On Wed, Sep 26, 2018 at 10:44:33AM -0700, Dennis Dalessandro wrote:
> +/* platform specific: cacheless copy */
> +static void cacheless_memcpy(void *dst, void *src, size_t n)
> +{
> + /*
> + * Use the only available X64 cacheless copy. Add a __user cast
> + * to quiet sparse. The src agument is already in the kernel so
> + * there are no security issues. The extra fault recovery machinery
> + * is not invoked.
> + */
> + __copy_user_nocache(dst, (void __user *)src, n, 0);
> +}
No way you can call copy_user on kernel pointers. Test this with PTI
turned on and see it break.
Jason
