* [dovetail][PATCH] irq_pipeline: Mark inband stalled also on exceptions
@ 2021-06-09 16:24 Jan Kiszka
2021-06-09 16:40 ` Philippe Gerum
0 siblings, 1 reply; 3+ messages in thread
From: Jan Kiszka @ 2021-06-09 16:24 UTC (permalink / raw
To: Xenomai, Philippe Gerum
From: Philippe Gerum <rpm@xenomai.org>
Make sure that inband is marked stalled when entering from user mode,
taking an exception.
This affects x86 which is currently the only arch using generic
irqentry_enter_from_user_mode on exceptions. It fixes this lockdep
warning:
DEBUG_LOCKS_WARN_ON(!lockdep_stage_disabled())
WARNING: CPU: 2 PID: 1477 at ../kernel/locking/lockdep.c:4129 lockdep_hardirqs_on_prepare+0x160/0x1a0
Signed-off-by: Philippe Gerum <rpm@xenomai.org>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
---
Works as it should here. If the wording is fine, please add.
kernel/entry/common.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index 995123075375..51af58e61cb8 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -343,6 +343,8 @@ __visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)
noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs)
{
+ WARN_ON_ONCE(irq_pipeline_debug() && irqs_disabled());
+ stall_inband_nocheck();
enter_from_user_mode(regs);
}
@@ -373,8 +375,6 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
if (user_mode(regs)) {
#ifdef CONFIG_IRQ_PIPELINE
- WARN_ON_ONCE(irq_pipeline_debug() && irqs_disabled());
- stall_inband_nocheck();
ret.stage_info = IRQENTRY_INBAND_UNSTALLED;
#endif
irqentry_enter_from_user_mode(regs);
--
2.26.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [dovetail][PATCH] irq_pipeline: Mark inband stalled also on exceptions
2021-06-09 16:24 [dovetail][PATCH] irq_pipeline: Mark inband stalled also on exceptions Jan Kiszka
@ 2021-06-09 16:40 ` Philippe Gerum
2021-06-09 18:34 ` Jan Kiszka
0 siblings, 1 reply; 3+ messages in thread
From: Philippe Gerum @ 2021-06-09 16:40 UTC (permalink / raw
To: Jan Kiszka; +Cc: Xenomai
Jan Kiszka <jan.kiszka@siemens.com> writes:
> From: Philippe Gerum <rpm@xenomai.org>
>
> Make sure that inband is marked stalled when entering from user mode,
> taking an exception.
>
> This affects x86 which is currently the only arch using generic
> irqentry_enter_from_user_mode on exceptions. It fixes this lockdep
> warning:
>
> DEBUG_LOCKS_WARN_ON(!lockdep_stage_disabled())
> WARNING: CPU: 2 PID: 1477 at ../kernel/locking/lockdep.c:4129 lockdep_hardirqs_on_prepare+0x160/0x1a0
>
> Signed-off-by: Philippe Gerum <rpm@xenomai.org>
> Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
> ---
>
> Works as it should here. If the wording is fine, please add.
>
> kernel/entry/common.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/entry/common.c b/kernel/entry/common.c
> index 995123075375..51af58e61cb8 100644
> --- a/kernel/entry/common.c
> +++ b/kernel/entry/common.c
> @@ -343,6 +343,8 @@ __visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)
>
> noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs)
> {
> + WARN_ON_ONCE(irq_pipeline_debug() && irqs_disabled());
> + stall_inband_nocheck();
> enter_from_user_mode(regs);
> }
>
> @@ -373,8 +375,6 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
>
> if (user_mode(regs)) {
> #ifdef CONFIG_IRQ_PIPELINE
> - WARN_ON_ONCE(irq_pipeline_debug() && irqs_disabled());
> - stall_inband_nocheck();
> ret.stage_info = IRQENTRY_INBAND_UNSTALLED;
> #endif
> irqentry_enter_from_user_mode(regs);
Ok, picked it. Thanks.
--
Philippe.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [dovetail][PATCH] irq_pipeline: Mark inband stalled also on exceptions
2021-06-09 16:40 ` Philippe Gerum
@ 2021-06-09 18:34 ` Jan Kiszka
0 siblings, 0 replies; 3+ messages in thread
From: Jan Kiszka @ 2021-06-09 18:34 UTC (permalink / raw
To: Philippe Gerum; +Cc: Xenomai
On 09.06.21 18:40, Philippe Gerum wrote:
>
> Jan Kiszka <jan.kiszka@siemens.com> writes:
>
>> From: Philippe Gerum <rpm@xenomai.org>
>>
>> Make sure that inband is marked stalled when entering from user mode,
>> taking an exception.
>>
>> This affects x86 which is currently the only arch using generic
>> irqentry_enter_from_user_mode on exceptions. It fixes this lockdep
>> warning:
>>
>> DEBUG_LOCKS_WARN_ON(!lockdep_stage_disabled())
>> WARNING: CPU: 2 PID: 1477 at ../kernel/locking/lockdep.c:4129 lockdep_hardirqs_on_prepare+0x160/0x1a0
>>
>> Signed-off-by: Philippe Gerum <rpm@xenomai.org>
>> Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
>> ---
>>
>> Works as it should here. If the wording is fine, please add.
>>
>> kernel/entry/common.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/kernel/entry/common.c b/kernel/entry/common.c
>> index 995123075375..51af58e61cb8 100644
>> --- a/kernel/entry/common.c
>> +++ b/kernel/entry/common.c
>> @@ -343,6 +343,8 @@ __visible noinstr void syscall_exit_to_user_mode(struct pt_regs *regs)
>>
>> noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs)
>> {
>> + WARN_ON_ONCE(irq_pipeline_debug() && irqs_disabled());
>> + stall_inband_nocheck();
>> enter_from_user_mode(regs);
>> }
>>
>> @@ -373,8 +375,6 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
>>
>> if (user_mode(regs)) {
>> #ifdef CONFIG_IRQ_PIPELINE
>> - WARN_ON_ONCE(irq_pipeline_debug() && irqs_disabled());
>> - stall_inband_nocheck();
>> ret.stage_info = IRQENTRY_INBAND_UNSTALLED;
>> #endif
>> irqentry_enter_from_user_mode(regs);
>
> Ok, picked it. Thanks.
>
For the sake of completeness: CONFIG_PROVE_RAW_LOCK_NESTING=y papered
over this. But I still don't get why as that only affects complete_all()...
Jan
--
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-06-09 18:34 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-06-09 16:24 [dovetail][PATCH] irq_pipeline: Mark inband stalled also on exceptions Jan Kiszka
2021-06-09 16:40 ` Philippe Gerum
2021-06-09 18:34 ` Jan Kiszka
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.