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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Jason Yan <yanaijie@huawei.com>, linuxppc-dev@lists.ozlabs.org,
        diana.craciun@nxp.com, christophe.leroy@c-s.fr,
        benh@kernel.crashing.org, paulus@samba.org, npiggin@gmail.com,
        keescook@chromium.org, kernel-hardening@lists.openwall.com
Cc:     linux-kernel@vger.kernel.org, wangkefeng.wang@huawei.com,
        yebin10@huawei.com, thunder.leizhen@huawei.com,
        jingxiangfeng@huawei.com, fanchengyang@huawei.com,
        zhaohongjiang@huawei.com, Jason Yan <yanaijie@huawei.com>
Subject: Re: [PATCH v5 09/10] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter
In-Reply-To: <20190807065706.11411-10-yanaijie@huawei.com>
References: <20190807065706.11411-1-yanaijie@huawei.com> <20190807065706.11411-10-yanaijie@huawei.com>
Date:   Wed, 07 Aug 2019 23:03:56 +1000
Message-ID: <87y305t9dv.fsf@concordia.ellerman.id.au>
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Sender: linux-kernel-owner@vger.kernel.org
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Jason Yan <yanaijie@huawei.com> writes:
> diff --git a/arch/powerpc/kernel/kaslr_booke.c b/arch/powerpc/kernel/kaslr_booke.c
> index c6b326424b54..436f9a03f385 100644
> --- a/arch/powerpc/kernel/kaslr_booke.c
> +++ b/arch/powerpc/kernel/kaslr_booke.c
> @@ -361,6 +361,18 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size
>  	return kaslr_offset;
>  }
>  
> +static inline __init bool kaslr_disabled(void)
> +{
> +	char *str;
> +
> +	str = strstr(boot_command_line, "nokaslr");
> +	if (str == boot_command_line ||
> +	    (str > boot_command_line && *(str - 1) == ' '))
> +		return true;

This extra logic doesn't work for "nokaslrfoo". Is it worth it?

cheers