| Date | Thu, 5 Nov 2020 17:42:39 +0000 | From | Catalin Marinas <> | Subject | Re: [PATCH v8 32/43] arm64: mte: Switch GCR_EL1 in kernel entry and exit |
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On Thu, Nov 05, 2020 at 12:18:47AM +0100, Andrey Konovalov wrote: > From: Vincenzo Frascino <vincenzo.frascino@arm.com> > > 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@arm.com> > Co-developed-by: Andrey Konovalov <andreyknvl@google.com> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
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