linux-kernel - Re: [PATCH] x86, vmlinux.lds: Page-Align end of ..page

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Message-ID: <202007211143.AC36D096@keescook>
Date:   Tue, 21 Jul 2020 11:44:07 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Joerg Roedel <joro@...tes.org>
Cc:     x86@...nel.org, hpa@...or.com, Arnd Bergmann <arnd@...db.de>,
        Heiko Carstens <hca@...ux.ibm.com>,
        Joerg Roedel <jroedel@...e.de>,
        Bob Haarman <inglorion@...gle.com>, hjl.tools@...il.com,
        Arvind Sankar <nivedita@...m.mit.edu>,
        Dmitry Safonov <0x7f454c46@...il.com>,
        linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org
Subject: Re: [PATCH] x86, vmlinux.lds: Page-Align end of ..page_aligned
 sections

On Tue, Jul 21, 2020 at 11:34:48AM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@...e.de>
> 
> Align the end of the .bss..page_aligned and .data..page_aligned section
> on page-size too. Otherwise the linker might place other objects on the
> page of the last ..page_aligned object. This is inconsistent with other
> objects in those sections, which all have their own page.

What problem was actually encountered? (i.e. why is it a problem for the
other data to be in the page of the page-aligned data? shouldn't those
data have their own, separate, alignment hint?)

-- 
Kees Cook