[GIT pull] locking: Fixes for 4.15

[Thomas Gleixner]

Linus,

please pull the latest locking-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
locking-urgent-for-linus

Two final fixes for 4.15:

 - Repair the OWNER_DIED logic in the futex code which got wreckaged with the
   recent fix for a subtle race condition.

 - Prevent the hard lockup detector from triggering when dumping all held
   locks in the system.

Thanks,

        tglx

------------------>
Peter Zijlstra (1):
      futex: Fix OWNER_DEAD fixup

Tejun Heo (1):
      locking/lockdep: Avoid triggering hardlockup from debug_show_all_locks()


 kernel/futex.c           | 6 +++---
 kernel/locking/lockdep.c | 2 ++
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index 8c5424dd5924..7f719d110908 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2311,9 +2311,6 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct 
futex_q *q,
        raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock);
 
        oldowner = pi_state->owner;
-       /* Owner died? */
-       if (!pi_state->owner)
-               newtid |= FUTEX_OWNER_DIED;
 
        /*
         * We are here because either:
@@ -2374,6 +2371,9 @@ static int fixup_pi_state_owner(u32 __user *uaddr, struct 
futex_q *q,
        }
 
        newtid = task_pid_vnr(newowner) | FUTEX_WAITERS;
+       /* Owner died? */
+       if (!pi_state->owner)
+               newtid |= FUTEX_OWNER_DIED;
 
        if (get_futex_value_locked(&uval, uaddr))
                goto handle_fault;
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 5fa1324a4f29..521659044719 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -49,6 +49,7 @@
 #include <linux/gfp.h>
 #include <linux/random.h>
 #include <linux/jhash.h>
+#include <linux/nmi.h>
 
 #include <asm/sections.h>
 
@@ -4490,6 +4491,7 @@ void debug_show_all_locks(void)
                if (!unlock)
                        if (read_trylock(&tasklist_lock))
                                unlock = 1;
+               touch_nmi_watchdog();
        } while_each_thread(g, p);
 
        pr_warn("\n");