linux/arch/mips/kernel/ptrace32.c
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   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/page.h>
  34#include <asm/reg.h>
  35#include <asm/syscall.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 */
  43long 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                unsigned int tmp;
  85
  86                regs = task_pt_regs(child);
  87                ret = 0;  /* Default return value. */
  88
  89                switch (addr) {
  90                case 0 ... 31:
  91                        tmp = regs->regs[addr];
  92                        break;
  93#ifdef CONFIG_MIPS_FP_SUPPORT
  94                case FPR_BASE ... FPR_BASE + 31: {
  95                        union fpureg *fregs;
  96
  97                        if (!tsk_used_math(child)) {
  98                                /* FP not yet used */
  99                                tmp = -1;
 100                                break;
 101                        }
 102                        fregs = get_fpu_regs(child);
 103                        if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 104                                /*
 105                                 * The odd registers are actually the high
 106                                 * order bits of the values stored in the even
 107                                 * registers.
 108                                 */
 109                                tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 110                                                addr & 1);
 111                                break;
 112                        }
 113                        tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
 114                        break;
 115                }
 116                case FPC_CSR:
 117                        tmp = child->thread.fpu.fcr31;
 118                        break;
 119                case FPC_EIR:
 120                        /* implementation / version register */
 121                        tmp = boot_cpu_data.fpu_id;
 122                        break;
 123#endif /* CONFIG_MIPS_FP_SUPPORT */
 124                case PC:
 125                        tmp = regs->cp0_epc;
 126                        break;
 127                case CAUSE:
 128                        tmp = regs->cp0_cause;
 129                        break;
 130                case BADVADDR:
 131                        tmp = regs->cp0_badvaddr;
 132                        break;
 133                case MMHI:
 134                        tmp = regs->hi;
 135                        break;
 136                case MMLO:
 137                        tmp = regs->lo;
 138                        break;
 139                case DSP_BASE ... DSP_BASE + 5: {
 140                        dspreg_t *dregs;
 141
 142                        if (!cpu_has_dsp) {
 143                                tmp = 0;
 144                                ret = -EIO;
 145                                goto out;
 146                        }
 147                        dregs = __get_dsp_regs(child);
 148                        tmp = dregs[addr - DSP_BASE];
 149                        break;
 150                }
 151                case DSP_CONTROL:
 152                        if (!cpu_has_dsp) {
 153                                tmp = 0;
 154                                ret = -EIO;
 155                                goto out;
 156                        }
 157                        tmp = child->thread.dsp.dspcontrol;
 158                        break;
 159                default:
 160                        tmp = 0;
 161                        ret = -EIO;
 162                        goto out;
 163                }
 164                ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
 165                break;
 166        }
 167
 168        /*
 169         * Write 4 bytes into the other process' storage
 170         *  data is the 4 bytes that the user wants written
 171         *  addr is a pointer in the user's storage that contains an
 172         *      8 byte address in the other process where the 4 bytes
 173         *      that is to be written
 174         * (this is run in a 32-bit process looking at a 64-bit process)
 175         * when I and D space are separate, these will need to be fixed.
 176         */
 177        case PTRACE_POKETEXT_3264:
 178        case PTRACE_POKEDATA_3264: {
 179                u32 __user * addrOthers;
 180
 181                /* Get the addr in the other process that we want to write into */
 182                ret = -EIO;
 183                if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
 184                        break;
 185                ret = 0;
 186                if (ptrace_access_vm(child, (u64)addrOthers, &data,
 187                                        sizeof(data),
 188                                        FOLL_FORCE | FOLL_WRITE) == sizeof(data))
 189                        break;
 190                ret = -EIO;
 191                break;
 192        }
 193
 194        case PTRACE_POKEUSR: {
 195                struct pt_regs *regs;
 196                ret = 0;
 197                regs = task_pt_regs(child);
 198
 199                switch (addr) {
 200                case 0 ... 31:
 201                        regs->regs[addr] = data;
 202                        /* System call number may have been changed */
 203                        if (addr == 2)
 204                                mips_syscall_update_nr(child, regs);
 205                        else if (addr == 4 &&
 206                                 mips_syscall_is_indirect(child, regs))
 207                                mips_syscall_update_nr(child, regs);
 208                        break;
 209#ifdef CONFIG_MIPS_FP_SUPPORT
 210                case FPR_BASE ... FPR_BASE + 31: {
 211                        union fpureg *fregs = get_fpu_regs(child);
 212
 213                        if (!tsk_used_math(child)) {
 214                                /* FP not yet used  */
 215                                memset(&child->thread.fpu, ~0,
 216                                       sizeof(child->thread.fpu));
 217                                child->thread.fpu.fcr31 = 0;
 218                        }
 219                        if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
 220                                /*
 221                                 * The odd registers are actually the high
 222                                 * order bits of the values stored in the even
 223                                 * registers.
 224                                 */
 225                                set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
 226                                          addr & 1, data);
 227                                break;
 228                        }
 229                        set_fpr64(&fregs[addr - FPR_BASE], 0, data);
 230                        break;
 231                }
 232                case FPC_CSR:
 233                        child->thread.fpu.fcr31 = data;
 234                        break;
 235#endif /* CONFIG_MIPS_FP_SUPPORT */
 236                case PC:
 237                        regs->cp0_epc = data;
 238                        break;
 239                case MMHI:
 240                        regs->hi = data;
 241                        break;
 242                case MMLO:
 243                        regs->lo = data;
 244                        break;
 245                case DSP_BASE ... DSP_BASE + 5: {
 246                        dspreg_t *dregs;
 247
 248                        if (!cpu_has_dsp) {
 249                                ret = -EIO;
 250                                break;
 251                        }
 252
 253                        dregs = __get_dsp_regs(child);
 254                        dregs[addr - DSP_BASE] = data;
 255                        break;
 256                }
 257                case DSP_CONTROL:
 258                        if (!cpu_has_dsp) {
 259                                ret = -EIO;
 260                                break;
 261                        }
 262                        child->thread.dsp.dspcontrol = data;
 263                        break;
 264                default:
 265                        /* The rest are not allowed. */
 266                        ret = -EIO;
 267                        break;
 268                }
 269                break;
 270                }
 271
 272        case PTRACE_GETREGS:
 273                ret = ptrace_getregs(child,
 274                                (struct user_pt_regs __user *) (__u64) data);
 275                break;
 276
 277        case PTRACE_SETREGS:
 278                ret = ptrace_setregs(child,
 279                                (struct user_pt_regs __user *) (__u64) data);
 280                break;
 281
 282#ifdef CONFIG_MIPS_FP_SUPPORT
 283        case PTRACE_GETFPREGS:
 284                ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
 285                break;
 286
 287        case PTRACE_SETFPREGS:
 288                ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
 289                break;
 290#endif
 291        case PTRACE_GET_THREAD_AREA:
 292                ret = put_user(task_thread_info(child)->tp_value,
 293                                (unsigned int __user *) (unsigned long) data);
 294                break;
 295
 296        case PTRACE_GET_THREAD_AREA_3264:
 297                ret = put_user(task_thread_info(child)->tp_value,
 298                                (unsigned long __user *) (unsigned long) data);
 299                break;
 300
 301        case PTRACE_GET_WATCH_REGS:
 302                ret = ptrace_get_watch_regs(child,
 303                        (struct pt_watch_regs __user *) (unsigned long) addr);
 304                break;
 305
 306        case PTRACE_SET_WATCH_REGS:
 307                ret = ptrace_set_watch_regs(child,
 308                        (struct pt_watch_regs __user *) (unsigned long) addr);
 309                break;
 310
 311        default:
 312                ret = compat_ptrace_request(child, request, addr, data);
 313                break;
 314        }
 315out:
 316        return ret;
 317}
 318