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                 /* See arch/i386/kernel/ptrace.c for an explanation of
 113                  * this awkward check.*/
 114                 for(i=0; i<4; i++)
 115                         if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1)
 116                                return -EIO;
 117                 child->thread.debugreg7 = val;
 118                 break;
 119
 120         default:
 121                 if (regno > sizeof(struct user32) || (regno & 3))
 122                         return -EIO;
 123
 124                 /* Other dummy fields in the virtual user structure are ignored */
 125                 break;
 126         }
 127         return 0;
 128 }
 129
 130 #undef R32
 131
 132 #define R32(l,q) \
 133         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 134
 135 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 136 {
 137         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
 138
 139         switch (regno) {
 140         case offsetof(struct user32, regs.fs):
 141                 *val = child->thread.fs;
 142                 break;
 143         case offsetof(struct user32, regs.gs):
 144                 *val = child->thread.gs;
 145                 break;
 146         case offsetof(struct user32, regs.ds):
 147                 *val = child->thread.ds;
 148                 break;
 149         case offsetof(struct user32, regs.es):
 150                 *val = child->thread.es;
 151                 break;
 152
 153         R32(cs, cs);
 154         R32(ss, ss);
 155         R32(ebx, rbx);
 156         R32(ecx, rcx);
 157         R32(edx, rdx);
 158         R32(edi, rdi);
 159         R32(esi, rsi);
 160         R32(ebp, rbp);
 161         R32(eax, rax);
 162         R32(orig_eax, orig_rax);
 163         R32(eip, rip);
 164         R32(eflags, eflags);
 165         R32(esp, rsp);
 166
 167         case offsetof(struct user32, u_debugreg[0]):
 168                 *val = child->thread.debugreg0;
 169                 break;
 170         case offsetof(struct user32, u_debugreg[1]):
 171                 *val = child->thread.debugreg1;
 172                 break;
 173         case offsetof(struct user32, u_debugreg[2]):
 174                 *val = child->thread.debugreg2;
 175                 break;
 176         case offsetof(struct user32, u_debugreg[3]):
 177                 *val = child->thread.debugreg3;
 178                 break;
 179         case offsetof(struct user32, u_debugreg[6]):
 180                 *val = child->thread.debugreg6;
 181                 break;
 182         case offsetof(struct user32, u_debugreg[7]):
 183                 *val = child->thread.debugreg7;
 184                 break;
 185
 186         default:
 187                 if (regno > sizeof(struct user32) || (regno & 3))
 188                         return -EIO;
 189
 190                 /* Other dummy fields in the virtual user structure are ignored */
 191                 *val = 0;
 192                 break;
 193         }
 194         return 0;
 195 }
 196
 197 #undef R32
 198
 199 static struct task_struct *find_target(int request, int pid, int *err)
 200 {
 201         struct task_struct *child;
 202
 203         *err = -EPERM;
 204         if (pid == 1)
 205                 return NULL;
 206
 207         *err = -ESRCH;
 208         read_lock(&tasklist_lock);
 209         child = find_task_by_pid(pid);
 210         if (child)
 211                 get_task_struct(child);
 212         read_unlock(&tasklist_lock);
 213         if (child) {
 214                 *err = -EPERM;
 215                 if (child->pid == 1)
 216                         goto out;
 217                 *err = ptrace_check_attach(child, request == PTRACE_KILL);
 218                 if (*err < 0)
 219                         goto out;
 220                 return child;
 221         }
 222  out:
 223         if (child)
 224         put_task_struct(child);
 225         return NULL;
 226
 227 }
 228
 229 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 230 {
 231         struct task_struct *child;
 232         struct pt_regs *childregs;
 233         void __user *datap = compat_ptr(data);
 234         int ret;
 235         __u32 val;
 236
 237         switch (request) {
 238         default:
 239                 return sys_ptrace(request, pid, addr, data);
 240
 241         case PTRACE_PEEKTEXT:
 242         case PTRACE_PEEKDATA:
 243         case PTRACE_POKEDATA:
 244         case PTRACE_POKETEXT:
 245         case PTRACE_POKEUSR:
 246         case PTRACE_PEEKUSR:
 247         case PTRACE_GETREGS:
 248         case PTRACE_SETREGS:
 249         case PTRACE_SETFPREGS:
 250         case PTRACE_GETFPREGS:
 251         case PTRACE_SETFPXREGS:
 252         case PTRACE_GETFPXREGS:
 253         case PTRACE_GETEVENTMSG:
 254                 break;
 255         }
 256
 257         child = find_target(request, pid, &ret);
 258         if (!child)
 259                 return ret;
 260
 261         childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs));
 262
 263         switch (request) {
 264         case PTRACE_PEEKDATA:
 265         case PTRACE_PEEKTEXT:
 266                 ret = 0;
 267                 if (access_process_vm(child, addr, &val, sizeof(u32), 0)!=sizeof(u32))
 268                         ret = -EIO;
 269                 else
 270                         ret = put_user(val, (unsigned int __user *)datap);
 271                 break;
 272
 273         case PTRACE_POKEDATA:
 274         case PTRACE_POKETEXT:
 275                 ret = 0;
 276                 if (access_process_vm(child, addr, &data, sizeof(u32), 1)!=sizeof(u32))
 277                         ret = -EIO;
 278                 break;
 279
 280         case PTRACE_PEEKUSR:
 281                 ret = getreg32(child, addr, &val);
 282                 if (ret == 0)
 283                         ret = put_user(val, (__u32 __user *)datap);
 284                 break;
 285
 286         case PTRACE_POKEUSR:
 287                 ret = putreg32(child, addr, data);
 288                 break;
 289
 290         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 291                 int i;
 292                 if (!access_ok(VERIFY_WRITE, datap, 16*4)) {
 293                         ret = -EIO;
 294                         break;
 295                 }
 296                 ret = 0;
 297                 for ( i = 0; i <= 16*4 ; i += sizeof(__u32) ) {
 298                         getreg32(child, i, &val);
 299                         ret |= __put_user(val,(u32 __user *)datap);
 300                         datap += sizeof(u32);
 301                 }
 302                 break;
 303         }
 304
 305         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 306                 unsigned long tmp;
 307                 int i;
 308                 if (!access_ok(VERIFY_READ, datap, 16*4)) {
 309                         ret = -EIO;
 310                         break;
 311                 }
 312                 ret = 0;
 313                 for ( i = 0; i <= 16*4; i += sizeof(u32) ) {
 314                         ret |= __get_user(tmp, (u32 __user *)datap);
 315                         putreg32(child, i, tmp);
 316                         datap += sizeof(u32);
 317                 }
 318                 break;
 319         }
 320
 321         case PTRACE_GETFPREGS:
 322                 ret = -EIO;
 323                 if (!access_ok(VERIFY_READ, compat_ptr(data),
 324                                sizeof(struct user_i387_struct)))
 325                         break;
 326                 save_i387_ia32(child, datap, childregs, 1);
 327                 ret = 0;
 328                         break;
 329
 330         case PTRACE_SETFPREGS:
 331                 ret = -EIO;
 332                 if (!access_ok(VERIFY_WRITE, datap,
 333                                sizeof(struct user_i387_struct)))
 334                         break;
 335                 ret = 0;
 336                 /* don't check EFAULT to be bug-to-bug compatible to i386 */
 337                 restore_i387_ia32(child, datap, 1);
 338                 break;
 339
 340         case PTRACE_GETFPXREGS: {
 341                 struct user32_fxsr_struct __user *u = datap;
 342                 init_fpu(child);
 343                 ret = -EIO;
 344                 if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
 345                         break;
 346                         ret = -EFAULT;
 347                 if (__copy_to_user(u, &child->thread.i387.fxsave, sizeof(*u)))
 348                         break;
 349                 ret = __put_user(childregs->cs, &u->fcs);
 350                 ret |= __put_user(child->thread.ds, &u->fos);
 351                 break;
 352         }
 353         case PTRACE_SETFPXREGS: {
 354                 struct user32_fxsr_struct __user *u = datap;
 355                 unlazy_fpu(child);
 356                 ret = -EIO;
 357                 if (!access_ok(VERIFY_READ, u, sizeof(*u)))
 358                         break;
 359                 /* no checking to be bug-to-bug compatible with i386 */
 360                 __copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u));
 361                 set_stopped_child_used_math(child);
 362                 child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
 363                 ret = 0;
 364                 break;
 365         }
 366
 367         case PTRACE_GETEVENTMSG:
 368                 ret = put_user(child->ptrace_message,(unsigned int __user *)compat_ptr(data));
 369                 break;
 370
 371         default:
 372                 ret = -EINVAL;
 373                 break;
 374         }
 375
 376         put_task_struct(child);
 377         return ret;
 378 }
 379