On Thu, Feb 18, 2016 at 11:45 PM, Paul Bolle <pebo...@tiscali.nl> wrote: > Dmitry, > > On ma, 2016-02-15 at 11:42 +0100, Dmitry Vyukov wrote: >> When I am running the following program in a parallel loop, kmemleak >> starts reporting memory leaks of objects allocated in >> tty_register_driver during boot. > > Because these tty drivers are built in? > >> These leaks start popping up >> chaotically and as you can see they originate in different drivers >> (synclinkmp_init, isdn_init, chr_dev_init, sysfs_init). >> >> On commit 388f7b1d6e8ca06762e2454d28d6c3c55ad0fe95 (4.5-rc3). >> >> // autogenerated by syzkaller (http://github.com/google/syzkaller) >> #include <sys/types.h> >> #include <sys/stat.h> >> #include <fcntl.h> >> #include <sys/ioctl.h> > > If you (or syzkaller) add > #include <linux/tty.h> > > here... > >> int main() >> { >> int fd, val; >> >> fd = open("/dev/ptmx", O_RDWR); >> val = 21; > > you can use > val = N_GSM0710; > > here. That is probably much clearer for the readers of this report. (No > one bothers to remember these values. No one sane, at least.) > >> ioctl(fd, TIOCSETD, &val); >> return 0; >> } > > Fascinating issue. Makes zero sense to me. sysfs_init? Anyhow, since the > people actually familiar with this code have stayed silent until now, I > have some obvious questions: > - does this only trigger with line discipline N_GSM0710? > - is this a new issue or do older trees also trigger it (in other > words: have you tried bisecting this)?
I can say that it does not happen with 1, 2, 3, 4 and 7. So there are chances that it is N_GSM0710-specific. 5 and 6 trigger lots of leaks, but they are different. I did not try to bisect it.
