Will Deacon a534759658 arm64: SW PAN: Point saved ttbr0 at the zero page when switching to init_mm ... commit 0adbdfde8c upstream. update_saved_ttbr0 mandates that mm->pgd is not swapper, since swapper contains kernel mappings and should never be installed into ttbr0. However, this means that callers must avoid passing the init_mm to update_saved_ttbr0 which in turn can cause the saved ttbr0 value to be out-of-date in the context of the idle thread. For example, EFI runtime services may leave the saved ttbr0 pointing at the EFI page table, and kernel threads may end up with stale references to freed page tables. This patch changes update_saved_ttbr0 so that the init_mm points the saved ttbr0 value to the empty zero page, which always exists and never contains valid translations. EFI and switch can then call into update_saved_ttbr0 unconditionally. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Fixes: 39bc88e5e3 ("arm64: Disable TTBR0_EL1 during normal kernel execution") Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reported-by: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2017-12-14 09:53:02 +01:00
..
boot	ARM64: dts: meson-gxl: Add alternate ARM Trusted Firmware reserved memory zone	2017-11-30 08:40:58 +00:00
configs	ARM/arm64: SoC platform updates for v4.14	2017-09-10 20:35:46 -07:00
crypto	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
include	arm64: SW PAN: Point saved ttbr0 at the zero page when switching to init_mm	2017-12-14 09:53:02 +01:00
kernel	arm64: fpsimd: Prevent registers leaking from dead tasks	2017-12-14 09:53:02 +01:00
kvm	Fixes for interrupt controller emulation in ARM/ARM64 and x86, plus a one-liner	2017-11-04 11:44:55 -07:00
lib	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
mm	License cleanup: add SPDX GPL-2.0 license identifier to files with no license	2017-11-02 11:10:55 +01:00
net	bpf, arm64: implement jiting of BPF_J{LT, LE, SLT, SLE}	2017-08-09 16:53:56 -07:00
xen
Kconfig	Merge branch 'arm64/vmap-stack' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux into for-next/core	2017-08-15 18:40:58 +01:00
Kconfig.debug
Kconfig.platforms	ARM: arm64: Devicetree updates for v4.14	2017-09-10 20:54:48 -07:00
Makefile	arm64: ftrace: emit ftrace-mod.o contents through code	2017-12-05 11:26:31 +01:00