Messages in this thread Patch in this message | | | From | Pierre Gondois <> | Subject | [PATCH] firmware: arm_sdei: Make sdei_list_lock a raw spinlock | Date | Thu, 25 Aug 2022 17:25:56 +0200 |
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On an Ampere Altra, running a preemp_rt kernel based on v5.19-rc3-rt5, the following happens:
[ 15.683141] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 [ 15.683154] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 24, name: cpuhp/0 [ 15.683157] preempt_count: 0, expected: 0 [ 15.683159] RCU nest depth: 0, expected: 0 [ 15.683163] 3 locks held by cpuhp/0/24: [ 15.683167] #0: ffffda30217c70d0 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 [ 15.683201] #1: ffffda30217c7120 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 [ 15.683205] #2: ffffda3021c711f0 (sdei_list_lock){....}-{3:3}, at: sdei_cpuhp_up+0x3c/0x130 [ 15.683224] irq event stamp: 36 [ 15.683226] hardirqs last enabled at (35): [<ffffda301e85b7bc>] finish_task_switch+0xb4/0x2b0 [ 15.683236] hardirqs last disabled at (36): [<ffffda301e812fec>] cpuhp_thread_fun+0x21c/0x248 [ 15.683238] softirqs last enabled at (0): [<ffffda301e80b184>] copy_process+0x63c/0x1ac0 [ 15.683245] softirqs last disabled at (0): [<0000000000000000>] 0x0 [ 15.683258] CPU: 0 PID: 24 Comm: cpuhp/0 Not tainted 5.19.0-rc3-rt5-[...] [ 15.683265] Hardware name: WIWYNN Mt.Jade Server System B81.03001.0005/Mt.Jade Motherboard, BIOS 1.08.20220218 (SCP: 1.08.20220218) 2022/02/18 [ 15.683268] Call trace: [ 15.683271] dump_backtrace+0x114/0x120 [ 15.683277] show_stack+0x20/0x70 [ 15.683279] dump_stack_lvl+0x9c/0xd8 [ 15.683288] dump_stack+0x18/0x34 [ 15.683289] __might_resched+0x188/0x228 [ 15.683292] rt_spin_lock+0x70/0x120 [ 15.683301] sdei_cpuhp_up+0x3c/0x130 [ 15.683303] cpuhp_invoke_callback+0x250/0xf08 [ 15.683305] cpuhp_thread_fun+0x120/0x248 [ 15.683308] smpboot_thread_fn+0x280/0x320 [ 15.683315] kthread+0x130/0x140 [ 15.683321] ret_from_fork+0x10/0x20
sdei_cpuhp_up() is called in the STARTING hotplug section, which runs whith interrupts disabled. Convert sdei_list_lock to a raw spinlock to avoid sleeping with interrupt disabled.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> --- drivers/firmware/arm_sdei.c | 46 ++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 23 deletions(-)
diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index 1e1a51510e83..d2d596166f03 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -67,7 +67,7 @@ struct sdei_event { static DEFINE_MUTEX(sdei_events_lock); /* and then hold this when modifying the list */ -static DEFINE_SPINLOCK(sdei_list_lock); +static DEFINE_RAW_SPINLOCK(sdei_list_lock); static LIST_HEAD(sdei_list); /* Private events are registered/enabled via IPI passing one of these */ @@ -167,14 +167,14 @@ static struct sdei_event *sdei_event_find(u32 event_num) lockdep_assert_held(&sdei_events_lock); - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); list_for_each_entry(e, &sdei_list, list) { if (e->event_num == event_num) { found = e; break; } } - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); return found; } @@ -259,9 +259,9 @@ static struct sdei_event *sdei_event_create(u32 event_num, event->private_registered = regs; } - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); list_add(&event->list, &sdei_list); - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); return event; @@ -287,9 +287,9 @@ static void sdei_event_destroy_llocked(struct sdei_event *event) static void sdei_event_destroy(struct sdei_event *event) { - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); sdei_event_destroy_llocked(event); - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); } static int sdei_api_get_version(u64 *version) @@ -416,9 +416,9 @@ int sdei_event_enable(u32 event_num) err = sdei_do_cross_call(_local_event_enable, event); if (!err) { - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); event->reenable = true; - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); } cpus_read_unlock(); mutex_unlock(&sdei_events_lock); @@ -454,9 +454,9 @@ int sdei_event_disable(u32 event_num) return -ENOENT; } - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); event->reenable = false; - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); if (event->type == SDEI_EVENT_TYPE_SHARED) err = sdei_api_event_disable(event->event_num); @@ -501,10 +501,10 @@ int sdei_event_unregister(u32 event_num) goto unlock; } - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); event->reregister = false; event->reenable = false; - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); if (event->type == SDEI_EVENT_TYPE_SHARED) err = sdei_api_event_unregister(event->event_num); @@ -531,7 +531,7 @@ static int sdei_unregister_shared(void) struct sdei_event *event; mutex_lock(&sdei_events_lock); - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); list_for_each_entry(event, &sdei_list, list) { if (event->type != SDEI_EVENT_TYPE_SHARED) continue; @@ -540,7 +540,7 @@ static int sdei_unregister_shared(void) if (err) break; } - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); mutex_unlock(&sdei_events_lock); return err; @@ -609,9 +609,9 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg) goto cpu_unlock; } - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); event->reregister = true; - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); cpu_unlock: cpus_read_unlock(); unlock: @@ -625,7 +625,7 @@ static int sdei_reregister_shared(void) struct sdei_event *event; mutex_lock(&sdei_events_lock); - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); list_for_each_entry(event, &sdei_list, list) { if (event->type != SDEI_EVENT_TYPE_SHARED) continue; @@ -651,7 +651,7 @@ static int sdei_reregister_shared(void) } } } - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); mutex_unlock(&sdei_events_lock); return err; @@ -663,7 +663,7 @@ static int sdei_cpuhp_down(unsigned int cpu) int err; /* un-register private events */ - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); list_for_each_entry(event, &sdei_list, list) { if (event->type == SDEI_EVENT_TYPE_SHARED) continue; @@ -674,7 +674,7 @@ static int sdei_cpuhp_down(unsigned int cpu) event->event_num, err); } } - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); return sdei_mask_local_cpu(); } @@ -685,7 +685,7 @@ static int sdei_cpuhp_up(unsigned int cpu) int err; /* re-register/enable private events */ - spin_lock(&sdei_list_lock); + raw_spin_lock(&sdei_list_lock); list_for_each_entry(event, &sdei_list, list) { if (event->type == SDEI_EVENT_TYPE_SHARED) continue; @@ -706,7 +706,7 @@ static int sdei_cpuhp_up(unsigned int cpu) } } } - spin_unlock(&sdei_list_lock); + raw_spin_unlock(&sdei_list_lock); return sdei_unmask_local_cpu(); } -- 2.25.1
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