From mboxrd@z Thu Jan 1 00:00:00 1970 From: mark.rutland@arm.com (Mark Rutland) Date: Thu, 5 Oct 2017 15:59:48 +0100 Subject: undefined instruction d5380001 (arm64 mrs emulation) In-Reply-To: References: <20171002112433.GM3611@e103592.cambridge.arm.com> <59D24906.4060104@arm.com> <20171002155638.GA18543@e107814-lin.cambridge.arm.com> Message-ID: <20171005145948.GE5235@leverpostej> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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: > >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 : > >>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 > >> > >>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.