This is a note to let you know that I've just added the patch titled
arm64: Fix incorrect per-cpu usage for boot CPU
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-fix-incorrect-per-cpu-usage-for-boot-cpu.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9113c2aa05e9848cd4f1154abee17d4f265f012d Mon Sep 17 00:00:00 2001
From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Date: Thu, 21 Jul 2016 11:12:55 +0100
Subject: arm64: Fix incorrect per-cpu usage for boot CPU
From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
commit 9113c2aa05e9848cd4f1154abee17d4f265f012d upstream.
In smp_prepare_boot_cpu(), we invoke cpuinfo_store_boot_cpu to store
the cpuinfo in a per-cpu ptr, before initialising the per-cpu offset for
the boot CPU. This patch reorders the sequence to make sure we initialise
the per-cpu offset before accessing the per-cpu area.
Commit 4b998ff1885eec ("arm64: Delay cpuinfo_store_boot_cpu") fixed the
issue where we modified the per-cpu area even before the kernel initialises
the per-cpu areas, but failed to wait until the boot cpu updated it's
offset.
Fixes: 4b998ff1885e ("arm64: Delay cpuinfo_store_boot_cpu")
Cc: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/kernel/smp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -436,9 +436,9 @@ void __init smp_cpus_done(unsigned int m
void __init smp_prepare_boot_cpu(void)
{
+ set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
cpuinfo_store_boot_cpu();
save_boot_cpu_run_el();
- set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
}
static u64 __init of_get_cpu_mpidr(struct device_node *dn)
Patches currently in stable-queue which might be from suzuki.poulose@xxxxxxx are
queue-4.7/arm64-fix-incorrect-per-cpu-usage-for-boot-cpu.patch
queue-4.7/arm64-honor-nosmp-kernel-command-line-option.patch
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