arch/powerpc/kernel/ptrace32.c

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