linux-kernel - Re: [PATCH 8/8] arm64: irq: allow FIQs to be handled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 19 Feb 2021 15:37:25 +0000
From:   Joey Gouly <joey.gouly@....com>
To:     Mark Rutland <mark.rutland@....com>
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        catalin.marinas@....com, marcan@...can.st, james.morse@....com,
        maz@...nel.org, tglx@...utronix.de, will@...nel.org, nd@....com
Subject: Re: [PATCH 8/8] arm64: irq: allow FIQs to be handled

Hi Mark,

On Fri, Feb 19, 2021 at 11:39:04AM +0000, Mark Rutland wrote:
> On contemporary platforms we don't use FIQ, and treat any stray FIQ as a
> fatal event. However, some platforms have an interrupt controller wired
> to FIQ, and need to handle FIQ as part of regular operation.
> 

[...]

> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index 0474cca9f1a9..a8290bd87a49 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -586,23 +586,23 @@ SYM_CODE_START(vectors)
>  
>  	kernel_ventry	1, sync				// Synchronous EL1h
>  	kernel_ventry	1, irq				// IRQ EL1h
> -	kernel_ventry	1, fiq_invalid			// FIQ EL1h
> +	kernel_ventry	1, fiq				// FIQ EL1h
>  	kernel_ventry	1, error			// Error EL1h
>  
>  	kernel_ventry	0, sync				// Synchronous 64-bit EL0
>  	kernel_ventry	0, irq				// IRQ 64-bit EL0
> -	kernel_ventry	0, fiq_invalid			// FIQ 64-bit EL0
> +	kernel_ventry	0, fiq				// FIQ 64-bit EL0
>  	kernel_ventry	0, error			// Error 64-bit EL0
>  
>  #ifdef CONFIG_COMPAT
>  	kernel_ventry	0, sync_compat, 32		// Synchronous 32-bit EL0
>  	kernel_ventry	0, irq_compat, 32		// IRQ 32-bit EL0
> -	kernel_ventry	0, fiq_invalid_compat, 32	// FIQ 32-bit EL0
> +	kernel_ventry	0, fiq_compat, 32		// FIQ 32-bit EL0
>  	kernel_ventry	0, error_compat, 32		// Error 32-bit EL0
>  #else
>  	kernel_ventry	0, sync_invalid, 32		// Synchronous 32-bit EL0
>  	kernel_ventry	0, irq_invalid, 32		// IRQ 32-bit EL0
> -	kernel_ventry	0, fiq_invalid, 32		// FIQ 32-bit EL0
> +	kernel_ventry	0, fiq, 32			// FIQ 32-bit EL0
>  	kernel_ventry	0, error_invalid, 32		// Error 32-bit EL0
>  #endif
>  SYM_CODE_END(vectors)

I believe you can now remove functions `el0_fiq_invalid` and `el0_fiq_invalid_compat`.
`el1_fiq_invalid` is still used by Synchronous EL1t, so can't be removed.

Thanks,
Joey