linux-kernel - Re: [PATCH 25/43] x86/mm/kaiser: Unmap kernel from userspace page tables (core patch)

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 for Android: free password hash cracker in your pocket

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

Message-ID: <20171126151330.otk6576fi5aae64h@gmail.com>
Date:   Sun, 26 Nov 2017 16:13:30 +0100
From:   Ingo Molnar <mingo@...nel.org>
To:     Dave Hansen <dave.hansen@...ux.intel.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        linux-kernel@...r.kernel.org,
        Andy Lutomirski <luto@...capital.net>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H . Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...en8.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 25/43] x86/mm/kaiser: Unmap kernel from userspace page
 tables (core patch)


* Dave Hansen <dave.hansen@...ux.intel.com> wrote:

> On 11/24/2017 04:16 AM, Peter Zijlstra wrote:
> > On Fri, Nov 24, 2017 at 10:14:30AM +0100, Ingo Molnar wrote:
> >> +The minimalistic kernel portion of the user page tables try to
> >> +map only what is needed to enter/exit the kernel such as the
> >> +entry/exit functions themselves and the interrupt descriptor
> >> +table (IDT).  
> > 
> >                 There are a few unnecessary things that get mapped
> >> +such as the first C function when entering an interrupt (see
> >> +comments in kaiser.c).
> > 
> > If I understood Andy's patches correctly, this should no longer be
> > required. Is this text still correct?
> 
> It is out of date.  We were able to remove the irq handler mappings.

I have updated the Documentation/x86/kaiser.txt file accordingly.

Thanks,

	Ingo