arch/x86/um/ptrace_32.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <linux/mm.h>
   7 #include <linux/sched.h>
   8 #include <asm/uaccess.h>
   9 #include <asm/ptrace-abi.h>
  10 #include <skas.h>
  11
  12 extern int arch_switch_tls(struct task_struct *to);
  13
  14 void arch_switch_to(struct task_struct *to)
  15 {
  16         int err = arch_switch_tls(to);
  17         if (!err)
  18                 return;
  19
  20         if (err != -EINVAL)
  21                 printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
  22                        "not EINVAL\n", -err);
  23         else
  24                 printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
  25 }
  26
  27 int is_syscall(unsigned long addr)
  28 {
  29         unsigned short instr;
  30         int n;
  31
  32         n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
  33         if (n) {
  34                 /* access_process_vm() grants access to vsyscall and stub,
  35                  * while copy_from_user doesn't. Maybe access_process_vm is
  36                  * slow, but that doesn't matter, since it will be called only
  37                  * in case of singlestepping, if copy_from_user failed.
  38                  */
  39                 n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
  40                 if (n != sizeof(instr)) {
  41                         printk(KERN_ERR "is_syscall : failed to read "
  42                                "instruction from 0x%lx\n", addr);
  43                         return 1;
  44                 }
  45         }
  46         /* int 0x80 or sysenter */
  47         return (instr == 0x80cd) || (instr == 0x340f);
  48 }
  49
  50 /* determines which flags the user has access to. */
  51 /* 1 = access 0 = no access */
  52 #define FLAG_MASK 0x00044dd5
  53
  54 static const int reg_offsets[] = {
  55         [EBX] = HOST_BX,
  56         [ECX] = HOST_CX,
  57         [EDX] = HOST_DX,
  58         [ESI] = HOST_SI,
  59         [EDI] = HOST_DI,
  60         [EBP] = HOST_BP,
  61         [EAX] = HOST_AX,
  62         [DS] = HOST_DS,
  63         [ES] = HOST_ES,
  64         [FS] = HOST_FS,
  65         [GS] = HOST_GS,
  66         [EIP] = HOST_IP,
  67         [CS] = HOST_CS,
  68         [EFL] = HOST_EFLAGS,
  69         [UESP] = HOST_SP,
  70         [SS] = HOST_SS,
  71         [ORIG_EAX] = HOST_ORIG_AX,
  72 };
  73
  74 int putreg(struct task_struct *child, int regno, unsigned long value)
  75 {
  76         regno >>= 2;
  77         switch (regno) {
  78         case EBX:
  79         case ECX:
  80         case EDX:
  81         case ESI:
  82         case EDI:
  83         case EBP:
  84         case EAX:
  85         case EIP:
  86         case UESP:
  87         case ORIG_EAX:
  88                 break;
  89         case FS:
  90                 if (value && (value & 3) != 3)
  91                         return -EIO;
  92                 break;
  93         case GS:
  94                 if (value && (value & 3) != 3)
  95                         return -EIO;
  96                 break;
  97         case DS:
  98         case ES:
  99                 if (value && (value & 3) != 3)
 100                         return -EIO;
 101                 value &= 0xffff;
 102                 break;
 103         case SS:
 104         case CS:
 105                 if ((value & 3) != 3)
 106                         return -EIO;
 107                 value &= 0xffff;
 108                 break;
 109         case EFL:
 110                 value &= FLAG_MASK;
 111                 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
 112                 return 0;
 113         default :
 114                 panic("Bad register in putreg() : %d\n", regno);
 115         }
 116         child->thread.regs.regs.gp[reg_offsets[regno]] = value;
 117         return 0;
 118 }
 119
 120 int poke_user(struct task_struct *child, long addr, long data)
 121 {
 122         if ((addr & 3) || addr < 0)
 123                 return -EIO;
 124
 125         if (addr < MAX_REG_OFFSET)
 126                 return putreg(child, addr, data);
 127         else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
 128                  (addr <= offsetof(struct user, u_debugreg[7]))) {
 129                 addr -= offsetof(struct user, u_debugreg[0]);
 130                 addr = addr >> 2;
 131                 if ((addr == 4) || (addr == 5))
 132                         return -EIO;
 133                 child->thread.arch.debugregs[addr] = data;
 134                 return 0;
 135         }
 136         return -EIO;
 137 }
 138
 139 unsigned long getreg(struct task_struct *child, int regno)
 140 {
 141         unsigned long mask = ~0UL;
 142
 143         regno >>= 2;
 144         switch (regno) {
 145         case FS:
 146         case GS:
 147         case DS:
 148         case ES:
 149         case SS:
 150         case CS:
 151                 mask = 0xffff;
 152                 break;
 153         case EIP:
 154         case UESP:
 155         case EAX:
 156         case EBX:
 157         case ECX:
 158         case EDX:
 159         case ESI:
 160         case EDI:
 161         case EBP:
 162         case EFL:
 163         case ORIG_EAX:
 164                 break;
 165         default:
 166                 panic("Bad register in getreg() : %d\n", regno);
 167         }
 168         return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
 169 }
 170
 171 /* read the word at location addr in the USER area. */
 172 int peek_user(struct task_struct *child, long addr, long data)
 173 {
 174         unsigned long tmp;
 175
 176         if ((addr & 3) || addr < 0)
 177                 return -EIO;
 178
 179         tmp = 0;  /* Default return condition */
 180         if (addr < MAX_REG_OFFSET) {
 181                 tmp = getreg(child, addr);
 182         }
 183         else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
 184                  (addr <= offsetof(struct user, u_debugreg[7]))) {
 185                 addr -= offsetof(struct user, u_debugreg[0]);
 186                 addr = addr >> 2;
 187                 tmp = child->thread.arch.debugregs[addr];
 188         }
 189         return put_user(tmp, (unsigned long __user *) data);
 190 }
 191
 192 static int get_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
 193 {
 194         int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
 195         struct user_i387_struct fpregs;
 196
 197         err = save_i387_registers(userspace_pid[cpu],
 198                                   (unsigned long *) &fpregs);
 199         if (err)
 200                 return err;
 201
 202         n = copy_to_user(buf, &fpregs, sizeof(fpregs));
 203         if(n > 0)
 204                 return -EFAULT;
 205
 206         return n;
 207 }
 208
 209 static int set_fpregs(struct user_i387_struct __user *buf, struct task_struct *child)
 210 {
 211         int n, cpu = ((struct thread_info *) child->stack)->cpu;
 212         struct user_i387_struct fpregs;
 213
 214         n = copy_from_user(&fpregs, buf, sizeof(fpregs));
 215         if (n > 0)
 216                 return -EFAULT;
 217
 218         return restore_i387_registers(userspace_pid[cpu],
 219                                     (unsigned long *) &fpregs);
 220 }
 221
 222 static int get_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
 223 {
 224         int err, n, cpu = ((struct thread_info *) child->stack)->cpu;
 225         struct user_fxsr_struct fpregs;
 226
 227         err = save_fpx_registers(userspace_pid[cpu], (unsigned long *) &fpregs);
 228         if (err)
 229                 return err;
 230
 231         n = copy_to_user(buf, &fpregs, sizeof(fpregs));
 232         if(n > 0)
 233                 return -EFAULT;
 234
 235         return n;
 236 }
 237
 238 static int set_fpxregs(struct user_fxsr_struct __user *buf, struct task_struct *child)
 239 {
 240         int n, cpu = ((struct thread_info *) child->stack)->cpu;
 241         struct user_fxsr_struct fpregs;
 242
 243         n = copy_from_user(&fpregs, buf, sizeof(fpregs));
 244         if (n > 0)
 245                 return -EFAULT;
 246
 247         return restore_fpx_registers(userspace_pid[cpu],
 248                                      (unsigned long *) &fpregs);
 249 }
 250
 251 long subarch_ptrace(struct task_struct *child, long request,
 252                     unsigned long addr, unsigned long data)
 253 {
 254         int ret = -EIO;
 255         void __user *datap = (void __user *) data;
 256         switch (request) {
 257         case PTRACE_GETFPREGS: /* Get the child FPU state. */
 258                 ret = get_fpregs(datap, child);
 259                 break;
 260         case PTRACE_SETFPREGS: /* Set the child FPU state. */
 261                 ret = set_fpregs(datap, child);
 262                 break;
 263         case PTRACE_GETFPXREGS: /* Get the child FPU state. */
 264                 ret = get_fpxregs(datap, child);
 265                 break;
 266         case PTRACE_SETFPXREGS: /* Set the child FPU state. */
 267                 ret = set_fpxregs(datap, child);
 268                 break;
 269         default:
 270                 ret = -EIO;
 271         }
 272         return ret;
 273 }