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/switch_to.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 /* Macros to workout the correct index for the FPR in the thread struct */
  43 #define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
  44 #define FPRHALF(i) (((i) - PT_FPR0) & 1)
  45 #define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) * 2 + FPRHALF(i)
  46 #define FPRINDEX_3264(i) (TS_FPRWIDTH * ((i) - PT_FPR0))
  47
  48 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
  49                         compat_ulong_t caddr, compat_ulong_t cdata)
  50 {
  51         unsigned long addr = caddr;
  52         unsigned long data = cdata;
  53         int ret;
  54
  55         switch (request) {
  56         /*
  57          * Read 4 bytes of the other process' storage
  58          *  data is a pointer specifying where the user wants the
  59          *      4 bytes copied into
  60          *  addr is a pointer in the user's storage that contains an 8 byte
  61          *      address in the other process of the 4 bytes that is to be read
  62          * (this is run in a 32-bit process looking at a 64-bit process)
  63          * when I and D space are separate, these will need to be fixed.
  64          */
  65         case PPC_PTRACE_PEEKTEXT_3264:
  66         case PPC_PTRACE_PEEKDATA_3264: {
  67                 u32 tmp;
  68                 int copied;
  69                 u32 __user * addrOthers;
  70
  71                 ret = -EIO;
  72
  73                 /* Get the addr in the other process that we want to read */
  74                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
  75                         break;
  76
  77                 copied = access_process_vm(child, (u64)addrOthers, &tmp,
  78                                 sizeof(tmp), 0);
  79                 if (copied != sizeof(tmp))
  80                         break;
  81                 ret = put_user(tmp, (u32 __user *)data);
  82                 break;
  83         }
  84
  85         /* Read a register (specified by ADDR) out of the "user area" */
  86         case PTRACE_PEEKUSR: {
  87                 int index;
  88                 unsigned long tmp;
  89
  90                 ret = -EIO;
  91                 /* convert to index and check */
  92                 index = (unsigned long) addr >> 2;
  93                 if ((addr & 3) || (index > PT_FPSCR32))
  94                         break;
  95
  96                 CHECK_FULL_REGS(child->thread.regs);
  97                 if (index < PT_FPR0) {
  98                         tmp = ptrace_get_reg(child, index);
  99                 } else {
 100                         flush_fp_to_thread(child);
 101                         /*
 102                          * the user space code considers the floating point
 103                          * to be an array of unsigned int (32 bits) - the
 104                          * index passed in is based on this assumption.
 105                          */
 106                         tmp = ((unsigned int *)child->thread.fpr)
 107                                 [FPRINDEX(index)];
 108                 }
 109                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 110                 break;
 111         }
 112
 113         /*
 114          * Read 4 bytes out of the other process' pt_regs area
 115          *  data is a pointer specifying where the user wants the
 116          *      4 bytes copied into
 117          *  addr is the offset into the other process' pt_regs structure
 118          *      that is to be read
 119          * (this is run in a 32-bit process looking at a 64-bit process)
 120          */
 121         case PPC_PTRACE_PEEKUSR_3264: {
 122                 u32 index;
 123                 u32 reg32bits;
 124                 u64 tmp;
 125                 u32 numReg;
 126                 u32 part;
 127
 128                 ret = -EIO;
 129                 /* Determine which register the user wants */
 130                 index = (u64)addr >> 2;
 131                 numReg = index / 2;
 132                 /* Determine which part of the register the user wants */
 133                 if (index % 2)
 134                         part = 1;  /* want the 2nd half of the register (right-most). */
 135                 else
 136                         part = 0;  /* want the 1st half of the register (left-most). */
 137
 138                 /* Validate the input - check to see if address is on the wrong boundary
 139                  * or beyond the end of the user area
 140                  */
 141                 if ((addr & 3) || numReg > PT_FPSCR)
 142                         break;
 143
 144                 CHECK_FULL_REGS(child->thread.regs);
 145                 if (numReg >= PT_FPR0) {
 146                         flush_fp_to_thread(child);
 147                         /* get 64 bit FPR */
 148                         tmp = ((u64 *)child->thread.fpr)
 149                                 [FPRINDEX_3264(numReg)];
 150                 } else { /* register within PT_REGS struct */
 151                         tmp = ptrace_get_reg(child, numReg);
 152                 }
 153                 reg32bits = ((u32*)&tmp)[part];
 154                 ret = put_user(reg32bits, (u32 __user *)data);
 155                 break;
 156         }
 157
 158         /*
 159          * Write 4 bytes into the other process' storage
 160          *  data is the 4 bytes that the user wants written
 161          *  addr is a pointer in the user's storage that contains an
 162          *      8 byte address in the other process where the 4 bytes
 163          *      that is to be written
 164          * (this is run in a 32-bit process looking at a 64-bit process)
 165          * when I and D space are separate, these will need to be fixed.
 166          */
 167         case PPC_PTRACE_POKETEXT_3264:
 168         case PPC_PTRACE_POKEDATA_3264: {
 169                 u32 tmp = data;
 170                 u32 __user * addrOthers;
 171
 172                 /* Get the addr in the other process that we want to write into */
 173                 ret = -EIO;
 174                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 175                         break;
 176                 ret = 0;
 177                 if (access_process_vm(child, (u64)addrOthers, &tmp,
 178                                         sizeof(tmp), 1) == sizeof(tmp))
 179                         break;
 180                 ret = -EIO;
 181                 break;
 182         }
 183
 184         /* write the word at location addr in the USER area */
 185         case PTRACE_POKEUSR: {
 186                 unsigned long index;
 187
 188                 ret = -EIO;
 189                 /* convert to index and check */
 190                 index = (unsigned long) addr >> 2;
 191                 if ((addr & 3) || (index > PT_FPSCR32))
 192                         break;
 193
 194                 CHECK_FULL_REGS(child->thread.regs);
 195                 if (index < PT_FPR0) {
 196                         ret = ptrace_put_reg(child, index, data);
 197                 } else {
 198                         flush_fp_to_thread(child);
 199                         /*
 200                          * the user space code considers the floating point
 201                          * to be an array of unsigned int (32 bits) - the
 202                          * index passed in is based on this assumption.
 203                          */
 204                         ((unsigned int *)child->thread.fpr)
 205                                 [FPRINDEX(index)] = data;
 206                         ret = 0;
 207                 }
 208                 break;
 209         }
 210
 211         /*
 212          * Write 4 bytes into the other process' pt_regs area
 213          *  data is the 4 bytes that the user wants written
 214          *  addr is the offset into the other process' pt_regs structure
 215          *      that is to be written into
 216          * (this is run in a 32-bit process looking at a 64-bit process)
 217          */
 218         case PPC_PTRACE_POKEUSR_3264: {
 219                 u32 index;
 220                 u32 numReg;
 221
 222                 ret = -EIO;
 223                 /* Determine which register the user wants */
 224                 index = (u64)addr >> 2;
 225                 numReg = index / 2;
 226
 227                 /*
 228                  * Validate the input - check to see if address is on the
 229                  * wrong boundary or beyond the end of the user area
 230                  */
 231                 if ((addr & 3) || (numReg > PT_FPSCR))
 232                         break;
 233                 CHECK_FULL_REGS(child->thread.regs);
 234                 if (numReg < PT_FPR0) {
 235                         unsigned long freg = ptrace_get_reg(child, numReg);
 236                         if (index % 2)
 237                                 freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
 238                         else
 239                                 freg = (freg & 0xfffffffful) | (data << 32);
 240                         ret = ptrace_put_reg(child, numReg, freg);
 241                 } else {
 242                         u64 *tmp;
 243                         flush_fp_to_thread(child);
 244                         /* get 64 bit FPR ... */
 245                         tmp = &(((u64 *)child->thread.fpr)
 246                                 [FPRINDEX_3264(numReg)]);
 247                         /* ... write the 32 bit part we want */
 248                         ((u32 *)tmp)[index % 2] = data;
 249                         ret = 0;
 250                 }
 251                 break;
 252         }
 253
 254         case PTRACE_GET_DEBUGREG: {
 255                 ret = -EINVAL;
 256                 /* We only support one DABR and no IABRS at the moment */
 257                 if (addr > 0)
 258                         break;
 259 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 260                 ret = put_user(child->thread.dac1, (u32 __user *)data);
 261 #else
 262                 ret = put_user(child->thread.dabr, (u32 __user *)data);
 263 #endif
 264                 break;
 265         }
 266
 267         case PTRACE_GETREGS:    /* Get all pt_regs from the child. */
 268                 return copy_regset_to_user(
 269                         child, task_user_regset_view(current), 0,
 270                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 271                         compat_ptr(data));
 272
 273         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 274                 return copy_regset_from_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_GETFPREGS:
 280         case PTRACE_SETFPREGS:
 281         case PTRACE_GETVRREGS:
 282         case PTRACE_SETVRREGS:
 283         case PTRACE_GETVSRREGS:
 284         case PTRACE_SETVSRREGS:
 285         case PTRACE_GETREGS64:
 286         case PTRACE_SETREGS64:
 287         case PTRACE_KILL:
 288         case PTRACE_SINGLESTEP:
 289         case PTRACE_DETACH:
 290         case PTRACE_SET_DEBUGREG:
 291         case PTRACE_SYSCALL:
 292         case PTRACE_CONT:
 293         case PPC_PTRACE_GETHWDBGINFO:
 294         case PPC_PTRACE_SETHWDEBUG:
 295         case PPC_PTRACE_DELHWDEBUG:
 296                 ret = arch_ptrace(child, request, addr, data);
 297                 break;
 298
 299         default:
 300                 ret = compat_ptrace_request(child, request, addr, data);
 301                 break;
 302         }
 303
 304         return ret;
 305 }