From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47177) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8aCk-0004rO-6y for qemu-devel@nongnu.org; Fri, 26 Jun 2015 16:26:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z8aCf-0000RM-4a for qemu-devel@nongnu.org; Fri, 26 Jun 2015 16:26:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45976) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8aCe-0000RA-SY for qemu-devel@nongnu.org; Fri, 26 Jun 2015 16:26:25 -0400 From: Paul Moore Date: Fri, 26 Jun 2015 16:26:22 -0400 Message-ID: <17948100.v63oBISXG4@sifl> In-Reply-To: <20150626160318.GC3215@hawk.localdomain> References: <1428670681-23032-1-git-send-email-peter.maydell@linaro.org> <20150626160318.GC3215@hawk.localdomain> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [Qemu-devel] [PATCH for-2.3] Revert seccomp tests that allow it to be used on non-x86 architectures List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Andrew Jones Cc: Peter Maydell , Marcus Meissner , Karl-Philipp Richter , Patch Tracking , Riku Voipio , Alexander Graf , QEMU Developers , Eduardo Otubo , Andreas =?ISO-8859-1?Q?F=E4rber?= On Friday, June 26, 2015 06:03:18 PM Andrew Jones wrote: > On Tue, Jun 16, 2015 at 02:16:03PM +0100, Peter Maydell wrote: > > On 16 June 2015 at 14:12, Andrew Jones wrote: > > > Can we now revert this revert, along with bumping the non-x86 arch > > > atleast-version to v2.2.1 > > > > Probably. I suggest you submit a patch and test it on the > > relevant architectures and seccomp versions. > > I don't see any problems with the light testing (booting a guest) > I've done on my mustang, but AArch64 worked with libseccomp 2.2.0 > too. So I dusted off my Midway (updated to Fedora 21 that has > libseccomp 2.2.1 packaged), and gave it a try, but unfortunately > it still doesn't work... > > I found that we needed to add another syscall to the whitelist; > the arm-private 'cacheflush', as it's used by __builtin___clear_cache. > And, from libseccomp's git history it appears that syscall is known > > commit a710a2d246bdc73ba77e3ff5624e790688cc51fd > Author: Paul Moore > Date: Wed May 6 12:05:45 2015 -0400 > > arm: add some missing syscalls > > Add the following syscalls to the ARM arch/ABI and update the syscall > validation script. > > * breakpoint() > * cacheflush() > * usr26() > * usr32() > * set_tls() > > Reported-by: Purcareata Bogdan > Signed-off-by: Paul Moore > > > And also appears to be in 2.2.1 > $ git describe a710a2d246bdc73ba77e3ff5624e790688cc51fd > v2.2.0-10-ga710a2d246bdc > > However the qemu thread that makes that syscall still dies, even > with this patch > > diff --git a/qemu-seccomp.c b/qemu-seccomp.c > index f9de0d3390feb..33644a4e3c3d3 100644 > --- a/qemu-seccomp.c > +++ b/qemu-seccomp.c > @@ -237,7 +237,8 @@ static const struct QemuSeccompSyscall > seccomp_whitelist[] = { > { SCMP_SYS(fadvise64), 240 }, > { SCMP_SYS(inotify_init1), 240 }, > { SCMP_SYS(inotify_add_watch), 240 }, > - { SCMP_SYS(mbind), 240 } > + { SCMP_SYS(mbind), 240 }, > + { SCMP_SYS(cacheflush), 240 }, > }; > > int seccomp_start(void) > > > Paul, can you help me figure out what I'm missing? Perhaps a stupid question, but you did verify that it is cacheflush that is causing the problem? The seccomp filter code will emit a message to syslog or the audit log, depending on your configuration, with the syscall number. #./tools/scmp_sys_resolver -a arm cacheflush 983042 #./tools/scmp_sys_resolver -a arm 983042 -- paul moore security @ redhat