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/errno.h>
  25 #include <linux/ptrace.h>
  26 #include <linux/regset.h>
  27 #include <linux/user.h>
  28 #include <linux/security.h>
  29 #include <linux/signal.h>
  30 #include <linux/compat.h>
  31
  32 #include <asm/uaccess.h>
  33 #include <asm/page.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/system.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 /*
  43  * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
  44  * we mark them as obsolete now, they will be removed in a future version
  45  */
  46 static long compat_ptrace_old(struct task_struct *child, long request,
  47                               long addr, long data)
  48 {
  49         switch (request) {
  50         case PPC_PTRACE_GETREGS:        /* Get GPRs 0 - 31. */
  51                 return copy_regset_to_user(child,
  52                                            task_user_regset_view(current), 0,
  53                                            0, 32 * sizeof(compat_long_t),
  54                                            compat_ptr(data));
  55
  56         case PPC_PTRACE_SETREGS:        /* Set GPRs 0 - 31. */
  57                 return copy_regset_from_user(child,
  58                                              task_user_regset_view(current), 0,
  59                                              0, 32 * sizeof(compat_long_t),
  60                                              compat_ptr(data));
  61         }
  62
  63         return -EPERM;
  64 }
  65
  66 /* Macros to workout the correct index for the FPR in the thread struct */
  67 #define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
  68 #define FPRHALF(i) (((i) - PT_FPR0) & 1)
  69 #define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) * 2 + FPRHALF(i)
  70 #define FPRINDEX_3264(i) (TS_FPRWIDTH * ((i) - PT_FPR0))
  71
  72 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
  73                         compat_ulong_t caddr, compat_ulong_t cdata)
  74 {
  75         unsigned long addr = caddr;
  76         unsigned long data = cdata;
  77         int ret;
  78
  79         switch (request) {
  80         /*
  81          * Read 4 bytes of the other process' storage
  82          *  data is a pointer specifying where the user wants the
  83          *      4 bytes copied into
  84          *  addr is a pointer in the user's storage that contains an 8 byte
  85          *      address in the other process of the 4 bytes that is to be read
  86          * (this is run in a 32-bit process looking at a 64-bit process)
  87          * when I and D space are separate, these will need to be fixed.
  88          */
  89         case PPC_PTRACE_PEEKTEXT_3264:
  90         case PPC_PTRACE_PEEKDATA_3264: {
  91                 u32 tmp;
  92                 int copied;
  93                 u32 __user * addrOthers;
  94
  95                 ret = -EIO;
  96
  97                 /* Get the addr in the other process that we want to read */
  98                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
  99                         break;
 100
 101                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
 102                                 sizeof(tmp), 0);
 103                 if (copied != sizeof(tmp))
 104                         break;
 105                 ret = put_user(tmp, (u32 __user *)data);
 106                 break;
 107         }
 108
 109         /* Read a register (specified by ADDR) out of the "user area" */
 110         case PTRACE_PEEKUSR: {
 111                 int index;
 112                 unsigned long tmp;
 113
 114                 ret = -EIO;
 115                 /* convert to index and check */
 116                 index = (unsigned long) addr >> 2;
 117                 if ((addr & 3) || (index > PT_FPSCR32))
 118                         break;
 119
 120                 CHECK_FULL_REGS(child->thread.regs);
 121                 if (index < PT_FPR0) {
 122                         tmp = ptrace_get_reg(child, index);
 123                 } else {
 124                         flush_fp_to_thread(child);
 125                         /*
 126                          * the user space code considers the floating point
 127                          * to be an array of unsigned int (32 bits) - the
 128                          * index passed in is based on this assumption.
 129                          */
 130                         tmp = ((unsigned int *)child->thread.fpr)
 131                                 [FPRINDEX(index)];
 132                 }
 133                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 134                 break;
 135         }
 136
 137         /*
 138          * Read 4 bytes out of the other process' pt_regs area
 139          *  data is a pointer specifying where the user wants the
 140          *      4 bytes copied into
 141          *  addr is the offset into the other process' pt_regs structure
 142          *      that is to be read
 143          * (this is run in a 32-bit process looking at a 64-bit process)
 144          */
 145         case PPC_PTRACE_PEEKUSR_3264: {
 146                 u32 index;
 147                 u32 reg32bits;
 148                 u64 tmp;
 149                 u32 numReg;
 150                 u32 part;
 151
 152                 ret = -EIO;
 153                 /* Determine which register the user wants */
 154                 index = (u64)addr >> 2;
 155                 numReg = index / 2;
 156                 /* Determine which part of the register the user wants */
 157                 if (index % 2)
 158                         part = 1;  /* want the 2nd half of the register (right-most). */
 159                 else
 160                         part = 0;  /* want the 1st half of the register (left-most). */
 161
 162                 /* Validate the input - check to see if address is on the wrong boundary
 163                  * or beyond the end of the user area
 164                  */
 165                 if ((addr & 3) || numReg > PT_FPSCR)
 166                         break;
 167
 168                 CHECK_FULL_REGS(child->thread.regs);
 169                 if (numReg >= PT_FPR0) {
 170                         flush_fp_to_thread(child);
 171                         /* get 64 bit FPR */
 172                         tmp = ((u64 *)child->thread.fpr)
 173                                 [FPRINDEX_3264(numReg)];
 174                 } else { /* register within PT_REGS struct */
 175                         tmp = ptrace_get_reg(child, numReg);
 176                 }
 177                 reg32bits = ((u32*)&tmp)[part];
 178                 ret = put_user(reg32bits, (u32 __user *)data);
 179                 break;
 180         }
 181
 182         /*
 183          * Write 4 bytes into the other process' storage
 184          *  data is the 4 bytes that the user wants written
 185          *  addr is a pointer in the user's storage that contains an
 186          *      8 byte address in the other process where the 4 bytes
 187          *      that is to be written
 188          * (this is run in a 32-bit process looking at a 64-bit process)
 189          * when I and D space are separate, these will need to be fixed.
 190          */
 191         case PPC_PTRACE_POKETEXT_3264:
 192         case PPC_PTRACE_POKEDATA_3264: {
 193                 u32 tmp = data;
 194                 u32 __user * addrOthers;
 195
 196                 /* Get the addr in the other process that we want to write into */
 197                 ret = -EIO;
 198                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 199                         break;
 200                 ret = 0;
 201                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 202                                         sizeof(tmp), 1) == sizeof(tmp))
 203                         break;
 204                 ret = -EIO;
 205                 break;
 206         }
 207
 208         /* write the word at location addr in the USER area */
 209         case PTRACE_POKEUSR: {
 210                 unsigned long index;
 211
 212                 ret = -EIO;
 213                 /* convert to index and check */
 214                 index = (unsigned long) addr >> 2;
 215                 if ((addr & 3) || (index > PT_FPSCR32))
 216                         break;
 217
 218                 CHECK_FULL_REGS(child->thread.regs);
 219                 if (index < PT_FPR0) {
 220                         ret = ptrace_put_reg(child, index, data);
 221                 } else {
 222                         flush_fp_to_thread(child);
 223                         /*
 224                          * the user space code considers the floating point
 225                          * to be an array of unsigned int (32 bits) - the
 226                          * index passed in is based on this assumption.
 227                          */
 228                         ((unsigned int *)child->thread.fpr)
 229                                 [FPRINDEX(index)] = data;
 230                         ret = 0;
 231                 }
 232                 break;
 233         }
 234
 235         /*
 236          * Write 4 bytes into the other process' pt_regs area
 237          *  data is the 4 bytes that the user wants written
 238          *  addr is the offset into the other process' pt_regs structure
 239          *      that is to be written into
 240          * (this is run in a 32-bit process looking at a 64-bit process)
 241          */
 242         case PPC_PTRACE_POKEUSR_3264: {
 243                 u32 index;
 244                 u32 numReg;
 245
 246                 ret = -EIO;
 247                 /* Determine which register the user wants */
 248                 index = (u64)addr >> 2;
 249                 numReg = index / 2;
 250
 251                 /*
 252                  * Validate the input - check to see if address is on the
 253                  * wrong boundary or beyond the end of the user area
 254                  */
 255                 if ((addr & 3) || (numReg > PT_FPSCR))
 256                         break;
 257                 CHECK_FULL_REGS(child->thread.regs);
 258                 if (numReg < PT_FPR0) {
 259                         unsigned long freg = ptrace_get_reg(child, numReg);
 260                         if (index % 2)
 261                                 freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
 262                         else
 263                                 freg = (freg & 0xfffffffful) | (data << 32);
 264                         ret = ptrace_put_reg(child, numReg, freg);
 265                 } else {
 266                         u64 *tmp;
 267                         flush_fp_to_thread(child);
 268                         /* get 64 bit FPR ... */
 269                         tmp = &(((u64 *)child->thread.fpr)
 270                                 [FPRINDEX_3264(numReg)]);
 271                         /* ... write the 32 bit part we want */
 272                         ((u32 *)tmp)[index % 2] = data;
 273                         ret = 0;
 274                 }
 275                 break;
 276         }
 277
 278         case PTRACE_GET_DEBUGREG: {
 279                 ret = -EINVAL;
 280                 /* We only support one DABR and no IABRS at the moment */
 281                 if (addr > 0)
 282                         break;
 283                 ret = put_user(child->thread.dabr, (u32 __user *)data);
 284                 break;
 285         }
 286
 287         case PTRACE_GETREGS:    /* Get all pt_regs from the child. */
 288                 return copy_regset_to_user(
 289                         child, task_user_regset_view(current), 0,
 290                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 291                         compat_ptr(data));
 292
 293         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 294                 return copy_regset_from_user(
 295                         child, task_user_regset_view(current), 0,
 296                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 297                         compat_ptr(data));
 298
 299         case PTRACE_GETFPREGS:
 300         case PTRACE_SETFPREGS:
 301         case PTRACE_GETVRREGS:
 302         case PTRACE_SETVRREGS:
 303         case PTRACE_GETVSRREGS:
 304         case PTRACE_SETVSRREGS:
 305         case PTRACE_GETREGS64:
 306         case PTRACE_SETREGS64:
 307         case PPC_PTRACE_GETFPREGS:
 308         case PPC_PTRACE_SETFPREGS:
 309         case PTRACE_KILL:
 310         case PTRACE_SINGLESTEP:
 311         case PTRACE_DETACH:
 312         case PTRACE_SET_DEBUGREG:
 313         case PTRACE_SYSCALL:
 314         case PTRACE_CONT:
 315                 ret = arch_ptrace(child, request, addr, data);
 316                 break;
 317
 318         /* Old reverse args ptrace callss */
 319         case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
 320         case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
 321                 ret = compat_ptrace_old(child, request, addr, data);
 322                 break;
 323
 324         default:
 325                 ret = compat_ptrace_request(child, request, addr, data);
 326                 break;
 327         }
 328
 329         return ret;
 330 }