arch/um/sys-i386/ldt.c

   1 /*
   2  * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/config.h"
   7 #include "linux/slab.h"
   8 #include "asm/uaccess.h"
   9 #include "asm/ptrace.h"
  10 #include "choose-mode.h"
  11 #include "kern.h"
  12
  13 #ifdef CONFIG_MODE_TT
  14 extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
  15
  16 /* XXX this needs copy_to_user and copy_from_user */
  17
  18 int sys_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
  19 {
  20         if(verify_area(VERIFY_READ, ptr, bytecount)) return(-EFAULT);
  21         return(modify_ldt(func, ptr, bytecount));
  22 }
  23 #endif
  24
  25 #ifdef CONFIG_MODE_SKAS
  26 extern int userspace_pid;
  27
  28 int sys_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
  29 {
  30         struct ptrace_ldt ldt;
  31         void *buf;
  32         int res, n;
  33
  34         buf = kmalloc(bytecount, GFP_KERNEL);
  35         if(buf == NULL)
  36                 return(-ENOMEM);
  37
  38         res = 0;
  39
  40         switch(func){
  41         case 1:
  42         case 0x11:
  43                 res = copy_from_user(buf, ptr, bytecount);
  44                 break;
  45         }
  46
  47         if(res != 0){
  48                 res = -EFAULT;
  49                 goto out;
  50         }
  51
  52         ldt = ((struct ptrace_ldt) { .func      = func,
  53                                      .ptr       = buf,
  54                                      .bytecount = bytecount });
  55         res = ptrace(PTRACE_LDT, userspace_pid, 0, (unsigned long) &ldt);
  56         if(res < 0)
  57                 goto out;
  58
  59         switch(func){
  60         case 0:
  61         case 2:
  62                 n = res;
  63                 res = copy_to_user(ptr, buf, n);
  64                 if(res != 0)
  65                         res = -EFAULT;
  66                 else
  67                         res = n;
  68                 break;
  69         }
  70
  71  out:
  72         kfree(buf);
  73         return(res);
  74 }
  75 #endif
  76
  77 int sys_modify_ldt(int func, void *ptr, unsigned long bytecount)
  78 {
  79         return(CHOOSE_MODE_PROC(sys_modify_ldt_tt, sys_modify_ldt_skas, func,
  80                                 ptr, bytecount));
  81 }
  82
  83
  84
  85 /*
  86  * Overrides for Emacs so that we follow Linus's tabbing style.
  87  * Emacs will notice this stuff at the end of the file and automatically
  88  * adjust the settings for this buffer only.  This must remain at the end
  89  * of the file.
  90  * ---------------------------------------------------------------------------
  91  * Local variables:
  92  * c-file-style: "linux"
  93  * End:
  94  */