On Tue, Mar 14, 2017 at 2:04 PM, Pavel Machek <pavel@xxxxxx> wrote: > On Tue 2017-03-14 10:05:08, Thomas Garnier wrote: >> This patch makes the GDT remapped pages read-only to prevent corruption. >> This change is done only on 64-bit. >> >> The native_load_tr_desc function was adapted to correctly handle a >> read-only GDT. The LTR instruction always writes to the GDT TSS entry. >> This generates a page fault if the GDT is read-only. This change checks >> if the current GDT is a remap and swap GDTs as needed. This function was >> tested by booting multiple machines and checking hibernation works >> properly. >> >> KVM SVM and VMX were adapted to use the writeable GDT. On VMX, the >> per-cpu variable was removed for functions to fetch the original GDT. >> Instead of reloading the previous GDT, VMX will reload the fixmap GDT as >> expected. For testing, VMs were started and restored on multiple >> configurations. >> >> Signed-off-by: Thomas Garnier <thgarnie@xxxxxxxxxx> > > Can we get the same change for 32-bit, too? Growing differences > between 32 and 64 bit are a bit of a problem... > Pavel It was discussed on previous versions that 32-bit read-only support would create issues that why it was favor for 64-bit only right now. > > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- Thomas -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
