Kernel text patching framework relies on IPI to ensure that other SMP cores observe the change. Target core calls isb() in IPI handler path, but not at the beginning of el1_irq entry. There's a chance that modified instruction will appear prior isb(), and so will not be observed. This patch inserts isb early at el1_irq entry to avoid that chance. Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx> --- arch/arm64/kernel/entry.S | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index ec2ee720e33e..9c06b4b80060 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -593,6 +593,7 @@ ENDPROC(el1_sync) .align 6 el1_irq: + isb // pairs with aarch64_insn_patch_text kernel_entry 1 enable_da_f #ifdef CONFIG_TRACE_IRQFLAGS -- 2.14.1
