2 * LDT manipulation functions
4 * Copyright 1993 Robert J. Amstadt
5 * Copyright 1995 Alexandre Julliard
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
23 #include "wine/port.h"
34 #define WINE_EXPORT_LDT_COPY
35 #include "wine/library.h"
41 #ifdef HAVE_SYS_SYSCALL_H
42 # include <sys/syscall.h>
47 unsigned int entry_number
;
48 unsigned long base_addr
;
50 unsigned int seg_32bit
: 1;
51 unsigned int contents
: 2;
52 unsigned int read_exec_only
: 1;
53 unsigned int limit_in_pages
: 1;
54 unsigned int seg_not_present
: 1;
55 unsigned int useable
: 1;
56 unsigned int garbage
: 25;
59 static inline void fill_modify_ldt_struct( struct modify_ldt_s
*ptr
, const LDT_ENTRY
*entry
)
61 ptr
->base_addr
= (unsigned long)wine_ldt_get_base(entry
);
62 ptr
->limit
= entry
->LimitLow
| (entry
->HighWord
.Bits
.LimitHi
<< 16);
63 ptr
->seg_32bit
= entry
->HighWord
.Bits
.Default_Big
;
64 ptr
->contents
= (entry
->HighWord
.Bits
.Type
>> 2) & 3;
65 ptr
->read_exec_only
= !(entry
->HighWord
.Bits
.Type
& 2);
66 ptr
->limit_in_pages
= entry
->HighWord
.Bits
.Granularity
;
67 ptr
->seg_not_present
= !entry
->HighWord
.Bits
.Pres
;
68 ptr
->useable
= entry
->HighWord
.Bits
.Sys
;
72 static inline int modify_ldt( int func
, struct modify_ldt_s
*ptr
, unsigned long count
)
75 __asm__
__volatile__( "pushl %%ebx\n\t"
80 : "0" (SYS_modify_ldt
),
85 if (res
>= 0) return res
;
90 static inline int set_thread_area( struct modify_ldt_s
*ptr
)
93 __asm__
__volatile__( "pushl %%ebx\n\t"
97 : "=a" (res
), "=m" (*ptr
)
98 : "0" (243) /* SYS_set_thread_area */, "q" (ptr
), "m" (*ptr
) );
99 if (res
>= 0) return res
;
106 #if defined(__svr4__) || defined(_SCO_DS)
107 #include <sys/sysi86.h>
113 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
114 #include <machine/segments.h>
116 extern int i386_get_ldt(int, union descriptor
*, int);
117 extern int i386_set_ldt(int, union descriptor
*, int);
118 #endif /* __NetBSD__ || __FreeBSD__ || __OpenBSD__ */
121 #include <i386/user_ldt.h>
124 #endif /* __i386__ */
126 /* local copy of the LDT */
128 struct __wine_ldt_copy wine_ldt_copy
= { { 0, 0, 0 } };
130 struct __wine_ldt_copy wine_ldt_copy
;
133 static const LDT_ENTRY null_entry
; /* all-zeros, used to clear LDT entries */
135 #define LDT_FIRST_ENTRY 512
136 #define LDT_SIZE 8192
138 /* empty function for default locks */
139 static void nop(void) { }
141 static void (*lock_ldt
)(void) = nop
;
142 static void (*unlock_ldt
)(void) = nop
;
145 static inline int is_gdt_sel( unsigned short sel
) { return !(sel
& 4); }
147 /***********************************************************************
148 * wine_ldt_init_locking
150 * Set the LDT locking/unlocking functions.
152 void wine_ldt_init_locking( void (*lock_func
)(void), void (*unlock_func
)(void) )
154 lock_ldt
= lock_func
;
155 unlock_ldt
= unlock_func
;
159 /***********************************************************************
162 * Retrieve an LDT entry. Return a null entry if selector is not allocated.
164 void wine_ldt_get_entry( unsigned short sel
, LDT_ENTRY
*entry
)
166 int index
= sel
>> 3;
174 if (wine_ldt_copy
.flags
[index
] & WINE_LDT_FLAGS_ALLOCATED
)
176 wine_ldt_set_base( entry
, wine_ldt_copy
.base
[index
] );
177 wine_ldt_set_limit( entry
, wine_ldt_copy
.limit
[index
] );
178 wine_ldt_set_flags( entry
, wine_ldt_copy
.flags
[index
] );
180 else *entry
= null_entry
;
185 /***********************************************************************
188 * Set an LDT entry, without locking. For internal use only.
190 static int internal_set_entry( unsigned short sel
, const LDT_ENTRY
*entry
)
192 int ret
= 0, index
= sel
>> 3;
194 if (index
< LDT_FIRST_ENTRY
) return 0; /* cannot modify reserved entries */
200 struct modify_ldt_s ldt_info
;
202 ldt_info
.entry_number
= index
;
203 fill_modify_ldt_struct( &ldt_info
, entry
);
204 if ((ret
= modify_ldt(0x11, &ldt_info
, sizeof(ldt_info
))) < 0)
205 perror( "modify_ldt" );
207 #elif defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
209 LDT_ENTRY entry_copy
= *entry
;
210 /* The kernel will only let us set LDTs with user priority level */
211 if (entry_copy
.HighWord
.Bits
.Pres
212 && entry_copy
.HighWord
.Bits
.Dpl
!= 3)
213 entry_copy
.HighWord
.Bits
.Dpl
= 3;
214 ret
= i386_set_ldt(index
, (union descriptor
*)&entry_copy
, 1);
217 perror("i386_set_ldt");
218 fprintf( stderr
, "Did you reconfigure the kernel with \"options USER_LDT\"?\n" );
222 #elif defined(__svr4__) || defined(_SCO_DS)
226 ldt_mod
.bo
= (unsigned long)wine_ldt_get_base(entry
);
227 ldt_mod
.ls
= entry
->LimitLow
| (entry
->HighWord
.Bits
.LimitHi
<< 16);
228 ldt_mod
.acc1
= entry
->HighWord
.Bytes
.Flags1
;
229 ldt_mod
.acc2
= entry
->HighWord
.Bytes
.Flags2
>> 4;
230 if ((ret
= sysi86(SI86DSCR
, &ldt_mod
)) == -1) perror("sysi86");
232 #elif defined(__APPLE__)
233 if ((ret
= i386_set_ldt(index
, (union ldt_entry
*)entry
, 1)) < 0)
234 perror("i386_set_ldt");
236 fprintf( stderr
, "No LDT support on this platform\n" );
240 #endif /* __i386__ */
244 wine_ldt_copy
.base
[index
] = wine_ldt_get_base(entry
);
245 wine_ldt_copy
.limit
[index
] = wine_ldt_get_limit(entry
);
246 wine_ldt_copy
.flags
[index
] = (entry
->HighWord
.Bits
.Type
|
247 (entry
->HighWord
.Bits
.Default_Big
? WINE_LDT_FLAGS_32BIT
: 0) |
248 (wine_ldt_copy
.flags
[index
] & WINE_LDT_FLAGS_ALLOCATED
));
254 /***********************************************************************
259 int wine_ldt_set_entry( unsigned short sel
, const LDT_ENTRY
*entry
)
264 ret
= internal_set_entry( sel
, entry
);
270 /***********************************************************************
273 * Check if the selector is a system selector (i.e. not managed by Wine).
275 int wine_ldt_is_system( unsigned short sel
)
277 return is_gdt_sel(sel
) || ((sel
>> 3) < LDT_FIRST_ENTRY
);
281 /***********************************************************************
284 * Convert a segment:offset pair to a linear pointer.
285 * Note: we don't lock the LDT since this has to be fast.
287 void *wine_ldt_get_ptr( unsigned short sel
, unsigned long offset
)
291 if (is_gdt_sel(sel
)) /* GDT selector */
292 return (void *)offset
;
293 if ((index
= (sel
>> 3)) < LDT_FIRST_ENTRY
) /* system selector */
294 return (void *)offset
;
295 if (!(wine_ldt_copy
.flags
[index
] & WINE_LDT_FLAGS_32BIT
)) offset
&= 0xffff;
296 return (char *)wine_ldt_copy
.base
[index
] + offset
;
300 /***********************************************************************
301 * wine_ldt_alloc_entries
303 * Allocate a number of consecutive ldt entries, without setting the LDT contents.
304 * Return a selector for the first entry.
306 unsigned short wine_ldt_alloc_entries( int count
)
308 int i
, index
, size
= 0;
310 if (count
<= 0) return 0;
312 for (i
= LDT_FIRST_ENTRY
; i
< LDT_SIZE
; i
++)
314 if (wine_ldt_copy
.flags
[i
] & WINE_LDT_FLAGS_ALLOCATED
) size
= 0;
315 else if (++size
>= count
) /* found a large enough block */
317 index
= i
- size
+ 1;
319 /* mark selectors as allocated */
320 for (i
= 0; i
< count
; i
++) wine_ldt_copy
.flags
[index
+ i
] |= WINE_LDT_FLAGS_ALLOCATED
;
322 return (index
<< 3) | 7;
330 /***********************************************************************
331 * wine_ldt_realloc_entries
333 * Reallocate a number of consecutive ldt entries, without changing the LDT contents.
334 * Return a selector for the first entry.
336 unsigned short wine_ldt_realloc_entries( unsigned short sel
, int oldcount
, int newcount
)
340 if (oldcount
< newcount
) /* we need to add selectors */
342 int index
= sel
>> 3;
345 /* check if the next selectors are free */
346 if (index
+ newcount
> LDT_SIZE
) i
= oldcount
;
348 for (i
= oldcount
; i
< newcount
; i
++)
349 if (wine_ldt_copy
.flags
[index
+i
] & WINE_LDT_FLAGS_ALLOCATED
) break;
351 if (i
< newcount
) /* they are not free */
353 wine_ldt_free_entries( sel
, oldcount
);
354 sel
= wine_ldt_alloc_entries( newcount
);
356 else /* mark the selectors as allocated */
358 for (i
= oldcount
; i
< newcount
; i
++)
359 wine_ldt_copy
.flags
[index
+i
] |= WINE_LDT_FLAGS_ALLOCATED
;
363 else if (oldcount
> newcount
) /* we need to remove selectors */
365 wine_ldt_free_entries( sel
+ (newcount
<< 3), newcount
- oldcount
);
371 /***********************************************************************
372 * wine_ldt_free_entries
374 * Free a number of consecutive ldt entries and clear their contents.
376 void wine_ldt_free_entries( unsigned short sel
, int count
)
381 for (index
= sel
>> 3; count
> 0; count
--, index
++)
383 internal_set_entry( sel
, &null_entry
);
384 wine_ldt_copy
.flags
[index
] = 0;
392 static int global_fs_sel
= -1; /* global selector for %fs shared among all threads */
394 /***********************************************************************
397 * Allocate an LDT entry for a %fs selector, reusing a global
398 * GDT selector if possible. Return the selector value.
400 unsigned short wine_ldt_alloc_fs(void)
402 if (global_fs_sel
== -1)
405 struct modify_ldt_s ldt_info
;
408 ldt_info
.entry_number
= -1;
409 fill_modify_ldt_struct( &ldt_info
, &null_entry
);
410 if ((ret
= set_thread_area( &ldt_info
) < 0))
412 global_fs_sel
= 0; /* don't try it again */
413 if (errno
!= ENOSYS
) perror( "set_thread_area" );
415 else global_fs_sel
= (ldt_info
.entry_number
<< 3) | 3;
418 if (global_fs_sel
> 0) return global_fs_sel
;
419 return wine_ldt_alloc_entries( 1 );
423 /***********************************************************************
426 * Initialize the entry for the %fs selector of the current thread, and
427 * set the thread %fs register.
429 * Note: this runs in the context of the new thread, so cannot acquire locks.
431 void wine_ldt_init_fs( unsigned short sel
, const LDT_ENTRY
*entry
)
433 if ((sel
& ~3) == (global_fs_sel
& ~3))
436 struct modify_ldt_s ldt_info
;
439 ldt_info
.entry_number
= sel
>> 3;
440 fill_modify_ldt_struct( &ldt_info
, entry
);
441 if ((ret
= set_thread_area( &ldt_info
) < 0)) perror( "set_thread_area" );
444 else /* LDT selector */
446 internal_set_entry( sel
, entry
);
452 /***********************************************************************
455 * Free a %fs selector returned by wine_ldt_alloc_fs.
457 void wine_ldt_free_fs( unsigned short sel
)
459 if (is_gdt_sel(sel
)) return; /* nothing to do */
460 if (!((wine_get_fs() ^ sel
) & ~3))
462 /* FIXME: if freeing current %fs we cannot acquire locks */
464 internal_set_entry( sel
, &null_entry
);
465 wine_ldt_copy
.flags
[sel
>> 3] = 0;
467 else wine_ldt_free_entries( sel
, 1 );
471 /***********************************************************************
472 * selector access functions
475 /* Nothing needs to be done for MS C, it will do with inline versions from the winnt.h */
476 __ASM_GLOBAL_FUNC( wine_get_cs
, "movw %cs,%ax\n\tret" )
477 __ASM_GLOBAL_FUNC( wine_get_ds
, "movw %ds,%ax\n\tret" )
478 __ASM_GLOBAL_FUNC( wine_get_es
, "movw %es,%ax\n\tret" )
479 __ASM_GLOBAL_FUNC( wine_get_fs
, "movw %fs,%ax\n\tret" )
480 __ASM_GLOBAL_FUNC( wine_get_gs
, "movw %gs,%ax\n\tret" )
481 __ASM_GLOBAL_FUNC( wine_get_ss
, "movw %ss,%ax\n\tret" )
482 __ASM_GLOBAL_FUNC( wine_set_fs
, "movl 4(%esp),%eax\n\tmovw %ax,%fs\n\tret" )
483 __ASM_GLOBAL_FUNC( wine_set_gs
, "movl 4(%esp),%eax\n\tmovw %ax,%gs\n\tret" )
484 # endif /* defined(_MSC_VER) */
486 #endif /* __i386__ */