On Fri, Jul 26, 2019 at 11:01 AM Sean Christopherson <sean.j.christopher...@intel.com> wrote: > > +cc Paul > > On Wed, Jul 24, 2019 at 01:56:34AM +0200, Thomas Gleixner wrote: > > On Tue, 23 Jul 2019, Kees Cook wrote: > > > > > On Wed, Jul 24, 2019 at 12:59:03AM +0200, Thomas Gleixner wrote: > > > > And as we have sys_clock_gettime64() exposed for 32bit anyway you need > > > > to > > > > deal with that in seccomp independently of the VDSO. It does not make > > > > sense > > > > to treat sys_clock_gettime() differently than sys_clock_gettime64(). > > > > They > > > > both expose the same information, but the latter is y2038 safe. > > > > > > Okay, so combining Andy's ideas on aliasing and "more seccomp flags", > > > we could declare that clock_gettime64() is not filterable on 32-bit at > > > all without the magic SECCOMP_IGNORE_ALIASES flag or something. Then we > > > would alias clock_gettime64 to clock_gettime _before_ the first evaluation > > > (unless SECCOMP_IGNORE_ALIASES is set)? > > > > > > (When was clock_gettime64() introduced? Is it too long ago to do this > > > "you can't filter it without a special flag" change?) > > > > clock_gettime64() and the other sys_*time64() syscalls which address the > > y2038 issue were added in 5.1 > > Paul Bolle pointed out that this regression showed up in v5.3-rc1, not > v5.2. In Paul's case, systemd-journal is failing.
I think it's getting quite late to start inventing new seccomp features to fix this. I think the right solution for 5.3 is to change the 32-bit vdso fallback to use the old clock_gettime, i.e. clock_gettime32. This is obviously not an acceptable long-term solution.
