* Andreas Schwab <schwab@xxxxxxxxxxxxxx> [230912 14:15]: > Any news? This is still broken. I have a proposed fix. I seem to have caused a pre-existing problem to show up. Please see if the attached works for you, and I'll send it to a lot of people. Thanks, Liam
>From 9ef8f834bb0342dc26464b9dd0165929d3e6a7e5 Mon Sep 17 00:00:00 2001 From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> Date: Tue, 12 Sep 2023 13:45:29 -0400 Subject: [PATCH] init/main: Clear boot task idle flag Initial booting was setting the task flag to idle (PF_IDLE) by the call path sched_init() -> init_idle(). Having the task idle and calling call_rcu() in kernel/rcu/tiny.c means that TIF_NEED_RESCHED will be enabled. Subsequent calls to any cond_resched() will enable IRQs, potentially earlier than the enabling of IRQs. This causes a warning later in start_kernel() as interrupts are enabled before the are fully set up. Fix this issue by clearing the PF_IDLE flag on return from sched_init() and restore the flag in rest_init(). Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> --- init/main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/init/main.c b/init/main.c index ad920fac325c..46b35be8f00a 100644 --- a/init/main.c +++ b/init/main.c @@ -696,7 +696,7 @@ noinline void __ref __noreturn rest_init(void) */ rcu_read_lock(); tsk = find_task_by_pid_ns(pid, &init_pid_ns); - tsk->flags |= PF_NO_SETAFFINITY; + tsk->flags |= PF_NO_SETAFFINITY | PF_IDLE; set_cpus_allowed_ptr(tsk, cpumask_of(smp_processor_id())); rcu_read_unlock(); @@ -938,6 +938,7 @@ void start_kernel(void) * time - but meanwhile we still have a functioning scheduler. */ sched_init(); + current->flags &= ~PF_IDLE; if (WARN(!irqs_disabled(), "Interrupts were enabled *very* early, fixing it\n")) -- 2.39.2
