[RFC PATCH 17/17] KVM: PPC: Add an ioctl for userspace to select which platform to emulate
benh at kernel.crashing.org
Fri Jul 1 09:13:12 EST 2011
> Regarding that. There's another option - the ioctl code embeds the
> structure size. So if we extend the ioctl parsing to pad up (or
> truncate down) from the user's size to our size, and similarly in the
> other direction, we can get away from this ugliness.
I don't like relying on that much ... I prefer having an explicit
version in the structure head (or use a flag).
> Some years ago I posted a generic helper that did this (and also
> kmalloc'ed and kfree'd the data itself), but it wasn't received
> favourably. Maybe I should try again (and we can possibly use it in kvm
> even if it is rejected for general use, though that's against our
> principles of pushing all generic infrastructure to the wider kernel).
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