linux-kernel - Re: [patch V2 05/17] x86/traps: Make interrupt enable/disable symmetric in C code

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Message-ID: <alpine.DEB.2.21.1910240121460.1852@nanos.tec.linutronix.de>
Date:   Thu, 24 Oct 2019 01:23:59 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Josh Poimboeuf <jpoimboe@...hat.com>
cc:     LKML <linux-kernel@...r.kernel.org>, x86@...nel.org,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Will Deacon <will@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>, kvm@...r.kernel.org,
        linux-arch@...r.kernel.org, Mike Rapoport <rppt@...ux.ibm.com>,
        Miroslav Benes <mbenes@...e.cz>
Subject: Re: [patch V2 05/17] x86/traps: Make interrupt enable/disable
 symmetric in C code

On Wed, 23 Oct 2019, Josh Poimboeuf wrote:
> On Wed, Oct 23, 2019 at 02:27:10PM +0200, Thomas Gleixner wrote:
> > --- a/arch/x86/mm/fault.c
> > +++ b/arch/x86/mm/fault.c
> > @@ -1500,10 +1500,13 @@ static noinline void
> >  		return;
> >  
> >  	/* Was the fault on kernel-controlled part of the address space? */
> > -	if (unlikely(fault_in_kernel_space(address)))
> > +	if (unlikely(fault_in_kernel_space(address))) {
> >  		do_kern_addr_fault(regs, hw_error_code, address);
> > -	else
> > +	} else {
> >  		do_user_addr_fault(regs, hw_error_code, address);
> > +		if (regs->flags & X86_EFLAGS_IF)
> > +			local_irq_disable();
> > +	}
> 
> The corresponding irq enable is in do_user_addr_fault(), why not do the
> disable there?

Yeah, will do. Was just as lazy as Peter and did not want to touch the
gazillion of returns. :)

Thanks,

	tglx