Re: [dovetail][PATCH] x86: dovetail: Drop bogus local_irq_disable_full from __bad_area_nosemaphore

[Philippe Gerum <rpm@xenomai.org>]

Jan Kiszka <jan.kiszka@siemens.com> writes:

> On 12.11.26 14:09, Philippe Gerum wrote:
>> Jan Kiszka <jan.kiszka@siemens.com> writes:
>> 
>>> From: Jan Kiszka <jan.kiszka@siemens.com>
>>>
>>> There is no technical reason to disable IRQs here again, neither when
>>> the IRQ pipeline is enable nor when it is off, which this change also
>>> causes. We are never passing this point from OOB because of the
>>> !running_inband check and jump earlier in function. The inband case is
>>> identical to the !IRQ_PIPELINE case, and that one does not need any
>>> additional IRQ disabling as well (upstream code path).
>>>
>>> The addition was most likely a mismerged during the forward-port from
>>> 6.18 to 6.19. Remove it.
>>>
>>> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
>>> ---
>>>  arch/x86/mm/fault.c | 2 --
>>>  1 file changed, 2 deletions(-)
>>>
>>> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
>>> index e41ed2092730c..e9a08a5d26e60 100644
>>> --- a/arch/x86/mm/fault.c
>>> +++ b/arch/x86/mm/fault.c
>>> @@ -886,8 +886,6 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long error_code,
>>>  		force_sig_pkuerr((void __user *)address, pkey);
>>>  	else
>>>  		force_sig_fault(SIGSEGV, si_code, (void __user *)address);
>>> -
>>> -	local_irq_disable_full();
>>>  out:
>>>  	oob_trap_unwind(X86_TRAP_PF, regs);
>>>  }
>> 
>> When removing such code, replacing it by an assertion like
>> WARN_ON_ONCE(irqs_pipelined() && !irqs_disabled()) would catch wrong
>> moves.
>> 
>
> IRQs are enabled at the point where local_irq_disable_full was located
> (-> cond_reenable_irqs_user / local_irq_enable), so this warning would
> always trigger.
>

See my previous answer.

-- 
Philippe.