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/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
  30 /* determines which flags the user has access to. */
  31 /* 1 = access 0 = no access */
  32 #define FLAG_MASK 0x44dd5UL
  33
  34 #define R32(l,q) \
  35         case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
  36
  37 static int putreg32(struct task_struct *child, unsigned regno, u32 val)
  38 {
  39         int i;
  40         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
  41
  42         switch (regno) {
  43         case offsetof(struct user32, regs.fs):
  44                 if (val && (val & 3) != 3) return -EIO;
  45                 child->thread.fs = val & 0xffff;
  46                 break;
  47         case offsetof(struct user32, regs.gs):
  48                 if (val && (val & 3) != 3) return -EIO;
  49                 child->thread.gs = val & 0xffff;
  50                 break;
  51         case offsetof(struct user32, regs.ds):
  52                 if (val && (val & 3) != 3) return -EIO;
  53                 child->thread.ds = val & 0xffff;
  54                 break;
  55         case offsetof(struct user32, regs.es):
  56                 child->thread.es = val & 0xffff;
  57                 break;
  58         case offsetof(struct user32, regs.ss):
  59                 if ((val & 3) != 3) return -EIO;
  60                 stack[offsetof(struct pt_regs, ss)/8] = val & 0xffff;
  61                 break;
  62         case offsetof(struct user32, regs.cs):
  63                 if ((val & 3) != 3) return -EIO;
  64                 stack[offsetof(struct pt_regs, cs)/8] = val & 0xffff;
  65                 break;
  66
  67         R32(ebx, rbx);
  68         R32(ecx, rcx);
  69         R32(edx, rdx);
  70         R32(edi, rdi);
  71         R32(esi, rsi);
  72         R32(ebp, rbp);
  73         R32(eax, rax);
  74         R32(orig_eax, orig_rax);
  75         R32(eip, rip);
  76         R32(esp, rsp);
  77
  78         case offsetof(struct user32, regs.eflags): {
  79                 __u64 *flags = &stack[offsetof(struct pt_regs, eflags)/8];
  80                 val &= FLAG_MASK;
  81                 *flags = val | (*flags & ~FLAG_MASK);
  82                 break;
  83         }
  84
  85         case offsetof(struct user32, u_debugreg[4]):
  86         case offsetof(struct user32, u_debugreg[5]):
  87                 return -EIO;
  88
  89         case offsetof(struct user32, u_debugreg[0]):
  90                 child->thread.debugreg0 = val;
  91                 break;
  92
  93         case offsetof(struct user32, u_debugreg[1]):
  94                 child->thread.debugreg1 = val;
  95                 break;
  96
  97         case offsetof(struct user32, u_debugreg[2]):
  98                 child->thread.debugreg2 = val;
  99                 break;
 100
 101         case offsetof(struct user32, u_debugreg[3]):
 102                 child->thread.debugreg3 = val;
 103                 break;
 104
 105         case offsetof(struct user32, u_debugreg[6]):
 106                 child->thread.debugreg6 = val;
 107                 break;
 108
 109         case offsetof(struct user32, u_debugreg[7]):
 110                 val &= ~DR_CONTROL_RESERVED;
 111                 /* You are not expected to understand this ... I don't neither. */
 112                 for(i=0; i<4; i++)
 113                         if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1)
 114                                return -EIO;
 115                 child->thread.debugreg7 = val;
 116                 break;
 117
 118         default:
 119                 if (regno > sizeof(struct user32) || (regno & 3))
 120                         return -EIO;
 121
 122                 /* Other dummy fields in the virtual user structure are ignored */
 123                 break;
 124         }
 125         return 0;
 126 }
 127
 128 #undef R32
 129
 130 #define R32(l,q) \
 131         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 132
 133 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 134 {
 135         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
 136
 137         switch (regno) {
 138         case offsetof(struct user32, regs.fs):
 139                 *val = child->thread.fs;
 140                 break;
 141         case offsetof(struct user32, regs.gs):
 142                 *val = child->thread.gs;
 143                 break;
 144         case offsetof(struct user32, regs.ds):
 145                 *val = child->thread.ds;
 146                 break;
 147         case offsetof(struct user32, regs.es):
 148                 *val = child->thread.es;
 149                 break;
 150
 151         R32(cs, cs);
 152         R32(ss, ss);
 153         R32(ebx, rbx);
 154         R32(ecx, rcx);
 155         R32(edx, rdx);
 156         R32(edi, rdi);
 157         R32(esi, rsi);
 158         R32(ebp, rbp);
 159         R32(eax, rax);
 160         R32(orig_eax, orig_rax);
 161         R32(eip, rip);
 162         R32(eflags, eflags);
 163         R32(esp, rsp);
 164
 165         case offsetof(struct user32, u_debugreg[0]):
 166                 *val = child->thread.debugreg0;
 167                 break;
 168         case offsetof(struct user32, u_debugreg[1]):
 169                 *val = child->thread.debugreg1;
 170                 break;
 171         case offsetof(struct user32, u_debugreg[2]):
 172                 *val = child->thread.debugreg2;
 173                 break;
 174         case offsetof(struct user32, u_debugreg[3]):
 175                 *val = child->thread.debugreg3;
 176                 break;
 177         case offsetof(struct user32, u_debugreg[6]):
 178                 *val = child->thread.debugreg6;
 179                 break;
 180         case offsetof(struct user32, u_debugreg[7]):
 181                 *val = child->thread.debugreg7;
 182                 break;
 183
 184         default:
 185                 if (regno > sizeof(struct user32) || (regno & 3))
 186                         return -EIO;
 187
 188                 /* Other dummy fields in the virtual user structure are ignored */
 189                 *val = 0;
 190                 break;
 191         }
 192         return 0;
 193 }
 194
 195 #undef R32
 196
 197 static struct task_struct *find_target(int request, int pid, int *err)
 198 {
 199         struct task_struct *child;
 200
 201         *err = -EPERM;
 202         if (pid == 1)
 203                 return NULL;
 204
 205         *err = -ESRCH;
 206         read_lock(&tasklist_lock);
 207         child = find_task_by_pid(pid);
 208         if (child)
 209                 get_task_struct(child);
 210         read_unlock(&tasklist_lock);
 211         if (child) {
 212                 *err = -EPERM;
 213                 if (child->pid == 1)
 214                         goto out;
 215                 *err = ptrace_check_attach(child, request == PTRACE_KILL);
 216                 if (*err < 0)
 217                         goto out;
 218                 return child;
 219         }
 220  out:
 221         if (child)
 222         put_task_struct(child);
 223         return NULL;
 224
 225 }
 226
 227 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 228 {
 229         struct task_struct *child;
 230         struct pt_regs *childregs;
 231         int ret;
 232         __u32 val;
 233
 234         switch (request) {
 235         default:
 236                 return sys_ptrace(request, pid, addr, data);
 237
 238         case PTRACE_PEEKTEXT:
 239         case PTRACE_PEEKDATA:
 240         case PTRACE_POKEDATA:
 241         case PTRACE_POKETEXT:
 242         case PTRACE_POKEUSR:
 243         case PTRACE_PEEKUSR:
 244         case PTRACE_GETREGS:
 245         case PTRACE_SETREGS:
 246         case PTRACE_SETFPREGS:
 247         case PTRACE_GETFPREGS:
 248         case PTRACE_SETFPXREGS:
 249         case PTRACE_GETFPXREGS:
 250                 break;
 251
 252         }
 253
 254         child = find_target(request, pid, &ret);
 255         if (!child)
 256                 return ret;
 257
 258         childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs));
 259
 260         switch (request) {
 261         case PTRACE_PEEKDATA:
 262         case PTRACE_PEEKTEXT:
 263                 ret = 0;
 264                 if (access_process_vm(child, addr, &val, sizeof(u32), 0)!=sizeof(u32))
 265                         ret = -EIO;
 266                 else
 267                         ret = put_user(val, (unsigned int *)(u64)data);
 268                 break;
 269
 270         case PTRACE_POKEDATA:
 271         case PTRACE_POKETEXT:
 272                 ret = 0;
 273                 if (access_process_vm(child, addr, &data, sizeof(u32), 1)!=sizeof(u32))
 274                         ret = -EIO;
 275                 break;
 276
 277         case PTRACE_PEEKUSR:
 278                 ret = getreg32(child, addr, &val);
 279                 if (ret == 0)
 280                         ret = put_user(val, (__u32 *)(unsigned long) data);
 281                 break;
 282
 283         case PTRACE_POKEUSR:
 284                 ret = putreg32(child, addr, data);
 285                 break;
 286
 287         case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 288                 int i;
 289                 if (!access_ok(VERIFY_WRITE, (unsigned *)(unsigned long)data, 16*4)) {
 290                         ret = -EIO;
 291                         break;
 292                 }
 293                 ret = 0;
 294                 for ( i = 0; i <= 16*4 ; i += sizeof(__u32) ) {
 295                         getreg32(child, i, &val);
 296                         ret |= __put_user(val,(u32 *) (unsigned long) data);
 297                         data += sizeof(u32);
 298                 }
 299                 break;
 300         }
 301
 302         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 303                 unsigned long tmp;
 304                 int i;
 305                 if (!access_ok(VERIFY_READ, (unsigned *)(unsigned long)data, 16*4)) {
 306                         ret = -EIO;
 307                         break;
 308                 }
 309                 ret = 0;
 310                 for ( i = 0; i <= 16*4; i += sizeof(u32) ) {
 311                         ret |= __get_user(tmp, (u32 *) (unsigned long) data);
 312                         putreg32(child, i, tmp);
 313                         data += sizeof(u32);
 314                 }
 315                 break;
 316         }
 317
 318         case PTRACE_GETFPREGS:
 319                 ret = -EIO;
 320                 if (!access_ok(VERIFY_READ, (void *)(u64)data,
 321                                sizeof(struct user_i387_struct)))
 322                         break;
 323                 save_i387_ia32(child, (void *)(u64)data, childregs, 1);
 324                 ret = 0;
 325                         break;
 326
 327         case PTRACE_SETFPREGS:
 328                 ret = -EIO;
 329                 if (!access_ok(VERIFY_WRITE, (void *)(u64)data,
 330                                sizeof(struct user_i387_struct)))
 331                         break;
 332                 ret = 0;
 333                 /* don't check EFAULT to be bug-to-bug compatible to i386 */
 334                 restore_i387_ia32(child, (void *)(u64)data, 1);
 335                 break;
 336
 337         case PTRACE_GETFPXREGS: {
 338                 struct user32_fxsr_struct *u = (void *)(u64)data;
 339                 init_fpu(child);
 340                 ret = -EIO;
 341                 if (!access_ok(VERIFY_WRITE, u, sizeof(*u)))
 342                         break;
 343                         ret = -EFAULT;
 344                 if (__copy_to_user(u, &child->thread.i387.fxsave, sizeof(*u)))
 345                         break;
 346                 ret = __put_user(childregs->cs, &u->fcs);
 347                 ret |= __put_user(child->thread.ds, &u->fos);
 348                 break;
 349         }
 350         case PTRACE_SETFPXREGS: {
 351                 struct user32_fxsr_struct *u = (void *)(u64)data;
 352                 unlazy_fpu(child);
 353                 ret = -EIO;
 354                 if (!access_ok(VERIFY_READ, u, sizeof(*u)))
 355                         break;
 356                 /* no checking to be bug-to-bug compatible with i386 */
 357                 __copy_from_user(&child->thread.i387.fxsave, u, sizeof(*u));
 358                 child->used_math = 1;
 359                 child->thread.i387.fxsave.mxcsr &= mxcsr_feature_mask;
 360                 ret = 0;
 361                 break;
 362         }
 363
 364         default:
 365                 ret = -EINVAL;
 366                 break;
 367         }
 368
 369         put_task_struct(child);
 370         return ret;
 371 }
 372