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/regset.h>
  28 #include <linux/user.h>
  29 #include <linux/security.h>
  30 #include <linux/signal.h>
  31 #include <linux/compat.h>
  32
  33 #include <asm/uaccess.h>
  34 #include <asm/page.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/system.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 /*
  44  * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
  45  * we mark them as obsolete now, they will be removed in a future version
  46  */
  47 static long compat_ptrace_old(struct task_struct *child, long request,
  48                               long addr, long data)
  49 {
  50         switch (request) {
  51         case PPC_PTRACE_GETREGS:        /* Get GPRs 0 - 31. */
  52                 return copy_regset_to_user(child,
  53                                            task_user_regset_view(current), 0,
  54                                            0, 32 * sizeof(compat_long_t),
  55                                            compat_ptr(data));
  56
  57         case PPC_PTRACE_SETREGS:        /* Set GPRs 0 - 31. */
  58                 return copy_regset_from_user(child,
  59                                              task_user_regset_view(current), 0,
  60                                              0, 32 * sizeof(compat_long_t),
  61                                              compat_ptr(data));
  62         }
  63
  64         return -EPERM;
  65 }
  66
  67 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
  68                         compat_ulong_t caddr, compat_ulong_t cdata)
  69 {
  70         unsigned long addr = caddr;
  71         unsigned long data = cdata;
  72         int ret;
  73
  74         switch (request) {
  75         /*
  76          * Read 4 bytes of the other process' storage
  77          *  data is a pointer specifying where the user wants the
  78          *      4 bytes copied into
  79          *  addr is a pointer in the user's storage that contains an 8 byte
  80          *      address in the other process of the 4 bytes that is to be read
  81          * (this is run in a 32-bit process looking at a 64-bit process)
  82          * when I and D space are separate, these will need to be fixed.
  83          */
  84         case PPC_PTRACE_PEEKTEXT_3264:
  85         case PPC_PTRACE_PEEKDATA_3264: {
  86                 u32 tmp;
  87                 int copied;
  88                 u32 __user * addrOthers;
  89
  90                 ret = -EIO;
  91
  92                 /* Get the addr in the other process that we want to read */
  93                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
  94                         break;
  95
  96                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
  97                                 sizeof(tmp), 0);
  98                 if (copied != sizeof(tmp))
  99                         break;
 100                 ret = put_user(tmp, (u32 __user *)data);
 101                 break;
 102         }
 103
 104         /* Read a register (specified by ADDR) out of the "user area" */
 105         case PTRACE_PEEKUSR: {
 106                 int index;
 107                 unsigned long tmp;
 108
 109                 ret = -EIO;
 110                 /* convert to index and check */
 111                 index = (unsigned long) addr >> 2;
 112                 if ((addr & 3) || (index > PT_FPSCR32))
 113                         break;
 114
 115                 CHECK_FULL_REGS(child->thread.regs);
 116                 if (index < PT_FPR0) {
 117                         tmp = ptrace_get_reg(child, index);
 118                 } else {
 119                         flush_fp_to_thread(child);
 120                         /*
 121                          * the user space code considers the floating point
 122                          * to be an array of unsigned int (32 bits) - the
 123                          * index passed in is based on this assumption.
 124                          */
 125                         tmp = ((unsigned int *)child->thread.fpr)[index - PT_FPR0];
 126                 }
 127                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 128                 break;
 129         }
 130
 131         /*
 132          * Read 4 bytes out of the other process' pt_regs area
 133          *  data is a pointer specifying where the user wants the
 134          *      4 bytes copied into
 135          *  addr is the offset into the other process' pt_regs structure
 136          *      that is to be read
 137          * (this is run in a 32-bit process looking at a 64-bit process)
 138          */
 139         case PPC_PTRACE_PEEKUSR_3264: {
 140                 u32 index;
 141                 u32 reg32bits;
 142                 u64 tmp;
 143                 u32 numReg;
 144                 u32 part;
 145
 146                 ret = -EIO;
 147                 /* Determine which register the user wants */
 148                 index = (u64)addr >> 2;
 149                 numReg = index / 2;
 150                 /* Determine which part of the register the user wants */
 151                 if (index % 2)
 152                         part = 1;  /* want the 2nd half of the register (right-most). */
 153                 else
 154                         part = 0;  /* want the 1st half of the register (left-most). */
 155
 156                 /* Validate the input - check to see if address is on the wrong boundary
 157                  * or beyond the end of the user area
 158                  */
 159                 if ((addr & 3) || numReg > PT_FPSCR)
 160                         break;
 161
 162                 CHECK_FULL_REGS(child->thread.regs);
 163                 if (numReg >= PT_FPR0) {
 164                         flush_fp_to_thread(child);
 165                         tmp = ((unsigned long int *)child->thread.fpr)[numReg - PT_FPR0];
 166                 } else { /* register within PT_REGS struct */
 167                         tmp = ptrace_get_reg(child, numReg);
 168                 }
 169                 reg32bits = ((u32*)&tmp)[part];
 170                 ret = put_user(reg32bits, (u32 __user *)data);
 171                 break;
 172         }
 173
 174         /*
 175          * Write 4 bytes into the other process' storage
 176          *  data is the 4 bytes that the user wants written
 177          *  addr is a pointer in the user's storage that contains an
 178          *      8 byte address in the other process where the 4 bytes
 179          *      that is to be written
 180          * (this is run in a 32-bit process looking at a 64-bit process)
 181          * when I and D space are separate, these will need to be fixed.
 182          */
 183         case PPC_PTRACE_POKETEXT_3264:
 184         case PPC_PTRACE_POKEDATA_3264: {
 185                 u32 tmp = data;
 186                 u32 __user * addrOthers;
 187
 188                 /* Get the addr in the other process that we want to write into */
 189                 ret = -EIO;
 190                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 191                         break;
 192                 ret = 0;
 193                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 194                                         sizeof(tmp), 1) == sizeof(tmp))
 195                         break;
 196                 ret = -EIO;
 197                 break;
 198         }
 199
 200         /* write the word at location addr in the USER area */
 201         case PTRACE_POKEUSR: {
 202                 unsigned long index;
 203
 204                 ret = -EIO;
 205                 /* convert to index and check */
 206                 index = (unsigned long) addr >> 2;
 207                 if ((addr & 3) || (index > PT_FPSCR32))
 208                         break;
 209
 210                 CHECK_FULL_REGS(child->thread.regs);
 211                 if (index < PT_FPR0) {
 212                         ret = ptrace_put_reg(child, index, data);
 213                 } else {
 214                         flush_fp_to_thread(child);
 215                         /*
 216                          * the user space code considers the floating point
 217                          * to be an array of unsigned int (32 bits) - the
 218                          * index passed in is based on this assumption.
 219                          */
 220                         ((unsigned int *)child->thread.fpr)[index - PT_FPR0] = data;
 221                         ret = 0;
 222                 }
 223                 break;
 224         }
 225
 226         /*
 227          * Write 4 bytes into the other process' pt_regs area
 228          *  data is the 4 bytes that the user wants written
 229          *  addr is the offset into the other process' pt_regs structure
 230          *      that is to be written into
 231          * (this is run in a 32-bit process looking at a 64-bit process)
 232          */
 233         case PPC_PTRACE_POKEUSR_3264: {
 234                 u32 index;
 235                 u32 numReg;
 236
 237                 ret = -EIO;
 238                 /* Determine which register the user wants */
 239                 index = (u64)addr >> 2;
 240                 numReg = index / 2;
 241
 242                 /*
 243                  * Validate the input - check to see if address is on the
 244                  * wrong boundary or beyond the end of the user area
 245                  */
 246                 if ((addr & 3) || (numReg > PT_FPSCR))
 247                         break;
 248                 CHECK_FULL_REGS(child->thread.regs);
 249                 if (numReg < PT_FPR0) {
 250                         unsigned long freg = ptrace_get_reg(child, numReg);
 251                         if (index % 2)
 252                                 freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
 253                         else
 254                                 freg = (freg & 0xfffffffful) | (data << 32);
 255                         ret = ptrace_put_reg(child, numReg, freg);
 256                 } else {
 257                         flush_fp_to_thread(child);
 258                         ((unsigned int *)child->thread.regs)[index] = data;
 259                         ret = 0;
 260                 }
 261                 break;
 262         }
 263
 264         case PTRACE_GET_DEBUGREG: {
 265                 ret = -EINVAL;
 266                 /* We only support one DABR and no IABRS at the moment */
 267                 if (addr > 0)
 268                         break;
 269                 ret = put_user(child->thread.dabr, (u32 __user *)data);
 270                 break;
 271         }
 272
 273         case PTRACE_GETREGS:    /* Get all pt_regs from the child. */
 274                 return copy_regset_to_user(
 275                         child, task_user_regset_view(current), 0,
 276                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 277                         compat_ptr(data));
 278
 279         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 280                 return copy_regset_from_user(
 281                         child, task_user_regset_view(current), 0,
 282                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 283                         compat_ptr(data));
 284
 285         case PTRACE_GETFPREGS:
 286         case PTRACE_SETFPREGS:
 287         case PTRACE_GETVRREGS:
 288         case PTRACE_SETVRREGS:
 289         case PTRACE_GETREGS64:
 290         case PTRACE_SETREGS64:
 291         case PPC_PTRACE_GETFPREGS:
 292         case PPC_PTRACE_SETFPREGS:
 293         case PTRACE_KILL:
 294         case PTRACE_SINGLESTEP:
 295         case PTRACE_DETACH:
 296         case PTRACE_SET_DEBUGREG:
 297         case PTRACE_SYSCALL:
 298         case PTRACE_CONT:
 299                 ret = arch_ptrace(child, request, addr, data);
 300                 break;
 301
 302         /* Old reverse args ptrace callss */
 303         case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
 304         case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
 305                 ret = compat_ptrace_old(child, request, addr, data);
 306                 break;
 307
 308         default:
 309                 ret = compat_ptrace_request(child, request, addr, data);
 310                 break;
 311         }
 312
 313         return ret;
 314 }