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:	Sun, 09 Mar 2014 17:16:12 -0700
From:	"H. Peter Anvin" <>
To:	Stefani Seibold <>,
	Andy Lutomirski <>
CC:	"" <>,
	Martin Runge <>,
	Andreas Brief <>,
	Linus Torvalds <>
Subject: Re: [x86, vdso] BUG: unable to handle kernel paging request at d34bd000

On 03/09/2014 12:47 AM, Stefani Seibold wrote:
> But let me ask an other question: Is the compat mode still needed
> anymore?
> Since Lguest, XEN, OPLC and the reservetop kernel parameter will change
> the __FIXADDR_TOP, there is no fix place for the VDSO page. Also in the
> 32 bit emulation layer the address is not fix.
> So all applications can fail when try directly access the VDSO page with
> a hard coded address 0xffffe000.
> IMHO this is broken. So an other solution is to remove the whole VDSO
> compat code.

Lguest, Xen, OLPC and reservetop are corner cases.  My understanding is
that at least one widely used distro actually cared about this, and
Linus especially is adamant that "we don't break userspace."

The dual vdso approach might be the best bet, for the cases where
compatibility is even possible.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

Powered by blists - more mailing lists