linux-kernel - Re: [patch V3 01/11] x86/mm/init32: Mark text and rodata RO in one go

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Message-ID: <bd7b4774-61d8-4b4e-56da-546d5576ddff@intel.com>
Date:   Fri, 21 Sep 2018 09:15:03 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>
Cc:     x86@...nel.org, Peter Zijlstra <peterz@...radead.org>,
        Bin Yang <bin.yang@...el.com>,
        Mark Gross <mark.gross@...el.com>,
        kernel test robot <rong.a.chen@...el.com>
Subject: Re: [patch V3 01/11] x86/mm/init32: Mark text and rodata RO in one go

On 09/17/2018 07:29 AM, Thomas Gleixner wrote:
> The sequence of marking text and rodata read-only in 32bit init is:
> 
>   set_ro(text);
>   kernel_set_to_readonly = 1;
>   set_ro(rodata);
> 
> When kernel_set_to_readonly is 1 it enables the protection mechanism in CPA
> for the read only regions. With the upcoming checks for existing mappings
> this consequently triggers the warning about an existing mapping being
> incorrect vs. static protections because rodata has not been converted yet.
> 
> There is no technical reason to split the two, so just combine the RO
> protection to convert text and rodata in one go.
> 
> Convert the printks to pr_info while at it.
> 
> Reported-by: kernel test robot <rong.a.chen@...el.com>
> Signed-off-by: Thomas Gleixner <tglx@...utronix.de>


Reviewed-by: Dave Hansen <dave.hansen@...el.com>