libs/newlib-cygwin
libs
/
newlib-cygwin
mirror of git://sourceware.org/git/newlib-cygwin.git
4
0
Fork 0
Code Issues Projects Releases Wiki Activity

Clarify entry

This commit is contained in:
Christopher Faylor 2011-12-10 17:40:20 +00:00
parent 51d406aaa7
commit dfbab81589
4 changed files with 88 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
winsup/cygwin/ChangeLog
View File

@ -86,7 +86,7 @@
2011-12-07 Christopher Faylor <me.cygwin2011@cgf.cx>
* fhandler_termios.cc (tty_min::kill_pgrp): Don't send __SIGSETPGRP
since presumably we are already initialized.
to ourselves since presumably we are already initialized.
2011-12-07 Christopher Faylor <me.cygwin2011@cgf.cx>

83
winsup/cygwin/dcrt0.cc
View File

@ -646,10 +646,89 @@ init_windows_system_directory ()
windows_system_directory[windows_system_directory_length] = L'\0';
}
bool NO_COPY wow64_respawn = false;
inline static bool
wow64_started_from_native64 ()
{
/* On Windows XP 64 and 2003 64 there's a problem with processes running
under WOW64. The first process started from a 64 bit process has an
unusual stack address for the main thread. That is, an address which
is in the usual space occupied by the process image, but below the auto
load address of DLLs. If we encounter this situation, check if we
really have been started from a 64 bit process here. If so, we exit
early from dll_crt0_0 and respawn first thing in dll_crt0_1. This
ping-pong game is necessary to workaround a problem observed on
Windows 2003 R2 64. Starting with Cygwin 1.7.10 we don't link against
advapi32.dll anymore. However, *any* process linked against advapi32,
directly or indirectly, now fails to respawn if respawn_wow_64_process
is called during DLL_PROCESS_ATTACH initialization. In that case
CreateProcessW returns with ERROR_ACCESS_DENIED for some reason.
Calling CreateProcessW later, inside dll_crt0_1 and so outside of
dll initialization works as before, though. */
NTSTATUS ret;
PROCESS_BASIC_INFORMATION pbi;
HANDLE parent;
ULONG wow64 = TRUE; /* Opt on the safe side. */
/* Unfortunately there's no simpler way to retrieve the
parent process in NT, as far as I know. Hints welcome. */
ret = NtQueryInformationProcess (NtCurrentProcess (),
ProcessBasicInformation,
&pbi, sizeof pbi, NULL);
if (NT_SUCCESS (ret)
&& (parent = OpenProcess (PROCESS_QUERY_INFORMATION,
FALSE,
pbi.InheritedFromUniqueProcessId)))
{
NtQueryInformationProcess (parent, ProcessWow64Information,
&wow64, sizeof wow64, NULL);
CloseHandle (parent);
}
return !wow64;
}
inline static void
respawn_wow64_process ()
{
/* The parent is a real 64 bit process. Respawn. */
WCHAR path[PATH_MAX];
PROCESS_INFORMATION pi;
STARTUPINFOW si;
DWORD ret = 0;
GetModuleFileNameW (NULL, path, PATH_MAX);
GetStartupInfoW (&si);
if (!CreateProcessW (path, GetCommandLineW (), NULL, NULL, TRUE,
CREATE_DEFAULT_ERROR_MODE
| GetPriorityClass (GetCurrentProcess ()),
NULL, NULL, &si, &pi))
api_fatal ("Failed to create process <%W> <%W>, %E",
path, GetCommandLineW ());
CloseHandle (pi.hThread);
if (WaitForSingleObject (pi.hProcess, INFINITE) == WAIT_FAILED)
api_fatal ("Waiting for process %d failed, %E", pi.dwProcessId);
GetExitCodeProcess (pi.hProcess, &ret);
CloseHandle (pi.hProcess);
TerminateProcess (GetCurrentProcess (), ret);
ExitProcess (ret);
}
void
dll_crt0_0 ()
{
child_proc_info = get_cygwin_startup_info ();
BOOL wow64_test_stack_marker;
if (!child_proc_info
&& wincap.is_wow64 ()
/* WOW64 bit process with stack at unusual address? Check if we
have been started from 64 bit process ans set wow64_respawn.
Full description in wow64_started_from_native64 above. */
&& &wow64_test_stack_marker >= (PBOOL) 0x400000
&& &wow64_test_stack_marker <= (PBOOL) 0x10000000
&& (wow64_respawn = wow64_started_from_native64 ()))
return;
init_windows_system_directory ();
init_global_security ();
initial_env ();
@ -912,6 +991,10 @@ __cygwin_exit_return: \n\
extern "C" void __stdcall
_dll_crt0 ()
{
/* Respawn WOW64 process started from native 64 bit process. See comment
in wow64_started_from_native64 above for a full description. */
if (wow64_respawn)
respawn_wow64_process ();
#ifdef __i386__
_feinitialise ();
#endif

60
winsup/cygwin/init.cc
View File

@ -64,58 +64,12 @@ munge_threadfunc ()
}
}
inline static void
respawn_wow64_process ()
{
NTSTATUS ret;
PROCESS_BASIC_INFORMATION pbi;
HANDLE parent;
ULONG wow64 = TRUE; /* Opt on the safe side. */
/* Unfortunately there's no simpler way to retrieve the
parent process in NT, as far as I know. Hints welcome. */
ret = NtQueryInformationProcess (NtCurrentProcess (),
ProcessBasicInformation,
&pbi, sizeof pbi, NULL);
if (NT_SUCCESS (ret)
&& (parent = OpenProcess (PROCESS_QUERY_INFORMATION,
FALSE,
pbi.InheritedFromUniqueProcessId)))
{
NtQueryInformationProcess (parent, ProcessWow64Information,
&wow64, sizeof wow64, NULL);
CloseHandle (parent);
}
/* The parent is a real 64 bit process? Respawn! */
if (!wow64)
{
PROCESS_INFORMATION pi;
STARTUPINFOW si;
DWORD ret = 0;
GetStartupInfoW (&si);
if (!CreateProcessW (NULL, GetCommandLineW (), NULL, NULL, TRUE,
CREATE_DEFAULT_ERROR_MODE
| GetPriorityClass (GetCurrentProcess ()),
NULL, NULL, &si, &pi))
api_fatal ("Failed to create process <%s>, %E", GetCommandLineA ());
CloseHandle (pi.hThread);
if (WaitForSingleObject (pi.hProcess, INFINITE) == WAIT_FAILED)
api_fatal ("Waiting for process %d failed, %E", pi.dwProcessId);
GetExitCodeProcess (pi.hProcess, &ret);
CloseHandle (pi.hProcess);
ExitProcess (ret);
}
}
void dll_crt0_0 ();
extern "C" BOOL WINAPI
dll_entry (HANDLE h, DWORD reason, void *static_load)
{
BOOL wow64_test_stack_marker;
extern bool wow64_respawn;
switch (reason)
{
@ -126,16 +80,6 @@ dll_entry (HANDLE h, DWORD reason, void *static_load)
cygwin_hmodule = (HMODULE) h;
dynamically_loaded = (static_load == NULL);
/* Is the stack at an unusual address? That is, an address which
is in the usual space occupied by the process image, but below
the auto load address of DLLs?
Check if we're running in WOW64 on a 64 bit machine *and* are
spawned by a genuine 64 bit process. If so, respawn. */
if (wincap.is_wow64 ()
&& &wow64_test_stack_marker >= (PBOOL) 0x400000
&& &wow64_test_stack_marker <= (PBOOL) 0x10000000)
respawn_wow64_process ();
dll_crt0_0 ();
_my_oldfunc = TlsAlloc ();
dll_finished_loading = true;
@ -150,7 +94,7 @@ dll_entry (HANDLE h, DWORD reason, void *static_load)
break;
case DLL_THREAD_DETACH:
if (dll_finished_loading
&& (PVOID) &_my_tls > (PVOID) &wow64_test_stack_marker
&& !wow64_respawn
&& _my_tls.isinitialized ())
_my_tls.remove (0);
/* Windows 2000 has a bug in NtTerminateThread. Instead of releasing

5
winsup/cygwin/sigproc.h
View File

@ -91,9 +91,8 @@ cygwait (DWORD n, DWORD howlong, ...)
for (unsigned i = 0; i < n; i++)
w4[i] = va_arg (ap, HANDLE);
w4[n++] = signal_arrived;
w4[n++] = pthread::get_cancel_event ();
if (!w4[n - 1])
n--;
if ((w4[n] = pthread::get_cancel_event ()) != NULL)
n++;
return WaitForMultipleObjects (n, w4, FALSE, howlong);
}