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, [email protected] and Carsten Langgaard, [email protected]
  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                 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 #ifdef CONFIG_MIPS_FP_SUPPORT
  95                 case FPR_BASE ... FPR_BASE + 31: {
  96                         union fpureg *fregs;
  97
  98                         if (!tsk_used_math(child)) {
  99                                 /* FP not yet used */
 100                                 tmp = -1;
 101                                 break;
 102                         }
 103                         fregs = get_fpu_regs(child);
 104                         if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 105                                 /*
 106                                  * The odd registers are actually the high
 107                                  * order bits of the values stored in the even
 108                                  * registers.
 109                                  */
 110                                 tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 111                                                 addr & 1);
 112                                 break;
 113                         }
 114                         tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
 115                         break;
 116                 }
 117                 case FPC_CSR:
 118                         tmp = child->thread.fpu.fcr31;
 119                         break;
 120                 case FPC_EIR:
 121                         /* implementation / version register */
 122                         tmp = boot_cpu_data.fpu_id;
 123                         break;
 124 #endif /* CONFIG_MIPS_FP_SUPPORT */
 125                 case PC:
 126                         tmp = regs->cp0_epc;
 127                         break;
 128                 case CAUSE:
 129                         tmp = regs->cp0_cause;
 130                         break;
 131                 case BADVADDR:
 132                         tmp = regs->cp0_badvaddr;
 133                         break;
 134                 case MMHI:
 135                         tmp = regs->hi;
 136                         break;
 137                 case MMLO:
 138                         tmp = regs->lo;
 139                         break;
 140                 case DSP_BASE ... DSP_BASE + 5: {
 141                         dspreg_t *dregs;
 142
 143                         if (!cpu_has_dsp) {
 144                                 tmp = 0;
 145                                 ret = -EIO;
 146                                 goto out;
 147                         }
 148                         dregs = __get_dsp_regs(child);
 149                         tmp = dregs[addr - DSP_BASE];
 150                         break;
 151                 }
 152                 case DSP_CONTROL:
 153                         if (!cpu_has_dsp) {
 154                                 tmp = 0;
 155                                 ret = -EIO;
 156                                 goto out;
 157                         }
 158                         tmp = child->thread.dsp.dspcontrol;
 159                         break;
 160                 default:
 161                         tmp = 0;
 162                         ret = -EIO;
 163                         goto out;
 164                 }
 165                 ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
 166                 break;
 167         }
 168
 169         /*
 170          * Write 4 bytes into the other process' storage
 171          *  data is the 4 bytes that the user wants written
 172          *  addr is a pointer in the user's storage that contains an
 173          *      8 byte address in the other process where the 4 bytes
 174          *      that is to be written
 175          * (this is run in a 32-bit process looking at a 64-bit process)
 176          * when I and D space are separate, these will need to be fixed.
 177          */
 178         case PTRACE_POKETEXT_3264:
 179         case PTRACE_POKEDATA_3264: {
 180                 u32 __user * addrOthers;
 181
 182                 /* Get the addr in the other process that we want to write into */
 183                 ret = -EIO;
 184                 if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 185                         break;
 186                 ret = 0;
 187                 if (ptrace_access_vm(child, (u64)addrOthers, &data,
 188                                         sizeof(data),
 189                                         FOLL_FORCE | FOLL_WRITE) == sizeof(data))
 190                         break;
 191                 ret = -EIO;
 192                 break;
 193         }
 194
 195         case PTRACE_POKEUSR: {
 196                 struct pt_regs *regs;
 197                 ret = 0;
 198                 regs = task_pt_regs(child);
 199
 200                 switch (addr) {
 201                 case 0 ... 31:
 202                         regs->regs[addr] = data;
 203                         /* System call number may have been changed */
 204                         if (addr == 2)
 205                                 mips_syscall_update_nr(child, regs);
 206                         else if (addr == 4 &&
 207                                  mips_syscall_is_indirect(child, regs))
 208                                 mips_syscall_update_nr(child, regs);
 209                         break;
 210 #ifdef CONFIG_MIPS_FP_SUPPORT
 211                 case FPR_BASE ... FPR_BASE + 31: {
 212                         union fpureg *fregs = get_fpu_regs(child);
 213
 214                         if (!tsk_used_math(child)) {
 215                                 /* FP not yet used  */
 216                                 memset(&child->thread.fpu, ~0,
 217                                        sizeof(child->thread.fpu));
 218                                 child->thread.fpu.fcr31 = 0;
 219                         }
 220                         if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 221                                 /*
 222                                  * The odd registers are actually the high
 223                                  * order bits of the values stored in the even
 224                                  * registers.
 225                                  */
 226                                 set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 227                                           addr & 1, data);
 228                                 break;
 229                         }
 230                         set_fpr64(&fregs[addr - FPR_BASE], 0, data);
 231                         break;
 232                 }
 233                 case FPC_CSR:
 234                         child->thread.fpu.fcr31 = data;
 235                         break;
 236 #endif /* CONFIG_MIPS_FP_SUPPORT */
 237                 case PC:
 238                         regs->cp0_epc = data;
 239                         break;
 240                 case MMHI:
 241                         regs->hi = data;
 242                         break;
 243                 case MMLO:
 244                         regs->lo = data;
 245                         break;
 246                 case DSP_BASE ... DSP_BASE + 5: {
 247                         dspreg_t *dregs;
 248
 249                         if (!cpu_has_dsp) {
 250                                 ret = -EIO;
 251                                 break;
 252                         }
 253
 254                         dregs = __get_dsp_regs(child);
 255                         dregs[addr - DSP_BASE] = data;
 256                         break;
 257                 }
 258                 case DSP_CONTROL:
 259                         if (!cpu_has_dsp) {
 260                                 ret = -EIO;
 261                                 break;
 262                         }
 263                         child->thread.dsp.dspcontrol = data;
 264                         break;
 265                 default:
 266                         /* The rest are not allowed. */
 267                         ret = -EIO;
 268                         break;
 269                 }
 270                 break;
 271                 }
 272
 273         case PTRACE_GETREGS:
 274                 ret = ptrace_getregs(child,
 275                                 (struct user_pt_regs __user *) (__u64) data);
 276                 break;
 277
 278         case PTRACE_SETREGS:
 279                 ret = ptrace_setregs(child,
 280                                 (struct user_pt_regs __user *) (__u64) data);
 281                 break;
 282
 283 #ifdef CONFIG_MIPS_FP_SUPPORT
 284         case PTRACE_GETFPREGS:
 285                 ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
 286                 break;
 287
 288         case PTRACE_SETFPREGS:
 289                 ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
 290                 break;
 291 #endif
 292         case PTRACE_GET_THREAD_AREA:
 293                 ret = put_user(task_thread_info(child)->tp_value,
 294                                 (unsigned int __user *) (unsigned long) data);
 295                 break;
 296
 297         case PTRACE_GET_THREAD_AREA_3264:
 298                 ret = put_user(task_thread_info(child)->tp_value,
 299                                 (unsigned long __user *) (unsigned long) data);
 300                 break;
 301
 302         case PTRACE_GET_WATCH_REGS:
 303                 ret = ptrace_get_watch_regs(child,
 304                         (struct pt_watch_regs __user *) (unsigned long) addr);
 305                 break;
 306
 307         case PTRACE_SET_WATCH_REGS:
 308                 ret = ptrace_set_watch_regs(child,
 309                         (struct pt_watch_regs __user *) (unsigned long) addr);
 310                 break;
 311
 312         default:
 313                 ret = compat_ptrace_request(child, request, addr, data);
 314                 break;
 315         }
 316 out:
 317         return ret;
 318 }