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  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]
Date:   Thu, 2 Nov 2017 22:41:35 +0100 (CET)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
cc:     Andy Lutomirski <luto@...capital.net>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-mm@...ck.org" <linux-mm@...ck.org>,
        moritz.lipp@...k.tugraz.at,
        Daniel Gruss <daniel.gruss@...k.tugraz.at>,
        michael.schwarz@...k.tugraz.at, Kees Cook <keescook@...gle.com>,
        Hugh Dickins <hughd@...gle.com>, X86 ML <x86@...nel.org>
Subject: Re: [PATCH 02/23] x86, kaiser: do not set _PAGE_USER for init_mm
 page tables


On Thu, 2 Nov 2017, Linus Torvalds wrote:

> On Thu, Nov 2, 2017 at 11:40 AM, Thomas Gleixner <tglx@...utronix.de> wrote:
> >
> > Hmm. Not sure. IIRC you need to be able to read it to figure out where the
> > entry points are. They are at fixed offsets, but there is some voodoo out
> > there which reads the 'elf' to get to them.
> 
> That would actually be really painful.
> 
> But I *think* you're confusing it with the vdso case, which really
> does do that whole "generate ELF information for debuggers and dynamic
> linkers" thing. The vsyscall page never did that afaik, and purely
> relied on fixed addresses.

Yes, managed to confuse myself. The vsycall page has only the fixed offset
entry points at least when its in emulation mode.

Thanks,

	tglx


Powered by blists - more mailing lists