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  * $Id: ptrace32.c,v 1.16 2003/03/14 16:06:35 ak Exp $
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/stddef.h>
  16 #include <linux/sched.h>
  17 #include <linux/syscalls.h>
  18 #include <linux/unistd.h>
  19 #include <linux/mm.h>
  20 #include <linux/ptrace.h>
  21 #include <asm/ptrace.h>
  22 #include <asm/compat.h>
  23 #include <asm/uaccess.h>
  24 #include <asm/user32.h>
  25 #include <asm/user.h>
  26 #include <asm/errno.h>
  27 #include <asm/debugreg.h>
  28 #include <asm/i387.h>
  29 #include <asm/fpu32.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                 break;
 122
 123         default:
 124                 if (regno > sizeof(struct user32) || (regno & 3))
 125                         return -EIO;
 126
 127                 /* Other dummy fields in the virtual user structure are ignored */
 128                 break;
 129         }
 130         return 0;
 131 }
 132
 133 #undef R32
 134
 135 #define R32(l,q) \
 136         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 137
 138 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 139 {
 140         __u64 *stack = (__u64 *)task_pt_regs(child);
 141
 142         switch (regno) {
 143         case offsetof(struct user32, regs.fs):
 144                 *val = child->thread.fsindex;
 145                 break;
 146         case offsetof(struct user32, regs.gs):
 147                 *val = child->thread.gsindex;
 148                 break;
 149         case offsetof(struct user32, regs.ds):
 150                 *val = child->thread.ds;
 151                 break;
 152         case offsetof(struct user32, regs.es):
 153                 *val = child->thread.es;
 154                 break;
 155
 156         R32(cs, cs);
 157         R32(ss, ss);
 158         R32(ebx, rbx);
 159         R32(ecx, rcx);
 160         R32(edx, rdx);
 161         R32(edi, rdi);
 162         R32(esi, rsi);
 163         R32(ebp, rbp);
 164         R32(eax, rax);
 165         R32(orig_eax, orig_rax);
 166         R32(eip, rip);
 167         R32(eflags, eflags);
 168         R32(esp, rsp);
 169
 170         case offsetof(struct user32, u_debugreg[0]):
 171                 *val = child->thread.debugreg0;
 172                 break;
 173         case offsetof(struct user32, u_debugreg[1]):
 174                 *val = child->thread.debugreg1;
 175                 break;
 176         case offsetof(struct user32, u_debugreg[2]):
 177                 *val = child->thread.debugreg2;
 178                 break;
 179         case offsetof(struct user32, u_debugreg[3]):
 180                 *val = child->thread.debugreg3;
 181                 break;
 182         case offsetof(struct user32, u_debugreg[6]):
 183                 *val = child->thread.debugreg6;
 184                 break;
 185         case offsetof(struct user32, u_debugreg[7]):
 186                 *val = child->thread.debugreg7;
 187                 break;
 188
 189         default:
 190                 if (regno > sizeof(struct user32) || (regno & 3))
 191                         return -EIO;
 192
 193                 /* Other dummy fields in the virtual user structure are ignored */
 194                 *val = 0;
 195                 break;
 196         }
 197         return 0;
 198 }
 199
 200 #undef R32
 201
 202 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 203 {
 204         struct task_struct *child;
 205         struct pt_regs *childregs;
 206         void __user *datap = compat_ptr(data);
 207         int ret;
 208         __u32 val;
 209
 210         switch (request) {
 211         default:
 212                 return sys_ptrace(request, pid, addr, data);
 213
 214         case PTRACE_PEEKTEXT:
 215         case PTRACE_PEEKDATA:
 216         case PTRACE_POKEDATA:
 217         case PTRACE_POKETEXT:
 218         case PTRACE_POKEUSR:
 219         case PTRACE_PEEKUSR:
 220         case PTRACE_GETREGS:
 221         case PTRACE_SETREGS:
 222         case PTRACE_SETFPREGS:
 223         case PTRACE_GETFPREGS:
 224         case PTRACE_SETFPXREGS:
 225         case PTRACE_GETFPXREGS:
 226         case PTRACE_GETEVENTMSG:
 227                 break;
 228         }
 229
 230         if (request == PTRACE_TRACEME)
 231                 return ptrace_traceme();
 232
 233         child = ptrace_get_task_struct(pid);
 234         if (IS_ERR(child))
 235                 return PTR_ERR(child);
 236
 237         ret = ptrace_check_attach(child, request == PTRACE_KILL);
 238         if (ret < 0)
 239                 goto out;
 240
 241         childregs = task_pt_regs(child);
 242
 243         switch (request) {
 244         case PTRACE_PEEKDATA:
 245         case PTRACE_PEEKTEXT:
 246                 ret = 0;
 247                 if (access_process_vm(child, addr, &val, sizeof(u32), 0)!=sizeof(u32))
 248                         ret = -EIO;
 249                 else
 250                         ret = put_user(val, (unsigned int __user *)datap);
 251                 break;
 252
 253         case PTRACE_POKEDATA:
 254         case PTRACE_POKETEXT:
 255                 ret = 0;
 256                 if (access_process_vm(child, addr, &data, sizeof(u32), 1)!=sizeof(u32))
 257                         ret = -EIO;
 258                 break;
 259
 260         case PTRACE_PEEKUSR:
 261                 ret = getreg32(child, addr, &val);
 262                 if (ret == 0)
 263                         ret = put_user(val, (__u32 __user *)datap);
 264                 break;
 265
 266         case PTRACE_POKEUSR:
 267                 ret = putreg32(child, addr, data);
 268                 break;
 269
 270         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 271                 int i;
 272                 if (!access_ok(VERIFY_WRITE, datap, 16*4)) {
 273                         ret = -EIO;
 274                         break;
 275                 }
 276                 ret = 0;
 277                 for ( i = 0; i <= 16*4 ; i += sizeof(__u32) ) {
 278                         getreg32(child, i, &val);
 279                         ret |= __put_user(val,(u32 __user *)datap);
 280                         datap += sizeof(u32);
 281                 }
 282                 break;
 283         }
 284
 285         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 286                 unsigned long tmp;
 287                 int i;
 288                 if (!access_ok(VERIFY_READ, datap, 16*4)) {
 289                         ret = -EIO;
 290                         break;
 291                 }
 292                 ret = 0;
 293                 for ( i = 0; i <= 16*4; i += sizeof(u32) ) {
 294                         ret |= __get_user(tmp, (u32 __user *)datap);
 295                         putreg32(child, i, tmp);
 296                         datap += sizeof(u32);
 297                 }
 298                 break;
 299         }
 300
 301         case PTRACE_GETFPREGS:
 302                 ret = -EIO;
 303                 if (!access_ok(VERIFY_READ, compat_ptr(data),
 304                                sizeof(struct user_i387_struct)))
 305                         break;
 306                 save_i387_ia32(child, datap, childregs, 1);
 307                 ret = 0;
 308                         break;
 309
 310         case PTRACE_SETFPREGS:
 311                 ret = -EIO;
 312                 if (!access_ok(VERIFY_WRITE, datap,
 313                                sizeof(struct user_i387_struct)))
 314                         break;
 315                 ret = 0;
 316                 /* don't check EFAULT to be bug-to-bug compatible to i386 */
 317                 restore_i387_ia32(child, datap, 1);
 318                 break;
 319
 320         case PTRACE_GETFPXREGS: {
 321                 struct user32_fxsr_struct __user *u = datap;
 322                 init_fpu(child);
 323                 ret = -EIO;
 324                 if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
 325                         break;
 326                         ret = -EFAULT;
 327                 if (__copy_to_user(u, &child->thread.i387.fxsave, sizeof(*u)))
 328                         break;
 329                 ret = __put_user(childregs->cs, &u->fcs);
 330                 ret |= __put_user(child->thread.ds, &u->fos);
 331                 break;
 332         }
 333         case PTRACE_SETFPXREGS: {
 334                 struct user32_fxsr_struct __user *u = datap;
 335                 unlazy_fpu(child);
 336                 ret = -EIO;
 337                 if (!access_ok(VERIFY_READ, u, sizeof(*u)))
 338                         break;
 339                 /* no checking to be bug-to-bug compatible with i386 */
 340                 __copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u));
 341                 set_stopped_child_used_math(child);
 342                 child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
 343                 ret = 0;
 344                 break;
 345         }
 346
 347         case PTRACE_GETEVENTMSG:
 348                 ret = put_user(child->ptrace_message,(unsigned int __user *)compat_ptr(data));
 349                 break;
 350
 351         default:
 352                 ret = -EINVAL;
 353                 break;
 354         }
 355
 356  out:
 357         put_task_struct(child);
 358         return ret;
 359 }
 360