On Friday, October 28, 2016 2:39:35 PM CEST Deepa Dinamani wrote:

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@@ -55,24 +60,24 @@ struct ff_effect_compat {

 static inline size_t input_event_size(void)
 {
-       return (in_compat_syscall() && !COMPAT_USE_64BIT_TIME) ?
-               sizeof(struct input_event_compat) : sizeof(struct input_event);
+       return in_compat_syscall() ? sizeof(struct raw_input_event_compat) :
+                                    sizeof(struct raw_input_event);
 }

I think the COMPAT_USE_64BIT_TIME check has to stay here,
it's needed for x32 mode on x86-64.

There is no time_t anymore in the raw_input_event structure.
The struct uses __kernel_ulong_t type.
This should take care of x32 support.

I don't think it does.

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From this cover letter:
https://www.spinics.net/lists/linux-arch/msg16356.html

I see that that the __kernel types were introduced to address the ABI
issues for x32.

This is a variation of the problem we are trying to solve for
the other architectures in your patch set:

On x32, the kernel uses produces a structure with the 64-bit
layout, using __u64 tv_sec, to match the current user space
that has 64-bit __kernel_ulong_t and 64-bit time_t, but
in_compat_syscall() also returns 'true' here, as this is
mostly a 32-bit ABI (time_t being one of the exceptions).

Yes, I missed this.

in_compat_syscall() is true for x32, this would mean we end up here
even if it is a x32 syscall.
But, wouldn't it be better to use in_x32_syscall() here since there is
no timeval any more?

We have to distinguish four cases on x86:

- native 32-bit, input_event with 32-bit time_t
- compat 32-bit, input_event_compat with 32-bit time_t
- native 64-bit, input_event with 64-bit time_t
- compat x32, input_event with 64-bit time_t

The first three can happen on other architectures too,
the last one is x86 specific. There are probably other ways
to express the condition above, but I can't think of one
that is better than the one we have today.

	Arnd