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