[PATCH 1/2] arm64: Ensure the instruction emulation is ready for userspace

From: Suzuki K Poulose
Date: Fri Oct 06 2017 - 09:17:49 EST

We trap and emulate some instructions (e.g, mrs, deprecated instructions)
for the userspace. However the handlers for these are registered as
late_initcalls and the userspace could be up and running from the initramfs
by that time (with populate_rootfs, which is a rootfs_initcall()). This
could cause problems for the early applications ending up in failure
like :

[ 11.152061] modprobe[93]: undefined instruction: pc=0000ffff8ca48ff4

This patch promotes the specific calls to core_initcalls, which are
guaranteed to be completed before we hit userspace.

Cc: stable@xxxxxxxxxxxxxxx
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dave Martin <dave.martin@xxxxxxx>
Cc: Matthias Brugger <mbrugger@xxxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Reported-by: Matwey V. Kornilov <matwey.kornilov@xxxxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
arch/arm64/kernel/armv8_deprecated.c | 2 +-
arch/arm64/kernel/cpufeature.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index f0e6d717885b..d06fbe4cd38d 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -649,4 +649,4 @@ static int __init armv8_deprecated_init(void)
return 0;

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index cd52d365d1f0..21e2c95d24e7 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1307,4 +1307,4 @@ static int __init enable_mrs_emulation(void)
return 0;