arch/mips/kernel/ptrace32.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1992 Ross Biro
   7  * Copyright (C) Linus Torvalds
   8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
   9  * Copyright (C) 1996 David S. Miller
  10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
  11  * Copyright (C) 1999 MIPS Technologies, Inc.
  12  * Copyright (C) 2000 Ulf Carlsson
  13  *
  14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
  15  * binaries.
  16  */
  17 #include <linux/compiler.h>
  18 #include <linux/compat.h>
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/sched/task_stack.h>
  22 #include <linux/mm.h>
  23 #include <linux/errno.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/smp.h>
  26 #include <linux/security.h>
  27
  28 #include <asm/cpu.h>
  29 #include <asm/dsp.h>
  30 #include <asm/fpu.h>
  31 #include <asm/mipsregs.h>
  32 #include <asm/mipsmtregs.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/page.h>
  35 #include <asm/reg.h>
  36 #include <linux/uaccess.h>
  37 #include <asm/bootinfo.h>
  38
  39 /*
  40  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
  41  * work.  I don't know how to fix this.
  42  */
  43 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
  44                         compat_ulong_t caddr, compat_ulong_t cdata)
  45 {
  46         int addr = caddr;
  47         int data = cdata;
  48         int ret;
  49
  50         switch (request) {
  51
  52         /*
  53          * Read 4 bytes of the other process' storage
  54          *  data is a pointer specifying where the user wants the
  55          *      4 bytes copied into
  56          *  addr is a pointer in the user's storage that contains an 8 byte
  57          *      address in the other process of the 4 bytes that is to be read
  58          * (this is run in a 32-bit process looking at a 64-bit process)
  59          * when I and D space are separate, these will need to be fixed.
  60          */
  61         case PTRACE_PEEKTEXT_3264:
  62         case PTRACE_PEEKDATA_3264: {
  63                 u32 tmp;
  64                 int copied;
  65                 u32 __user * addrOthers;
  66
  67                 ret = -EIO;
  68
  69                 /* Get the addr in the other process that we want to read */
  70                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
  71                         break;
  72
  73                 copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
  74                                 sizeof(tmp), FOLL_FORCE);
  75                 if (copied != sizeof(tmp))
  76                         break;
  77                 ret = put_user(tmp, (u32 __user *) (unsigned long) data);
  78                 break;
  79         }
  80
  81         /* Read the word at location addr in the USER area. */
  82         case PTRACE_PEEKUSR: {
  83                 struct pt_regs *regs;
  84                 union fpureg *fregs;
  85                 unsigned int tmp;
  86
  87                 regs = task_pt_regs(child);
  88                 ret = 0;  /* Default return value. */
  89
  90                 switch (addr) {
  91                 case 0 ... 31:
  92                         tmp = regs->regs[addr];
  93                         break;
  94                 case FPR_BASE ... FPR_BASE + 31:
  95                         if (!tsk_used_math(child)) {
  96                                 /* FP not yet used */
  97                                 tmp = -1;
  98                                 break;
  99                         }
 100                         fregs = get_fpu_regs(child);
 101                         if (test_thread_flag(TIF_32BIT_FPREGS)) {
 102                                 /*
 103                                  * The odd registers are actually the high
 104                                  * order bits of the values stored in the even
 105                                  * registers - unless we're using r2k_switch.S.
 106                                  */
 107                                 tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 108                                                 addr & 1);
 109                                 break;
 110                         }
 111                         tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
 112                         break;
 113                 case PC:
 114                         tmp = regs->cp0_epc;
 115                         break;
 116                 case CAUSE:
 117                         tmp = regs->cp0_cause;
 118                         break;
 119                 case BADVADDR:
 120                         tmp = regs->cp0_badvaddr;
 121                         break;
 122                 case MMHI:
 123                         tmp = regs->hi;
 124                         break;
 125                 case MMLO:
 126                         tmp = regs->lo;
 127                         break;
 128                 case FPC_CSR:
 129                         tmp = child->thread.fpu.fcr31;
 130                         break;
 131                 case FPC_EIR:
 132                         /* implementation / version register */
 133                         tmp = boot_cpu_data.fpu_id;
 134                         break;
 135                 case DSP_BASE ... DSP_BASE + 5: {
 136                         dspreg_t *dregs;
 137
 138                         if (!cpu_has_dsp) {
 139                                 tmp = 0;
 140                                 ret = -EIO;
 141                                 goto out;
 142                         }
 143                         dregs = __get_dsp_regs(child);
 144                         tmp = (unsigned long) (dregs[addr - DSP_BASE]);
 145                         break;
 146                 }
 147                 case DSP_CONTROL:
 148                         if (!cpu_has_dsp) {
 149                                 tmp = 0;
 150                                 ret = -EIO;
 151                                 goto out;
 152                         }
 153                         tmp = child->thread.dsp.dspcontrol;
 154                         break;
 155                 default:
 156                         tmp = 0;
 157                         ret = -EIO;
 158                         goto out;
 159                 }
 160                 ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
 161                 break;
 162         }
 163
 164         /*
 165          * Write 4 bytes into the other process' storage
 166          *  data is the 4 bytes that the user wants written
 167          *  addr is a pointer in the user's storage that contains an
 168          *      8 byte address in the other process where the 4 bytes
 169          *      that is to be written
 170          * (this is run in a 32-bit process looking at a 64-bit process)
 171          * when I and D space are separate, these will need to be fixed.
 172          */
 173         case PTRACE_POKETEXT_3264:
 174         case PTRACE_POKEDATA_3264: {
 175                 u32 __user * addrOthers;
 176
 177                 /* Get the addr in the other process that we want to write into */
 178                 ret = -EIO;
 179                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 180                         break;
 181                 ret = 0;
 182                 if (ptrace_access_vm(child, (u64)addrOthers, &data,
 183                                         sizeof(data),
 184                                         FOLL_FORCE | FOLL_WRITE) == sizeof(data))
 185                         break;
 186                 ret = -EIO;
 187                 break;
 188         }
 189
 190         case PTRACE_POKEUSR: {
 191                 struct pt_regs *regs;
 192                 ret = 0;
 193                 regs = task_pt_regs(child);
 194
 195                 switch (addr) {
 196                 case 0 ... 31:
 197                         regs->regs[addr] = data;
 198                         break;
 199                 case FPR_BASE ... FPR_BASE + 31: {
 200                         union fpureg *fregs = get_fpu_regs(child);
 201
 202                         if (!tsk_used_math(child)) {
 203                                 /* FP not yet used  */
 204                                 memset(&child->thread.fpu, ~0,
 205                                        sizeof(child->thread.fpu));
 206                                 child->thread.fpu.fcr31 = 0;
 207                         }
 208                         if (test_thread_flag(TIF_32BIT_FPREGS)) {
 209                                 /*
 210                                  * The odd registers are actually the high
 211                                  * order bits of the values stored in the even
 212                                  * registers - unless we're using r2k_switch.S.
 213                                  */
 214                                 set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 215                                           addr & 1, data);
 216                                 break;
 217                         }
 218                         set_fpr64(&fregs[addr - FPR_BASE], 0, data);
 219                         break;
 220                 }
 221                 case PC:
 222                         regs->cp0_epc = data;
 223                         break;
 224                 case MMHI:
 225                         regs->hi = data;
 226                         break;
 227                 case MMLO:
 228                         regs->lo = data;
 229                         break;
 230                 case FPC_CSR:
 231                         child->thread.fpu.fcr31 = data;
 232                         break;
 233                 case DSP_BASE ... DSP_BASE + 5: {
 234                         dspreg_t *dregs;
 235
 236                         if (!cpu_has_dsp) {
 237                                 ret = -EIO;
 238                                 break;
 239                         }
 240
 241                         dregs = __get_dsp_regs(child);
 242                         dregs[addr - DSP_BASE] = data;
 243                         break;
 244                 }
 245                 case DSP_CONTROL:
 246                         if (!cpu_has_dsp) {
 247                                 ret = -EIO;
 248                                 break;
 249                         }
 250                         child->thread.dsp.dspcontrol = data;
 251                         break;
 252                 default:
 253                         /* The rest are not allowed. */
 254                         ret = -EIO;
 255                         break;
 256                 }
 257                 break;
 258                 }
 259
 260         case PTRACE_GETREGS:
 261                 ret = ptrace_getregs(child,
 262                                 (struct user_pt_regs __user *) (__u64) data);
 263                 break;
 264
 265         case PTRACE_SETREGS:
 266                 ret = ptrace_setregs(child,
 267                                 (struct user_pt_regs __user *) (__u64) data);
 268                 break;
 269
 270         case PTRACE_GETFPREGS:
 271                 ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
 272                 break;
 273
 274         case PTRACE_SETFPREGS:
 275                 ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
 276                 break;
 277
 278         case PTRACE_GET_THREAD_AREA:
 279                 ret = put_user(task_thread_info(child)->tp_value,
 280                                 (unsigned int __user *) (unsigned long) data);
 281                 break;
 282
 283         case PTRACE_GET_THREAD_AREA_3264:
 284                 ret = put_user(task_thread_info(child)->tp_value,
 285                                 (unsigned long __user *) (unsigned long) data);
 286                 break;
 287
 288         case PTRACE_GET_WATCH_REGS:
 289                 ret = ptrace_get_watch_regs(child,
 290                         (struct pt_watch_regs __user *) (unsigned long) addr);
 291                 break;
 292
 293         case PTRACE_SET_WATCH_REGS:
 294                 ret = ptrace_set_watch_regs(child,
 295                         (struct pt_watch_regs __user *) (unsigned long) addr);
 296                 break;
 297
 298         default:
 299                 ret = compat_ptrace_request(child, request, addr, data);
 300                 break;
 301         }
 302 out:
 303         return ret;
 304 }