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 #include "wine/library.h"
40 #ifdef HAVE_SYS_SYSCALL_H
41 # include <sys/syscall.h>
46 unsigned int entry_number
;
47 unsigned long base_addr
;
49 unsigned int seg_32bit
: 1;
50 unsigned int contents
: 2;
51 unsigned int read_exec_only
: 1;
52 unsigned int limit_in_pages
: 1;
53 unsigned int seg_not_present
: 1;
54 unsigned int usable
: 1;
55 unsigned int garbage
: 25;
58 static inline void fill_modify_ldt_struct( struct modify_ldt_s
*ptr
, const LDT_ENTRY
*entry
)
60 ptr
->base_addr
= (unsigned long)wine_ldt_get_base(entry
);
61 ptr
->limit
= entry
->LimitLow
| (entry
->HighWord
.Bits
.LimitHi
<< 16);
62 ptr
->seg_32bit
= entry
->HighWord
.Bits
.Default_Big
;
63 ptr
->contents
= (entry
->HighWord
.Bits
.Type
>> 2) & 3;
64 ptr
->read_exec_only
= !(entry
->HighWord
.Bits
.Type
& 2);
65 ptr
->limit_in_pages
= entry
->HighWord
.Bits
.Granularity
;
66 ptr
->seg_not_present
= !entry
->HighWord
.Bits
.Pres
;
67 ptr
->usable
= entry
->HighWord
.Bits
.Sys
;
71 static inline int modify_ldt( int func
, struct modify_ldt_s
*ptr
, unsigned long count
)
74 __asm__
__volatile__( "pushl %%ebx\n\t"
79 : "0" (SYS_modify_ldt
),
84 if (res
>= 0) return res
;
89 static inline int set_thread_area( struct modify_ldt_s
*ptr
)
92 __asm__
__volatile__( "pushl %%ebx\n\t"
96 : "=a" (res
), "=m" (*ptr
)
97 : "0" (243) /* SYS_set_thread_area */, "q" (ptr
), "m" (*ptr
) );
98 if (res
>= 0) return res
;
105 #if defined(__svr4__) || defined(_SCO_DS)
106 #include <sys/sysi86.h>
112 #if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
113 #include <machine/segments.h>
114 #include <machine/sysarch.h>
115 #endif /* __NetBSD__ || __FreeBSD__ || __OpenBSD__ */
118 #include <i386/user_ldt.h>
121 #endif /* __i386__ */
123 /* local copy of the LDT */
125 struct __wine_ldt_copy wine_ldt_copy
= { { 0, 0, 0 } };
127 struct __wine_ldt_copy wine_ldt_copy
;
130 static const LDT_ENTRY null_entry
; /* all-zeros, used to clear LDT entries */
132 #define LDT_FIRST_ENTRY 512
133 #define LDT_SIZE 8192
135 /* empty function for default locks */
136 static void nop(void) { }
138 static void (*lock_ldt
)(void) = nop
;
139 static void (*unlock_ldt
)(void) = nop
;
142 static inline int is_gdt_sel( unsigned short sel
) { return !(sel
& 4); }
144 /***********************************************************************
145 * wine_ldt_init_locking
147 * Set the LDT locking/unlocking functions.
149 void wine_ldt_init_locking( void (*lock_func
)(void), void (*unlock_func
)(void) )
151 lock_ldt
= lock_func
;
152 unlock_ldt
= unlock_func
;
156 /***********************************************************************
159 * Retrieve an LDT entry. Return a null entry if selector is not allocated.
161 void wine_ldt_get_entry( unsigned short sel
, LDT_ENTRY
*entry
)
163 int index
= sel
>> 3;
171 if (wine_ldt_copy
.flags
[index
] & WINE_LDT_FLAGS_ALLOCATED
)
173 wine_ldt_set_base( entry
, wine_ldt_copy
.base
[index
] );
174 wine_ldt_set_limit( entry
, wine_ldt_copy
.limit
[index
] );
175 wine_ldt_set_flags( entry
, wine_ldt_copy
.flags
[index
] );
177 else *entry
= null_entry
;
182 /***********************************************************************
185 * Set an LDT entry, without locking. For internal use only.
187 static int internal_set_entry( unsigned short sel
, const LDT_ENTRY
*entry
)
189 int ret
= 0, index
= sel
>> 3;
191 if (index
< LDT_FIRST_ENTRY
) return 0; /* cannot modify reserved entries */
197 struct modify_ldt_s ldt_info
;
199 ldt_info
.entry_number
= index
;
200 fill_modify_ldt_struct( &ldt_info
, entry
);
201 if ((ret
= modify_ldt(0x11, &ldt_info
, sizeof(ldt_info
))) < 0)
202 perror( "modify_ldt" );
204 #elif defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
206 LDT_ENTRY entry_copy
= *entry
;
207 /* The kernel will only let us set LDTs with user priority level */
208 if (entry_copy
.HighWord
.Bits
.Pres
209 && entry_copy
.HighWord
.Bits
.Dpl
!= 3)
210 entry_copy
.HighWord
.Bits
.Dpl
= 3;
211 ret
= i386_set_ldt(index
, (union descriptor
*)&entry_copy
, 1);
214 perror("i386_set_ldt");
215 fprintf( stderr
, "Did you reconfigure the kernel with \"options USER_LDT\"?\n" );
219 #elif defined(__svr4__) || defined(_SCO_DS)
223 ldt_mod
.bo
= (unsigned long)wine_ldt_get_base(entry
);
224 ldt_mod
.ls
= entry
->LimitLow
| (entry
->HighWord
.Bits
.LimitHi
<< 16);
225 ldt_mod
.acc1
= entry
->HighWord
.Bytes
.Flags1
;
226 ldt_mod
.acc2
= entry
->HighWord
.Bytes
.Flags2
>> 4;
227 if ((ret
= sysi86(SI86DSCR
, &ldt_mod
)) == -1) perror("sysi86");
229 #elif defined(__APPLE__)
230 if ((ret
= i386_set_ldt(index
, (union ldt_entry
*)entry
, 1)) < 0)
231 perror("i386_set_ldt");
233 fprintf( stderr
, "No LDT support on this platform\n" );
237 #endif /* __i386__ */
241 wine_ldt_copy
.base
[index
] = wine_ldt_get_base(entry
);
242 wine_ldt_copy
.limit
[index
] = wine_ldt_get_limit(entry
);
243 wine_ldt_copy
.flags
[index
] = (entry
->HighWord
.Bits
.Type
|
244 (entry
->HighWord
.Bits
.Default_Big
? WINE_LDT_FLAGS_32BIT
: 0) |
245 (wine_ldt_copy
.flags
[index
] & WINE_LDT_FLAGS_ALLOCATED
));
251 /***********************************************************************
256 int wine_ldt_set_entry( unsigned short sel
, const LDT_ENTRY
*entry
)
261 ret
= internal_set_entry( sel
, entry
);
267 /***********************************************************************
270 * Check if the selector is a system selector (i.e. not managed by Wine).
272 int wine_ldt_is_system( unsigned short sel
)
274 return is_gdt_sel(sel
) || ((sel
>> 3) < LDT_FIRST_ENTRY
);
278 /***********************************************************************
281 * Convert a segment:offset pair to a linear pointer.
282 * Note: we don't lock the LDT since this has to be fast.
284 void *wine_ldt_get_ptr( unsigned short sel
, unsigned long offset
)
288 if (is_gdt_sel(sel
)) /* GDT selector */
289 return (void *)offset
;
290 if ((index
= (sel
>> 3)) < LDT_FIRST_ENTRY
) /* system selector */
291 return (void *)offset
;
292 if (!(wine_ldt_copy
.flags
[index
] & WINE_LDT_FLAGS_32BIT
)) offset
&= 0xffff;
293 return (char *)wine_ldt_copy
.base
[index
] + offset
;
297 /***********************************************************************
298 * wine_ldt_alloc_entries
300 * Allocate a number of consecutive ldt entries, without setting the LDT contents.
301 * Return a selector for the first entry.
303 unsigned short wine_ldt_alloc_entries( int count
)
305 int i
, index
, size
= 0;
307 if (count
<= 0) return 0;
309 for (i
= LDT_FIRST_ENTRY
; i
< LDT_SIZE
; i
++)
311 if (wine_ldt_copy
.flags
[i
] & WINE_LDT_FLAGS_ALLOCATED
) size
= 0;
312 else if (++size
>= count
) /* found a large enough block */
314 index
= i
- size
+ 1;
316 /* mark selectors as allocated */
317 for (i
= 0; i
< count
; i
++) wine_ldt_copy
.flags
[index
+ i
] |= WINE_LDT_FLAGS_ALLOCATED
;
319 return (index
<< 3) | 7;
327 /***********************************************************************
328 * wine_ldt_realloc_entries
330 * Reallocate a number of consecutive ldt entries, without changing the LDT contents.
331 * Return a selector for the first entry.
333 unsigned short wine_ldt_realloc_entries( unsigned short sel
, int oldcount
, int newcount
)
337 if (oldcount
< newcount
) /* we need to add selectors */
339 int index
= sel
>> 3;
342 /* check if the next selectors are free */
343 if (index
+ newcount
> LDT_SIZE
) i
= oldcount
;
345 for (i
= oldcount
; i
< newcount
; i
++)
346 if (wine_ldt_copy
.flags
[index
+i
] & WINE_LDT_FLAGS_ALLOCATED
) break;
348 if (i
< newcount
) /* they are not free */
350 wine_ldt_free_entries( sel
, oldcount
);
351 sel
= wine_ldt_alloc_entries( newcount
);
353 else /* mark the selectors as allocated */
355 for (i
= oldcount
; i
< newcount
; i
++)
356 wine_ldt_copy
.flags
[index
+i
] |= WINE_LDT_FLAGS_ALLOCATED
;
360 else if (oldcount
> newcount
) /* we need to remove selectors */
362 wine_ldt_free_entries( sel
+ (newcount
<< 3), newcount
- oldcount
);
368 /***********************************************************************
369 * wine_ldt_free_entries
371 * Free a number of consecutive ldt entries and clear their contents.
373 void wine_ldt_free_entries( unsigned short sel
, int count
)
378 for (index
= sel
>> 3; count
> 0; count
--, index
++)
380 internal_set_entry( sel
, &null_entry
);
381 wine_ldt_copy
.flags
[index
] = 0;
387 #if defined(__i386__) && !defined(__MINGW32__) && !defined(_MSC_VER)
389 static int global_fs_sel
= -1; /* global selector for %fs shared among all threads */
391 /***********************************************************************
394 * Allocate an LDT entry for a %fs selector, reusing a global
395 * GDT selector if possible. Return the selector value.
397 unsigned short wine_ldt_alloc_fs(void)
399 if (global_fs_sel
== -1)
402 struct modify_ldt_s ldt_info
;
405 /* the preloader may have allocated it already */
406 global_fs_sel
= wine_get_fs();
407 if (global_fs_sel
&& is_gdt_sel(global_fs_sel
)) return global_fs_sel
;
409 ldt_info
.entry_number
= -1;
410 fill_modify_ldt_struct( &ldt_info
, &null_entry
);
411 if ((ret
= set_thread_area( &ldt_info
) < 0))
413 global_fs_sel
= 0; /* don't try it again */
414 if (errno
!= ENOSYS
) perror( "set_thread_area" );
416 else global_fs_sel
= (ldt_info
.entry_number
<< 3) | 3;
417 #elif defined(__FreeBSD__)
418 global_fs_sel
= GSEL( GUFS_SEL
, SEL_UPL
);
421 if (global_fs_sel
> 0) return global_fs_sel
;
422 return wine_ldt_alloc_entries( 1 );
426 /***********************************************************************
429 * Initialize the entry for the %fs selector of the current thread, and
430 * set the thread %fs register.
432 * Note: this runs in the context of the new thread, so cannot acquire locks.
434 void wine_ldt_init_fs( unsigned short sel
, const LDT_ENTRY
*entry
)
436 if ((sel
& ~3) == (global_fs_sel
& ~3))
439 struct modify_ldt_s ldt_info
;
442 ldt_info
.entry_number
= sel
>> 3;
443 fill_modify_ldt_struct( &ldt_info
, entry
);
444 if ((ret
= set_thread_area( &ldt_info
) < 0)) perror( "set_thread_area" );
445 #elif defined(__FreeBSD__)
446 i386_set_fsbase( wine_ldt_get_base( entry
));
449 else /* LDT selector */
451 internal_set_entry( sel
, entry
);
457 /***********************************************************************
460 * Free a %fs selector returned by wine_ldt_alloc_fs.
462 void wine_ldt_free_fs( unsigned short sel
)
464 if (is_gdt_sel(sel
)) return; /* nothing to do */
465 if (!((wine_get_fs() ^ sel
) & ~3))
467 /* FIXME: if freeing current %fs we cannot acquire locks */
469 internal_set_entry( sel
, &null_entry
);
470 wine_ldt_copy
.flags
[sel
>> 3] = 0;
472 else wine_ldt_free_entries( sel
, 1 );
476 /***********************************************************************
477 * selector access functions
479 __ASM_GLOBAL_FUNC( wine_get_cs
, "movw %cs,%ax\n\tret" )
480 __ASM_GLOBAL_FUNC( wine_get_ds
, "movw %ds,%ax\n\tret" )
481 __ASM_GLOBAL_FUNC( wine_get_es
, "movw %es,%ax\n\tret" )
482 __ASM_GLOBAL_FUNC( wine_get_fs
, "movw %fs,%ax\n\tret" )
483 __ASM_GLOBAL_FUNC( wine_get_gs
, "movw %gs,%ax\n\tret" )
484 __ASM_GLOBAL_FUNC( wine_get_ss
, "movw %ss,%ax\n\tret" )
485 __ASM_GLOBAL_FUNC( wine_set_fs
, "movl 4(%esp),%eax\n\tmovw %ax,%fs\n\tret" )
486 __ASM_GLOBAL_FUNC( wine_set_gs
, "movl 4(%esp),%eax\n\tmovw %ax,%gs\n\tret" )
488 #endif /* __i386__ */