On Thu, Dec 3, 2015 at 9:51 PM, Joe Perches <joe@xxxxxxxxxxx> wrote: > (adding lkml as this is likely better discussed there) > > On Thu, 2015-12-03 at 15:42 -0500, Jason Baron wrote: >> On 12/03/2015 03:24 PM, Joe Perches wrote: >> > On Thu, 2015-12-03 at 15:10 -0500, Jason Baron wrote: >> > > On 12/03/2015 03:03 PM, Joe Perches wrote: >> > > > On Thu, 2015-12-03 at 14:32 -0500, Jason Baron wrote: >> > > > > On 12/03/2015 01:52 PM, Aaron Conole wrote: >> > > > > > I think that as a minimum, the following patch should be evaluted, >> > > > > > but am unsure to whom I should submit it (after I test): >> > > > [] >> > > > > Agreed - the intention here is certainly to have no side effects. It >> > > > > looks like 'no_printk()' is used in quite a few other places that would >> > > > > benefit from this change. So we probably want a generic >> > > > > 'really_no_printk()' macro. >> > > > >> > > > https://lkml.org/lkml/2012/6/17/231 >> > > >> > > I don't see this in the tree. >> > >> > It never got applied. >> > >> > > Also maybe we should just convert >> > > no_printk() to do what your 'eliminated_printk()'. >> > >> > Some of them at least. >> > >> > > So we can convert all users with this change? >> > >> > I don't think so, I think there are some >> > function evaluation/side effects that are >> > required. I believe some do hardware I/O. >> > >> > It'd be good to at least isolate them. >> > >> > I'm not sure how to find them via some >> > automated tool/mechanism though. >> > >> > I asked Julia Lawall about it once in this >> > thread: https://lkml.org/lkml/2014/12/3/696 >> > >> >> Seems rather fragile to have side effects that we rely >> upon hidden in a printk(). > > Yup. > >> Just convert them and see what breaks :) > > I appreciate your optimism. It's very 1995. > Try it and see what happens. Whatever is the resolution for pr_debug, we still need to fix this particular use-after-free. It affects stability of debug builds, gives invalid debug output, prevents us from finding more bugs in SCTP. And maybe somebody uses CONFIG_DYNAMIC_DEBUG in production. -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
