Messages in this thread | | | Date | Thu, 21 Jul 2016 11:33:07 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH] arm64: Fix incorrect per-cpu usage for boot CPU |
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On Thu, Jul 21, 2016 at 11:12:55AM +0100, Suzuki K Poulose wrote: > 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: commit 4b998ff1885eec ("arm64: Delay cpuinfo_store_boot_cpu") > Cc: <stable@vger.kernel.org> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> --- > arch/arm64/kernel/smp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index 62ff3c0..d242e81 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -437,9 +437,9 @@ void __init smp_cpus_done(unsigned int max_cpus) > > 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) > -- > 2.7.4 >
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