Commit b154886f authored Jun 12, 2018 by Zhizhou Zhang Committed by Catalin Marinas Jun 19, 2018

arm64: make secondary_start_kernel() notrace



We can't call function trace hook before setup percpu offset.
When entering secondary_start_kernel(), percpu offset has not
been initialized.  So this lead hotplug malfunction.
Here is the flow to reproduce this bug:

echo 0 > /sys/devices/system/cpu/cpu1/online
echo function > /sys/kernel/debug/tracing/current_tracer
echo 1 > /sys/kernel/debug/tracing/tracing_on
echo 1 > /sys/devices/system/cpu/cpu1/online

Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Zhizhou Zhang <zhizhouzhang@asrmicro.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

parent dd65a941

arch/arm64/kernel/smp.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -179,7 +179,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
	* This is the secondary CPU boot entry. We're using this CPUs		* This is the secondary CPU boot entry. We're using this CPUs
	* idle thread stack, but a set of temporary page tables.		* idle thread stack, but a set of temporary page tables.
	*/		*/
	asmlinkage void secondary_start_kernel(void)		asmlinkage notrace void secondary_start_kernel(void)
	{		{
	u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;		u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
	struct mm_struct *mm = &init_mm;		struct mm_struct *mm = &init_mm;

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