On Fri, Jun 15, 2012 at 07:06:10PM +0000, Blue Swirl wrote: > On Wed, Jun 13, 2012 at 8:30 PM, Daniel P. Berrange <berra...@redhat.com> > wrote: > > On Wed, Jun 13, 2012 at 04:20:22PM -0300, Eduardo Otubo wrote: > >> I added a syscall struct using priority levels as described in the > >> libseccomp man page. The priority numbers are based to the frequency > >> they appear in a sample strace from a regular qemu guest run under > >> libvirt. > >> > >> Libseccomp generates linear BPF code to filter system calls, those rules > >> are read one after another. The priority system places the most common > >> rules first in order to reduce the overhead when processing them. > >> > >> Also, since this is just a first RFC, the whitelist is a little raw. We > >> might need your help to improve, test and fine tune the set of system > >> calls. > >> > >> v2: Fixed some style issues > >> Removed code from vl.c and created qemu-seccomp.[ch] > >> Now using ARRAY_SIZE macro > >> Added more syscalls without priority/frequency set yet > >> > >> Signed-off-by: Eduardo Otubo <ot...@linux.vnet.ibm.com> > >> --- > >> qemu-seccomp.c | 73 > >> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >> qemu-seccomp.h | 9 +++++++ > >> vl.c | 7 ++++++ > >> 3 files changed, 89 insertions(+) > >> create mode 100644 qemu-seccomp.c > >> create mode 100644 qemu-seccomp.h > >> > >> diff --git a/qemu-seccomp.c b/qemu-seccomp.c > >> new file mode 100644 > >> index 0000000..048b7ba > >> --- /dev/null > >> +++ b/qemu-seccomp.c > >> @@ -0,0 +1,73 @@ > >> +#include <stdio.h> > >> +#include <seccomp.h> > >> +#include "qemu-seccomp.h" > >> + > >> +static struct QemuSeccompSyscall seccomp_whitelist[] = { > >> + { SCMP_SYS(timer_settime), 255 }, > >> + { SCMP_SYS(timer_gettime), 254 }, > >> + { SCMP_SYS(futex), 253 }, > >> + { SCMP_SYS(select), 252 }, > >> + { SCMP_SYS(recvfrom), 251 }, > >> + { SCMP_SYS(sendto), 250 }, > >> + { SCMP_SYS(read), 249 }, > >> + { SCMP_SYS(brk), 248 }, > >> + { SCMP_SYS(clone), 247 }, > >> + { SCMP_SYS(mmap), 247 }, > >> + { SCMP_SYS(mprotect), 246 }, > >> + { SCMP_SYS(ioctl), 245 }, > >> + { SCMP_SYS(recvmsg), 245 }, > >> + { SCMP_SYS(sendmsg), 245 }, > >> + { SCMP_SYS(accept), 245 }, > >> + { SCMP_SYS(connect), 245 }, > >> + { SCMP_SYS(bind), 245 }, > >> + { SCMP_SYS(listen), 245 }, > >> + { SCMP_SYS(ioctl), 245 }, > >> + { SCMP_SYS(eventfd), 245 }, > >> + { SCMP_SYS(rt_sigprocmask), 245 }, > >> + { SCMP_SYS(write), 244 }, > >> + { SCMP_SYS(fcntl), 243 }, > >> + { SCMP_SYS(tgkill), 242 }, > >> + { SCMP_SYS(rt_sigaction), 242 }, > >> + { SCMP_SYS(pipe2), 242 }, > >> + { SCMP_SYS(munmap), 242 }, > >> + { SCMP_SYS(mremap), 242 }, > >> + { SCMP_SYS(getsockname), 242 }, > >> + { SCMP_SYS(getpeername), 242 }, > >> + { SCMP_SYS(fdatasync), 242 }, > >> + { SCMP_SYS(close), 242 } > > > > execve(), so QEMU can run things like the ifup/down > > scripts, the samba daemon (sic), exec: migration protocol, > > etc, etc > > I think allowing execve() would render seccomp pretty much useless.
So do I, but in the previous posting it was stated[1] that the intent is to allow all syscalls QEMU needs, and not have any loss of current functionality. Hence I'm reporting all syscalls that are missing that QEMU needs. Daniel [1] https://lists.gnu.org/archive/html/qemu-devel/2012-05/msg00928.html -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|