On Mon, 30 Apr 2018 19:58:58 -0400 Steven Rostedt <rost...@goodmis.org> wrote:
> On Mon, 30 Apr 2018 16:26:58 -0700 > Andrew Morton <a...@linux-foundation.org> wrote: > > > On Thu, 26 Apr 2018 16:26:19 -0400 Pavel Tatashin > > <pasha.tatas...@oracle.com> wrote: > > > > > The following two bugs were reported by Fengguang Wu: > > > > > > kernel reboot-without-warning in early-boot stage, last printk: > > > early console in setup code > > > > > > http://lkml.kernel.org/r/20180418135300.inazvpxjxowog...@wfg-t540p.sh.intel.com > > > > > > ... > > > > > > --- a/init/main.c > > > +++ b/init/main.c > > > @@ -585,8 +585,8 @@ asmlinkage __visible void __init start_kernel(void) > > > setup_log_buf(0); > > > vfs_caches_init_early(); > > > sort_main_extable(); > > > - trap_init(); > > > mm_init(); > > > + trap_init(); > > > > > > ftrace_init(); > > > > Gulp. Let's hope that nothing in mm_init() requires that trap_init() > > has been run. What happens if something goes wrong during mm_init() > > and the architecture attempts to raise a software exception, hits a bus > > error, div-by-zero, etc, etc? Might there be hard-to-discover > > dependencies in such a case? > > I mentioned the same thing. > I guess the same concern applies to all the code which we've always run before trap_init(), and that's quite a lot of stuff. So we should be OK. But don't quote me ;)
