linux-kernel - Re: [PATCH v4 15/16] module: Move where we mark modules RO,X

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Date:   Wed, 23 Oct 2019 12:15:14 -0500
From:   Josh Poimboeuf <jpoimboe@...hat.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     x86@...nel.org, linux-kernel@...r.kernel.org, rostedt@...dmis.org,
        mhiramat@...nel.org, bristot@...hat.com, jbaron@...mai.com,
        torvalds@...ux-foundation.org, tglx@...utronix.de,
        mingo@...nel.org, namit@...are.com, hpa@...or.com, luto@...nel.org,
        ard.biesheuvel@...aro.org, jeyu@...nel.org
Subject: Re: [PATCH v4 15/16] module: Move where we mark modules RO,X

On Wed, Oct 23, 2019 at 05:16:54PM +0200, Peter Zijlstra wrote:
> @@ -157,6 +158,14 @@ static int __apply_relocate_add(Elf64_Sh
>  
>  		val = sym->st_value + rel[i].r_addend;
>  
> +		/*
> +		 * .klp.rela.* sections should only contain module
> +		 * related RELAs. All core-kernel RELAs should be in
> +		 * normal .rela.* sections and be applied when loading
> +		 * the patch module itself.
> +		 */
> +		WARN_ON_ONCE(klp && core_kernel_text(val));
> +

This isn't quite true, we also use .klp.rela sections to access
unexported vmlinux symbols.

-- 
Josh