On Thu, Nov 05, 2020 at 12:18:47AM +0100, Andrey Konovalov wrote: > From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > > When MTE is present, the GCR_EL1 register contains the tags mask that > allows to exclude tags from the random generation via the IRG instruction. > > With the introduction of the new Tag-Based KASAN API that provides a > mechanism to reserve tags for special reasons, the MTE implementation > has to make sure that the GCR_EL1 setting for the kernel does not affect > the userspace processes and viceversa. > > Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit. > > Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> > Co-developed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
