LXR linux/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 */
  44long 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        }
 316out:
 317        return ret;
 318}
 319