arch/x86/ia32/ptrace32.c

   1 /*
   2  * 32bit ptrace for x86-64.
   3  *
   4  * Copyright 2001,2002 Andi Kleen, SuSE Labs.
   5  * Some parts copied from arch/i386/kernel/ptrace.c. See that file for earlier
   6  * copyright.
   7  *
   8  * This allows to access 64bit processes too; but there is no way to see the extended
   9  * register contents.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/stddef.h>
  14 #include <linux/sched.h>
  15 #include <linux/syscalls.h>
  16 #include <linux/unistd.h>
  17 #include <linux/mm.h>
  18 #include <linux/err.h>
  19 #include <linux/ptrace.h>
  20 #include <asm/ptrace.h>
  21 #include <asm/compat.h>
  22 #include <asm/uaccess.h>
  23 #include <asm/user32.h>
  24 #include <asm/user.h>
  25 #include <asm/errno.h>
  26 #include <asm/debugreg.h>
  27 #include <asm/i387.h>
  28 #include <asm/fpu32.h>
  29 #include <asm/ia32.h>
  30
  31 /*
  32  * Determines which flags the user has access to [1 = access, 0 = no access].
  33  * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
  34  * Also masks reserved bits (31-22, 15, 5, 3, 1).
  35  */
  36 #define FLAG_MASK 0x54dd5UL
  37
  38 #define R32(l,q) \
  39         case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
  40
  41 static int putreg32(struct task_struct *child, unsigned regno, u32 val)
  42 {
  43         int i;
  44         __u64 *stack = (__u64 *)task_pt_regs(child);
  45
  46         switch (regno) {
  47         case offsetof(struct user32, regs.fs):
  48                 if (val && (val & 3) != 3) return -EIO;
  49                 child->thread.fsindex = val & 0xffff;
  50                 break;
  51         case offsetof(struct user32, regs.gs):
  52                 if (val && (val & 3) != 3) return -EIO;
  53                 child->thread.gsindex = val & 0xffff;
  54                 break;
  55         case offsetof(struct user32, regs.ds):
  56                 if (val && (val & 3) != 3) return -EIO;
  57                 child->thread.ds = val & 0xffff;
  58                 break;
  59         case offsetof(struct user32, regs.es):
  60                 child->thread.es = val & 0xffff;
  61                 break;
  62         case offsetof(struct user32, regs.ss):
  63                 if ((val & 3) != 3) return -EIO;
  64                 stack[offsetof(struct pt_regs, ss)/8] = val & 0xffff;
  65                 break;
  66         case offsetof(struct user32, regs.cs):
  67                 if ((val & 3) != 3) return -EIO;
  68                 stack[offsetof(struct pt_regs, cs)/8] = val & 0xffff;
  69                 break;
  70
  71         R32(ebx, rbx);
  72         R32(ecx, rcx);
  73         R32(edx, rdx);
  74         R32(edi, rdi);
  75         R32(esi, rsi);
  76         R32(ebp, rbp);
  77         R32(eax, rax);
  78         R32(orig_eax, orig_rax);
  79         R32(eip, rip);
  80         R32(esp, rsp);
  81
  82         case offsetof(struct user32, regs.eflags): {
  83                 __u64 *flags = &stack[offsetof(struct pt_regs, eflags)/8];
  84                 val &= FLAG_MASK;
  85                 *flags = val | (*flags & ~FLAG_MASK);
  86                 break;
  87         }
  88
  89         case offsetof(struct user32, u_debugreg[4]):
  90         case offsetof(struct user32, u_debugreg[5]):
  91                 return -EIO;
  92
  93         case offsetof(struct user32, u_debugreg[0]):
  94                 child->thread.debugreg0 = val;
  95                 break;
  96
  97         case offsetof(struct user32, u_debugreg[1]):
  98                 child->thread.debugreg1 = val;
  99                 break;
 100
 101         case offsetof(struct user32, u_debugreg[2]):
 102                 child->thread.debugreg2 = val;
 103                 break;
 104
 105         case offsetof(struct user32, u_debugreg[3]):
 106                 child->thread.debugreg3 = val;
 107                 break;
 108
 109         case offsetof(struct user32, u_debugreg[6]):
 110                 child->thread.debugreg6 = val;
 111                 break;
 112
 113         case offsetof(struct user32, u_debugreg[7]):
 114                 val &= ~DR_CONTROL_RESERVED;
 115                 /* See arch/i386/kernel/ptrace.c for an explanation of
 116                  * this awkward check.*/
 117                 for(i=0; i<4; i++)
 118                         if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1)
 119                                return -EIO;
 120                 child->thread.debugreg7 = val;
 121                 if (val)
 122                         set_tsk_thread_flag(child, TIF_DEBUG);
 123                 else
 124                         clear_tsk_thread_flag(child, TIF_DEBUG);
 125                 break;
 126
 127         default:
 128                 if (regno > sizeof(struct user32) || (regno & 3))
 129                         return -EIO;
 130
 131                 /* Other dummy fields in the virtual user structure are ignored */
 132                 break;
 133         }
 134         return 0;
 135 }
 136
 137 #undef R32
 138
 139 #define R32(l,q) \
 140         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 141
 142 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 143 {
 144         __u64 *stack = (__u64 *)task_pt_regs(child);
 145
 146         switch (regno) {
 147         case offsetof(struct user32, regs.fs):
 148                 *val = child->thread.fsindex;
 149                 break;
 150         case offsetof(struct user32, regs.gs):
 151                 *val = child->thread.gsindex;
 152                 break;
 153         case offsetof(struct user32, regs.ds):
 154                 *val = child->thread.ds;
 155                 break;
 156         case offsetof(struct user32, regs.es):
 157                 *val = child->thread.es;
 158                 break;
 159
 160         R32(cs, cs);
 161         R32(ss, ss);
 162         R32(ebx, rbx);
 163         R32(ecx, rcx);
 164         R32(edx, rdx);
 165         R32(edi, rdi);
 166         R32(esi, rsi);
 167         R32(ebp, rbp);
 168         R32(eax, rax);
 169         R32(orig_eax, orig_rax);
 170         R32(eip, rip);
 171         R32(eflags, eflags);
 172         R32(esp, rsp);
 173
 174         case offsetof(struct user32, u_debugreg[0]):
 175                 *val = child->thread.debugreg0;
 176                 break;
 177         case offsetof(struct user32, u_debugreg[1]):
 178                 *val = child->thread.debugreg1;
 179                 break;
 180         case offsetof(struct user32, u_debugreg[2]):
 181                 *val = child->thread.debugreg2;
 182                 break;
 183         case offsetof(struct user32, u_debugreg[3]):
 184                 *val = child->thread.debugreg3;
 185                 break;
 186         case offsetof(struct user32, u_debugreg[6]):
 187                 *val = child->thread.debugreg6;
 188                 break;
 189         case offsetof(struct user32, u_debugreg[7]):
 190                 *val = child->thread.debugreg7;
 191                 break;
 192
 193         default:
 194                 if (regno > sizeof(struct user32) || (regno & 3))
 195                         return -EIO;
 196
 197                 /* Other dummy fields in the virtual user structure are ignored */
 198                 *val = 0;
 199                 break;
 200         }
 201         return 0;
 202 }
 203
 204 #undef R32
 205
 206 static long ptrace32_siginfo(unsigned request, u32 pid, u32 addr, u32 data)
 207 {
 208         int ret;
 209         compat_siginfo_t __user *si32 = compat_ptr(data);
 210         siginfo_t ssi;
 211         siginfo_t __user *si = compat_alloc_user_space(sizeof(siginfo_t));
 212         if (request == PTRACE_SETSIGINFO) {
 213                 memset(&ssi, 0, sizeof(siginfo_t));
 214                 ret = copy_siginfo_from_user32(&ssi, si32);
 215                 if (ret)
 216                         return ret;
 217                 if (copy_to_user(si, &ssi, sizeof(siginfo_t)))
 218                         return -EFAULT;
 219         }
 220         ret = sys_ptrace(request, pid, addr, (unsigned long)si);
 221         if (ret)
 222                 return ret;
 223         if (request == PTRACE_GETSIGINFO) {
 224                 if (copy_from_user(&ssi, si, sizeof(siginfo_t)))
 225                         return -EFAULT;
 226                 ret = copy_siginfo_to_user32(si32, &ssi);
 227         }
 228         return ret;
 229 }
 230
 231 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 232 {
 233         struct task_struct *child;
 234         struct pt_regs *childregs;
 235         void __user *datap = compat_ptr(data);
 236         int ret;
 237         __u32 val;
 238
 239         switch (request) {
 240         case PTRACE_TRACEME:
 241         case PTRACE_ATTACH:
 242         case PTRACE_KILL:
 243         case PTRACE_CONT:
 244         case PTRACE_SINGLESTEP:
 245         case PTRACE_DETACH:
 246         case PTRACE_SYSCALL:
 247         case PTRACE_OLDSETOPTIONS:
 248         case PTRACE_SETOPTIONS:
 249         case PTRACE_SET_THREAD_AREA:
 250         case PTRACE_GET_THREAD_AREA:
 251                 return sys_ptrace(request, pid, addr, data);
 252
 253         default:
 254                 return -EINVAL;
 255
 256         case PTRACE_PEEKTEXT:
 257         case PTRACE_PEEKDATA:
 258         case PTRACE_POKEDATA:
 259         case PTRACE_POKETEXT:
 260         case PTRACE_POKEUSR:
 261         case PTRACE_PEEKUSR:
 262         case PTRACE_GETREGS:
 263         case PTRACE_SETREGS:
 264         case PTRACE_SETFPREGS:
 265         case PTRACE_GETFPREGS:
 266         case PTRACE_SETFPXREGS:
 267         case PTRACE_GETFPXREGS:
 268         case PTRACE_GETEVENTMSG:
 269                 break;
 270
 271         case PTRACE_SETSIGINFO:
 272         case PTRACE_GETSIGINFO:
 273                 return ptrace32_siginfo(request, pid, addr, data);
 274         }
 275
 276         child = ptrace_get_task_struct(pid);
 277         if (IS_ERR(child))
 278                 return PTR_ERR(child);
 279
 280         ret = ptrace_check_attach(child, request == PTRACE_KILL);
 281         if (ret < 0)
 282                 goto out;
 283
 284         childregs = task_pt_regs(child);
 285
 286         switch (request) {
 287         case PTRACE_PEEKDATA:
 288         case PTRACE_PEEKTEXT:
 289                 ret = 0;
 290                 if (access_process_vm(child, addr, &val, sizeof(u32), 0)!=sizeof(u32))
 291                         ret = -EIO;
 292                 else
 293                         ret = put_user(val, (unsigned int __user *)datap);
 294                 break;
 295
 296         case PTRACE_POKEDATA:
 297         case PTRACE_POKETEXT:
 298                 ret = 0;
 299                 if (access_process_vm(child, addr, &data, sizeof(u32), 1)!=sizeof(u32))
 300                         ret = -EIO;
 301                 break;
 302
 303         case PTRACE_PEEKUSR:
 304                 ret = getreg32(child, addr, &val);
 305                 if (ret == 0)
 306                         ret = put_user(val, (__u32 __user *)datap);
 307                 break;
 308
 309         case PTRACE_POKEUSR:
 310                 ret = putreg32(child, addr, data);
 311                 break;
 312
 313         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 314                 int i;
 315                 if (!access_ok(VERIFY_WRITE, datap, 16*4)) {
 316                         ret = -EIO;
 317                         break;
 318                 }
 319                 ret = 0;
 320                 for ( i = 0; i <= 16*4 ; i += sizeof(__u32) ) {
 321                         getreg32(child, i, &val);
 322                         ret |= __put_user(val,(u32 __user *)datap);
 323                         datap += sizeof(u32);
 324                 }
 325                 break;
 326         }
 327
 328         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 329                 unsigned long tmp;
 330                 int i;
 331                 if (!access_ok(VERIFY_READ, datap, 16*4)) {
 332                         ret = -EIO;
 333                         break;
 334                 }
 335                 ret = 0;
 336                 for ( i = 0; i <= 16*4; i += sizeof(u32) ) {
 337                         ret |= __get_user(tmp, (u32 __user *)datap);
 338                         putreg32(child, i, tmp);
 339                         datap += sizeof(u32);
 340                 }
 341                 break;
 342         }
 343
 344         case PTRACE_GETFPREGS:
 345                 ret = -EIO;
 346                 if (!access_ok(VERIFY_READ, compat_ptr(data),
 347                                sizeof(struct user_i387_struct)))
 348                         break;
 349                 save_i387_ia32(child, datap, childregs, 1);
 350                 ret = 0;
 351                         break;
 352
 353         case PTRACE_SETFPREGS:
 354                 ret = -EIO;
 355                 if (!access_ok(VERIFY_WRITE, datap,
 356                                sizeof(struct user_i387_struct)))
 357                         break;
 358                 ret = 0;
 359                 /* don't check EFAULT to be bug-to-bug compatible to i386 */
 360                 restore_i387_ia32(child, datap, 1);
 361                 break;
 362
 363         case PTRACE_GETFPXREGS: {
 364                 struct user32_fxsr_struct __user *u = datap;
 365                 init_fpu(child);
 366                 ret = -EIO;
 367                 if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
 368                         break;
 369                         ret = -EFAULT;
 370                 if (__copy_to_user(u, &child->thread.i387.fxsave, sizeof(*u)))
 371                         break;
 372                 ret = __put_user(childregs->cs, &u->fcs);
 373                 ret |= __put_user(child->thread.ds, &u->fos);
 374                 break;
 375         }
 376         case PTRACE_SETFPXREGS: {
 377                 struct user32_fxsr_struct __user *u = datap;
 378                 unlazy_fpu(child);
 379                 ret = -EIO;
 380                 if (!access_ok(VERIFY_READ, u, sizeof(*u)))
 381                         break;
 382                 /* no checking to be bug-to-bug compatible with i386. */
 383                 /* but silence warning */
 384                 if (__copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u)))
 385                         ;
 386                 set_stopped_child_used_math(child);
 387                 child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
 388                 ret = 0;
 389                 break;
 390         }
 391
 392         case PTRACE_GETEVENTMSG:
 393                 ret = put_user(child->ptrace_message,(unsigned int __user *)compat_ptr(data));
 394                 break;
 395
 396         default:
 397                 BUG();
 398         }
 399
 400  out:
 401         put_task_struct(child);
 402         return ret;
 403 }
 404