From mboxrd@z Thu Jan 1 00:00:00 1970 From: Denys Vlasenko Subject: Re: Compat 32-bit syscall entry from 64-bit task!? Date: Thu, 26 Jan 2012 02:22:44 +0100 Message-ID: <201201260222.44225.vda.linux@googlemail.com> References: <20120126010858.GD18613@jl-vm1.vm.bytemark.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Cc: Indan Zupancic , Oleg Nesterov , Linus Torvalds , Andi Kleen , Andrew Lutomirski , Will Drewry , linux-kernel@vger.kernel.org, keescook@chromium.org, john.johansen@canonical.com, serge.hallyn@canonical.com, coreyb@linux.vnet.ibm.com, pmoore@redhat.com, eparis@redhat.com, djm@mindrot.org, segoon@openwall.com, rostedt@goodmis.org, jmorris@namei.org, scarybeasts@gmail.com, avi@redhat.com, penberg@cs.helsinki.fi, viro@zeniv.linux.org.uk, mingo@elte.hu, akpm@linux-foundation.org, khilman@ti.com, borislav.petkov@amd.com, amwang@redhat.com, ak@linux.intel.com, eric.dumazet@gmail.com, gregkh@suse.de, dhowells@redhat.com, daniel.lezcano@free.fr, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, olofj@chromium.org, mhalcrow@google.com, dlaor@red To: Jamie Lokier Return-path: In-Reply-To: <20120126010858.GD18613@jl-vm1.vm.bytemark.co.uk> Content-Disposition: inline Sender: linux-security-module-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thursday 26 January 2012 02:08, Jamie Lokier wrote: > Indan Zupancic wrote: > > > (2) syscall exit compat-ness is known from entry type - no need to indicate it; and > > > (3) if we would flag syscall entry with an event value in wait status, then syscall > > > exit will be already distinquisable. > > > > False for execve which messes everything up by changing TID sometimes. > > Is it disambiguated by PTRACE_EVENT_EXEC happening before the execve > returns, and you knowing the TID always changes to the PID? I haven't > yet checked which TID gets the PTRACE_EVENT_EXEC event, tid change happens before PTRACE_EVENT_EXEC event generation. -- vda