Re: [PATCH v5 0/6] Add multiple address spaces support to VDUSE

[Michael S. Tsirkin]

On Fri, Sep 26, 2025 at 12:14:26PM +0200, Eugenio Pérez wrote:
> PATCH v5:
> * Properly return errno if copy_to_user returns >0 in VDUSE_IOTLB_GET_FD
>   ioctl (Jason).

???

I think copy_to_user returns an unsigned value: the number of bytes copied.


static __always_inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
        if (!check_copy_size(to, n, false))
                return n;
#ifdef INLINE_COPY_FROM_USER
        return _inline_copy_from_user(to, from, n);
#else
        return _copy_from_user(to, from, n);
#endif
}


so, how does the patch work then?

-- 
MST