linux_dsm_epyc7002/arch/arm64
Mark Rutland 3fabb43818 arm64: sync kernel APIAKey when installing
A direct write to a APxxKey_EL1 register requires a context
synchronization event to ensure that indirect reads made by subsequent
instructions (e.g. AUTIASP, PACIASP) observe the new value.

When we initialize the boot task's APIAKey in boot_init_stack_canary()
via ptrauth_keys_switch_kernel() we miss the necessary ISB, and so there
is a window where instructions are not guaranteed to use the new APIAKey
value. This has been observed to result in boot-time crashes where
PACIASP and AUTIASP within a function used a mixture of the old and new
key values.

Fix this by having ptrauth_keys_switch_kernel() synchronize the new key
value with an ISB. At the same time, __ptrauth_key_install() is renamed
to __ptrauth_key_install_nosync() so that it is obvious that this
performs no synchronization itself.

Fixes: 2832158233 ("arm64: initialize ptrauth keys for kernel booting task")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reported-by: Will Deacon <will@kernel.org>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Will Deacon <will@kernel.org>
2020-04-21 15:52:56 +01:00
..
boot ARM: devicetree updates for v5.7 2020-04-03 15:22:05 -07:00
configs ARM: defconfig updates 2020-04-03 15:15:10 -07:00
crypto SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
include arm64: sync kernel APIAKey when installing 2020-04-21 15:52:56 +01:00
kernel arm64: vdso: don't free unallocated pages 2020-04-15 11:13:16 +01:00
kvm virtio: fixes, vdpa 2020-04-08 10:51:53 -07:00
lib arm64: fix spelling mistake "ca not" -> "cannot" 2020-03-17 18:22:40 +00:00
mm mm/memory_hotplug: add pgprot_t to mhp_params 2020-04-10 15:36:21 -07:00
net arm64: bpf: optimize modulo operation 2019-09-03 15:44:40 +02:00
xen arm64: xen: Use modern annotations for assembly functions 2020-01-09 16:09:42 +00:00
Kbuild arm64: add arch/arm64/Kbuild 2019-08-21 18:47:15 +01:00
Kconfig arm64 fixes: 2020-04-09 11:04:16 -07:00
Kconfig.debug arm64: remove CONFIG_DEBUG_ALIGN_RODATA feature 2020-04-01 21:44:43 +01:00
Kconfig.platforms ARM: SoC updates 2020-04-03 15:02:35 -07:00
Makefile arm64: Always force a branch protection mode when the compiler has one 2020-04-01 21:23:40 +01:00