Commit c0d8832e authored Oct 06, 2017 by Suzuki K Poulose Committed by Catalin Marinas Oct 06, 2017

arm64: Ensure the instruction emulation is ready for userspace



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@vger.kernel.org
Cc: Dave Martin <dave.martin@arm.com>
Cc: Matthias Brugger <mbrugger@suse.com>
Cc: James Morse <james.morse@arm.com>
Reported-by: Matwey V. Kornilov <matwey.kornilov@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent b02faed1

arch/arm64/kernel/armv8_deprecated.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -649,4 +649,4 @@ static int __init armv8_deprecated_init(void)
		return 0;
		}

		late_initcall(armv8_deprecated_init);
		core_initcall(armv8_deprecated_init);

arch/arm64/kernel/cpufeature.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1307,4 +1307,4 @@ static int __init enable_mrs_emulation(void)
		return 0;
		}

		late_initcall(enable_mrs_emulation);
		core_initcall(enable_mrs_emulation);