undefined instruction d5380001 (arm64 mrs emulation)

Hi Matthias,

On Thu, Oct 05, 2017 at 04:54:09PM +0200, Matthias Brugger wrote:

On 10/04/2017 11:11 AM, Matwey V. Kornilov wrote:

quoted

The patch helps to overcome the issue, Probably it should be applied
to all stable releases affected by this behaviour.
modprobe in initrd may load quite required things.

2017-10-02 18:56 GMT+03:00 Suzuki K Poulose [off-list ref]:

quoted

arm64: Enable MRS emulation early enough in the boot sequence

Make sure the MRS emulation is enabled early enough that the
early userspace applications (e.g, those run from initrd) could
run without any trouble.

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9f9e0064c8c1..048f5469531f 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c

@@ -1294,4 +1294,4 @@ static int __init enable_mrs_emulation(void)
        return 0;
 }

-late_initcall(enable_mrs_emulation);
+arch_initcall(enable_mrs_emulation);
---

I realized this patch did not land in v4.13.5
Did it got forgotten or are there any concerns?

This patch wasn't a complete fix, and the issue is still being discussed
at:

http://lists.infradead.org/pipermail/linux-arm-kernel/2017-October/534396.html

Thanks,
Mark.