linux-kernel - Re: [RFC 21/43] x86/KASLR: PKRAM: support physical kaslr

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: <202005071049.2D0939137D@keescook>
Date:   Thu, 7 May 2020 10:51:32 -0700
From:   Kees Cook <keescook@...omium.org>
To:     Anthony Yznaga <anthony.yznaga@...cle.com>
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        willy@...radead.org, corbet@....net, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, x86@...nel.org, hpa@...or.com,
        dave.hansen@...ux.intel.com, luto@...nel.org, peterz@...radead.org,
        rppt@...ux.ibm.com, akpm@...ux-foundation.org, hughd@...gle.com,
        ebiederm@...ssion.com, masahiroy@...nel.org, ardb@...nel.org,
        ndesaulniers@...gle.com, dima@...ovin.in, daniel.kiper@...cle.com,
        nivedita@...m.mit.edu, rafael.j.wysocki@...el.com,
        dan.j.williams@...el.com, zhenzhong.duan@...cle.com,
        jroedel@...e.de, bhe@...hat.com, guro@...com,
        Thomas.Lendacky@....com, andriy.shevchenko@...ux.intel.com,
        hannes@...xchg.org, minchan@...nel.org, mhocko@...nel.org,
        ying.huang@...el.com, yang.shi@...ux.alibaba.com,
        gustavo@...eddedor.com, ziqian.lzq@...fin.com,
        vdavydov.dev@...il.com, jason.zeng@...el.com, kevin.tian@...el.com,
        zhiyuan.lv@...el.com, lei.l.li@...el.com, paul.c.lai@...el.com,
        ashok.raj@...el.com, linux-fsdevel@...r.kernel.org,
        linux-doc@...r.kernel.org, kexec@...ts.infradead.org
Subject: Re: [RFC 21/43] x86/KASLR: PKRAM: support physical kaslr

On Wed, May 06, 2020 at 05:41:47PM -0700, Anthony Yznaga wrote:
> Avoid regions of memory that contain preserved pages when computing
> slots used to select where to put the decompressed kernel.

This is changing the slot-walking code instead of updating
mem_avoid_overlap() -- that's where the check for a "reserved" memory
area should live.

For example, this is how both mem_avoid_memmap() and the setup_data
memory areas are handled.

Is there a reason mem_avoid_overlap() can't be used here?

-- 
Kees Cook