linux-kernel - Re: [PATCH v2] core, x86: Add user return notifiers

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: <4AB904AB.3020307@redhat.com>
Date:	Tue, 22 Sep 2009 20:08:59 +0300
From:	Avi Kivity <avi@...hat.com>
To:	Ingo Molnar <mingo@...e.hu>
CC:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	kvm@...r.kernel.org, Marcelo Tosatti <mtosatti@...hat.com>
Subject: Re: [PATCH v2] core, x86: Add user return notifiers

On 09/22/2009 06:50 PM, Avi Kivity wrote:
> On 09/22/2009 05:45 PM, Avi Kivity wrote:
>>> Would be nice to convert some existing open-coded return-to-user-space
>>> logic to this facility. One such candidate would be lockdep_sys_exit?
>>
>> I only implemented this for x86, while lockdep is arch independent.  
>> If arch support is added, it should be trivial.
>>
>
> The lockdep_sys_exit bit is actually x86/s390 only, and can easily be 
> adapted to use the new functionality on x86 only.  I'll try it out.

Unfortunately it doesn't work out well.  The notifier is called until 
explicitly unregistered (since it relies on a bit in TIF_NOTIFY_MASK), 
so we have to disarm it on the first return to usersspace or it spins 
forever.  We could re-arm it on the next kernel entry, but we don't have 
a kernel entry notifier so we'll just be moving hooks from one point to 
another.

-- 
error compiling committee.c: too many arguments to function

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/