addr is the offset into the other process' pt_regs structure
 263          *      that is to be written into
 264          * (this is run in a 32-bit process looking at a 64-bit process)
 265          */
 266         case PPC_PTRACE_POKEUSR_3264: {
 267                 u32 index;
 268                 u32 numReg;
 269
 270                 ret = -EIO;
 271                 /* Determine which register the user wants */
 272                 index = (u64)addr >> 2;
 273                 numReg = index / 2;
 274                 /*
 275                  * Validate the input - check to see if address is on the
 276                  * wrong boundary or beyond the end of the user area
 277                  */
 278                 if ((addr & 3) || (numReg > PT_FPSCR))
 279                         break;
 280                 /* Insure it is a register we let them change */
 281                 if ((numReg == PT_ORIG_R3)
 282                                 || ((numReg > PT_CCR) && (numReg < PT_FPR0)))
 283                         break;
 284                 if (numReg >= PT_FPR0) {
 285                         flush_fp_to_thread(child);
 286                 }
 287                 if (numReg == PT_MSR)
 288                         data = (data & MSR_DEBUGCHANGE)
 289                                 | (child->thread.regs->msr & ~MSR_DEBUGCHANGE);
 290                 ((u32*)child->thread.regs)[index] = data;
 291                 ret = 0;
 292                 break;
 293         }
 294
 295         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 296         case PTRACE_CONT: { /* restart after signal. */
 297                 ret = -EIO;
 298                 if (!valid_signal(data))
 299                         break;
 300                 if (request == PTRACE_SYSCALL)
 301                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 302                 else
 303                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 304                 child->exit_code = data;
 305                 /* make sure the single step bit is not set. */
 306                 clear_single_step(child);
 307                 wake_up_process(child);
 308                 ret = 0;
 309                 break;
 310         }
 311
 312         /*
 313          * make the child exit.  Best I can do is send it a sigkill.
 314          * perhaps it should be put in the status that it wants to
 315          * exit.
 316          */
 317         case PTRACE_KILL: {
 318                 ret = 0;
 319                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 320                         break;
 321                 child->exit_code = SIGKILL;
 322                 /* make sure the single step bit is not set. */
 323                 clear_single_step(child);
 324                 wake_up_process(child);
 325                 break;
 326         }
 327
 328         case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 329                 ret = -EIO;
 330                 if (!valid_signal(data))
 331                         break;
 332                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 333                 set_single_step(child);
 334                 child->exit_code = data;
 335                 /* give it a chance to run. */
 336                 wake_up_process(child);
 337                 ret = 0;
 338                 break;
 339         }
 340
 341         case PTRACE_GET_DEBUGREG: {
 342                 ret = -EINVAL;
 343                 /* We only support one DABR and no IABRS at the moment */
 344                 if (addr > 0)
 345                         break;
 346                 ret = put_user(child->thread.dabr, (u32 __user *)data);
 347                 break;
 348         }
 349
 350         case PTRACE_SET_DEBUGREG:
 351                 ret = ptrace_set_debugreg(child, addr, data);
 352                 break;
 353
 354         case PTRACE_DETACH:
 355                 ret = ptrace_detach(child, data);
 356                 break;
 357
 358         case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
 359                 int i;
 360                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
 361                 unsigned int __user *tmp = (unsigned int __user *)addr;
 362
 363                 for (i = 0; i < 32; i++) {
 364                         ret = put_user(*reg, tmp);
 365                         if (ret)
 366                                 break;
 367                         reg++;
 368                         tmp++;
 369                 }
 370                 break;
 371         }
 372
 373         case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
 374                 int i;
 375                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
 376                 unsigned int __user *tmp = (unsigned int __user *)addr;
 377
 378                 for (i = 0; i < 32; i++) {
 379                         ret = get_user(*reg, tmp);
 380                         if (ret)
 381                                 break;
 382                         reg++;
 383                         tmp++;
 384                 }
 385                 break;
 386         }
 387
 388         case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
 389                 int i;
 390                 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
 391                 unsigned int __user *tmp = (unsigned int __user *)addr;
 392
 393                 flush_fp_to_thread(child);
 394
 395                 for (i = 0; i < 32; i++) {
 396                         ret = put_user(*reg, tmp);
 397                         if (ret)
 398                                 break;
 399                         reg++;
 400                         tmp++;
 401                 }
 402                 break;
 403         }
 404
 405         case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
 406                 int i;
 407                 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
 408                 unsigned int __user *tmp = (unsigned int __user *)addr;
 409
 410                 flush_fp_to_thread(child);
 411
 412                 for (i = 0; i < 32; i++) {
 413                         ret = get_user(*reg, tmp);
 414                         if (ret)
 415                                 break;
 416                         reg++;
 417                         tmp++;
 418                 }
 419                 break;
 420         }
 421
 422         case PTRACE_GETEVENTMSG:
 423                 ret = put_user(child->ptrace_message, (unsigned int __user *) data);
 424                 break;
 425
 426 #ifdef CONFIG_ALTIVEC
 427         case PTRACE_GETVRREGS:
 428                 /* Get the child altivec register state. */
 429                 flush_altivec_to_thread(child);
 430                 ret = get_vrregs((unsigned long __user *)data, child);
 431                 break;
 432
 433         case PTRACE_SETVRREGS:
 434                 /* Set the child altivec register state. */
 435                 flush_altivec_to_thread(child);
 436                 ret = set_vrregs(child, (unsigned long __user *)data);
 437                 break;
 438 #endif
 439
 440         default:
 441                 ret = ptrace_request(child, request, addr, data);
 442                 break;
 443         }
 444 out_tsk:
 445         put_task_struct(child);
 446 out:
 447         unlock_kernel();
 448         return ret;
 449 }