From 74018c2c09c70b9dbf7a22e4890c9d805506eecb Mon Sep 17 00:00:00 2001 From: arpi_esp Date: Wed, 28 Mar 2001 21:44:26 +0000 Subject: [PATCH] Setup_FS_Segment() for VoxWare audio git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@237 b3059339-0415-0410-9bf9-f77b7e298cf2 --- loader/driver.c | 5 ++ loader/setup_FS.c | 201 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 206 insertions(+) create mode 100644 loader/setup_FS.c diff --git a/loader/driver.c b/loader/driver.c index fab50d1046..ebb071802a 100644 --- a/loader/driver.c +++ b/loader/driver.c @@ -98,6 +98,7 @@ static NPDRVR DrvAlloc(HDRVR*lpDriver, LPUINT lpDrvResult) static void DrvFree(HDRVR hDriver) { int i; + setup_FS_Segment(); if(hDriver) if(((DRVR*)hDriver)->hDriverModule) if(((DRVR*)hDriver)->DriverProc) @@ -131,6 +132,8 @@ DrvOpen(LPARAM lParam2) char unknown[0x24]; // char* codec_name=icopen->fccHandler; + Setup_LDT_Keeper(); + if (!(npDriver = DrvAlloc(&hDriver, &uDrvResult))) return ((HDRVR) 0); @@ -193,6 +196,8 @@ DrvOpen(LPARAM lParam2) //TRACE("DriverProc == %X\n", npDriver->DriverProc); npDriver->dwDriverID = ++dwDrvID; + setup_FS_Segment(); + STORE_ALL; (npDriver->DriverProc)(0, hDriver, DRV_LOAD, 0, 0); REST_ALL; diff --git a/loader/setup_FS.c b/loader/setup_FS.c new file mode 100644 index 0000000000..84581f2aed --- /dev/null +++ b/loader/setup_FS.c @@ -0,0 +1,201 @@ +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef __linux__ +#include +#include +#else + +#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) +#include +#endif + +#ifdef __svr4__ +#include +#include +/* solaris x86: add missing prototype for sysi86() */ +extern int sysi86(int, void*); +#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) + +#ifndef TEB_SEL_IDX +#define TEB_SEL_IDX 1 +#endif + +#define TEB_SEL LDT_SEL(TEB_SEL_IDX) + +void setup_FS_Segment() +{ + printf("Setup FS...");fflush(stdout); + __asm__ __volatile__( + "movl %0,%%eax; movw %%ax, %%fs" : : "i" (TEB_SEL) + ); + printf("OK!\n"); +} + + +/** + * + * This should be performed before we create first thread. See remarks + * for write_ldt(), linux/kernel/ldt.c. + * + */ + +static void* fs_seg=NULL; + +#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 modify_ldt( 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 + +#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 Setup_LDT_Keeper(){ + struct modify_ldt_ldt_s array; + int fd; + int ret; + void* prev_struct; + + if(fs_seg) return; // already set! + + fd=open("/dev/zero", O_RDWR); + fs_seg=mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE, + fd, 0); + if(fs_seg==(void*)-1) + { + perror("ERROR: Couldn't allocate memory for fs segment"); + return; + } + array.base_addr=(int)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=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"); + } + printf("Set_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(); + + prev_struct=malloc(8); + *(void**)array.base_addr=prev_struct; + close(fd); +} + +void Restore_LDT_Keeper() +{ + if(fs_seg==0) return; + munmap((char*)fs_seg, getpagesize()); +} +