--- /dev/null
+/*
+ * $Id$
+ *
+ * Copyright 1993 Robert J. Amstadt
+ * Copyright 1995 Alexandre Julliard
+ *
+ * Originally distributed under LPGL 2.1 (or later) by the Wine project.
+ *
+ * Modified for use with MPlayer, detailed CVS changelog at
+ * http://www.mplayerhq.hu/cgi-bin/cvsweb.cgi/main/
+ *
+ * File now distributed as part of VLC media player with no modifications.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ */
+
+/**
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ * This file MUST be in main library because LDT must
+ * be modified before program creates first thread
+ * - avifile includes this file from C++ code
+ * and initializes it at the start of player!
+ * it might sound like a hack and it really is - but
+ * as aviplay is deconding video with more than just one
+ * thread currently it's necessary to do it this way
+ * this might change in the future
+ */
+
+/* applied some modification to make make our xine friend more happy */
+
+#include "ldt_keeper.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <unistd.h>
+#ifdef __linux__
+#include <asm/unistd.h>
+#include <asm/ldt.h>
+// 2.5.xx+ calls this user_desc:
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,47)
+#define modify_ldt_ldt_s user_desc
+#endif
+/* prototype it here, so we won't depend on kernel headers */
+#ifdef __cplusplus
+extern "C" {
+#endif
+/// declare modify_ldt with the _syscall3 macro for older glibcs
+#if defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 0))
+_syscall3( int, modify_ldt, int, func, void *, ptr, unsigned long, bytecount );
+#else
+int modify_ldt(int func, void *ptr, unsigned long bytecount);
+#endif
+#ifdef __cplusplus
+}
+#endif
+#else
+#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
+#include <machine/segments.h>
+#include <machine/sysarch.h>
+#endif
+
+#ifdef __svr4__
+#include <sys/segment.h>
+#include <sys/sysi86.h>
+
+/* solaris x86: add missing prototype for sysi86() */
+#ifdef __cplusplus
+extern "C" {
+#endif
+int sysi86(int, void*);
+#ifdef __cplusplus
+}
+#endif
+
+#ifndef NUMSYSLDTS /* SunOS 2.5.1 does not define NUMSYSLDTS */
+#define NUMSYSLDTS 6 /* Let's hope the SunOS 5.8 value is OK */
+#endif
+
+#define TEB_SEL_IDX NUMSYSLDTS
+#endif
+
+#define LDT_ENTRIES 8192
+#define LDT_ENTRY_SIZE 8
+#pragma pack(4)
+struct modify_ldt_ldt_s {
+ unsigned int entry_number;
+ unsigned long base_addr;
+ unsigned int limit;
+ unsigned int seg_32bit:1;
+ unsigned int contents:2;
+ unsigned int read_exec_only:1;
+ unsigned int limit_in_pages:1;
+ unsigned int seg_not_present:1;
+ unsigned int useable:1;
+};
+
+#define MODIFY_LDT_CONTENTS_DATA 0
+#define MODIFY_LDT_CONTENTS_STACK 1
+#define MODIFY_LDT_CONTENTS_CODE 2
+#endif
+
+
+/* user level (privilege level: 3) ldt (1<<2) segment selector */
+#define LDT_SEL(idx) ((idx) << 3 | 1 << 2 | 3)
+
+/* i got this value from wine sources, it's the first free LDT entry */
+#if defined(__FreeBSD__) && defined(LDT_AUTO_ALLOC)
+#define TEB_SEL_IDX LDT_AUTO_ALLOC
+#endif
+
+#ifndef TEB_SEL_IDX
+#define TEB_SEL_IDX 17
+#endif
+
+static unsigned int fs_ldt = TEB_SEL_IDX;
+
+
+/**
+ * here is a small logical problem with Restore for multithreaded programs -
+ * in C++ we use static class for this...
+ */
+
+#ifdef __cplusplus
+extern "C"
+#endif
+void Setup_FS_Segment(void)
+{
+ unsigned int ldt_desc = LDT_SEL(fs_ldt);
+
+ __asm__ __volatile__(
+ "movl %0,%%eax; movw %%ax, %%fs" : : "r" (ldt_desc)
+ :"eax"
+ );
+}
+
+/* we don't need this - use modify_ldt instead */
+#if 0
+#ifdef __linux__
+/* XXX: why is this routine from libc redefined here? */
+/* NOTE: the redefined version ignores the count param, count is hardcoded as 16 */
+static int LDT_Modify( int func, struct modify_ldt_ldt_s *ptr,
+ unsigned long count )
+{
+ int res;
+#ifdef __PIC__
+ __asm__ __volatile__( "pushl %%ebx\n\t"
+ "movl %2,%%ebx\n\t"
+ "int $0x80\n\t"
+ "popl %%ebx"
+ : "=a" (res)
+ : "0" (__NR_modify_ldt),
+ "r" (func),
+ "c" (ptr),
+ "d"(16)//sizeof(*ptr) from kernel point of view
+ :"esi" );
+#else
+ __asm__ __volatile__("int $0x80"
+ : "=a" (res)
+ : "0" (__NR_modify_ldt),
+ "b" (func),
+ "c" (ptr),
+ "d"(16)
+ :"esi");
+#endif /* __PIC__ */
+ if (res >= 0) return res;
+ errno = -res;
+ return -1;
+}
+#endif
+#endif
+
+#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
+static void LDT_EntryToBytes( unsigned long *buffer, const struct modify_ldt_ldt_s *content )
+{
+ *buffer++ = ((content->base_addr & 0x0000ffff) << 16) |
+ (content->limit & 0x0ffff);
+ *buffer = (content->base_addr & 0xff000000) |
+ ((content->base_addr & 0x00ff0000)>>16) |
+ (content->limit & 0xf0000) |
+ (content->contents << 10) |
+ ((content->read_exec_only == 0) << 9) |
+ ((content->seg_32bit != 0) << 22) |
+ ((content->limit_in_pages != 0) << 23) |
+ 0xf000;
+}
+#endif
+
+void* fs_seg=0;
+
+ldt_fs_t* Setup_LDT_Keeper(void)
+{
+ struct modify_ldt_ldt_s array;
+ int ret;
+ ldt_fs_t* ldt_fs = (ldt_fs_t*) malloc(sizeof(ldt_fs_t));
+
+ if (!ldt_fs)
+ return NULL;
+
+ ldt_fs->fd = open("/dev/zero", O_RDWR);
+ if(ldt_fs->fd<0){
+ perror( "Cannot open /dev/zero for READ+WRITE. Check permissions! error: ");
+ return NULL;
+ }
+ fs_seg=
+ ldt_fs->fs_seg = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE,
+ ldt_fs->fd, 0);
+ if (ldt_fs->fs_seg == (void*)-1)
+ {
+ perror("ERROR: Couldn't allocate memory for fs segment");
+ close(ldt_fs->fd);
+ free(ldt_fs);
+ return NULL;
+ }
+ *(void**)((char*)ldt_fs->fs_seg+0x18) = ldt_fs->fs_seg;
+ memset(&array, 0, sizeof(array));
+ array.base_addr=(int)ldt_fs->fs_seg;
+ array.entry_number=TEB_SEL_IDX;
+ array.limit=array.base_addr+getpagesize()-1;
+ array.seg_32bit=1;
+ array.read_exec_only=0;
+ array.seg_not_present=0;
+ array.contents=MODIFY_LDT_CONTENTS_DATA;
+ array.limit_in_pages=0;
+#ifdef __linux__
+ //ret=LDT_Modify(0x1, &array, sizeof(struct modify_ldt_ldt_s));
+ ret=modify_ldt(0x1, &array, sizeof(struct modify_ldt_ldt_s));
+ if(ret<0)
+ {
+ perror("install_fs");
+ printf("Couldn't install fs segment, expect segfault\n");
+ }
+#endif /*linux*/
+
+#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
+ {
+ unsigned long d[2];
+
+ LDT_EntryToBytes( d, &array );
+#if defined(__FreeBSD__) && defined(LDT_AUTO_ALLOC)
+ ret = i386_set_ldt(LDT_AUTO_ALLOC, (union descriptor *)d, 1);
+ array.entry_number = ret;
+ fs_ldt = ret;
+#else
+ ret = i386_set_ldt(array.entry_number, (union descriptor *)d, 1);
+#endif
+ if (ret < 0)
+ {
+ perror("install_fs");
+ printf("Couldn't install fs segment, expect segfault\n");
+ printf("Did you reconfigure the kernel with \"options USER_LDT\"?\n");
+ }
+ }
+#endif /* __NetBSD__ || __FreeBSD__ || __OpenBSD__ || __DragonFly__ */
+
+#if defined(__svr4__)
+ {
+ struct ssd ssd;
+ ssd.sel = LDT_SEL(TEB_SEL_IDX);
+ ssd.bo = array.base_addr;
+ ssd.ls = array.limit - array.base_addr;
+ ssd.acc1 = ((array.read_exec_only == 0) << 1) |
+ (array.contents << 2) |
+ 0xf0; /* P(resent) | DPL3 | S */
+ ssd.acc2 = 0x4; /* byte limit, 32-bit segment */
+ if (sysi86(SI86DSCR, &ssd) < 0) {
+ perror("sysi86(SI86DSCR)");
+ printf("Couldn't install fs segment, expect segfault\n");
+ }
+ }
+#endif
+
+ Setup_FS_Segment();
+
+ ldt_fs->prev_struct = (char*)malloc(sizeof(char) * 8);
+ *(void**)array.base_addr = ldt_fs->prev_struct;
+
+ return ldt_fs;
+}
+
+void Restore_LDT_Keeper(ldt_fs_t* ldt_fs)
+{
+ if (ldt_fs == NULL || ldt_fs->fs_seg == 0)
+ return;
+ if (ldt_fs->prev_struct)
+ free(ldt_fs->prev_struct);
+ munmap((char*)ldt_fs->fs_seg, getpagesize());
+ ldt_fs->fs_seg = 0;
+ close(ldt_fs->fd);
+ free(ldt_fs);
+}
projects / vlc / blobdiff