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 /*
  37  * does not yet catch signals sent when the child dies.
  38  * in exit.c or in signal.c.
  39  */
  40
  41 /*
  42  * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
  43  * we mark them as obsolete now, they will be removed in a future version
  44  */
  45 static long compat_ptrace_old(struct task_struct *child, long request,
  46                               long addr, long data)
  47 {
  48         int ret = -EPERM;
  49
  50         switch(request) {
  51         case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
  52                 int i;
  53                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
  54                 unsigned int __user *tmp = (unsigned int __user *)addr;
  55
  56                 CHECK_FULL_REGS(child->thread.regs);
  57                 for (i = 0; i < 32; i++) {
  58                         ret = put_user(*reg, tmp);
  59                         if (ret)
  60                                 break;
  61                         reg++;
  62                         tmp++;
  63                 }
  64                 break;
  65         }
  66
  67         case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
  68                 int i;
  69                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
  70                 unsigned int __user *tmp = (unsigned int __user *)addr;
  71
  72                 CHECK_FULL_REGS(child->thread.regs);
  73                 for (i = 0; i < 32; i++) {
  74                         ret = get_user(*reg, tmp);
  75                         if (ret)
  76                                 break;
  77                         reg++;
  78                         tmp++;
  79                 }
  80                 break;
  81         }
  82
  83         }
  84         return ret;
  85 }
  86
  87 long compat_sys_ptrace(int request, int pid, unsigned long addr,
  88                        unsigned long data)
  89 {
  90         struct task_struct *child;
  91         int ret;
  92
  93         lock_kernel();
  94         if (request == PTRACE_TRACEME) {
  95                 ret = ptrace_traceme();
  96                 goto out;
  97         }
  98
  99         child = ptrace_get_task_struct(pid);
 100         if (IS_ERR(child)) {
 101                 ret = PTR_ERR(child);
 102                 goto out;
 103         }
 104
 105         if (request == PTRACE_ATTACH) {
 106                 ret = ptrace_attach(child);
 107                 goto out_tsk;
 108         }
 109
 110         ret = ptrace_check_attach(child, request == PTRACE_KILL);
 111         if (ret < 0)
 112                 goto out_tsk;
 113
 114         switch (request) {
 115         /* when I and D space are separate, these will need to be fixed. */
 116         case PTRACE_PEEKTEXT: /* read word at location addr. */
 117         case PTRACE_PEEKDATA: {
 118                 unsigned int tmp;
 119                 int copied;
 120
 121                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
 122                 ret = -EIO;
 123                 if (copied != sizeof(tmp))
 124                         break;
 125                 ret = put_user(tmp, (u32 __user *)data);
 126                 break;
 127         }
 128
 129         /*
 130          * Read 4 bytes of the other process' storage
 131          *  data is a pointer specifying where the user wants the
 132          *      4 bytes copied into
 133          *  addr is a pointer in the user's storage that contains an 8 byte
 134          *      address in the other process of the 4 bytes that is to be read
 135          * (this is run in a 32-bit process looking at a 64-bit process)
 136          * when I and D space are separate, these will need to be fixed.
 137          */
 138         case PPC_PTRACE_PEEKTEXT_3264:
 139         case PPC_PTRACE_PEEKDATA_3264: {
 140                 u32 tmp;
 141                 int copied;
 142                 u32 __user * addrOthers;
 143
 144                 ret = -EIO;
 145
 146                 /* Get the addr in the other process that we want to read */
 147                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 148                         break;
 149
 150                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 151                                 sizeof(tmp), 0);
 152                 if (copied != sizeof(tmp))
 153                         break;
 154                 ret = put_user(tmp, (u32 __user *)data);
 155                 break;
 156         }
 157
 158         /* Read a register (specified by ADDR) out of the "user area" */
 159         case PTRACE_PEEKUSR: {
 160                 int index;
 161                 unsigned long tmp;
 162
 163                 ret = -EIO;
 164                 /* convert to index and check */
 165                 index = (unsigned long) addr >> 2;
 166                 if ((addr & 3) || (index > PT_FPSCR32))
 167                         break;
 168
 169                 CHECK_FULL_REGS(child->thread.regs);
 170                 if (index < PT_FPR0) {
 171                         tmp = ptrace_get_reg(child, index);
 172                 } else {
 173                         flush_fp_to_thread(child);
 174                         /*
 175                          * the user space code considers the floating point
 176                          * to be an array of unsigned int (32 bits) - the
 177                          * index passed in is based on this assumption.
 178                          */
 179                         tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
 180                 }
 181                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 182                 break;
 183         }
 184
 185         /*
 186          * Read 4 bytes out of the other process' pt_regs area
 187          *  data is a pointer specifying where the user wants the
 188          *      4 bytes copied into
 189          *  addr is the offset into the other process' pt_regs structure
 190          *      that is to be read
 191          * (this is run in a 32-bit process looking at a 64-bit process)
 192          */
 193         case PPC_PTRACE_PEEKUSR_3264: {
 194                 u32 index;
 195                 u32 reg32bits;
 196                 u64 tmp;
 197                 u32 numReg;
 198                 u32 part;
 199
 200                 ret = -EIO;
 201                 /* Determine which register the user wants */
 202                 index = (u64)addr >> 2;
 203                 numReg = index / 2;
 204                 /* Determine which part of the register the user wants */
 205                 if (index % 2)
 206                         part = 1;  /* want the 2nd half of the register (right-most). */
 207                 else
 208                         part = 0;  /* want the 1st half of the register (left-most). */
 209
 210                 /* Validate the input - check to see if address is on the wrong boundary
 211                  * or beyond the end of the user area
 212                  */
 213                 if ((addr & 3) || numReg > PT_FPSCR)
 214                         break;
 215
 216                 CHECK_FULL_REGS(child->thread.regs);
 217                 if (numReg >= PT_FPR0) {
 218                         flush_fp_to_thread(child);
 219                         tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
 220                 } else { /* register within PT_REGS struct */
 221                         tmp = ptrace_get_reg(child, numReg);
 222                 }
 223                 reg32bits = ((u32*)&tmp)[part];
 224                 ret = put_user(reg32bits, (u32 __user *)data);
 225                 break;
 226         }
 227
 228         /* If I and D space are separate, this will have to be fixed. */
 229         case PTRACE_POKETEXT: /* write the word at location addr. */
 230         case PTRACE_POKEDATA: {
 231                 unsigned int tmp;
 232                 tmp = data;
 233                 ret = 0;
 234                 if (access_process_vm(child, addr, &tmp, sizeof(tmp), 1)
 235                                 == sizeof(tmp))
 236                         break;
 237                 ret = -EIO;
 238                 break;
 239         }
 240
 241         /*
 242          * Write 4 bytes into the other process' storage
 243          *  data is the 4 bytes that the user wants written
 244          *  addr is a pointer in the user's storage that contains an
 245          *      8 byte address in the other process where the 4 bytes
 246          *      that is to be written
 247          * (this is run in a 32-bit process looking at a 64-bit process)
 248          * when I and D space are separate, these will need to be fixed.
 249          */
 250         case PPC_PTRACE_POKETEXT_3264:
 251         case PPC_PTRACE_POKEDATA_3264: {
 252                 u32 tmp = data;
 253                 u32 __user * addrOthers;
 254
 255                 /* Get the addr in the other process that we want to write into */
 256                 ret = -EIO;
 257                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 258                         break;
 259                 ret = 0;
 260                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 261                                         sizeof(tmp), 1) == sizeof(tmp))
 262                         break;
 263                 ret = -EIO;
 264                 break;
 265         }
 266
 267         /* write the word at location addr in the USER area */
 268         case PTRACE_POKEUSR: {
 269                 unsigned long index;
 270
 271                 ret = -EIO;
 272                 /* convert to index and check */
 273                 index = (unsigned long) addr >> 2;
 274                 if ((addr & 3) || (index > PT_FPSCR32))
 275                         break;
 276
 277                 CHECK_FULL_REGS(child->thread.regs);
 278                 if (index < PT_FPR0) {
 279                         ret = ptrace_put_reg(child, index, data);
 280                 } else {
 281                         flush_fp_to_thread(child);
 282                         /*
 283                          * the user space code considers the floating point
 284                          * to be an array of unsigned int (32 bits) - the
 285                          * index passed in is based on this assumption.
 286                          */
 287                         ((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
 288                         ret = 0;
 289                 }
 290                 break;
 291         }
 292
 293         /*
 294          * Write 4 bytes into the other process' pt_regs area
 295          *  data is the 4 bytes that the user wants written
 296          *  addr is the offset into the other process' pt_regs structure
 297          *      that is to be written into
 298          * (this is run in a 32-bit process looking at a 64-bit process)
 299          */
 300         case PPC_PTRACE_POKEUSR_3264: {
 301                 u32 index;
 302                 u32 numReg;
 303
 304                 ret = -EIO;
 305                 /* Determine which register the user wants */
 306                 index = (u64)addr >> 2;
 307                 numReg = index / 2;
 308
 309                 /*
 310                  * Validate the input - check to see if address is on the
 311                  * wrong boundary or beyond the end of the user area
 312                  */
 313                 if ((addr & 3) || (numReg > PT_FPSCR))
 314                         break;
 315                 CHECK_FULL_REGS(child->thread.regs);
 316                 if (numReg < PT_FPR0) {
 317                         unsigned long freg = ptrace_get_reg(child, numReg);
 318                         if (index % 2)
 319                                 freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
 320                         else
 321                                 freg = (freg & 0xfffffffful) | (data << 32);
 322                         ret = ptrace_put_reg(child, numReg, freg);
 323                 } else {
 324                         flush_fp_to_thread(child);
 325                         ((unsigned int *)child->thread.regs)[index] = data;
 326                         ret = 0;
 327                 }
 328                 break;
 329         }
 330
 331         case PTRACE_GET_DEBUGREG: {
 332                 ret = -EINVAL;
 333                 /* We only support one DABR and no IABRS at the moment */
 334                 if (addr > 0)
 335                         break;
 336                 ret = put_user(child->thread.dabr, (u32 __user *)data);
 337                 break;
 338         }
 339
 340         case PTRACE_GETEVENTMSG:
 341                 ret = put_user(child->ptrace_message, (unsigned int __user *) data);
 342                 break;
 343
 344         case PTRACE_GETREGS: { /* Get all pt_regs from the child. */
 345                 int ui;
 346                 if (!access_ok(VERIFY_WRITE, (void __user *)data,
 347                                PT_REGS_COUNT * sizeof(int))) {
 348                         ret = -EIO;
 349                         break;
 350                 }
 351                 CHECK_FULL_REGS(child->thread.regs);
 352                 ret = 0;
 353                 for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
 354                         ret |= __put_user(ptrace_get_reg(child, ui),
 355                                           (unsigned int __user *) data);
 356                         data += sizeof(int);
 357                 }
 358                 break;
 359         }
 360
 361         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 362                 unsigned long tmp;
 363                 int ui;
 364                 if (!access_ok(VERIFY_READ, (void __user *)data,
 365                                PT_REGS_COUNT * sizeof(int))) {
 366                         ret = -EIO;
 367                         break;
 368                 }
 369                 CHECK_FULL_REGS(child->thread.regs);
 370                 ret = 0;
 371                 for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
 372                         ret = __get_user(tmp, (unsigned int __user *) data);
 373                         if (ret)
 374                                 break;
 375                         ptrace_put_reg(child, ui, tmp);
 376                         data += sizeof(int);
 377                 }
 378                 break;
 379         }
 380
 381         case PTRACE_GETFPREGS:
 382         case PTRACE_SETFPREGS:
 383         case PTRACE_GETVRREGS:
 384         case PTRACE_SETVRREGS:
 385         case PTRACE_GETREGS64:
 386         case PTRACE_SETREGS64:
 387         case PPC_PTRACE_GETFPREGS:
 388         case PPC_PTRACE_SETFPREGS:
 389         case PTRACE_KILL:
 390         case PTRACE_SINGLESTEP:
 391         case PTRACE_DETACH:
 392         case PTRACE_SET_DEBUGREG:
 393         case PTRACE_SYSCALL:
 394         case PTRACE_CONT:
 395                 ret = arch_ptrace(child, request, addr, data);
 396                 break;
 397
 398         /* Old reverse args ptrace callss */
 399         case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
 400         case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
 401                 ret = compat_ptrace_old(child, request, addr, data);
 402                 break;
 403
 404         default:
 405                 ret = ptrace_request(child, request, addr, data);
 406                 break;
 407         }
 408 out_tsk:
 409         put_task_struct(child);
 410 out:
 411         unlock_kernel();
 412         return ret;
 413 }