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 #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 #include <asm/ptrace-common.h>
  36
  37 /*
  38  * does not yet catch signals sent when the child dies.
  39  * in exit.c or in signal.c.
  40  */
  41
  42 int sys32_ptrace(long request, long pid, unsigned long addr, unsigned long data)
  43 {
  44         struct task_struct *child;
  45         int ret = -EPERM;
  46
  47         lock_kernel();
  48         if (request == PTRACE_TRACEME) {
  49                 /* are we already being traced? */
  50                 if (current->ptrace & PT_PTRACED)
  51                         goto out;
  52                 ret = security_ptrace(current->parent, current);
  53                 if (ret)
  54                         goto out;
  55                 /* set the ptrace bit in the process flags. */
  56                 current->ptrace |= PT_PTRACED;
  57                 ret = 0;
  58                 goto out;
  59         }
  60         ret = -ESRCH;
  61         read_lock(&tasklist_lock);
  62         child = find_task_by_pid(pid);
  63         if (child)
  64                 get_task_struct(child);
  65         read_unlock(&tasklist_lock);
  66         if (!child)
  67                 goto out;
  68
  69         ret = -EPERM;
  70         if (pid == 1)           /* you may not mess with init */
  71                 goto out_tsk;
  72
  73         if (request == PTRACE_ATTACH) {
  74                 ret = ptrace_attach(child);
  75                 goto out_tsk;
  76         }
  77
  78         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  79         if (ret < 0)
  80                 goto out_tsk;
  81
  82         switch (request) {
  83         /* when I and D space are separate, these will need to be fixed. */
  84         case PTRACE_PEEKTEXT: /* read word at location addr. */
  85         case PTRACE_PEEKDATA: {
  86                 unsigned int tmp;
  87                 int copied;
  88
  89                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
  90                 ret = -EIO;
  91                 if (copied != sizeof(tmp))
  92                         break;
  93                 ret = put_user(tmp, (u32 __user *)data);
  94                 break;
  95         }
  96
  97         /*
  98          * Read 4 bytes of the other process' storage
  99          *  data is a pointer specifying where the user wants the
 100          *      4 bytes copied into
 101          *  addr is a pointer in the user's storage that contains an 8 byte
 102          *      address in the other process of the 4 bytes that is to be read
 103          * (this is run in a 32-bit process looking at a 64-bit process)
 104          * when I and D space are separate, these will need to be fixed.
 105          */
 106         case PPC_PTRACE_PEEKTEXT_3264:
 107         case PPC_PTRACE_PEEKDATA_3264: {
 108                 u32 tmp;
 109                 int copied;
 110                 u32 __user * addrOthers;
 111
 112                 ret = -EIO;
 113
 114                 /* Get the addr in the other process that we want to read */
 115                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 116                         break;
 117
 118                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 119                                 sizeof(tmp), 0);
 120                 if (copied != sizeof(tmp))
 121                         break;
 122                 ret = put_user(tmp, (u32 __user *)data);
 123                 break;
 124         }
 125
 126         /* Read a register (specified by ADDR) out of the "user area" */
 127         case PTRACE_PEEKUSR: {
 128                 int index;
 129                 unsigned long tmp;
 130
 131                 ret = -EIO;
 132                 /* convert to index and check */
 133                 index = (unsigned long) addr >> 2;
 134                 if ((addr & 3) || (index > PT_FPSCR32))
 135                         break;
 136
 137                 if (index < PT_FPR0) {
 138                         tmp = get_reg(child, index);
 139                 } else {
 140                         flush_fp_to_thread(child);
 141                         /*
 142                          * the user space code considers the floating point
 143                          * to be an array of unsigned int (32 bits) - the
 144                          * index passed in is based on this assumption.
 145                          */
 146                         tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
 147                 }
 148                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 149                 break;
 150         }
 151
 152         /*
 153          * Read 4 bytes out of the other process' pt_regs area
 154          *  data is a pointer specifying where the user wants the
 155          *      4 bytes copied into
 156          *  addr is the offset into the other process' pt_regs structure
 157          *      that is to be read
 158          * (this is run in a 32-bit process looking at a 64-bit process)
 159          */
 160         case PPC_PTRACE_PEEKUSR_3264: {
 161                 u32 index;
 162                 u32 reg32bits;
 163                 u64 tmp;
 164                 u32 numReg;
 165                 u32 part;
 166
 167                 ret = -EIO;
 168                 /* Determine which register the user wants */
 169                 index = (u64)addr >> 2;
 170                 numReg = index / 2;
 171                 /* Determine which part of the register the user wants */
 172                 if (index % 2)
 173                         part = 1;  /* want the 2nd half of the register (right-most). */
 174                 else
 175                         part = 0;  /* want the 1st half of the register (left-most). */
 176
 177                 /* Validate the input - check to see if address is on the wrong boundary or beyond the end of the user area */
 178                 if ((addr & 3) || numReg > PT_FPSCR)
 179                         break;
 180
 181                 if (numReg >= PT_FPR0) {
 182                         flush_fp_to_thread(child);
 183                         tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
 184                 } else { /* register within PT_REGS struct */
 185                         tmp = get_reg(child, numReg);
 186                 }
 187                 reg32bits = ((u32*)&tmp)[part];
 188                 ret = put_user(reg32bits, (u32 __user *)data);
 189                 break;
 190         }
 191
 192         /* If I and D space are separate, this will have to be fixed. */
 193         case PTRACE_POKETEXT: /* write the word at location addr. */
 194         case PTRACE_POKEDATA: {
 195                 unsigned int tmp;
 196                 tmp = data;
 197                 ret = 0;
 198                 if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1)
 199                                 == sizeof(tmp))
 200                         break;
 201                 ret = -EIO;
 202                 break;
 203         }
 204
 205         /*
 206          * Write 4 bytes into the other process' storage
 207          *  data is the 4 bytes that the user wants written
 208          *  addr is a pointer in the user's storage that contains an
 209          *      8 byte address in the other process where the 4 bytes
 210          *      that is to be written
 211          * (this is run in a 32-bit process looking at a 64-bit process)
 212          * when I and D space are separate, these will need to be fixed.
 213          */
 214         case PPC_PTRACE_POKETEXT_3264:
 215         case PPC_PTRACE_POKEDATA_3264: {
 216                 u32 tmp = data;
 217                 u32 __user * addrOthers;
 218
 219                 /* Get the addr in the other process that we want to write into */
 220                 ret = -EIO;
 221                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 222                         break;
 223                 ret = 0;
 224                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 225                                         sizeof(tmp), 1) == sizeof(tmp))
 226                         break;
 227                 ret = -EIO;
 228                 break;
 229         }
 230
 231         /* write the word at location addr in the USER area */
 232         case PTRACE_POKEUSR: {
 233                 unsigned long index;
 234
 235                 ret = -EIO;
 236                 /* convert to index and check */
 237                 index = (unsigned long) addr >> 2;
 238                 if ((addr & 3) || (index > PT_FPSCR32))
 239                         break;
 240
 241                 if (index == PT_ORIG_R3)
 242                         break;
 243                 if (index < PT_FPR0) {
 244                         ret = put_reg(child, index, data);
 245                 } else {
 246                         flush_fp_to_thread(child);
 247                         /*
 248                          * the user space code considers the floating point
 249                          * to be an array of unsigned int (32 bits) - the
 250                          * index passed in is based on this assumption.
 251                          */
 252                         ((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
 253                         ret = 0;
 254                 }
 255                 break;
 256         }
 257
 258         /*
 259          * Write 4 bytes into the other process' pt_regs area
 260          *  data is the 4 bytes that the user wants written
 261          *  addr is the offset into the other process' pt_regs structure
 262          *      that is to be written into
 263          * (this is run in a 32-bit process looking at a 64-bit process)
 264          */
 265         case PPC_PTRACE_POKEUSR_3264: {
 266                 u32 index;
 267                 u32 numReg;
 268
 269                 ret = -EIO;
 270                 /* Determine which register the user wants */
 271                 index = (u64)addr >> 2;
 272                 numReg = index / 2;
 273                 /*
 274                  * Validate the input - check to see if address is on the
 275                  * wrong boundary or beyond the end of the user area
 276                  */
 277                 if ((addr & 3) || (numReg > PT_FPSCR))
 278                         break;
 279                 /* Insure it is a register we let them change */
 280                 if ((numReg == PT_ORIG_R3)
 281                                 || ((numReg > PT_CCR) && (numReg < PT_FPR0)))
 282                         break;
 283                 if (numReg >= PT_FPR0) {
 284                         flush_fp_to_thread(child);
 285                 }
 286                 if (numReg == PT_MSR)
 287                         data = (data & MSR_DEBUGCHANGE)
 288                                 | (child->thread.regs->msr & ~MSR_DEBUGCHANGE);
 289                 ((u32*)child->thread.regs)[index] = data;
 290                 ret = 0;
 291                 break;
 292         }
 293
 294         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 295         case PTRACE_CONT: { /* restart after signal. */
 296                 ret = -EIO;
 297                 if (!valid_signal(data))
 298                         break;
 299                 if (request == PTRACE_SYSCALL)
 300                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 301                 else
 302                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 303                 child->exit_code = data;
 304                 /* make sure the single step bit is not set. */
 305                 clear_single_step(child);
 306                 wake_up_process(child);
 307                 ret = 0;
 308                 break;
 309         }
 310
 311         /*
 312          * make the child exit.  Best I can do is send it a sigkill.
 313          * perhaps it should be put in the status that it wants to
 314          * exit.
 315          */
 316         case PTRACE_KILL: {
 317                 ret = 0;
 318                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 319                         break;
 320                 child->exit_code = SIGKILL;
 321                 /* make sure the single step bit is not set. */
 322                 clear_single_step(child);
 323                 wake_up_process(child);
 324                 break;
 325         }
 326
 327         case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 328                 ret = -EIO;
 329                 if (!valid_signal(data))
 330                         break;
 331                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 332                 set_single_step(child);
 333                 child->exit_code = data;
 334                 /* give it a chance to run. */
 335                 wake_up_process(child);
 336                 ret = 0;
 337                 break;
 338         }
 339
 340         case PTRACE_DETACH:
 341                 ret = ptrace_detach(child, data);
 342                 break;
 343
 344         case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
 345                 int i;
 346                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
 347                 unsigned int __user *tmp = (unsigned int __user *)addr;
 348
 349                 for (i = 0; i < 32; i++) {
 350                         ret = put_user(*reg, tmp);
 351                         if (ret)
 352                                 break;
 353                         reg++;
 354                         tmp++;
 355                 }
 356                 break;
 357         }
 358
 359         case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
 360                 int i;
 361                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
 362                 unsigned int __user *tmp = (unsigned int __user *)addr;
 363
 364                 for (i = 0; i < 32; i++) {
 365                         ret = get_user(*reg, tmp);
 366                         if (ret)
 367                                 break;
 368                         reg++;
 369                         tmp++;
 370                 }
 371                 break;
 372         }
 373
 374         case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
 375                 int i;
 376                 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
 377                 unsigned int __user *tmp = (unsigned int __user *)addr;
 378
 379                 flush_fp_to_thread(child);
 380
 381                 for (i = 0; i < 32; i++) {
 382                         ret = put_user(*reg, tmp);
 383                         if (ret)
 384                                 break;
 385                         reg++;
 386                         tmp++;
 387                 }
 388                 break;
 389         }
 390
 391         case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
 392                 int i;
 393                 unsigned long *reg = &((unsigned long *)child->thread.fpr)[0];
 394                 unsigned int __user *tmp = (unsigned int __user *)addr;
 395
 396                 flush_fp_to_thread(child);
 397
 398                 for (i = 0; i < 32; i++) {
 399                         ret = get_user(*reg, tmp);
 400                         if (ret)
 401                                 break;
 402                         reg++;
 403                         tmp++;
 404                 }
 405                 break;
 406         }
 407
 408        case PTRACE_GETEVENTMSG:
 409                 ret = put_user(child->ptrace_message, (unsigned int __user *) data);
 410                 break;
 411
 412         default:
 413                 ret = ptrace_request(child, request, addr, data);
 414                 break;
 415         }
 416 out_tsk:
 417         put_task_struct(child);
 418 out:
 419         unlock_kernel();
 420         return ret;
 421 }