Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.7 011/186] arm64: Fix incorrect per-cpu usage for boot CPU | Date | Thu, 18 Aug 2016 15:57:08 +0200 |
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4.7-stable review patch. If anyone has any objections, please let me know.
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From: Suzuki K Poulose <suzuki.poulose@arm.com>
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@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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)
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