Messages in this thread Patch in this message | | | From | Zhen Lei <> | Subject | [PATCH v2 1/2] arm64/traps: Replace this_cpu_* with raw_cpu_* in panic_bad_stack() | Date | Fri, 26 Aug 2022 17:51:11 +0800 |
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The hardware automatically disable the IRQ interrupt before jumping to the interrupt or exception vector. Therefore, the preempt_disable() operation in this_cpu_read() after macro expansion is unnecessary for exception handler. Use raw_cpu_* instead of this_cpu_* can reduce a few lines of assembly code. To be honest, the fewer unnecessary operations in exception handler, the better.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- arch/arm64/kernel/traps.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index b7fed33981f7b76..e6b6f4650e3d895 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -871,8 +871,8 @@ DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack) void panic_bad_stack(struct pt_regs *regs, unsigned long esr, unsigned long far) { unsigned long tsk_stk = (unsigned long)current->stack; - unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr); - unsigned long ovf_stk = (unsigned long)this_cpu_ptr(overflow_stack); + unsigned long irq_stk = (unsigned long)raw_cpu_read(irq_stack_ptr); + unsigned long ovf_stk = (unsigned long)raw_cpu_ptr(overflow_stack); console_verbose(); pr_emerg("Insufficient stack space to handle exception!"); -- 2.25.1
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