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 1.19 2004/01/29 03:31:13 ak Exp $
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/stddef.h>
  16 #include <linux/sched.h>
  17 #include <linux/mm.h>
  18 #include <asm/ptrace.h>
  19 #include <asm/uaccess.h>
  20 #include <asm/user32.h>
  21 #include <asm/user.h>
  22 #include <asm/errno.h>
  23 #include <asm/debugreg.h>
  24 #include <asm/i387.h>
  25 #include <asm/fpu32.h>
  26 #include <linux/mm.h>
  27
  28 /* determines which flags the user has access to. */
  29 /* 1 = access 0 = no access */
  30 #define FLAG_MASK 0x44dd5UL
  31
  32 #define R32(l,q) \
  33         case offsetof(struct user32, regs.l): stack[offsetof(struct pt_regs, q)/8] = val; break
  34
  35 static int putreg32(struct task_struct *child, unsigned regno, u32 val)
  36 {
  37         int i;
  38         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
  39
  40         switch (regno) {
  41         case offsetof(struct user32, regs.fs):
  42         if (val && (val & 3) != 3) return -EIO;
  43         child->thread.fs = val & 0xffff;
  44                 break;
  45         case offsetof(struct user32, regs.gs):
  46             if (val && (val & 3) != 3) return -EIO;
  47                 child->thread.gs = val & 0xffff;
  48                 break;
  49         case offsetof(struct user32, regs.ds):
  50                 if (val && (val & 3) != 3) return -EIO;
  51                 child->thread.ds = val & 0xffff;
  52                 break;
  53         case offsetof(struct user32, regs.es):
  54                 child->thread.es = val & 0xffff;
  55                 break;
  56     case offsetof(struct user32, regs.ss):
  57                 if ((val & 3) != 3) return -EIO;
  58         stack[offsetof(struct pt_regs, ss)/8] = val & 0xffff;
  59         break;
  60         case offsetof(struct user32, regs.cs):
  61                 if ((val & 3) != 3) return -EIO;
  62                 stack[offsetof(struct pt_regs, cs)/8] = val & 0xffff;
  63                 break;
  64
  65         R32(ebx, rbx);
  66         R32(ecx, rcx);
  67         R32(edx, rdx);
  68         R32(edi, rdi);
  69         R32(esi, rsi);
  70         R32(ebp, rbp);
  71         R32(eax, rax);
  72         R32(orig_eax, orig_rax);
  73         R32(eip, rip);
  74         R32(esp, rsp);
  75
  76         case offsetof(struct user32, regs.eflags): {
  77                 __u64 *flags = &stack[offsetof(struct pt_regs, eflags)/8];
  78                 val &= FLAG_MASK;
  79                 *flags = val | (*flags & ~FLAG_MASK);
  80                 break;
  81         }
  82
  83         case offsetof(struct user32, u_debugreg[4]):
  84         case offsetof(struct user32, u_debugreg[5]):
  85                 return -EIO;
  86
  87         case offsetof(struct user32, u_debugreg[0]) ...
  88              offsetof(struct user32, u_debugreg[3]):
  89         case offsetof(struct user32, u_debugreg[6]):
  90                 child->thread.debugreg
  91                         [(regno-offsetof(struct user32, u_debugreg[0]))/4]
  92                         = val;
  93                 break;
  94
  95         case offsetof(struct user32, u_debugreg[7]):
  96                 val &= ~DR_CONTROL_RESERVED;
  97                 /* You are not expected to understand this ... I don't neither. */
  98                 for(i=0; i<4; i++)
  99                         if ((0x5454 >> ((val >> (16 + 4*i)) & 0xf)) & 1)
 100                                return -EIO;
 101                 child->thread.debugreg[7] = val;
 102                 break;
 103
 104         default:
 105                 if (regno > sizeof(struct user32) || (regno & 3))
 106                         return -EIO;
 107
 108                 /* Other dummy fields in the virtual user structure are ignored */
 109                 break;
 110         }
 111         return 0;
 112 }
 113
 114 #undef R32
 115
 116 #define R32(l,q) \
 117         case offsetof(struct user32, regs.l): *val = stack[offsetof(struct pt_regs, q)/8]; break
 118
 119 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 120 {
 121         __u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs));
 122
 123         switch (regno) {
 124         case offsetof(struct user32, regs.fs):
 125                 *val = child->thread.fs;
 126                 break;
 127         case offsetof(struct user32, regs.gs):
 128                 *val = child->thread.gs;
 129                 break;
 130         case offsetof(struct user32, regs.ds):
 131                 *val = child->thread.ds;
 132                 break;
 133         case offsetof(struct user32, regs.es):
 134                 *val = child->thread.es;
 135                 break;
 136
 137         R32(cs, cs);
 138         R32(ss, ss);
 139         R32(ebx, rbx);
 140         R32(ecx, rcx);
 141         R32(edx, rdx);
 142         R32(edi, rdi);
 143         R32(esi, rsi);
 144         R32(ebp, rbp);
 145         R32(eax, rax);
 146         R32(orig_eax, orig_rax);
 147         R32(eip, rip);
 148         R32(eflags, eflags);
 149         R32(esp, rsp);
 150
 151         case offsetof(struct user32, u_debugreg[0]) ... offsetof(struct user32, u_debugreg[7]):
 152                 *val = child->thread.debugreg[(regno-offsetof(struct user32, u_debugreg[0]))/4];
 153                 break;
 154
 155         default:
 156                 if (regno > sizeof(struct user32) || (regno & 3))
 157                         return -EIO;
 158
 159                 /* Other dummy fields in the virtual user structure are ignored */
 160                 *val = 0;
 161                 break;
 162         }
 163         return 0;
 164 }
 165
 166 #undef R32
 167
 168 static struct task_struct *find_target(int request, int pid, int *err)
 169 {
 170         struct task_struct *child;
 171
 172         *err = -EPERM;
 173         if (pid == 1)
 174                 return NULL;
 175
 176         *err = -ESRCH;
 177         read_lock(&tasklist_lock);
 178         child = find_task_by_pid(pid);
 179         if (child)
 180                 get_task_struct(child);
 181         read_unlock(&tasklist_lock);
 182         if (child) {
 183                 *err = -EPERM;
 184                 if (pid == 1)
 185                         goto out;
 186                 *err = ptrace_check_attach(child, request == PTRACE_KILL);
 187                 if (*err < 0)
 188                         goto out;
 189                 return child;
 190
 191  out:
 192                 free_task_struct(child);
 193         }
 194         return NULL;
 195
 196 }
 197
 198 extern asmlinkage long sys_ptrace(long request, long pid, unsigned long addr, unsigned long data);
 199
 200 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 201 {
 202         struct task_struct *child;
 203         struct pt_regs *childregs;
 204         int ret;
 205         __u32 val;
 206
 207         switch (request) {
 208         case PTRACE_TRACEME:
 209         case PTRACE_ATTACH:
 210         case PTRACE_SYSCALL:
 211         case PTRACE_CONT:
 212         case PTRACE_KILL:
 213         case PTRACE_SINGLESTEP:
 214         case PTRACE_DETACH:
 215         case PTRACE_SETOPTIONS:
 216                 ret = sys_ptrace(request, pid, addr, data);
 217                 return ret;
 218
 219         case PTRACE_PEEKTEXT:
 220         case PTRACE_PEEKDATA:
 221         case PTRACE_POKEDATA:
 222         case PTRACE_POKETEXT:
 223         case PTRACE_POKEUSR:
 224         case PTRACE_PEEKUSR:
 225         case PTRACE_GETREGS:
 226         case PTRACE_SETREGS:
 227         case PTRACE_SETFPREGS:
 228         case PTRACE_GETFPREGS:
 229         case PTRACE_SETFPXREGS:
 230         case PTRACE_GETFPXREGS:
 231                 break;
 232
 233         default:
 234                 return -EIO;
 235         }
 236
 237         child = find_target(request, pid, &ret);
 238         if (!child)
 239                 return ret;
 240
 241         childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs));
 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 *)(u64)data);
 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 *)(unsigned long) data);
 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, (unsigned *)(unsigned long)data, 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 *) (unsigned long) data);
 280                         data += 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, (unsigned *)(unsigned long)data, 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 *) (unsigned long) data);
 295                         putreg32(child, i, tmp);
 296                         data += sizeof(u32);
 297                 }
 298                 break;
 299         }
 300
 301         case PTRACE_GETFPREGS:
 302                 ret = -EIO;
 303                 if (!access_ok(VERIFY_READ, (void *)(u64)data,
 304                                sizeof(struct user_i387_struct)))
 305                         break;
 306                 save_i387_ia32(child, (void *)(u64)data, childregs, 1);
 307                 ret = 0;
 308                 break;
 309
 310         case PTRACE_SETFPREGS:
 311                 ret = -EIO;
 312                 if (!access_ok(VERIFY_WRITE, (void *)(u64)data,
 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, (void *)(u64)data, 1);
 318                 break;
 319
 320         case PTRACE_GETFPXREGS: {
 321                 struct user32_fxsr_struct *u = (void *)(u64)data;
 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 *u = (void *)(u64)data;
 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                 child->used_math = 1;
 342                 child->thread.i387.fxsave.mxcsr &= 0xffbf;
 343                 ret = 0;
 344                 break;
 345         }
 346
 347         default:
 348                 ret = -EINVAL;
 349                 break;
 350         }
 351
 352         free_task_struct(child);
 353         return ret;
 354 }
 355