linux-kernel - Re: [PATCH v14 07/11] arm64: kdump: introduce some macroes for crash kernel reservation

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]

Message-ID: <a7951d7f651681fcfd45cea4f8b173c23cc34aa0.camel@suse.de>
Date:   Thu, 04 Feb 2021 17:20:11 +0100
From:   Nicolas Saenz Julienne <nsaenzjulienne@...e.de>
To:     Chen Zhou <chenzhou10@...wei.com>, mingo@...hat.com,
        tglx@...utronix.de, rppt@...nel.org, dyoung@...hat.com,
        bhe@...hat.com, catalin.marinas@....com, will@...nel.org,
        corbet@....net, John.P.donnelly@...cle.com, bhsharma@...hat.com,
        prabhakar.pkin@...il.com
Cc:     horms@...ge.net.au, robh+dt@...nel.org, arnd@...db.de,
        james.morse@....com, xiexiuqi@...wei.com, guohanjun@...wei.com,
        huawei.libin@...wei.com, wangkefeng.wang@...wei.com,
        linux-doc@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-kernel@...r.kernel.org, kexec@...ts.infradead.org
Subject: Re: [PATCH v14 07/11] arm64: kdump: introduce some macroes for
 crash kernel reservation

Hi Chen,

On Sat, 2021-01-30 at 15:10 +0800, Chen Zhou wrote:
> Introduce macro CRASH_ALIGN for alignment, macro CRASH_ADDR_LOW_MAX
> for upper bound of low crash memory, macro CRASH_ADDR_HIGH_MAX for
> upper bound of high crash memory, use macroes instead.
> 
> Besides, keep consistent with x86, use CRASH_ALIGN as the lower bound
> of crash kernel reservation.
> 
> Signed-off-by: Chen Zhou <chenzhou10@...wei.com>
> Tested-by: John Donnelly <John.p.donnelly@...cle.com>
> ---
>  arch/arm64/include/asm/kexec.h | 6 ++++++
>  arch/arm64/mm/init.c           | 6 +++---
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h
> index d24b527e8c00..3f6ecae0bc68 100644
> --- a/arch/arm64/include/asm/kexec.h
> +++ b/arch/arm64/include/asm/kexec.h
> @@ -25,6 +25,12 @@
>  
> 
>  #define KEXEC_ARCH KEXEC_ARCH_AARCH64
>  
> 
> +/* 2M alignment for crash kernel regions */
> +#define CRASH_ALIGN	SZ_2M
> +
> +#define CRASH_ADDR_LOW_MAX	arm64_dma_phys_limit

I wonder if you could use 'ARCH_LOW_ADDRESS_LIMIT', instead of creating a new
define.

> +#define CRASH_ADDR_HIGH_MAX	MEMBLOCK_ALLOC_ACCESSIBLE
> +
>  #ifndef __ASSEMBLY__
>  
> 
>  /**
> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> index 709d98fea90c..912f64f505f7 100644
> --- a/arch/arm64/mm/init.c
> +++ b/arch/arm64/mm/init.c
> @@ -84,8 +84,8 @@ static void __init reserve_crashkernel(void)
>  
> 
>  	if (crash_base == 0) {
>  		/* Current arm64 boot protocol requires 2MB alignment */
> -		crash_base = memblock_find_in_range(0, arm64_dma_phys_limit,
> -				crash_size, SZ_2M);
> +		crash_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_LOW_MAX,
> +				crash_size, CRASH_ALIGN);

Actually we could get rid of CRASH_ADDR_LOW_MAX altogether if we used
memblock_alloc_low() here (modulo the slight refactoring needed to accommodate
it).

Regards,
Nicolas


Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)