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/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
  30 #include <asm/uaccess.h>
  31 #include <asm/page.h>
  32 #include <asm/pgtable.h>
  33 #include <asm/system.h>
  34 #include <asm/ptrace-common.h>
  35
  36 /*
  37  * does not yet catch signals sent when the child dies.
  38  * in exit.c or in signal.c.
  39  */
  40
  41 int sys32_ptrace(long request, long pid, unsigned long addr, unsigned long data)
  42 {
  43         struct task_struct *child;
  44         int ret = -EPERM;
  45
  46         lock_kernel();
  47         if (request == PTRACE_TRACEME) {
  48                 /* are we already being traced? */
  49                 if (current->ptrace & PT_PTRACED)
  50                         goto out;
  51                 ret = security_ptrace(current->parent, current);
  52                 if (ret)
  53                         goto out;
  54                 /* set the ptrace bit in the process flags. */
  55                 current->ptrace |= PT_PTRACED;
  56                 ret = 0;
  57                 goto out;
  58         }
  59         ret = -ESRCH;
  60         read_lock(&tasklist_lock);
  61         child = find_task_by_pid(pid);
  62         if (child)
  63                 get_task_struct(child);
  64         read_unlock(&tasklist_lock);
  65         if (!child)
  66                 goto out;
  67
  68         ret = -EPERM;
  69         if (pid == 1)           /* you may not mess with init */
  70                 goto out_tsk;
  71
  72         if (request == PTRACE_ATTACH) {
  73                 ret = ptrace_attach(child);
  74                 goto out_tsk;
  75         }
  76
  77         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  78         if (ret < 0)
  79                 goto out_tsk;
  80
  81         switch (request) {
  82         /* when I and D space are separate, these will need to be fixed. */
  83         case PTRACE_PEEKTEXT: /* read word at location addr. */
  84         case PTRACE_PEEKDATA: {
  85                 unsigned int tmp;
  86                 int copied;
  87
  88                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
  89                 ret = -EIO;
  90                 if (copied != sizeof(tmp))
  91                         break;
  92                 ret = put_user(tmp, (u32 __user *)data);
  93                 break;
  94         }
  95
  96         /*
  97          * Read 4 bytes of the other process' storage
  98          *  data is a pointer specifying where the user wants the
  99          *      4 bytes copied into
 100          *  addr is a pointer in the user's storage that contains an 8 byte
 101          *      address in the other process of the 4 bytes that is to be read
 102          * (this is run in a 32-bit process looking at a 64-bit process)
 103          * when I and D space are separate, these will need to be fixed.
 104          */
 105         case PPC_PTRACE_PEEKTEXT_3264:
 106         case PPC_PTRACE_PEEKDATA_3264: {
 107                 u32 tmp;
 108                 int copied;
 109                 u32 __user * addrOthers;
 110
 111                 ret = -EIO;
 112
 113                 /* Get the addr in the other process that we want to read */
 114                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 115                         break;
 116
 117                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 118                                 sizeof(tmp), 0);
 119                 if (copied != sizeof(tmp))
 120                         break;
 121                 ret = put_user(tmp, (u32 __user *)data);
 122                 break;
 123         }
 124
 125         /* Read a register (specified by ADDR) out of the "user area" */
 126         case PTRACE_PEEKUSR: {
 127                 int index;
 128                 unsigned long tmp;
 129
 130                 ret = -EIO;
 131                 /* convert to index and check */
 132                 index = (unsigned long) addr >> 2;
 133                 if ((addr & 3) || (index > PT_FPSCR32))
 134                         break;
 135
 136                 if (index < PT_FPR0) {
 137                         tmp = get_reg(child, index);
 138                 } else {
 139                         flush_fp_to_thread(child);
 140                         /*
 141                          * the user space code considers the floating point
 142                          * to be an array of unsigned int (32 bits) - the
 143                          * index passed in is based on this assumption.
 144                          */
 145                         tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
 146                 }
 147                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 148                 break;
 149         }
 150
 151         /*
 152          * Read 4 bytes out of the other process' pt_regs area
 153          *  data is a pointer specifying where the user wants the
 154          *      4 bytes copied into
 155          *  addr is the offset into the other process' pt_regs structure
 156          *      that is to be read
 157          * (this is run in a 32-bit process looking at a 64-bit process)
 158          */
 159         case PPC_PTRACE_PEEKUSR_3264: {
 160                 u32 index;
 161                 u32 reg32bits;
 162                 u64 tmp;
 163                 u32 numReg;
 164                 u32 part;
 165
 166                 ret = -EIO;
 167                 /* Determine which register the user wants */
 168                 index = (u64)addr >> 2;
 169                 numReg = index / 2;
 170                 /* Determine which part of the register the user wants */
 171                 if (index % 2)
 172                         part = 1;  /* want the 2nd half of the register (right-most). */
 173                 else
 174                         part = 0;  /* want the 1st half of the register (left-most). */
 175
 176                 /* Validate the input - check to see if address is on the wrong boundary or beyond the end of the user area */
 177                 if ((addr & 3) || numReg > PT_FPSCR)
 178                         break;
 179
 180                 if (numReg >= PT_FPR0) {
 181                         flush_fp_to_thread(child);
 182                         tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
 183                 } else { /* register within PT_REGS struct */
 184                         tmp = get_reg(child, numReg);
 185                 }
 186                 reg32bits = ((u32*)&tmp)[part];
 187                 ret = put_user(reg32bits, (u32 __user *)data);
 188                 break;
 189         }
 190
 191         /* If I and D space are separate, this will have to be fixed. */
 192         case PTRACE_POKETEXT: /* write the word at location addr. */
 193         case PTRACE_POKEDATA: {
 194                 unsigned int tmp;
 195                 tmp = data;
 196                 ret = 0;
 197                 if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1)
 198                                 == sizeof(tmp))
 199                         break;
 200                 ret = -EIO;
 201                 break;
 202         }
 203
 204         /*
 205          * Write 4 bytes into the other process' storage
 206          *  data is the 4 bytes that the user wants written
 207          *  addr is a pointer in the user's storage that contains an
 208          *      8 byte address in the other process where the 4 bytes
 209          *      that is to be written
 210          * (this is run in a 32-bit process looking at a 64-bit process)
 211          * when I and D space are separate, these will need to be fixed.
 212          */
 213         case PPC_PTRACE_POKETEXT_3264:
 214         case PPC_PTRACE_POKEDATA_3264: {
 215                 u32 tmp = data;
 216                 u32 __user * addrOthers;
 217
 218                 /* Get the addr in the other process that we want to write into */
 219                 ret = -EIO;
 220                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 221                         break;
 222                 ret = 0;
 223                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 224                                         sizeof(tmp), 1) == sizeof(tmp))
 225                         break;
 226                 ret = -EIO;
 227                 break;
 228         }
 229
 230         /* write the word at location addr in the USER area */
 231         case PTRACE_POKEUSR: {
 232                 unsigned long index;
 233
 234                 ret = -EIO;
 235                 /* convert to index and check */
 236                 index = (unsigned long) addr >> 2;
 237                 if ((addr & 3) || (index > PT_FPSCR32))
 238                         break;
 239
 240                 if (index == PT_ORIG_R3)
 241                         break;
 242                 if (index < PT_FPR0) {
 243                         ret = put_reg(child, index, data);
 244                 } else {
 245                         flush_fp_to_thread(child);
 246                         /*
 247                          * the user space code considers the floating point
 248                          * to be an array of unsigned int (32 bits) - the
 249                          * index passed in is based on this assumption.
 250                          */
 251                         ((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
 252                         ret = 0;
 253                 }
 254                 break;
 255         }
 256
 257         /*
 258          * Write 4 bytes into the other process' pt_regs area
 259          *  data is the 4 bytes that the user wants written
 260          *  addr is the offset into the other process' pt_regs structure
 261          *      that is to be written into
 262          * (this is run in a 32-bit process looking at a 64-bit process)
 263          */
 264         case PPC_PTRACE_POKEUSR_3264: {
 265                 u32 index;
 266                 u32 numReg;
 267
 268                 ret = -EIO;
 269                 /* Determine which register the user wants */
 270                 index = (u64)addr >> 2;
 271                 numReg = index / 2;
 272                 /*
 273                  * Validate the input - check to see if address is on the
 274                  * wrong boundary or beyond the end of the user area
 275                  */
 276                 if ((addr & 3) || (numReg > PT_FPSCR))
 277                         break;
 278                 /* Insure it is a register we let them change */
 279                 if ((numReg == PT_ORIG_R3)
 280                                 || ((numReg > PT_CCR) && (numReg < PT_FPR0)))
 281                         break;
 282                 if (numReg >= PT_FPR0) {
 283                         flush_fp_to_thread(child);
 284                 }
 285                 if (numReg == PT_MSR)
 286                         data = (data & MSR_DEBUGCHANGE)
 287                                 | (child->thread.regs->msr & ~MSR_DEBUGCHANGE);
 288                 ((u32*)child->thread.regs)[index] = data;
 289                 ret = 0;
 290                 break;
 291         }
 292
 293         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 294         case PTRACE_CONT: { /* restart after signal. */
 295                 ret = -EIO;
 296                 if ((unsigned long) data > _NSIG)
 297                         break;
 298                 if (request == PTRACE_SYSCALL)
 299                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 300                 else
 301                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 302                 child->exit_code = data;
 303                 /* make sure the single step bit is not set. */
 304                 clear_single_step(child);
 305                 wake_up_process(child);
 306                 ret = 0;
 307                 break;
 308         }
 309
 310         /*
 311          * make the child exit.  Best I can do is send it a sigkill.
 312          * perhaps it should be put in the status that it wants to
 313          * exit.
 314          */
 315         case PTRACE_KILL: {
 316                 ret = 0;
 317                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 318                         break;
 319                 child->exit_code = SIGKILL;
 320                 /* make sure the single step bit is not set. */
 321                 clear_single_step(child);
 322                 wake_up_process(child);
 323                 break;
 324         }
 325
 326         case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 327                 ret = -EIO;
 328                 if ((unsigned long) data > _NSIG)
 329                         break;
 330                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 331                 set_single_step(child);
 332                 child->exit_code = data;
 333                 /* give it a chance to run. */
 334                 wake_up_process(child);
 335                 ret = 0;
 336                 break;
 337         }
 338
 339         case PTRACE_DETACH:
 340                 ret = ptrace_detach(child, data);
 341                 break;
 342
 343         case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
 344                 int i;
 345                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
 346                 unsigned int __user *tmp = (unsigned int __user *)addr;
 347
 348                 for (i = 0; i < 32; i++) {
 349                         ret = put_user(*reg, tmp);
 350                         if (ret)
 351                                 break;
 352                         reg++;
 353                         tmp++;
 354                 }
 355                 break;
 356         }
 357
 358         case PPC_PTRACE_SETREGS: { /* Set 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 = get_user(*reg, tmp);
 365                         if (ret)
 366                                 break;
 367                         reg++;
 368                         tmp++;
 369                 }
 370                 break;
 371         }
 372
 373         case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
 374                 int i;
 375                 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
 376                 unsigned int __user *tmp = (unsigned int __user *)addr;
 377
 378                 flush_fp_to_thread(child);
 379
 380                 for (i = 0; i < 32; i++) {
 381                         ret = put_user(*reg, tmp);
 382                         if (ret)
 383                                 break;
 384                         reg++;
 385                         tmp++;
 386                 }
 387                 break;
 388         }
 389
 390         case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
 391                 int i;
 392                 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
 393                 unsigned int __user *tmp = (unsigned int __user *)addr;
 394
 395                 flush_fp_to_thread(child);
 396
 397                 for (i = 0; i < 32; i++) {
 398                         ret = get_user(*reg, tmp);
 399                         if (ret)
 400                                 break;
 401                         reg++;
 402                         tmp++;
 403                 }
 404                 break;
 405         }
 406
 407        case PTRACE_GETEVENTMSG:
 408                 ret = put_user(child->ptrace_message, (unsigned int __user *) data);
 409                 break;
 410
 411         default:
 412                 ret = ptrace_request(child, request, addr, data);
 413                 break;
 414         }
 415 out_tsk:
 416         put_task_struct(child);
 417 out:
 418         unlock_kernel();
 419         return ret;
 420 }