loader/ldtlib.c

   1 #ifndef WINELIB
   2 static char RCSId[] = "$Id: ldtlib.c,v 1.2 1993/07/04 04:04:21 root Exp root $";
   3 static char Copyright[] = "Copyright  Robert J. Amstadt, 1993";
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <errno.h>
   8 #include "autoconf.h"
   9 #include "stddebug.h"
  10 /* #define DEBUG_LDT /* */
  11 /* #undef DEBUG_LDT  /* */
  12 #include "debug.h"
  13
  14 #ifdef linux
  15 #include <linux/unistd.h>
  16 #include <linux/head.h>
  17 #include <linux/ldt.h>
  18
  19 _syscall3(int, modify_ldt, int, func, void *, ptr, unsigned long, bytecount)
  20 #endif
  21 #if defined(__NetBSD__) || defined(__FreeBSD__)
  22 #include <machine/segments.h>
  23
  24 extern int i386_get_ldt(int, union descriptor *, int);
  25 extern int i386_set_ldt(int, union descriptor *, int);
  26
  27 struct segment_descriptor *
  28 make_sd(unsigned base, unsigned limit, int contents, int read_exec_only, int seg32, int inpgs)
  29 {
  30         static long d[2];
  31
  32         d[0] = ((base & 0x0000ffff) << 16) |
  33                 (limit & 0x0ffff);
  34         d[1] = (base & 0xff000000) |
  35                 ((base & 0x00ff0000)>>16) |
  36                         (limit & 0xf0000) |
  37                                 (contents << 10) |
  38                                         ((read_exec_only ^ 1) << 9) |
  39                                                 (seg32 << 22) |
  40                                                         (inpgs << 23) |
  41                                                                 0xf000;
  42
  43         return ((struct segment_descriptor *)d);
  44 }
  45 #endif
  46
  47 int
  48 get_ldt(void *buffer)
  49 {
  50 #ifdef linux
  51     return modify_ldt(0, buffer, 32 * sizeof(struct modify_ldt_ldt_s));
  52 #endif
  53 #if defined(__NetBSD__) || defined(__FreeBSD__)
  54     return i386_get_ldt(0, (union descriptor *)buffer, 32);
  55 #endif
  56 }
  57
  58 int
  59 set_ldt_entry(int entry, unsigned long base, unsigned int limit,
  60               int seg_32bit_flag, int contents, int read_only_flag,
  61               int limit_in_pages_flag)
  62 {
  63 #ifdef linux
  64     struct modify_ldt_ldt_s ldt_info;
  65
  66     ldt_info.entry_number   = entry;
  67     ldt_info.base_addr      = base;
  68     ldt_info.limit          = limit;
  69     ldt_info.seg_32bit      = seg_32bit_flag;
  70     ldt_info.contents       = contents;
  71     ldt_info.read_exec_only = read_only_flag;
  72     ldt_info.limit_in_pages = limit_in_pages_flag;
  73 #ifdef NEW_LDT_STRUCT
  74     ldt_info.seg_not_present = 0;
  75 #endif
  76
  77     return modify_ldt(1, &ldt_info, sizeof(ldt_info));
  78 #endif
  79 #if defined(__NetBSD__) || defined(__FreeBSD__)
  80     struct segment_descriptor *sd;
  81     int ret;
  82
  83     dprintf_ldt(stddeb,
  84           "set_ldt_entry: entry=%x base=%x limit=%x%s %s-bit contents=%d %s\n",
  85           entry, base, limit, limit_in_pages_flag?"-pages":"",
  86           seg_32bit_flag?"32":"16",
  87           contents, read_only_flag?"read-only":"");
  88
  89     sd = make_sd(base, limit, contents, read_only_flag, seg_32bit_flag, limit_in_pages_flag);
  90     ret = i386_set_ldt(entry, (union descriptor *)sd, 1);
  91     if (ret < 0) {
  92             perror("i386_set_ldt");
  93             fprintf(stderr,
  94                 "Did you reconfigure the kernel with \"options USER_LDT\"?\n");
  95             exit(1);
  96     }
  97
  98     return ret;
  99
 100 #endif
 101 }
 102 #endif /* ifndef WINELIB */