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 /* determines which flags the user has access to. */
  32 /* 1 = access 0 = no access */
  33 #define FLAG_MASK 0x44dd5UL
  34
  35 #define R32(l,q) \
  36         case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
  37
  38 static int putreg32(struct task_struct *child, unsigned regno, u32 val)
  39 {
  40         int i;
  41         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
  42
  43         switch (regno) {
  44         case offsetof(struct user32, regs.fs):
  45                 if (val && (val & 3) != 3) return -EIO;
  46                 child->thread.fs = val & 0xffff;
  47                 break;
  48         case offsetof(struct user32, regs.gs):
  49                 if (val && (val & 3) != 3) return -EIO;
  50                 child->thread.gs = val & 0xffff;
  51                 break;
  52         case offsetof(struct user32, regs.ds):
  53                 if (val && (val & 3) != 3) return -EIO;
  54                 child->thread.ds = val & 0xffff;
  55                 break;
  56         case offsetof(struct user32, regs.es):
  57                 child->thread.es = val & 0xffff;
  58                 break;
  59         case offsetof(struct user32, regs.ss):
  60                 if ((val & 3) != 3) return -EIO;
  61                 stack[offsetof(struct pt_regs, ss)/8] = val & 0xffff;
  62                 break;
  63         case offsetof(struct user32, regs.cs):
  64                 if ((val & 3) != 3) return -EIO;
  65                 stack[offsetof(struct pt_regs, cs)/8] = val & 0xffff;
  66                 break;
  67
  68         R32(ebx, rbx);
  69         R32(ecx, rcx);
  70         R32(edx, rdx);
  71         R32(edi, rdi);
  72         R32(esi, rsi);
  73         R32(ebp, rbp);
  74         R32(eax, rax);
  75         R32(orig_eax, orig_rax);
  76         R32(eip, rip);
  77         R32(esp, rsp);
  78
  79         case offsetof(struct user32, regs.eflags): {
  80                 __u64 *flags = &stack[offsetof(struct pt_regs, eflags)/8];
  81                 val &= FLAG_MASK;
  82                 *flags = val | (*flags & ~FLAG_MASK);
  83                 break;
  84         }
  85
  86         case offsetof(struct user32, u_debugreg[4]):
  87         case offsetof(struct user32, u_debugreg[5]):
  88                 return -EIO;
  89
  90         case offsetof(struct user32, u_debugreg[0]):
  91                 child->thread.debugreg0 = val;
  92                 break;
  93
  94         case offsetof(struct user32, u_debugreg[1]):
  95                 child->thread.debugreg1 = val;
  96                 break;
  97
  98         case offsetof(struct user32, u_debugreg[2]):
  99                 child->thread.debugreg2 = val;
 100                 break;
 101
 102         case offsetof(struct user32, u_debugreg[3]):
 103                 child->thread.debugreg3 = val;
 104                 break;
 105
 106         case offsetof(struct user32, u_debugreg[6]):
 107                 child->thread.debugreg6 = val;
 108                 break;
 109
 110         case offsetof(struct user32, u_debugreg[7]):
 111                 val &= ~DR_CONTROL_RESERVED;
 112                 /* You are not expected to understand this ... I don't neither. */
 113                 for(i=0; i<4; i++)
 114                         if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1)
 115                                return -EIO;
 116                 child->thread.debugreg7 = val;
 117                 break;
 118
 119         default:
 120                 if (regno > sizeof(struct user32) || (regno & 3))
 121                         return -EIO;
 122
 123                 /* Other dummy fields in the virtual user structure are ignored */
 124                 break;
 125         }
 126         return 0;
 127 }
 128
 129 #undef R32
 130
 131 #define R32(l,q) \
 132         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 133
 134 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 135 {
 136         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
 137
 138         switch (regno) {
 139         case offsetof(struct user32, regs.fs):
 140                 *val = child->thread.fs;
 141                 break;
 142         case offsetof(struct user32, regs.gs):
 143                 *val = child->thread.gs;
 144                 break;
 145         case offsetof(struct user32, regs.ds):
 146                 *val = child->thread.ds;
 147                 break;
 148         case offsetof(struct user32, regs.es):
 149                 *val = child->thread.es;
 150                 break;
 151
 152         R32(cs, cs);
 153         R32(ss, ss);
 154         R32(ebx, rbx);
 155         R32(ecx, rcx);
 156         R32(edx, rdx);
 157         R32(edi, rdi);
 158         R32(esi, rsi);
 159         R32(ebp, rbp);
 160         R32(eax, rax);
 161         R32(orig_eax, orig_rax);
 162         R32(eip, rip);
 163         R32(eflags, eflags);
 164         R32(esp, rsp);
 165
 166         case offsetof(struct user32, u_debugreg[0]):
 167                 *val = child->thread.debugreg0;
 168                 break;
 169         case offsetof(struct user32, u_debugreg[1]):
 170                 *val = child->thread.debugreg1;
 171                 break;
 172         case offsetof(struct user32, u_debugreg[2]):
 173                 *val = child->thread.debugreg2;
 174                 break;
 175         case offsetof(struct user32, u_debugreg[3]):
 176                 *val = child->thread.debugreg3;
 177                 break;
 178         case offsetof(struct user32, u_debugreg[6]):
 179                 *val = child->thread.debugreg6;
 180                 break;
 181         case offsetof(struct user32, u_debugreg[7]):
 182                 *val = child->thread.debugreg7;
 183                 break;
 184
 185         default:
 186                 if (regno > sizeof(struct user32) || (regno & 3))
 187                         return -EIO;
 188
 189                 /* Other dummy fields in the virtual user structure are ignored */
 190                 *val = 0;
 191                 break;
 192         }
 193         return 0;
 194 }
 195
 196 #undef R32
 197
 198 static struct task_struct *find_target(int request, int pid, int *err)
 199 {
 200         struct task_struct *child;
 201
 202         *err = -EPERM;
 203         if (pid == 1)
 204                 return NULL;
 205
 206         *err = -ESRCH;
 207         read_lock(&tasklist_lock);
 208         child = find_task_by_pid(pid);
 209         if (child)
 210                 get_task_struct(child);
 211         read_unlock(&tasklist_lock);
 212         if (child) {
 213                 *err = -EPERM;
 214                 if (child->pid == 1)
 215                         goto out;
 216                 *err = ptrace_check_attach(child, request == PTRACE_KILL);
 217                 if (*err < 0)
 218                         goto out;
 219                 return child;
 220         }
 221  out:
 222         if (child)
 223         put_task_struct(child);
 224         return NULL;
 225
 226 }
 227
 228 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 229 {
 230         struct task_struct *child;
 231         struct pt_regs *childregs;
 232         void __user *datap = compat_ptr(data);
 233         int ret;
 234         __u32 val;
 235
 236         switch (request) {
 237         default:
 238                 return sys_ptrace(request, pid, addr, data);
 239
 240         case PTRACE_PEEKTEXT:
 241         case PTRACE_PEEKDATA:
 242         case PTRACE_POKEDATA:
 243         case PTRACE_POKETEXT:
 244         case PTRACE_POKEUSR:
 245         case PTRACE_PEEKUSR:
 246         case PTRACE_GETREGS:
 247         case PTRACE_SETREGS:
 248         case PTRACE_SETFPREGS:
 249         case PTRACE_GETFPREGS:
 250         case PTRACE_SETFPXREGS:
 251         case PTRACE_GETFPXREGS:
 252         case PTRACE_GETEVENTMSG:
 253                 break;
 254         }
 255
 256         child = find_target(request, pid, &ret);
 257         if (!child)
 258                 return ret;
 259
 260         childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs));
 261
 262         switch (request) {
 263         case PTRACE_PEEKDATA:
 264         case PTRACE_PEEKTEXT:
 265                 ret = 0;
 266                 if (access_process_vm(child, addr, &val, sizeof(u32), 0)!=sizeof(u32))
 267                         ret = -EIO;
 268                 else
 269                         ret = put_user(val, (unsigned int __user *)datap);
 270                 break;
 271
 272         case PTRACE_POKEDATA:
 273         case PTRACE_POKETEXT:
 274                 ret = 0;
 275                 if (access_process_vm(child, addr, &data, sizeof(u32), 1)!=sizeof(u32))
 276                         ret = -EIO;
 277                 break;
 278
 279         case PTRACE_PEEKUSR:
 280                 ret = getreg32(child, addr, &val);
 281                 if (ret == 0)
 282                         ret = put_user(val, (__u32 __user *)datap);
 283                 break;
 284
 285         case PTRACE_POKEUSR:
 286                 ret = putreg32(child, addr, data);
 287                 break;
 288
 289         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 290                 int i;
 291                 if (!access_ok(VERIFY_WRITE, datap, 16*4)) {
 292                         ret = -EIO;
 293                         break;
 294                 }
 295                 ret = 0;
 296                 for ( i = 0; i <= 16*4 ; i += sizeof(__u32) ) {
 297                         getreg32(child, i, &val);
 298                         ret |= __put_user(val,(u32 __user *)datap);
 299                         datap += sizeof(u32);
 300                 }
 301                 break;
 302         }
 303
 304         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 305                 unsigned long tmp;
 306                 int i;
 307                 if (!access_ok(VERIFY_READ, datap, 16*4)) {
 308                         ret = -EIO;
 309                         break;
 310                 }
 311                 ret = 0;
 312                 for ( i = 0; i <= 16*4; i += sizeof(u32) ) {
 313                         ret |= __get_user(tmp, (u32 __user *)datap);
 314                         putreg32(child, i, tmp);
 315                         datap += sizeof(u32);
 316                 }
 317                 break;
 318         }
 319
 320         case PTRACE_GETFPREGS:
 321                 ret = -EIO;
 322                 if (!access_ok(VERIFY_READ, compat_ptr(data),
 323                                sizeof(struct user_i387_struct)))
 324                         break;
 325                 save_i387_ia32(child, datap, childregs, 1);
 326                 ret = 0;
 327                         break;
 328
 329         case PTRACE_SETFPREGS:
 330                 ret = -EIO;
 331                 if (!access_ok(VERIFY_WRITE, datap,
 332                                sizeof(struct user_i387_struct)))
 333                         break;
 334                 ret = 0;
 335                 /* don't check EFAULT to be bug-to-bug compatible to i386 */
 336                 restore_i387_ia32(child, datap, 1);
 337                 break;
 338
 339         case PTRACE_GETFPXREGS: {
 340                 struct user32_fxsr_struct __user *u = datap;
 341                 init_fpu(child);
 342                 ret = -EIO;
 343                 if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
 344                         break;
 345                         ret = -EFAULT;
 346                 if (__copy_to_user(u, &child->thread.i387.fxsave, sizeof(*u)))
 347                         break;
 348                 ret = __put_user(childregs->cs, &u->fcs);
 349                 ret |= __put_user(child->thread.ds, &u->fos);
 350                 break;
 351         }
 352         case PTRACE_SETFPXREGS: {
 353                 struct user32_fxsr_struct __user *u = datap;
 354                 unlazy_fpu(child);
 355                 ret = -EIO;
 356                 if (!access_ok(VERIFY_READ, u, sizeof(*u)))
 357                         break;
 358                 /* no checking to be bug-to-bug compatible with i386 */
 359                 __copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u));
 360                 child->used_math = 1;
 361                 child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
 362                 ret = 0;
 363                 break;
 364         }
 365
 366         case PTRACE_GETEVENTMSG:
 367                 ret = put_user(child->ptrace_message,(unsigned int __user *)(u64)data);
 368                 break;
 369
 370         default:
 371                 ret = -EINVAL;
 372                 break;
 373         }
 374
 375         put_task_struct(child);
 376         return ret;
 377 }
 378