From: xieyuanbin1 Sending a signal requires to acquire sighand_struct::siglock which is a spinlock_t. On PREEMPT_RT spinlock_t becomes a sleeping spin lock which requires interrupts to be enabled. Since the calling context is user land, interrupts must have been enabled so it is fine to enable them in this case. Signed-off-by: xieyuanbin1 Cc: Sebastian Andrzej Siewior --- This patch depends on patch Link: https://lore.kernel.org/20251029155918.503060-6-bigeasy@linutronix.de The commit message is copy from: Link: https://lore.kernel.org/20251029155918.503060-3-bigeasy@linutronix.de Maybe I should add: Signed-off-by: Sebastian Andrzej Siewior Or something else? Thanks! arch/arm/mm/fault.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c index 5c58072d8235..f8ee1854c854 100644 --- a/arch/arm/mm/fault.c +++ b/arch/arm/mm/fault.c @@ -184,10 +184,13 @@ __do_user_fault(unsigned long addr, unsigned int fsr, unsigned int sig, struct task_struct *tsk = current; if (addr > TASK_SIZE) harden_branch_predictor(); + if (IS_ENABLED(CONFIG_PREEMPT_RT)) + local_irq_enable(); + #ifdef CONFIG_DEBUG_USER if (((user_debug & UDBG_SEGV) && (sig == SIGSEGV)) || ((user_debug & UDBG_BUS) && (sig == SIGBUS))) { pr_err("8<--- cut here ---\n"); pr_err("%s: unhandled page fault (%d) at 0x%08lx, code 0x%03x\n", -- 2.51.0