Re: Pondering per-process vsyscall disablement

2014-05-30 Thread Andy Lutomirski
On Fri, May 30, 2014 at 1:20 PM, H. Peter Anvin wrote: > On 05/30/2014 01:11 PM, Andy Lutomirski wrote: >> On Fri, May 30, 2014 at 1:05 PM, H. Peter Anvin wrote: >>> On 05/30/2014 01:00 PM, Andy Lutomirski wrote: Do the flags go in the ELF loader or in the executable we're running?

Re: Pondering per-process vsyscall disablement

2014-05-30 Thread H. Peter Anvin
On 05/30/2014 01:11 PM, Andy Lutomirski wrote: > On Fri, May 30, 2014 at 1:05 PM, H. Peter Anvin wrote: >> On 05/30/2014 01:00 PM, Andy Lutomirski wrote: >>> >>> Do the flags go in the ELF loader or in the executable we're running? >>> Or both (and, if both, do we and them or or them)? >>> >>> I t

Re: Pondering per-process vsyscall disablement

2014-05-30 Thread Andy Lutomirski
On Fri, May 30, 2014 at 1:05 PM, H. Peter Anvin wrote: > On 05/30/2014 01:00 PM, Andy Lutomirski wrote: >> >> Do the flags go in the ELF loader or in the executable we're running? >> Or both (and, if both, do we and them or or them)? >> >> I think the interpreter makes a little more sense in gener

Re: Pondering per-process vsyscall disablement

2014-05-30 Thread H. Peter Anvin
On 05/30/2014 01:00 PM, Andy Lutomirski wrote: > > Do the flags go in the ELF loader or in the executable we're running? > Or both (and, if both, do we and them or or them)? > > I think the interpreter makes a little more sense in general: for the > most part, use of vsyscalls is a property of th

Re: Pondering per-process vsyscall disablement

2014-05-30 Thread Andy Lutomirski
On Wed, May 28, 2014 at 2:45 PM, H. Peter Anvin wrote: > On 05/23/2014 09:40 AM, Andy Lutomirski wrote: >> >> I don't think this should be something configured by the >> administrator, unless the administrator is the builder of a kiosky >> thing like Chromium OS. In that case, the administrator c

Re: Pondering per-process vsyscall disablement

2014-05-28 Thread H. Peter Anvin
On 05/23/2014 09:40 AM, Andy Lutomirski wrote: > > I don't think this should be something configured by the > administrator, unless the administrator is the builder of a kiosky > thing like Chromium OS. In that case, the administrator can use > vsyscall=none. > > I think this should be handled b

Re: Pondering per-process vsyscall disablement

2014-05-23 Thread Andy Lutomirski
On Thu, May 22, 2014 at 7:44 PM, Marian Marinov wrote: > -BEGIN PGP SIGNED MESSAGE- > Hash: SHA1 > > On 05/23/2014 02:04 AM, Andy Lutomirski wrote: >> It would be nice to have a way for new programs to declare that they don't >> need vsyscalls. What's the right way to >> do this? An ELF

Re: Pondering per-process vsyscall disablement

2014-05-22 Thread Marian Marinov
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 05/23/2014 02:04 AM, Andy Lutomirski wrote: > It would be nice to have a way for new programs to declare that they don't > need vsyscalls. What's the right way to > do this? An ELF header entry in the loader? An ELF header entry in the > progra

Pondering per-process vsyscall disablement

2014-05-22 Thread Andy Lutomirski
It would be nice to have a way for new programs to declare that they don't need vsyscalls. What's the right way to do this? An ELF header entry in the loader? An ELF header entry in the program? A new arch_prctl? As background, there's an old part of the x86_64 ABI that allows programs to do g