* dcrt0.cc (wow64_respawn): New static variable.

(wow64_started_from_native64): New function to check if a WOW64
	process got started from a native 64 bit process.
	(respawn_wow64_process): New function to respawn process.
	(dll_crt0_0): When started from a native parent, check if parent
	is a 64 bit process.  If so, return early.
	(_dll_crt0): Respawn WOW64 process here if required.
	* init.cc (respawn_wow64_process): Remove.
	(dll_entry): Rename wow64_test_stack_marker to test_stack_marker.
	Drop WOW64 test here.
This commit is contained in:
Corinna Vinschen 2011-12-12 10:16:53 +00:00
parent b11797ad17
commit cdce73f183
3 changed files with 101 additions and 59 deletions

View File

@ -1,3 +1,17 @@
2011-12-12 Corinna Vinschen <vinschen@redhat.com>
Christopher Faylor <me.cygwin2011@cgf.cx>
* dcrt0.cc (wow64_respawn): New static variable.
(wow64_started_from_native64): New function to check if a WOW64
process got started from a native 64 bit process.
(respawn_wow64_process): New function to respawn process.
(dll_crt0_0): When started from a native parent, check if parent
is a 64 bit process. If so, return early.
(_dll_crt0): Respawn WOW64 process here if required.
* init.cc (respawn_wow64_process): Remove.
(dll_entry): Rename wow64_test_stack_marker to test_stack_marker.
Drop WOW64 test here.
2011-12-11 Christopher Faylor <me.cygwin2011@cgf.cx>
* pipe.cc (fhandler_pipe::create): Use debug_printf to print debugging

View File

@ -646,6 +646,75 @@ init_windows_system_directory ()
windows_system_directory[windows_system_directory_length] = L'\0';
}
static 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 ()
{
@ -677,7 +746,18 @@ dll_crt0_0 ()
cygthread::init ();
if (!child_proc_info)
memory_init (true);
{
memory_init (true);
/* 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. */
BOOL wow64_test_stack_marker;
if (wincap.is_wow64 ()
&& &wow64_test_stack_marker >= (PBOOL) 0x400000
&& &wow64_test_stack_marker <= (PBOOL) 0x10000000
&& (wow64_respawn = wow64_started_from_native64 ()))
return;
}
else
{
cygwin_user_h = child_proc_info->user_h;
@ -912,6 +992,10 @@ __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

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;
BOOL test_stack_marker;
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
&& (PVOID) &_my_tls > (PVOID) &test_stack_marker
&& _my_tls.isinitialized ())
_my_tls.remove (0);
/* Windows 2000 has a bug in NtTerminateThread. Instead of releasing