arch/x86_64/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/ptrace.h>
  19 #include <asm/ptrace.h>
  20 #include <asm/compat.h>
  21 #include <asm/uaccess.h>
  22 #include <asm/user32.h>
  23 #include <asm/user.h>
  24 #include <asm/errno.h>
  25 #include <asm/debugreg.h>
  26 #include <asm/i387.h>
  27 #include <asm/fpu32.h>
  28 #include <asm/ia32.h>
  29
  30 /*
  31  * Determines which flags the user has access to [1 = access, 0 = no access].
  32  * Prohibits changing ID(21), VIP(20), VIF(19), VM(17), IOPL(12-13), IF(9).
  33  * Also masks reserved bits (31-22, 15, 5, 3, 1).
  34  */
  35 #define FLAG_MASK 0x54dd5UL
  36
  37 #define R32(l,q) \
  38         case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
  39
  40 static int putreg32(struct task_struct *child, unsigned regno, u32 val)
  41 {
  42         int i;
  43         __u64 *stack = (__u64 *)task_pt_regs(child);
  44
  45         switch (regno) {
  46         case offsetof(struct user32, regs.fs):
  47                 if (val && (val & 3) != 3) return -EIO;
  48                 child->thread.fsindex = val & 0xffff;
  49                 break;
  50         case offsetof(struct user32, regs.gs):
  51                 if (val && (val & 3) != 3) return -EIO;
  52                 child->thread.gsindex = val & 0xffff;
  53                 break;
  54         case offsetof(struct user32, regs.ds):
  55                 if (val && (val & 3) != 3) return -EIO;
  56                 child->thread.ds = val & 0xffff;
  57                 break;
  58         case offsetof(struct user32, regs.es):
  59                 child->thread.es = val & 0xffff;
  60                 break;
  61         case offsetof(struct user32, regs.ss):
  62                 if ((val & 3) != 3) return -EIO;
  63                 stack[offsetof(struct pt_regs, ss)/8] = val & 0xffff;
  64                 break;
  65         case offsetof(struct user32, regs.cs):
  66                 if ((val & 3) != 3) return -EIO;
  67                 stack[offsetof(struct pt_regs, cs)/8] = val & 0xffff;
  68                 break;
  69
  70         R32(ebx, rbx);
  71         R32(ecx, rcx);
  72         R32(edx, rdx);
  73         R32(edi, rdi);
  74         R32(esi, rsi);
  75         R32(ebp, rbp);
  76         R32(eax, rax);
  77         R32(orig_eax, orig_rax);
  78         R32(eip, rip);
  79         R32(esp, rsp);
  80
  81         case offsetof(struct user32, regs.eflags): {
  82                 __u64 *flags = &stack[offsetof(struct pt_regs, eflags)/8];
  83                 val &= FLAG_MASK;
  84                 *flags = val | (*flags & ~FLAG_MASK);
  85                 break;
  86         }
  87
  88         case offsetof(struct user32, u_debugreg[4]):
  89         case offsetof(struct user32, u_debugreg[5]):
  90                 return -EIO;
  91
  92         case offsetof(struct user32, u_debugreg[0]):
  93                 child->thread.debugreg0 = val;
  94                 break;
  95
  96         case offsetof(struct user32, u_debugreg[1]):
  97                 child->thread.debugreg1 = val;
  98                 break;
  99
 100         case offsetof(struct user32, u_debugreg[2]):
 101                 child->thread.debugreg2 = val;
 102                 break;
 103
 104         case offsetof(struct user32, u_debugreg[3]):
 105                 child->thread.debugreg3 = val;
 106                 break;
 107
 108         case offsetof(struct user32, u_debugreg[6]):
 109                 child->thread.debugreg6 = val;
 110                 break;
 111
 112         case offsetof(struct user32, u_debugreg[7]):
 113                 val &= ~DR_CONTROL_RESERVED;
 114                 /* See arch/i386/kernel/ptrace.c for an explanation of
 115                  * this awkward check.*/
 116                 for(i=0; i<4; i++)
 117                         if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1)
 118                                return -EIO;
 119                 child->thread.debugreg7 = val;
 120                 if (val)
 121                         set_tsk_thread_flag(child, TIF_DEBUG);
 122                 else
 123                         clear_tsk_thread_flag(child, TIF_DEBUG);
 124                 break;
 125
 126         default:
 127                 if (regno > sizeof(struct user32) || (regno & 3))
 128                         return -EIO;
 129
 130                 /* Other dummy fields in the virtual user structure are ignored */
 131                 break;
 132         }
 133         return 0;
 134 }
 135
 136 #undef R32
 137
 138 #define R32(l,q) \
 139         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 140
 141 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 142 {
 143         __u64 *stack = (__u64 *)task_pt_regs(child);
 144
 145         switch (regno) {
 146         case offsetof(struct user32, regs.fs):
 147                 *val = child->thread.fsindex;
 148                 break;
 149         case offsetof(struct user32, regs.gs):
 150                 *val = child->thread.gsindex;
 151                 break;
 152         case offsetof(struct user32, regs.ds):
 153                 *val = child->thread.ds;
 154                 break;
 155         case offsetof(struct user32, regs.es):
 156                 *val = child->thread.es;
 157                 break;
 158
 159         R32(cs, cs);
 160         R32(ss, ss);
 161         R32(ebx, rbx);
 162         R32(ecx, rcx);
 163         R32(edx, rdx);
 164         R32(edi, rdi);
 165         R32(esi, rsi);
 166         R32(ebp, rbp);
 167         R32(eax, rax);
 168         R32(orig_eax, orig_rax);
 169         R32(eip, rip);
 170         R32(eflags, eflags);
 171         R32(esp, rsp);
 172
 173         case offsetof(struct user32, u_debugreg[0]):
 174                 *val = child->thread.debugreg0;
 175                 break;
 176         case offsetof(struct user32, u_debugreg[1]):
 177                 *val = child->thread.debugreg1;
 178                 break;
 179         case offsetof(struct user32, u_debugreg[2]):
 180                 *val = child->thread.debugreg2;
 181                 break;
 182         case offsetof(struct user32, u_debugreg[3]):
 183                 *val = child->thread.debugreg3;
 184                 break;
 185         case offsetof(struct user32, u_debugreg[6]):
 186                 *val = child->thread.debugreg6;
 187                 break;
 188         case offsetof(struct user32, u_debugreg[7]):
 189                 *val = child->thread.debugreg7;
 190                 break;
 191
 192         default:
 193                 if (regno > sizeof(struct user32) || (regno & 3))
 194                         return -EIO;
 195
 196                 /* Other dummy fields in the virtual user structure are ignored */
 197                 *val = 0;
 198                 break;
 199         }
 200         return 0;
 201 }
 202
 203 #undef R32
 204
 205 static long ptrace32_siginfo(unsigned request, u32 pid, u32 addr, u32 data)
 206 {
 207         int ret;
 208         compat_siginfo_t *si32 = (compat_siginfo_t *)compat_ptr(data);
 209         siginfo_t ssi;
 210         siginfo_t *si = compat_alloc_user_space(sizeof(siginfo_t));
 211         if (request == PTRACE_SETSIGINFO) {
 212                 memset(&ssi, 0, sizeof(siginfo_t));
 213                 ret = copy_siginfo_from_user32(&ssi, si32);
 214                 if (ret)
 215                         return ret;
 216                 if (copy_to_user(si, &ssi, sizeof(siginfo_t)))
 217                         return -EFAULT;
 218         }
 219         ret = sys_ptrace(request, pid, addr, (unsigned long)si);
 220         if (ret)
 221                 return ret;
 222         if (request == PTRACE_GETSIGINFO) {
 223                 if (copy_from_user(&ssi, si, sizeof(siginfo_t)))
 224                         return -EFAULT;
 225                 ret = copy_siginfo_to_user32(si32, &ssi);
 226         }
 227         return ret;
 228 }
 229
 230 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 231 {
 232         struct task_struct *child;
 233         struct pt_regs *childregs;
 234         void __user *datap = compat_ptr(data);
 235         int ret;
 236         __u32 val;
 237
 238         switch (request) {
 239         case PTRACE_TRACEME:
 240         case PTRACE_ATTACH:
 241         case PTRACE_KILL:
 242         case PTRACE_CONT:
 243         case PTRACE_SINGLESTEP:
 244         case PTRACE_DETACH:
 245         case PTRACE_SYSCALL:
 246         case PTRACE_SETOPTIONS:
 247                 return sys_ptrace(request, pid, addr, data);
 248
 249         default:
 250                 return -EINVAL;
 251
 252         case PTRACE_PEEKTEXT:
 253         case PTRACE_PEEKDATA:
 254         case PTRACE_POKEDATA:
 255         case PTRACE_POKETEXT:
 256         case PTRACE_POKEUSR:
 257         case PTRACE_PEEKUSR:
 258         case PTRACE_GETREGS:
 259         case PTRACE_SETREGS:
 260         case PTRACE_SETFPREGS:
 261         case PTRACE_GETFPREGS:
 262         case PTRACE_SETFPXREGS:
 263         case PTRACE_GETFPXREGS:
 264         case PTRACE_GETEVENTMSG:
 265                 break;
 266
 267         case PTRACE_SETSIGINFO:
 268         case PTRACE_GETSIGINFO:
 269                 return ptrace32_siginfo(request, pid, addr, data);
 270         }
 271
 272         child = ptrace_get_task_struct(pid);
 273         if (IS_ERR(child))
 274                 return PTR_ERR(child);
 275
 276         ret = ptrace_check_attach(child, request == PTRACE_KILL);
 277         if (ret < 0)
 278                 goto out;
 279
 280         childregs = task_pt_regs(child);
 281
 282         switch (request) {
 283         case PTRACE_PEEKDATA:
 284         case PTRACE_PEEKTEXT:
 285                 ret = 0;
 286                 if (access_process_vm(child, addr, &val, sizeof(u32), 0)!=sizeof(u32))
 287                         ret = -EIO;
 288                 else
 289                         ret = put_user(val, (unsigned int __user *)datap);
 290                 break;
 291
 292         case PTRACE_POKEDATA:
 293         case PTRACE_POKETEXT:
 294                 ret = 0;
 295                 if (access_process_vm(child, addr, &data, sizeof(u32), 1)!=sizeof(u32))
 296                         ret = -EIO;
 297                 break;
 298
 299         case PTRACE_PEEKUSR:
 300                 ret = getreg32(child, addr, &val);
 301                 if (ret == 0)
 302                         ret = put_user(val, (__u32 __user *)datap);
 303                 break;
 304
 305         case PTRACE_POKEUSR:
 306                 ret = putreg32(child, addr, data);
 307                 break;
 308
 309         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 310                 int i;
 311                 if (!access_ok(VERIFY_WRITE, datap, 16*4)) {
 312                         ret = -EIO;
 313                         break;
 314                 }
 315                 ret = 0;
 316                 for ( i = 0; i <= 16*4 ; i += sizeof(__u32) ) {
 317                         getreg32(child, i, &val);
 318                         ret |= __put_user(val,(u32 __user *)datap);
 319                         datap += sizeof(u32);
 320                 }
 321                 break;
 322         }
 323
 324         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 325                 unsigned long tmp;
 326                 int i;
 327                 if (!access_ok(VERIFY_READ, datap, 16*4)) {
 328                         ret = -EIO;
 329                         break;
 330                 }
 331                 ret = 0;
 332                 for ( i = 0; i <= 16*4; i += sizeof(u32) ) {
 333                         ret |= __get_user(tmp, (u32 __user *)datap);
 334                         putreg32(child, i, tmp);
 335                         datap += sizeof(u32);
 336                 }
 337                 break;
 338         }
 339
 340         case PTRACE_GETFPREGS:
 341                 ret = -EIO;
 342                 if (!access_ok(VERIFY_READ, compat_ptr(data),
 343                                sizeof(struct user_i387_struct)))
 344                         break;
 345                 save_i387_ia32(child, datap, childregs, 1);
 346                 ret = 0;
 347                         break;
 348
 349         case PTRACE_SETFPREGS:
 350                 ret = -EIO;
 351                 if (!access_ok(VERIFY_WRITE, datap,
 352                                sizeof(struct user_i387_struct)))
 353                         break;
 354                 ret = 0;
 355                 /* don't check EFAULT to be bug-to-bug compatible to i386 */
 356                 restore_i387_ia32(child, datap, 1);
 357                 break;
 358
 359         case PTRACE_GETFPXREGS: {
 360                 struct user32_fxsr_struct __user *u = datap;
 361                 init_fpu(child);
 362                 ret = -EIO;
 363                 if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
 364                         break;
 365                         ret = -EFAULT;
 366                 if (__copy_to_user(u, &child->thread.i387.fxsave, sizeof(*u)))
 367                         break;
 368                 ret = __put_user(childregs->cs, &u->fcs);
 369                 ret |= __put_user(child->thread.ds, &u->fos);
 370                 break;
 371         }
 372         case PTRACE_SETFPXREGS: {
 373                 struct user32_fxsr_struct __user *u = datap;
 374                 unlazy_fpu(child);
 375                 ret = -EIO;
 376                 if (!access_ok(VERIFY_READ, u, sizeof(*u)))
 377                         break;
 378                 /* no checking to be bug-to-bug compatible with i386. */
 379                 /* but silence warning */
 380                 if (__copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u)))
 381                         ;
 382                 set_stopped_child_used_math(child);
 383                 child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
 384                 ret = 0;
 385                 break;
 386         }
 387
 388         case PTRACE_GETEVENTMSG:
 389                 ret = put_user(child->ptrace_message,(unsigned int __user *)compat_ptr(data));
 390                 break;
 391
 392         default:
 393                 BUG();
 394         }
 395
 396  out:
 397         put_task_struct(child);
 398         return ret;
 399 }
 400