113 lines
2.8 KiB
C++
113 lines
2.8 KiB
C++
/* init.cc
|
|
|
|
Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Red Hat, Inc.
|
|
|
|
This file is part of Cygwin.
|
|
|
|
This software is a copyrighted work licensed under the terms of the
|
|
Cygwin license. Please consult the file "CYGWIN_LICENSE" for
|
|
details. */
|
|
|
|
#include "winsup.h"
|
|
#include <stdlib.h>
|
|
#include "thread.h"
|
|
#include "perprocess.h"
|
|
#include "cygthread.h"
|
|
#include "cygtls.h"
|
|
|
|
int NO_COPY dynamically_loaded;
|
|
static char *search_for = (char *) cygthread::stub;
|
|
unsigned threadfunc_ix[8] __attribute__((section ("cygwin_dll_common"), shared));
|
|
DWORD tls_func;
|
|
|
|
HANDLE sync_startup;
|
|
|
|
#define OLDFUNC_OFFSET -1
|
|
|
|
static void WINAPI
|
|
threadfunc_fe (VOID *arg)
|
|
{
|
|
(void)__builtin_return_address(1);
|
|
asm volatile ("andl $-16,%%esp" ::: "%esp");
|
|
_cygtls::call ((DWORD (*) (void *, void *)) (((char **) _tlsbase)[OLDFUNC_OFFSET]), arg);
|
|
}
|
|
|
|
static DWORD WINAPI
|
|
calibration_thread (VOID *arg)
|
|
{
|
|
ExitThread (0);
|
|
}
|
|
|
|
/* We need to know where the OS stores the address of the thread function
|
|
on the stack so that we can intercept the call and insert some tls
|
|
stuff on the stack. This function starts a known calibration thread.
|
|
When it starts, a call will be made to dll_entry which will call munge_threadfunc
|
|
looking for the calibration thread offset on the stack. This offset will
|
|
be stored and used by all executing cygwin processes. */
|
|
void
|
|
prime_threads ()
|
|
{
|
|
if (!threadfunc_ix[0])
|
|
{
|
|
DWORD id;
|
|
search_for = (char *) calibration_thread;
|
|
sync_startup = CreateThread (NULL, 0, calibration_thread, 0, 0, &id);
|
|
}
|
|
}
|
|
|
|
/* If possible, redirect the thread entry point to a cygwin routine which
|
|
adds tls stuff to the stack. */
|
|
static void
|
|
munge_threadfunc ()
|
|
{
|
|
int i;
|
|
char **ebp = (char **) __builtin_frame_address (0);
|
|
if (!threadfunc_ix[0])
|
|
{
|
|
char **peb;
|
|
char **top = (char **) _tlsbase;
|
|
for (peb = ebp, i = 0; peb < top && i < 7; peb++)
|
|
if (*peb == search_for)
|
|
threadfunc_ix[i++] = peb - ebp;
|
|
if (!threadfunc_ix[0])
|
|
{
|
|
try_to_debug ();
|
|
return;
|
|
}
|
|
}
|
|
|
|
char *threadfunc = ebp[threadfunc_ix[0]];
|
|
if (threadfunc == (char *) calibration_thread)
|
|
/* no need for the overhead */;
|
|
else
|
|
{
|
|
for (i = 0; threadfunc_ix[i]; i++)
|
|
ebp[threadfunc_ix[i]] = (char *) threadfunc_fe;
|
|
((char **) _tlsbase)[OLDFUNC_OFFSET] = threadfunc;
|
|
}
|
|
}
|
|
|
|
extern void __stdcall dll_crt0_0 ();
|
|
|
|
extern "C" int WINAPI
|
|
dll_entry (HANDLE h, DWORD reason, void *static_load)
|
|
{
|
|
switch (reason)
|
|
{
|
|
case DLL_PROCESS_ATTACH:
|
|
prime_threads ();
|
|
dynamically_loaded = (static_load == NULL);
|
|
dll_crt0_0 ();
|
|
break;
|
|
case DLL_PROCESS_DETACH:
|
|
break;
|
|
case DLL_THREAD_ATTACH:
|
|
munge_threadfunc ();
|
|
break;
|
|
case DLL_THREAD_DETACH:
|
|
_my_tls.remove (0);
|
|
break;
|
|
}
|
|
return 1;
|
|
}
|