On 04/19/2018 04:35 PM, Andrey Ryabinin wrote: > > > On 04/18/2018 09:37 PM, Linus Torvalds wrote: >> Ugh, that lustre code is disgusting. >> >> I thought we were getting rid of it. >> >> Anyway, I started looking at why the stack trace is such an incredible >> mess, with lots of stale entries. >> >> The reason (well, _one_ reason) seems to be "ksocknal_startup". It has >> a 500-byte stack frame for some incomprehensible reason. I assume due >> to excessive inlining, because the function itself doesn't seem to be >> that bad. >> >> Similarly, LNetNIInit has a 300-byte stack frame. So it gets pretty deep. >> >> I'm getting the feeling that KASAN is making things worse because >> probably it's disabling all the sane stack frame stuff (ie no merging >> of stack slot entries, perhaps?). >> > > AFAIR no merging of stack slots policy enabled only if -fsanitize-address-use-after-scope > is on (which is CONFIG_KASAN_EXTRA). This feature does cause sometimes significant stack bloat, > but hasn't been proven to be very useful, so I wouldn't mind disabling it completely. > > So far I know only about a single BUG - https://lkml.kernel.org/r/<151238865557.4852.10258661301122491354@xxxxxxxxxxxxxxxxxxxx> > it has found. Actually, there is one more - https://syzkaller.appspot.com/bug?id=6a929b72a32ca0b1a6985126fa1bc77c03c12304 so two bugs. > There are also a lot of other I didn't finish this sentence: There are also a lot of other reports about use-after-scope, but seem all of them are false positives caused by STRUCTLEAK plugin. _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
