On Thu, Mar 22, 2018 at 2:25 AM, Stefan Hajnoczi <stefa...@gmail.com> wrote: > On Fri, Mar 16, 2018 at 7:30 PM, David Miller <da...@davemloft.net> wrote: >> Although the top level ioctls are probably size and layout compatible, >> I do not think that the deeper ioctls can be called by compat binaries >> without some translations in order for them to work. > > I audited the vhost ioctl code when reviewing this patch and was > unable to find anything that would break for a 32-bit userspace > process. > > drivers/vhost/net.c does the same thing already, which doesn't prove > it's correct but makes me more confident I didn't miss something while > auditing the vhost ioctl code. > > Did you have a specific ioctl in mind?
I think he means that we need to use the compat_ptr macro on any other pointers we get from userspace in those other ioctls. For most architectures this macro doesn't seem to do much but it does on some -- I think s390 modifies the pointer. > > Stefan
