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

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Message-ID: <20191023220109.jmbrluyjxenblcij@treble>
Date:   Wed, 23 Oct 2019 17:01:09 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Thomas Gleixner <tglx@...utronix.de>
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, 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?

-- 
Josh