"Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> writes: > Use force_fatal_sig instead of calling do_exit directly. This ensures > the ordinary signal handling path gets invoked, core dumps as > appropriate get created, and for multi-threaded processes all of the > threads are terminated not just a single thread. > > When asked Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> said [1]: >> ebiederm@xxxxxxxxxxxx (Eric W. Biederman) asked: >> >> > Why does do_syscal_user_dispatch call do_exit(SIGSEGV) and >> > do_exit(SIGSYS) instead of force_sig(SIGSEGV) and force_sig(SIGSYS)? >> > >> > Looking at the code these cases are not expected to happen, so I would >> > be surprised if userspace depends on any particular behaviour on the >> > failure path so I think we can change this. >> >> Hi Eric, >> >> There is not really a good reason, and the use case that originated the >> feature doesn't rely on it. >> >> Unless I'm missing yet another problem and others correct me, I think >> it makes sense to change it as you described. >> >> > Is using do_exit in this way something you copied from seccomp? >> >> I'm not sure, its been a while, but I think it might be just that. The >> first prototype of SUD was implemented as a seccomp mode. > > If at some point it becomes interesting we could relax > "force_fatal_sig(SIGSEGV)" to instead say > "force_sig_fault(SIGSEGV, SEGV_MAPERR, sd->selector)". > > I avoid doing that in this patch to avoid making it possible > to catch currently uncatchable signals. > > Cc: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Cc: Andy Lutomirski <luto@xxxxxxxxxx> > [1] https://lkml.kernel.org/r/87mtr6gdvi.fsf@xxxxxxxxxxxxx > Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> > --- > kernel/entry/syscall_user_dispatch.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > Hi Eric, Feel free to add: Reviewed-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> Thanks, -- Gabriel Krisman Bertazi
