Hi all, Here are fixes that worth to have in the @stable, as they were hit by different people, including Arista on v4.9 stable. And for linux-next - adding lockdep asserts for line discipline changing code, verifying that write ldisc sem will be held forthwith. Mikulas, can you add your tested-by on this patches set again, please? I tried to reproduce reboot issue on qemu-hppa and even built cross-compiler for pa-risc.. but was unlucky in reproducing. Thanks, Dima Changes since v5: - Better commit tags - Hopefully fixed issue with reboot on pa-risc with Debian 5 Changes since v4: - back to lock ldisc with (5*HZ) timeout in tty_reopen() (LKP report link: lkml.kernel.org/r/<1536940609.3185.29.camel@xxxxxxxxxx>) - reordered 3/7 with 2/7 for LKP robot Changes since v3: - Added tested-by Mark Rutland (thanks!) - Dropped patch with smp_wmb() - wrong idea - lockdep_assert_held() should be actually lockdep_assert_held_exclusive() - Described why tty_ldisc_open() can be called without ldisc_sem held for pty slave end (o_tty). - Added Peter's patch for dropping self-made lockdep annotations - Fix for a reader(s) of ldisc semaphore waiting for an active reader(s) Changes since v2: - Added reviewed-by tags - Hopefully, fixed reported by 0-day issue. - Added optional fix for wait_readers decrement Changes since v1: - Added tested-by/reported-by tags - Dropped 3/4 (locking tty pair for lockdep sake), Because of that - not adding lockdep_assert_held() in tty_ldisc_open() - Added 4/4 cleanup to inc tty->count only on success of tty_ldisc_reinit() - lock ldisc without (5*HZ) timeout in tty_reopen() v1 link: lkml.kernel.org/r/<20180829022353.23568-1-dima@xxxxxxxxxx> v2 link: lkml.kernel.org/r/<20180903165257.29227-1-dima@xxxxxxxxxx> v3 link: lkml.kernel.org/r/<20180911014821.26286-1-dima@xxxxxxxxxx> v4 link: lkml.kernel.org/r/<20180912001702.18522-1-dima@xxxxxxxxxx> Cc: Daniel Axtens <dja@xxxxxxxxxx> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Michael Neuling <mikey@xxxxxxxxxxx> Cc: Mikulas Patocka <mpatocka@xxxxxxxxxx> Cc: Nathan March <nathan@xxxxxx> Cc: Pasi Kärkkäinen <pasik@xxxxxx> Cc: Peter Hurley <peter@xxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: "Rong, Chen" <rong.a.chen@xxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> Cc: Tan Xiaojun <tanxiaojun@xxxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> (please, ignore if I Cc'ed you mistakenly) Dmitry Safonov (6): tty/ldsem: Wake up readers after timed out down_write() tty: Hold tty_ldisc_lock() during tty_reopen() tty: Don't block on IO when ldisc change is pending tty: Simplify tty->count math in tty_reopen() tty/ldsem: Add lockdep asserts for ldisc_sem tty/ldsem: Decrement wait_readers on timeouted down_read() Peter Zijlstra (1): tty/ldsem: Convert to regular lockdep annotations drivers/tty/n_hdlc.c | 4 +-- drivers/tty/n_r3964.c | 2 +- drivers/tty/n_tty.c | 8 +++--- drivers/tty/tty_io.c | 14 ++++++---- drivers/tty/tty_ldisc.c | 16 +++++++++++ drivers/tty/tty_ldsem.c | 62 +++++++++++++++++------------------------ include/linux/tty.h | 7 +++++ 7 files changed, 63 insertions(+), 50 deletions(-) -- 2.19.1
