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