| From foo@baz Wed Aug 22 09:42:09 CEST 2018 |
| From: Zhizhou Zhang <zhizhouzhang@asrmicro.com> |
| Date: Tue, 12 Jun 2018 17:07:37 +0800 |
| Subject: arm64: make secondary_start_kernel() notrace |
| |
| From: Zhizhou Zhang <zhizhouzhang@asrmicro.com> |
| |
| [ Upstream commit b154886f7892499d0d3054026e19dfb9a731df61 ] |
| |
| 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> |
| Signed-off-by: Sasha Levin <alexander.levin@microsoft.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 |
| @@ -205,7 +205,7 @@ int __cpu_up(unsigned int cpu, struct ta |
| * This is the secondary CPU boot entry. We're using this CPUs |
| * idle thread stack, but a set of temporary page tables. |
| */ |
| -asmlinkage void secondary_start_kernel(void) |
| +asmlinkage notrace void secondary_start_kernel(void) |
| { |
| struct mm_struct *mm = &init_mm; |
| unsigned int cpu = smp_processor_id(); |
