[Intel-gfx] [PATCH igt] lib: Assert that the internal gem_create interface matches the ioctl

[Chris Wilson]

Quoting Chris Wilson (2017-10-03 15:05:18)
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>  lib/igt_core.h       | 14 ++++++++++++++
>  lib/ioctl_wrappers.c |  4 ++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/lib/igt_core.h b/lib/igt_core.h
> index f8543d65..f5f65984 100644
> --- a/lib/igt_core.h
> +++ b/lib/igt_core.h
> @@ -932,4 +932,18 @@ int igt_system_quiet(const char *command);
>                 free(buf); \
>         } while (0)
>  
> +/**
> + * igt_typecheck:
> + * @type: The intended type we expect the variable to be
> + * @x: The variable we wish to check
> + *
> + * Performs a *compile-time* check that a variable is of a particular type.
> + */
> +#define igt_typecheck(type, x) ({ \
> +       type __dummy; \
> +        typeof(x) __dummy2; \
> +        (void)(&__dummy == &__dummy2); \
> +        1; \
> +})
> +
>  #endif /* IGT_CORE_H */
> diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
> index 87511fc6..0b523fac 100644
> --- a/lib/ioctl_wrappers.c
> +++ b/lib/ioctl_wrappers.c
> @@ -558,6 +558,10 @@ int __gem_create(int fd, uint64_t size, uint32_t *handle)
>         };
>         int err = 0;
>  
> +       /* Ensure that our internal interface matches the kernel's */
> +       igt_typecheck(typeof(create.size), size);
> +       igt_typecheck(typeof(create.handle), *handle);

Hmm, gcc doesn't allow pointer conversion between unsigned long long and
uint64_t?
-Chris