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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87r1t43a8e.fsf@nanos.tec.linutronix.de>
Date:   Tue, 21 Jul 2020 22:05:05 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Kees Cook <keescook@...omium.org>, 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

Kees,

Kees Cook <keescook@...omium.org> writes:
> 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?)

See: lore.kernel.org/r/87sgdmm8u4.fsf@...os.tec.linutronix.de

Thanks,

        tglx