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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-25 12:41:29 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-25 12:41:29 -0700 |
| commit | c86ad14d305d2429c3da19462440bac50c183def (patch) | |
| tree | bd794cd72476661faf82c440063c217bb978ce44 /kernel/exit.c | |
| parent | a2303849a6b4b7ba59667091e00d6bb194071d9a (diff) | |
| parent | f06628638cf6e75f179742b6c1b35076965b9fdd (diff) | |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"The locking tree was busier in this cycle than the usual pattern - a
couple of major projects happened to coincide.
The main changes are:
- implement the atomic_fetch_{add,sub,and,or,xor}() API natively
across all SMP architectures (Peter Zijlstra)
- add atomic_fetch_{inc/dec}() as well, using the generic primitives
(Davidlohr Bueso)
- optimize various aspects of rwsems (Jason Low, Davidlohr Bueso,
Waiman Long)
- optimize smp_cond_load_acquire() on arm64 and implement LSE based
atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
on arm64 (Will Deacon)
- introduce smp_acquire__after_ctrl_dep() and fix various barrier
mis-uses and bugs (Peter Zijlstra)
- after discovering ancient spin_unlock_wait() barrier bugs in its
implementation and usage, strengthen its semantics and update/fix
usage sites (Peter Zijlstra)
- optimize mutex_trylock() fastpath (Peter Zijlstra)
- ... misc fixes and cleanups"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (67 commits)
locking/atomic: Introduce inc/dec variants for the atomic_fetch_$op() API
locking/barriers, arch/arm64: Implement LDXR+WFE based smp_cond_load_acquire()
locking/static_keys: Fix non static symbol Sparse warning
locking/qspinlock: Use __this_cpu_dec() instead of full-blown this_cpu_dec()
locking/atomic, arch/tile: Fix tilepro build
locking/atomic, arch/m68k: Remove comment
locking/atomic, arch/arc: Fix build
locking/Documentation: Clarify limited control-dependency scope
locking/atomic, arch/rwsem: Employ atomic_long_fetch_add()
locking/atomic, arch/qrwlock: Employ atomic_fetch_add_acquire()
locking/atomic, arch/mips: Convert to _relaxed atomics
locking/atomic, arch/alpha: Convert to _relaxed atomics
locking/atomic: Remove the deprecated atomic_{set,clear}_mask() functions
locking/atomic: Remove linux/atomic.h:atomic_fetch_or()
locking/atomic: Implement atomic{,64,_long}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}()
locking/atomic: Fix atomic64_relaxed() bits
locking/atomic, arch/xtensa: Implement atomic_fetch_{add,sub,and,or,xor}()
locking/atomic, arch/x86: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
locking/atomic, arch/sparc: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()
...
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index 9e6e1356e6bb..0b40791b9e70 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -700,10 +700,14 @@ void do_exit(long code) exit_signals(tsk); /* sets PF_EXITING */ /* - * tsk->flags are checked in the futex code to protect against - * an exiting task cleaning up the robust pi futexes. + * Ensure that all new tsk->pi_lock acquisitions must observe + * PF_EXITING. Serializes against futex.c:attach_to_pi_owner(). */ smp_mb(); + /* + * Ensure that we must observe the pi_state in exit_mm() -> + * mm_release() -> exit_pi_state_list(). + */ raw_spin_unlock_wait(&tsk->pi_lock); if (unlikely(in_atomic())) { |