setup_FS.c -> ldt_keeper.c (avifile sync)

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@2068 b3059339-0415-0410-9bf9-f77b7e298cf2

5 files changed, 253 insertions, 10 deletions

diff --git a/loader/dshow/DS_AudioDec.c b/loader/dshow/DS_AudioDec.c
index 9b462f631f..d96d513072 100644
--- a/loader/dshow/DS_AudioDec.c
+++ b/loader/dshow/DS_AudioDec.c
@@ -18,6 +18,8 @@
 
 #include "DS_AudioDec.h"
 
+#include "ldt_keeper.h"
+
 //    DS_Decoder(const CodecInfo& info, const WAVEFORMATEX*);
 //    virtual ~DS_Decoder();
 //    virtual int Convert(const void*, size_t, void*, size_t, size_t*, size_t*);
@@ -25,13 +27,10 @@
 
 static void* _handle;
 
-extern "C" void Setup_LDT_Keeper();
-extern "C" void setup_FS_Segment();
-
 extern "C" int DS_AudioDecoder_Open(char* dllname, GUID* guid, WAVEFORMATEX* wf){
 
     Setup_LDT_Keeper();
-    setup_FS_Segment();
+    Setup_FS_Segment();
 
     CodecInfo ci;
     ci.dll=dllname;
@@ -55,7 +54,7 @@ extern "C" int DS_AudioDecoder_Convert(unsigned char* in_data, unsigned in_size,
 	     unsigned char* out_data, unsigned out_size,
 	     unsigned* size_read, unsigned* size_written){
     DS_AudioDecoder* dec=(DS_AudioDecoder*)_handle;
-    setup_FS_Segment();
+    Setup_FS_Segment();
     return dec->Convert( (void*)in_data,(size_t)in_size,
 			 (void*)out_data,(size_t)out_size,
 			 (size_t*)size_read, (size_t*)size_written );
diff --git a/loader/dshow/DS_VideoDec.c b/loader/dshow/DS_VideoDec.c
index 60eb1d8d82..541fc34fa3 100644
--- a/loader/dshow/DS_VideoDec.c
+++ b/loader/dshow/DS_VideoDec.c
@@ -20,12 +20,11 @@
 
 #include "DS_VideoDec.h"
 
+#include "ldt_keeper.h"
+
 static void* _handle; // will be parameter later...
 static char** _d_ptr;  // will be parameter later...
 
-extern "C" void Setup_LDT_Keeper();
-extern "C" void setup_FS_Segment();
-
 extern "C" int DS_VideoDecoder_Open(char* dllname, GUID* guid, BITMAPINFOHEADER* format, int flip,char** d_ptr){
 
     Setup_LDT_Keeper();
diff --git a/loader/dshow/DS_VideoDecoder.c b/loader/dshow/DS_VideoDecoder.c
index 60156166a3..c91eb70f77 100644
--- a/loader/dshow/DS_VideoDecoder.c
+++ b/loader/dshow/DS_VideoDecoder.c
@@ -24,8 +24,9 @@
 
 #define __MODULE__ "DirectShow_VideoDecoder"
 
+#include "ldt_keeper.h"
+
 extern "C" char* def_path;
-extern "C" void setup_FS_Segment();
 
 using namespace std;
 
@@ -232,7 +233,7 @@ int DS_VideoDecoder::DecodeInternal(void* src, size_t size, int is_keyframe, CIm
     // crashes inside ...->Receive() fixed now?
     //
     // nope - but this is surely helpfull - I'll try some more experiments
-    setup_FS_Segment();
+    Setup_FS_Segment();
 #if 0
     if (!m_pDS_Filter || !m_pDS_Filter->m_pImp
 	|| !m_pDS_Filter->m_pImp->vt
diff --git a/loader/ldt_keeper.c b/loader/ldt_keeper.c
new file mode 100644
index 0000000000..2ddbcb77b7
--- /dev/null
+++ b/loader/ldt_keeper.c
@@ -0,0 +1,229 @@
+/**
+ * !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+ * 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!
+ */
+
+#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>
+#else
+#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__)
+#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
+extern 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)
+
+#ifndef       TEB_SEL_IDX
+#define       TEB_SEL_IDX     1
+#endif
+#define       TEB_SEL LDT_SEL(TEB_SEL_IDX)
+
+/**
+ *
+ *  This should be performed before we create first thread. See remarks
+ *  for write_ldt(), linux/kernel/ldt.c.
+ *
+ */
+
+static void* fs_seg=NULL;
+static char* prev_struct=NULL;
+/**
+ * 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)
+    );
+}
+
+#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
+
+#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(void)
+{
+    struct modify_ldt_ldt_s array;
+    int fd;
+    int ret;
+
+    if (fs_seg)
+        return;
+
+    prev_struct = 0;
+    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=LDT_Modify(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 = (char*)malloc(sizeof(char) * 8);
+    *(void**)array.base_addr = prev_struct;
+    close(fd);
+}
+
+void Restore_LDT_Keeper(void)
+{
+    if (fs_seg == 0)
+	return;
+    if (prev_struct)
+	free(prev_struct);
+    munmap((char*)fs_seg, getpagesize());
+    fs_seg = 0;
+}
diff --git a/loader/ldt_keeper.h b/loader/ldt_keeper.h
new file mode 100644
index 0000000000..eec7da298a
--- /dev/null
+++ b/loader/ldt_keeper.h
@@ -0,0 +1,15 @@
+#ifndef LDT_KEEPER_H
+#define LDT_KEEPER_H
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+void Setup_FS_Segment(void);
+void Setup_LDT_Keeper(void);
+void Restore_LDT_Keeper(void);
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LDT_KEEPER_H */