newlib/winsup/cygwin/init.cc
Takashi Yano 169d65a577 Cygwin: pty: add pseudo console support.
- Support pseudo console in PTY. Pseudo console is a new feature
  in Windows 10 1809, which provides console APIs on virtual
  terminal. With this patch, native console applications can work
  in PTYs such as mintty, ssh, gnu screen or tmux.
2019-08-29 13:47:40 +02:00

128 lines
3.2 KiB
C++

/* init.cc
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 "cygtls.h"
#include "ntdll.h"
#include "shared_info.h"
static DWORD _my_oldfunc;
static char *search_for = (char *) cygthread::stub;
unsigned threadfunc_ix[8];
static bool dll_finished_loading;
#define OLDFUNC_OFFSET -1
static void WINAPI
threadfunc_fe (VOID *arg)
{
#ifdef __i386__
#if __GNUC_PREREQ(6,0)
#pragma GCC diagnostic ignored "-Wframe-address"
#endif
(void)__builtin_return_address(1);
#if __GNUC_PREREQ(6,0)
#pragma GCC diagnostic pop
#endif
asm volatile ("andl $-16,%%esp" ::: "%esp");
#endif
_cygtls::call ((DWORD (*) (void *, void *)) TlsGetValue (_my_oldfunc), arg);
}
/* 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 **) NtCurrentTeb()->Tib.StackBase;
for (peb = ebp, i = 0; peb < top && i < 7; peb++)
if (*peb == search_for)
threadfunc_ix[i++] = peb - ebp;
if (0 && !threadfunc_ix[0])
{
try_to_debug ();
return;
}
}
if (threadfunc_ix[0])
{
char *threadfunc = NULL;
NtQueryInformationThread (NtCurrentThread (),
ThreadQuerySetWin32StartAddress,
&threadfunc, sizeof threadfunc, NULL);
if (!search_for || threadfunc == search_for)
{
search_for = NULL;
for (i = 0; threadfunc_ix[i]; i++)
if (!threadfunc || ebp[threadfunc_ix[i]] == threadfunc)
ebp[threadfunc_ix[i]] = (char *) threadfunc_fe;
TlsSetValue (_my_oldfunc, threadfunc);
}
}
}
void dll_crt0_0 ();
/* Non-static fake variable so GCC doesn't second-guess if we *really*
need the alloca'd space in the DLL_PROCESS_ATTACH case below... */
void *alloca_dummy;
extern "C" BOOL WINAPI
dll_entry (HANDLE h, DWORD reason, void *static_load)
{
BOOL test_stack_marker;
switch (reason)
{
case DLL_PROCESS_ATTACH:
init_console_handler (false);
cygwin_hmodule = (HMODULE) h;
dynamically_loaded = (static_load == NULL);
/* Starting with adding the POSIX-1.2008 per-thread locale functionality,
we need an initalized _REENT area even for the functions called from
dll_crt0_0. Most importantly, we need the _REENT->_locale pointer
initialized to NULL, so subsequent calls to locale-specific functions
will always fall back to __global_locale, rather then crash due to
_REENT->_locale having an arbitrary value. */
alloca_dummy = alloca (CYGTLS_PADSIZE);
ZeroMemory (alloca_dummy, CYGTLS_PADSIZE);
memcpy (_REENT, _GLOBAL_REENT, sizeof (struct _reent));
dll_crt0_0 ();
_my_oldfunc = TlsAlloc ();
dll_finished_loading = true;
break;
case DLL_PROCESS_DETACH:
if (dynamically_loaded)
shared_destroy ();
break;
case DLL_THREAD_ATTACH:
if (dll_finished_loading)
munge_threadfunc ();
break;
case DLL_THREAD_DETACH:
if (dll_finished_loading
&& (PVOID) &_my_tls > (PVOID) &test_stack_marker
&& _my_tls.isinitialized ())
_my_tls.remove (0);
break;
}
return TRUE;
}