[PATCH 1/2] ntdll/tests: Check that creating huge thread stacks should work.

[Rémi Bernon]

On 5/7/21 1:38 PM, Gabriel Ivăncescu wrote:
> On 07/05/2021 13:20, Rémi Bernon wrote:
>> On 5/7/21 12:08 PM, Rémi Bernon wrote:
>>> Signed-off-by: Rémi Bernon <rbernon at codeweavers.com>
>>> ---
>>>
>>> I'm not completely sure what 789c1db18a4e192425da3771cac4726cda77130b
>>> was for, but it seems to be causing spurious failures. This fix is
>>> trying to keep the current behavior, but it may be better to completely
>>> revert the commit as, although less likely, TEB allocation could also
>>> fail much more often.
>>>
>>>   dlls/ntdll/tests/virtual.c | 10 ++++++++++
>>>   1 file changed, 10 insertions(+)
>>>
>>> diff --git a/dlls/ntdll/tests/virtual.c b/dlls/ntdll/tests/virtual.c
>>> index 8f5b0092bea..686b4076801 100644
>>> --- a/dlls/ntdll/tests/virtual.c
>>> +++ b/dlls/ntdll/tests/virtual.c
>>> @@ -488,6 +488,11 @@ static DWORD WINAPI test_stack_size_thread(void 
>>> *ptr)
>>>       return 0;
>>>   }
>>> +static DWORD WINAPI test_stack_size_dummy_thread(void *ptr)
>>> +{
>>> +    return 0;
>>> +}
>>> +
>>>   static void test_RtlCreateUserStack(void)
>>>   {
>>>       IMAGE_NT_HEADERS *nt = RtlImageNtHeader( 
>>> NtCurrentTeb()->Peb->ImageBaseAddress );
>>> @@ -563,6 +568,11 @@ static void test_RtlCreateUserStack(void)
>>>       thread = CreateThread(NULL, 0x3ff000, test_stack_size_thread, 
>>> &args, STACK_SIZE_PARAM_IS_A_RESERVATION, NULL);
>>>       WaitForSingleObject(thread, INFINITE);
>>>       CloseHandle(thread);
>>> +
>>> +    thread = CreateThread(NULL, 0x80000000, 
>>> test_stack_size_dummy_thread, NULL, 
>>> STACK_SIZE_PARAM_IS_A_RESERVATION, NULL);
>>> +    todo_wine ok(thread != NULL, "CreateThread with huge stack 
>>> failed\n");
>>> +    WaitForSingleObject(thread, INFINITE);
>>> +    CloseHandle(thread);
>>>   }
>>>   static void test_NtMapViewOfSection(void)
>>>
>>
>> Eh obviously that fails on 32bit. Anyway, I'm not sure at all about 
>> the fix, it's maybe something related to allocations that should be 
>> bottom-up by default?
> 
> There's a wine-staging patch that does this and fixes some bugs:
> 
> ntdll-ForceBottomUpAlloc
> 
> Does it help? Also what happens on Windows if you force top-down 
> allocation?

It doesn't help with the regression, because we now forcefully limit the 
address space where the thread stack / teb can be allocated.

What I meant was that although I don't know why it's been added, and if 
the reason was to make sure early threads are allocated on low 
addresses, maybe making default allocation strategy bottom-up is the 
correct fix (instead of trying to forcefully put them in the low 2G).

I think that patch set has been sent already before but it was 
considered a bit over complicated.
-- 
Rémi Bernon <rbernon at codeweavers.com>