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 <asm/syscall.h>
  37 #include <linux/uaccess.h>
  38 #include <asm/bootinfo.h>
  39
  40 /*
  41  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
  42  * work.  I don't know how to fix this.
  43  */
  44 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
  45                         compat_ulong_t caddr, compat_ulong_t cdata)
  46 {
  47         int addr = caddr;
  48         int data = cdata;
  49         int ret;
  50
  51         switch (request) {
  52
  53         /*
  54          * Read 4 bytes of the other process' storage
  55          *  data is a pointer specifying where the user wants the
  56          *      4 bytes copied into
  57          *  addr is a pointer in the user's storage that contains an 8 byte
  58          *      address in the other process of the 4 bytes that is to be read
  59          * (this is run in a 32-bit process looking at a 64-bit process)
  60          * when I and D space are separate, these will need to be fixed.
  61          */
  62         case PTRACE_PEEKTEXT_3264:
  63         case PTRACE_PEEKDATA_3264: {
  64                 u32 tmp;
  65                 int copied;
  66                 u32 __user * addrOthers;
  67
  68                 ret = -EIO;
  69
  70                 /* Get the addr in the other process that we want to read */
  71                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
  72                         break;
  73
  74                 copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
  75                                 sizeof(tmp), FOLL_FORCE);
  76                 if (copied != sizeof(tmp))
  77                         break;
  78                 ret = put_user(tmp, (u32 __user *) (unsigned long) data);
  79                 break;
  80         }
  81
  82         /* Read the word at location addr in the USER area. */
  83         case PTRACE_PEEKUSR: {
  84                 struct pt_regs *regs;
  85                 union fpureg *fregs;
  86                 unsigned int tmp;
  87
  88                 regs = task_pt_regs(child);
  89                 ret = 0;  /* Default return value. */
  90
  91                 switch (addr) {
  92                 case 0 ... 31:
  93                         tmp = regs->regs[addr];
  94                         break;
  95                 case FPR_BASE ... FPR_BASE + 31:
  96                         if (!tsk_used_math(child)) {
  97                                 /* FP not yet used */
  98                                 tmp = -1;
  99                                 break;
 100                         }
 101                         fregs = get_fpu_regs(child);
 102                         if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 103                                 /*
 104                                  * The odd registers are actually the high
 105                                  * order bits of the values stored in the even
 106                                  * registers.
 107                                  */
 108                                 tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 109                                                 addr & 1);
 110                                 break;
 111                         }
 112                         tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
 113                         break;
 114                 case PC:
 115                         tmp = regs->cp0_epc;
 116                         break;
 117                 case CAUSE:
 118                         tmp = regs->cp0_cause;
 119                         break;
 120                 case BADVADDR:
 121                         tmp = regs->cp0_badvaddr;
 122                         break;
 123                 case MMHI:
 124                         tmp = regs->hi;
 125                         break;
 126                 case MMLO:
 127                         tmp = regs->lo;
 128                         break;
 129                 case FPC_CSR:
 130                         tmp = child->thread.fpu.fcr31;
 131                         break;
 132                 case FPC_EIR:
 133                         /* implementation / version register */
 134                         tmp = boot_cpu_data.fpu_id;
 135                         break;
 136                 case DSP_BASE ... DSP_BASE + 5: {
 137                         dspreg_t *dregs;
 138
 139                         if (!cpu_has_dsp) {
 140                                 tmp = 0;
 141                                 ret = -EIO;
 142                                 goto out;
 143                         }
 144                         dregs = __get_dsp_regs(child);
 145                         tmp = dregs[addr - DSP_BASE];
 146                         break;
 147                 }
 148                 case DSP_CONTROL:
 149                         if (!cpu_has_dsp) {
 150                                 tmp = 0;
 151                                 ret = -EIO;
 152                                 goto out;
 153                         }
 154                         tmp = child->thread.dsp.dspcontrol;
 155                         break;
 156                 default:
 157                         tmp = 0;
 158                         ret = -EIO;
 159                         goto out;
 160                 }
 161                 ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
 162                 break;
 163         }
 164
 165         /*
 166          * Write 4 bytes into the other process' storage
 167          *  data is the 4 bytes that the user wants written
 168          *  addr is a pointer in the user's storage that contains an
 169          *      8 byte address in the other process where the 4 bytes
 170          *      that is to be written
 171          * (this is run in a 32-bit process looking at a 64-bit process)
 172          * when I and D space are separate, these will need to be fixed.
 173          */
 174         case PTRACE_POKETEXT_3264:
 175         case PTRACE_POKEDATA_3264: {
 176                 u32 __user * addrOthers;
 177
 178                 /* Get the addr in the other process that we want to write into */
 179                 ret = -EIO;
 180                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 181                         break;
 182                 ret = 0;
 183                 if (ptrace_access_vm(child, (u64)addrOthers, &data,
 184                                         sizeof(data),
 185                                         FOLL_FORCE | FOLL_WRITE) == sizeof(data))
 186                         break;
 187                 ret = -EIO;
 188                 break;
 189         }
 190
 191         case PTRACE_POKEUSR: {
 192                 struct pt_regs *regs;
 193                 ret = 0;
 194                 regs = task_pt_regs(child);
 195
 196                 switch (addr) {
 197                 case 0 ... 31:
 198                         regs->regs[addr] = data;
 199                         /* System call number may have been changed */
 200                         if (addr == 2)
 201                                 mips_syscall_update_nr(child, regs);
 202                         else if (addr == 4 &&
 203                                  mips_syscall_is_indirect(child, regs))
 204                                 mips_syscall_update_nr(child, regs);
 205                         break;
 206                 case FPR_BASE ... FPR_BASE + 31: {
 207                         union fpureg *fregs = get_fpu_regs(child);
 208
 209                         if (!tsk_used_math(child)) {
 210                                 /* FP not yet used  */
 211                                 memset(&child->thread.fpu, ~0,
 212                                        sizeof(child->thread.fpu));
 213                                 child->thread.fpu.fcr31 = 0;
 214                         }
 215                         if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 216                                 /*
 217                                  * The odd registers are actually the high
 218                                  * order bits of the values stored in the even
 219                                  * registers.
 220                                  */
 221                                 set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 222                                           addr & 1, data);
 223                                 break;
 224                         }
 225                         set_fpr64(&fregs[addr - FPR_BASE], 0, data);
 226                         break;
 227                 }
 228                 case PC:
 229                         regs->cp0_epc = data;
 230                         break;
 231                 case MMHI:
 232                         regs->hi = data;
 233                         break;
 234                 case MMLO:
 235                         regs->lo = data;
 236                         break;
 237                 case FPC_CSR:
 238                         child->thread.fpu.fcr31 = data;
 239                         break;
 240                 case DSP_BASE ... DSP_BASE + 5: {
 241                         dspreg_t *dregs;
 242
 243                         if (!cpu_has_dsp) {
 244                                 ret = -EIO;
 245                                 break;
 246                         }
 247
 248                         dregs = __get_dsp_regs(child);
 249                         dregs[addr - DSP_BASE] = data;
 250                         break;
 251                 }
 252                 case DSP_CONTROL:
 253                         if (!cpu_has_dsp) {
 254                                 ret = -EIO;
 255                                 break;
 256                         }
 257                         child->thread.dsp.dspcontrol = data;
 258                         break;
 259                 default:
 260                         /* The rest are not allowed. */
 261                         ret = -EIO;
 262                         break;
 263                 }
 264                 break;
 265                 }
 266
 267         case PTRACE_GETREGS:
 268                 ret = ptrace_getregs(child,
 269                                 (struct user_pt_regs __user *) (__u64) data);
 270                 break;
 271
 272         case PTRACE_SETREGS:
 273                 ret = ptrace_setregs(child,
 274                                 (struct user_pt_regs __user *) (__u64) data);
 275                 break;
 276
 277         case PTRACE_GETFPREGS:
 278                 ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
 279                 break;
 280
 281         case PTRACE_SETFPREGS:
 282                 ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
 283                 break;
 284
 285         case PTRACE_GET_THREAD_AREA:
 286                 ret = put_user(task_thread_info(child)->tp_value,
 287                                 (unsigned int __user *) (unsigned long) data);
 288                 break;
 289
 290         case PTRACE_GET_THREAD_AREA_3264:
 291                 ret = put_user(task_thread_info(child)->tp_value,
 292                                 (unsigned long __user *) (unsigned long) data);
 293                 break;
 294
 295         case PTRACE_GET_WATCH_REGS:
 296                 ret = ptrace_get_watch_regs(child,
 297                         (struct pt_watch_regs __user *) (unsigned long) addr);
 298                 break;
 299
 300         case PTRACE_SET_WATCH_REGS:
 301                 ret = ptrace_set_watch_regs(child,
 302                         (struct pt_watch_regs __user *) (unsigned long) addr);
 303                 break;
 304
 305         default:
 306                 ret = compat_ptrace_request(child, request, addr, data);
 307                 break;
 308         }
 309 out:
 310         return ret;
 311 }