Linux KVM/arm64 development list
 help / color / mirror / Atom feed
From: Mark Rutland <mark.rutland@arm.com>
To: "Rémi Denis-Courmont" <remi@remlab.net>
Cc: catalin.marinas@arm.com, ard.biesheuvel@linaro.org,
	linux-kernel@vger.kernel.org, maz@kernel.org, will@kernel.org,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm64: move kimage_vaddr to .rodata
Date: Thu, 12 Mar 2020 16:40:36 +0000	[thread overview]
Message-ID: <20200312164035.GA21120@lakrids.cambridge.arm.com> (raw)
In-Reply-To: <20200312094002.153302-1-remi@remlab.net>

On Thu, Mar 12, 2020 at 11:40:02AM +0200, Rémi Denis-Courmont wrote:
> From: Remi Denis-Courmont <remi.denis.courmont@huawei.com>
> 
> This datum is not referenced from .idmap.text: it does not need to be
> mapped in idmap. Lets move it to .rodata as it is never written to after
> early boot of the primary CPU.
> (Maybe .data.ro_after_init would be cleaner though?)

Can we move this into arch/arm64/mm/mmu.c, where we already have
kimage_voffset:

| u64 kimage_voffset __ro_after_init;
| EXPORT_SYMBOL(kimage_voffset);

... or is it not possible to initialize kimage_vaddr correctly in C?

Thanks,
Mark.

> 
> Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
> ---
>  arch/arm64/kernel/head.S | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
> index 6e08ee2b4d55..8e5c0e0040e4 100644
> --- a/arch/arm64/kernel/head.S
> +++ b/arch/arm64/kernel/head.S
> @@ -457,17 +457,19 @@ SYM_FUNC_START_LOCAL(__primary_switched)
>  	b	start_kernel
>  SYM_FUNC_END(__primary_switched)
>  
> +	.pushsection ".rodata", "a"
> +SYM_DATA_START(kimage_vaddr)
> +	.quad		_text - TEXT_OFFSET
> +SYM_DATA_END(kimage_vaddr)
> +EXPORT_SYMBOL(kimage_vaddr)
> +	.popsection
> +
>  /*
>   * end early head section, begin head code that is also used for
>   * hotplug and needs to have the same protections as the text region
>   */
>  	.section ".idmap.text","awx"
>  
> -SYM_DATA_START(kimage_vaddr)
> -	.quad		_text - TEXT_OFFSET
> -SYM_DATA_END(kimage_vaddr)
> -EXPORT_SYMBOL(kimage_vaddr)
> -
>  /*
>   * If we're fortunate enough to boot at EL2, ensure that the world is
>   * sane before dropping to EL1.
> -- 
> 2.25.1
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  reply	other threads:[~2020-03-12 16:40 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-12  9:40 [PATCH] arm64: move kimage_vaddr to .rodata Rémi Denis-Courmont
2020-03-12 16:40 ` Mark Rutland [this message]
2020-03-12 16:42   ` Remi Denis-Courmont
2020-03-17 22:26 ` Will Deacon
2020-03-20 18:24 ` Catalin Marinas

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200312164035.GA21120@lakrids.cambridge.arm.com \
    --to=mark.rutland@arm.com \
    --cc=ard.biesheuvel@linaro.org \
    --cc=catalin.marinas@arm.com \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maz@kernel.org \
    --cc=remi@remlab.net \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox