mirror of
https://github.com/mpv-player/mpv
synced 2024-12-22 06:42:03 +00:00
fbed04310e
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@8224 b3059339-0415-0410-9bf9-f77b7e298cf2
260 lines
6.7 KiB
C
260 lines
6.7 KiB
C
/**
|
|
* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
|
|
* 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
|
|
int modify_ldt(int func, void *ptr, unsigned long bytecount);
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
#else
|
|
#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
|
|
#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 */
|
|
#ifndef TEB_SEL_IDX
|
|
#define TEB_SEL_IDX 17
|
|
#endif
|
|
|
|
#define TEB_SEL LDT_SEL(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)
|
|
{
|
|
__asm__ __volatile__(
|
|
"movl %0,%%eax; movw %%ax, %%fs" : : "i" (TEB_SEL)
|
|
);
|
|
}
|
|
|
|
/* 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__)
|
|
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;
|
|
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__)
|
|
{
|
|
unsigned long d[2];
|
|
|
|
LDT_EntryToBytes( d, &array );
|
|
ret = i386_set_ldt(array.entry_number, (union descriptor *)d, 1);
|
|
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__ */
|
|
|
|
#if defined(__svr4__)
|
|
{
|
|
struct ssd ssd;
|
|
ssd.sel = TEB_SEL;
|
|
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);
|
|
}
|