ldt.c revision af062818b47340eef15700d2f0211576ba3506ee
af062818b47340eef15700d2f0211576ba3506eevboxsync * LDT manipulation functions
af062818b47340eef15700d2f0211576ba3506eevboxsync * Copyright 1993 Robert J. Amstadt
af062818b47340eef15700d2f0211576ba3506eevboxsync * Copyright 1995 Alexandre Julliard
af062818b47340eef15700d2f0211576ba3506eevboxsync * This library is free software; you can redistribute it and/or
af062818b47340eef15700d2f0211576ba3506eevboxsync * modify it under the terms of the GNU Lesser General Public
af062818b47340eef15700d2f0211576ba3506eevboxsync * License as published by the Free Software Foundation; either
af062818b47340eef15700d2f0211576ba3506eevboxsync * version 2.1 of the License, or (at your option) any later version.
af062818b47340eef15700d2f0211576ba3506eevboxsync * This library is distributed in the hope that it will be useful,
af062818b47340eef15700d2f0211576ba3506eevboxsync * but WITHOUT ANY WARRANTY; without even the implied warranty of
af062818b47340eef15700d2f0211576ba3506eevboxsync * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
af062818b47340eef15700d2f0211576ba3506eevboxsync * Lesser General Public License for more details.
af062818b47340eef15700d2f0211576ba3506eevboxsync * You should have received a copy of the GNU Lesser General Public
af062818b47340eef15700d2f0211576ba3506eevboxsync * License along with this library; if not, write to the Free Software
af062818b47340eef15700d2f0211576ba3506eevboxsync * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
af062818b47340eef15700d2f0211576ba3506eevboxsync unsigned int entry_number;
af062818b47340eef15700d2f0211576ba3506eevboxsync unsigned long base_addr;
af062818b47340eef15700d2f0211576ba3506eevboxsync unsigned int limit;
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic inline void fill_modify_ldt_struct( struct modify_ldt_s *ptr, const LDT_ENTRY *entry )
af062818b47340eef15700d2f0211576ba3506eevboxsync ptr->base_addr = (unsigned long)wine_ldt_get_base(entry);
af062818b47340eef15700d2f0211576ba3506eevboxsync ptr->limit = entry->LimitLow | (entry->HighWord.Bits.LimitHi << 16);
af062818b47340eef15700d2f0211576ba3506eevboxsync ptr->contents = (entry->HighWord.Bits.Type >> 2) & 3;
af062818b47340eef15700d2f0211576ba3506eevboxsync ptr->read_exec_only = !(entry->HighWord.Bits.Type & 2);
af062818b47340eef15700d2f0211576ba3506eevboxsync ptr->limit_in_pages = entry->HighWord.Bits.Granularity;
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic inline int modify_ldt( int func, struct modify_ldt_s *ptr, unsigned long count )
af062818b47340eef15700d2f0211576ba3506eevboxsync "movl %2,%%ebx\n\t"
af062818b47340eef15700d2f0211576ba3506eevboxsync "int $0x80\n\t"
af062818b47340eef15700d2f0211576ba3506eevboxsync "popl %%ebx"
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic inline int set_thread_area( struct modify_ldt_s *ptr )
af062818b47340eef15700d2f0211576ba3506eevboxsync "movl %3,%%ebx\n\t"
af062818b47340eef15700d2f0211576ba3506eevboxsync "int $0x80\n\t"
af062818b47340eef15700d2f0211576ba3506eevboxsync "popl %%ebx"
af062818b47340eef15700d2f0211576ba3506eevboxsync : "0" (243) /* SYS_set_thread_area */, "q" (ptr), "m" (*ptr) );
af062818b47340eef15700d2f0211576ba3506eevboxsync#endif /* linux */
af062818b47340eef15700d2f0211576ba3506eevboxsync#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
af062818b47340eef15700d2f0211576ba3506eevboxsync#endif /* __NetBSD__ || __FreeBSD__ || __OpenBSD__ */
af062818b47340eef15700d2f0211576ba3506eevboxsync#endif /* __i386__ */
af062818b47340eef15700d2f0211576ba3506eevboxsync/* local copy of the LDT */
af062818b47340eef15700d2f0211576ba3506eevboxsyncstruct __wine_ldt_copy wine_ldt_copy = { { 0, 0, 0 } };
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic const LDT_ENTRY null_entry; /* all-zeros, used to clear LDT entries */
af062818b47340eef15700d2f0211576ba3506eevboxsync/* empty function for default locks */
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic void nop(void) { }
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic inline int is_gdt_sel( unsigned short sel ) { return !(sel & 4); }
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_init_locking
af062818b47340eef15700d2f0211576ba3506eevboxsync * Set the LDT locking/unlocking functions.
af062818b47340eef15700d2f0211576ba3506eevboxsyncvoid wine_ldt_init_locking( void (*lock_func)(void), void (*unlock_func)(void) )
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_get_entry
af062818b47340eef15700d2f0211576ba3506eevboxsync * Retrieve an LDT entry. Return a null entry if selector is not allocated.
af062818b47340eef15700d2f0211576ba3506eevboxsyncvoid wine_ldt_get_entry( unsigned short sel, LDT_ENTRY *entry )
af062818b47340eef15700d2f0211576ba3506eevboxsync if (wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED)
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_set_base( entry, wine_ldt_copy.base[index] );
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_set_limit( entry, wine_ldt_copy.limit[index] );
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_set_flags( entry, wine_ldt_copy.flags[index] );
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * internal_set_entry
af062818b47340eef15700d2f0211576ba3506eevboxsync * Set an LDT entry, without locking. For internal use only.
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic int internal_set_entry( unsigned short sel, const LDT_ENTRY *entry )
af062818b47340eef15700d2f0211576ba3506eevboxsync if (index < LDT_FIRST_ENTRY) return 0; /* cannot modify reserved entries */
af062818b47340eef15700d2f0211576ba3506eevboxsync if ((ret = modify_ldt(0x11, &ldt_info, sizeof(ldt_info))) < 0)
af062818b47340eef15700d2f0211576ba3506eevboxsync#elif defined(__NetBSD__) || defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
af062818b47340eef15700d2f0211576ba3506eevboxsync /* The kernel will only let us set LDTs with user priority level */
af062818b47340eef15700d2f0211576ba3506eevboxsync ret = i386_set_ldt(index, (union descriptor *)&entry_copy, 1);
af062818b47340eef15700d2f0211576ba3506eevboxsync fprintf( stderr, "Did you reconfigure the kernel with \"options USER_LDT\"?\n" );
af062818b47340eef15700d2f0211576ba3506eevboxsync ldt_mod.bo = (unsigned long)wine_ldt_get_base(entry);
af062818b47340eef15700d2f0211576ba3506eevboxsync ldt_mod.ls = entry->LimitLow | (entry->HighWord.Bits.LimitHi << 16);
af062818b47340eef15700d2f0211576ba3506eevboxsync if ((ret = sysi86(SI86DSCR, &ldt_mod)) == -1) perror("sysi86");
af062818b47340eef15700d2f0211576ba3506eevboxsync if ((ret = i386_set_ldt(index, (union ldt_entry *)entry, 1)) < 0)
af062818b47340eef15700d2f0211576ba3506eevboxsync fprintf( stderr, "No LDT support on this platform\n" );
af062818b47340eef15700d2f0211576ba3506eevboxsync#endif /* __i386__ */
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_copy.base[index] = wine_ldt_get_base(entry);
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_copy.limit[index] = wine_ldt_get_limit(entry);
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_copy.flags[index] = (entry->HighWord.Bits.Type |
af062818b47340eef15700d2f0211576ba3506eevboxsync (entry->HighWord.Bits.Default_Big ? WINE_LDT_FLAGS_32BIT : 0) |
af062818b47340eef15700d2f0211576ba3506eevboxsync (wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_ALLOCATED));
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_set_entry
af062818b47340eef15700d2f0211576ba3506eevboxsync * Set an LDT entry.
af062818b47340eef15700d2f0211576ba3506eevboxsyncint wine_ldt_set_entry( unsigned short sel, const LDT_ENTRY *entry )
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_is_system
af062818b47340eef15700d2f0211576ba3506eevboxsync * Check if the selector is a system selector (i.e. not managed by Wine).
af062818b47340eef15700d2f0211576ba3506eevboxsync return is_gdt_sel(sel) || ((sel >> 3) < LDT_FIRST_ENTRY);
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_get_ptr
af062818b47340eef15700d2f0211576ba3506eevboxsync * Convert a segment:offset pair to a linear pointer.
af062818b47340eef15700d2f0211576ba3506eevboxsync * Note: we don't lock the LDT since this has to be fast.
af062818b47340eef15700d2f0211576ba3506eevboxsyncvoid *wine_ldt_get_ptr( unsigned short sel, unsigned long offset )
af062818b47340eef15700d2f0211576ba3506eevboxsync return (void *)offset;
af062818b47340eef15700d2f0211576ba3506eevboxsync if ((index = (sel >> 3)) < LDT_FIRST_ENTRY) /* system selector */
af062818b47340eef15700d2f0211576ba3506eevboxsync return (void *)offset;
af062818b47340eef15700d2f0211576ba3506eevboxsync if (!(wine_ldt_copy.flags[index] & WINE_LDT_FLAGS_32BIT)) offset &= 0xffff;
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_alloc_entries
af062818b47340eef15700d2f0211576ba3506eevboxsync * Allocate a number of consecutive ldt entries, without setting the LDT contents.
af062818b47340eef15700d2f0211576ba3506eevboxsync * Return a selector for the first entry.
af062818b47340eef15700d2f0211576ba3506eevboxsync if (count <= 0) return 0;
af062818b47340eef15700d2f0211576ba3506eevboxsync if (wine_ldt_copy.flags[i] & WINE_LDT_FLAGS_ALLOCATED) size = 0;
af062818b47340eef15700d2f0211576ba3506eevboxsync else if (++size >= count) /* found a large enough block */
af062818b47340eef15700d2f0211576ba3506eevboxsync /* mark selectors as allocated */
af062818b47340eef15700d2f0211576ba3506eevboxsync for (i = 0; i < count; i++) wine_ldt_copy.flags[index + i] |= WINE_LDT_FLAGS_ALLOCATED;
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_realloc_entries
af062818b47340eef15700d2f0211576ba3506eevboxsync * Reallocate a number of consecutive ldt entries, without changing the LDT contents.
af062818b47340eef15700d2f0211576ba3506eevboxsync * Return a selector for the first entry.
af062818b47340eef15700d2f0211576ba3506eevboxsyncunsigned short wine_ldt_realloc_entries( unsigned short sel, int oldcount, int newcount )
af062818b47340eef15700d2f0211576ba3506eevboxsync if (oldcount < newcount) /* we need to add selectors */
af062818b47340eef15700d2f0211576ba3506eevboxsync /* check if the next selectors are free */
af062818b47340eef15700d2f0211576ba3506eevboxsync if (wine_ldt_copy.flags[index+i] & WINE_LDT_FLAGS_ALLOCATED) break;
af062818b47340eef15700d2f0211576ba3506eevboxsync else /* mark the selectors as allocated */
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_copy.flags[index+i] |= WINE_LDT_FLAGS_ALLOCATED;
af062818b47340eef15700d2f0211576ba3506eevboxsync else if (oldcount > newcount) /* we need to remove selectors */
af062818b47340eef15700d2f0211576ba3506eevboxsync wine_ldt_free_entries( sel + (newcount << 3), newcount - oldcount );
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_free_entries
af062818b47340eef15700d2f0211576ba3506eevboxsync * Free a number of consecutive ldt entries and clear their contents.
af062818b47340eef15700d2f0211576ba3506eevboxsyncvoid wine_ldt_free_entries( unsigned short sel, int count )
af062818b47340eef15700d2f0211576ba3506eevboxsync for (index = sel >> 3; count > 0; count--, index++)
af062818b47340eef15700d2f0211576ba3506eevboxsync#if defined(__i386__) && !defined(__MINGW32__) && !defined(_MSC_VER)
af062818b47340eef15700d2f0211576ba3506eevboxsyncstatic int global_fs_sel = -1; /* global selector for %fs shared among all threads */
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_alloc_fs
af062818b47340eef15700d2f0211576ba3506eevboxsync * Allocate an LDT entry for a %fs selector, reusing a global
af062818b47340eef15700d2f0211576ba3506eevboxsync * GDT selector if possible. Return the selector value.
af062818b47340eef15700d2f0211576ba3506eevboxsyncunsigned short wine_ldt_alloc_fs(void)
af062818b47340eef15700d2f0211576ba3506eevboxsync /* the preloader may have allocated it already */
af062818b47340eef15700d2f0211576ba3506eevboxsync if (global_fs_sel && is_gdt_sel(global_fs_sel)) return global_fs_sel;
af062818b47340eef15700d2f0211576ba3506eevboxsync else global_fs_sel = (ldt_info.entry_number << 3) | 3;
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_init_fs
af062818b47340eef15700d2f0211576ba3506eevboxsync * Initialize the entry for the %fs selector of the current thread, and
af062818b47340eef15700d2f0211576ba3506eevboxsync * set the thread %fs register.
af062818b47340eef15700d2f0211576ba3506eevboxsync * Note: this runs in the context of the new thread, so cannot acquire locks.
af062818b47340eef15700d2f0211576ba3506eevboxsyncvoid wine_ldt_init_fs( unsigned short sel, const LDT_ENTRY *entry )
af062818b47340eef15700d2f0211576ba3506eevboxsync if ((ret = set_thread_area( &ldt_info ) < 0)) perror( "set_thread_area" );
af062818b47340eef15700d2f0211576ba3506eevboxsync else /* LDT selector */
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * wine_ldt_free_fs
af062818b47340eef15700d2f0211576ba3506eevboxsync * Free a %fs selector returned by wine_ldt_alloc_fs.
af062818b47340eef15700d2f0211576ba3506eevboxsync /* FIXME: if freeing current %fs we cannot acquire locks */
af062818b47340eef15700d2f0211576ba3506eevboxsync/***********************************************************************
af062818b47340eef15700d2f0211576ba3506eevboxsync * selector access functions
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_get_cs, "movw %cs,%ax\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_get_ds, "movw %ds,%ax\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_get_es, "movw %es,%ax\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_get_fs, "movw %fs,%ax\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_get_gs, "movw %gs,%ax\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_get_ss, "movw %ss,%ax\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_set_fs, "movl 4(%esp),%eax\n\tmovw %ax,%fs\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync__ASM_GLOBAL_FUNC( wine_set_gs, "movl 4(%esp),%eax\n\tmovw %ax,%gs\n\tret" )
af062818b47340eef15700d2f0211576ba3506eevboxsync#endif /* __i386__ */