[PATCH v2 2/2] ARM: replace this_cpu_* with raw_cpu_* in panic_bad_stack()

Zhen Lei
2022-08-26T09:56:48Z

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>
---
KernelVersion: v6.0-rc2
arch/arm/kernel/traps.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 1518a1f443ff866..d5903d790cf3b7e 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -927,9 +927,9 @@ asmlinkage void handle_bad_stack(struct pt_regs *regs)
{
unsigned long tsk_stk = (unsigned long)current->stack;
#ifdef CONFIG_IRQSTACKS
- unsigned long irq_stk = (unsigned long)this_cpu_read(irq_stack_ptr);
+ unsigned long irq_stk = (unsigned long)raw_cpu_read(irq_stack_ptr);
#endif
- unsigned long ovf_stk = (unsigned long)this_cpu_read(overflow_stack_ptr);
+ unsigned long ovf_stk = (unsigned long)raw_cpu_read(overflow_stack_ptr);

console_verbose();
pr_emerg("Insufficient stack space to handle exception!");
--
2.25.1