arm64: Ensure the instruction emulation is ready for userspace

Suzuki K Poulose · ctmarinas · commit c0d8832e78cb · 2017-10-06T16:35:21.000+01:00
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 &lt;dave.martin@arm.com&gt;
Cc: Matthias Brugger &lt;mbrugger@suse.com&gt;
Cc: James Morse &lt;james.morse@arm.com&gt;
Reported-by: Matwey V. Kornilov &lt;matwey.kornilov@gmail.com&gt;
Signed-off-by: Suzuki K Poulose &lt;suzuki.poulose@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
diff --git 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;
 }
 
-late_initcall(armv8_deprecated_init);
+core_initcall(armv8_deprecated_init);
diff --git 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;
 }
 
-late_initcall(enable_mrs_emulation);
+core_initcall(enable_mrs_emulation);

Original file line number	Diff line number	Diff line change
`@@ -649,4 +649,4 @@ static int __init armv8_deprecated_init(void)`
`649`	`649`	`return 0;`
`650`	`650`	`}`
`651`	`651`
`652`		`-late_initcall(armv8_deprecated_init);`
	`652`	`+core_initcall(armv8_deprecated_init);`
Original file line number	Diff line number	Diff line change
`@@ -1307,4 +1307,4 @@ static int __init enable_mrs_emulation(void)`
`1307`	`1307`	`return 0;`
`1308`	`1308`	`}`
`1309`	`1309`
`1310`		`-late_initcall(enable_mrs_emulation);`
	`1310`	`+core_initcall(enable_mrs_emulation);`