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Subject[GIT pull] locking: Fixes for 4.15
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");
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