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 <linux/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
  47 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
  48                         compat_ulong_t caddr, compat_ulong_t cdata)
  49 {
  50         unsigned long addr = caddr;
  51         unsigned long data = cdata;
  52         int ret;
  53
  54         switch (request) {
  55         /*
  56          * Read 4 bytes of the other process' storage
  57          *  data is a pointer specifying where the user wants the
  58          *      4 bytes copied into
  59          *  addr is a pointer in the user's storage that contains an 8 byte
  60          *      address in the other process of the 4 bytes that is to be read
  61          * (this is run in a 32-bit process looking at a 64-bit process)
  62          * when I and D space are separate, these will need to be fixed.
  63          */
  64         case PPC_PTRACE_PEEKTEXT_3264:
  65         case PPC_PTRACE_PEEKDATA_3264: {
  66                 u32 tmp;
  67                 int copied;
  68                 u32 __user * addrOthers;
  69
  70                 ret = -EIO;
  71
  72                 /* Get the addr in the other process that we want to read */
  73                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
  74                         break;
  75
  76                 copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
  77                                 sizeof(tmp), FOLL_FORCE);
  78                 if (copied != sizeof(tmp))
  79                         break;
  80                 ret = put_user(tmp, (u32 __user *)data);
  81                 break;
  82         }
  83
  84         /* Read a register (specified by ADDR) out of the "user area" */
  85         case PTRACE_PEEKUSR: {
  86                 int index;
  87                 unsigned long tmp;
  88
  89                 ret = -EIO;
  90                 /* convert to index and check */
  91                 index = (unsigned long) addr >> 2;
  92                 if ((addr & 3) || (index > PT_FPSCR32))
  93                         break;
  94
  95                 CHECK_FULL_REGS(child->thread.regs);
  96                 if (index < PT_FPR0) {
  97                         ret = ptrace_get_reg(child, index, &tmp);
  98                         if (ret)
  99                                 break;
 100                 } else {
 101                         flush_fp_to_thread(child);
 102                         /*
 103                          * the user space code considers the floating point
 104                          * to be an array of unsigned int (32 bits) - the
 105                          * index passed in is based on this assumption.
 106                          */
 107                         tmp = ((unsigned int *)child->thread.fp_state.fpr)
 108                                 [FPRINDEX(index)];
 109                 }
 110                 ret = put_user((unsigned int)tmp, (u32 __user *)data);
 111                 break;
 112         }
 113
 114         /*
 115          * Read 4 bytes out of the other process' pt_regs area
 116          *  data is a pointer specifying where the user wants the
 117          *      4 bytes copied into
 118          *  addr is the offset into the other process' pt_regs structure
 119          *      that is to be read
 120          * (this is run in a 32-bit process looking at a 64-bit process)
 121          */
 122         case PPC_PTRACE_PEEKUSR_3264: {
 123                 u32 index;
 124                 u32 reg32bits;
 125                 u64 tmp;
 126                 u32 numReg;
 127                 u32 part;
 128
 129                 ret = -EIO;
 130                 /* Determine which register the user wants */
 131                 index = (u64)addr >> 2;
 132                 numReg = index / 2;
 133                 /* Determine which part of the register the user wants */
 134                 if (index % 2)
 135                         part = 1;  /* want the 2nd half of the register (right-most). */
 136                 else
 137                         part = 0;  /* want the 1st half of the register (left-most). */
 138
 139                 /* Validate the input - check to see if address is on the wrong boundary
 140                  * or beyond the end of the user area
 141                  */
 142                 if ((addr & 3) || numReg > PT_FPSCR)
 143                         break;
 144
 145                 CHECK_FULL_REGS(child->thread.regs);
 146                 if (numReg >= PT_FPR0) {
 147                         flush_fp_to_thread(child);
 148                         /* get 64 bit FPR */
 149                         tmp = child->thread.fp_state.fpr[numReg - PT_FPR0][0];
 150                 } else { /* register within PT_REGS struct */
 151                         unsigned long tmp2;
 152                         ret = ptrace_get_reg(child, numReg, &tmp2);
 153                         if (ret)
 154                                 break;
 155                         tmp = tmp2;
 156                 }
 157                 reg32bits = ((u32*)&tmp)[part];
 158                 ret = put_user(reg32bits, (u32 __user *)data);
 159                 break;
 160         }
 161
 162         /*
 163          * Write 4 bytes into the other process' storage
 164          *  data is the 4 bytes that the user wants written
 165          *  addr is a pointer in the user's storage that contains an
 166          *      8 byte address in the other process where the 4 bytes
 167          *      that is to be written
 168          * (this is run in a 32-bit process looking at a 64-bit process)
 169          * when I and D space are separate, these will need to be fixed.
 170          */
 171         case PPC_PTRACE_POKETEXT_3264:
 172         case PPC_PTRACE_POKEDATA_3264: {
 173                 u32 tmp = data;
 174                 u32 __user * addrOthers;
 175
 176                 /* Get the addr in the other process that we want to write into */
 177                 ret = -EIO;
 178                 if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
 179                         break;
 180                 ret = 0;
 181                 if (ptrace_access_vm(child, (u64)addrOthers, &tmp,
 182                                         sizeof(tmp),
 183                                         FOLL_FORCE | FOLL_WRITE) == sizeof(tmp))
 184                         break;
 185                 ret = -EIO;
 186                 break;
 187         }
 188
 189         /* write the word at location addr in the USER area */
 190         case PTRACE_POKEUSR: {
 191                 unsigned long index;
 192
 193                 ret = -EIO;
 194                 /* convert to index and check */
 195                 index = (unsigned long) addr >> 2;
 196                 if ((addr & 3) || (index > PT_FPSCR32))
 197                         break;
 198
 199                 CHECK_FULL_REGS(child->thread.regs);
 200                 if (index < PT_FPR0) {
 201                         ret = ptrace_put_reg(child, index, data);
 202                 } else {
 203                         flush_fp_to_thread(child);
 204                         /*
 205                          * the user space code considers the floating point
 206                          * to be an array of unsigned int (32 bits) - the
 207                          * index passed in is based on this assumption.
 208                          */
 209                         ((unsigned int *)child->thread.fp_state.fpr)
 210                                 [FPRINDEX(index)] = data;
 211                         ret = 0;
 212                 }
 213                 break;
 214         }
 215
 216         /*
 217          * Write 4 bytes into the other process' pt_regs area
 218          *  data is the 4 bytes that the user wants written
 219          *  addr is the offset into the other process' pt_regs structure
 220          *      that is to be written into
 221          * (this is run in a 32-bit process looking at a 64-bit process)
 222          */
 223         case PPC_PTRACE_POKEUSR_3264: {
 224                 u32 index;
 225                 u32 numReg;
 226
 227                 ret = -EIO;
 228                 /* Determine which register the user wants */
 229                 index = (u64)addr >> 2;
 230                 numReg = index / 2;
 231
 232                 /*
 233                  * Validate the input - check to see if address is on the
 234                  * wrong boundary or beyond the end of the user area
 235                  */
 236                 if ((addr & 3) || (numReg > PT_FPSCR))
 237                         break;
 238                 CHECK_FULL_REGS(child->thread.regs);
 239                 if (numReg < PT_FPR0) {
 240                         unsigned long freg;
 241                         ret = ptrace_get_reg(child, numReg, &freg);
 242                         if (ret)
 243                                 break;
 244                         if (index % 2)
 245                                 freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
 246                         else
 247                                 freg = (freg & 0xfffffffful) | (data << 32);
 248                         ret = ptrace_put_reg(child, numReg, freg);
 249                 } else {
 250                         u64 *tmp;
 251                         flush_fp_to_thread(child);
 252                         /* get 64 bit FPR ... */
 253                         tmp = &child->thread.fp_state.fpr[numReg - PT_FPR0][0];
 254                         /* ... write the 32 bit part we want */
 255                         ((u32 *)tmp)[index % 2] = data;
 256                         ret = 0;
 257                 }
 258                 break;
 259         }
 260
 261         case PTRACE_GET_DEBUGREG: {
 262 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
 263                 unsigned long dabr_fake;
 264 #endif
 265                 ret = -EINVAL;
 266                 /* We only support one DABR and no IABRS at the moment */
 267                 if (addr > 0)
 268                         break;
 269 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 270                 ret = put_user(child->thread.debug.dac1, (u32 __user *)data);
 271 #else
 272                 dabr_fake = (
 273                         (child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
 274                         (child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
 275                 ret = put_user(dabr_fake, (u32 __user *)data);
 276 #endif
 277                 break;
 278         }
 279
 280         case PTRACE_GETREGS:    /* Get all pt_regs from the child. */
 281                 return copy_regset_to_user(
 282                         child, task_user_regset_view(current), 0,
 283                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 284                         compat_ptr(data));
 285
 286         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
 287                 return copy_regset_from_user(
 288                         child, task_user_regset_view(current), 0,
 289                         0, PT_REGS_COUNT * sizeof(compat_long_t),
 290                         compat_ptr(data));
 291
 292         case PTRACE_GETFPREGS:
 293         case PTRACE_SETFPREGS:
 294         case PTRACE_GETVRREGS:
 295         case PTRACE_SETVRREGS:
 296         case PTRACE_GETVSRREGS:
 297         case PTRACE_SETVSRREGS:
 298         case PTRACE_GETREGS64:
 299         case PTRACE_SETREGS64:
 300         case PTRACE_KILL:
 301         case PTRACE_SINGLESTEP:
 302         case PTRACE_DETACH:
 303         case PTRACE_SET_DEBUGREG:
 304         case PTRACE_SYSCALL:
 305         case PTRACE_CONT:
 306         case PPC_PTRACE_GETHWDBGINFO:
 307         case PPC_PTRACE_SETHWDEBUG:
 308         case PPC_PTRACE_DELHWDEBUG:
 309                 ret = arch_ptrace(child, request, addr, data);
 310                 break;
 311
 312         default:
 313                 ret = compat_ptrace_request(child, request, addr, data);
 314                 break;
 315         }
 316
 317         return ret;
 318 }