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