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authorMike Galbraith <umgwanakikbuti@gmail.com>2014-06-02 15:12:44 +0200
committerAnders Roxell <anders.roxell@linaro.org>2015-06-01 12:03:34 +0200
commit610ebefe7591b6a2df8e346a98025fd8a1e8b355 (patch)
tree9e9708f483ba5757c7a50cd5c093b553010f1ae2
parent46c709a5a34046f45388f4ae01a33ef8e7b168ab (diff)
downloadlinux-linaro-stable-610ebefe7591b6a2df8e346a98025fd8a1e8b355.tar.gz
rt,locking: fix __ww_mutex_lock_interruptible() lockdep annotation
Using mutex_acquire_nest() as used in __ww_mutex_lock() fixes the splat below. Remove superfluous line break in __ww_mutex_lock() as well. |============================================= |[ INFO: possible recursive locking detected ] |3.14.4-rt5 #26 Not tainted |--------------------------------------------- |Xorg/4298 is trying to acquire lock: | (reservation_ww_class_mutex){+.+.+.}, at: [<ffffffffa02b4270>] nouveau_gem_ioctl_pushbuf+0x870/0x19f0 [nouveau] |but task is already holding lock: | (reservation_ww_class_mutex){+.+.+.}, at: [<ffffffffa02b4270>] nouveau_gem_ioctl_pushbuf+0x870/0x19f0 [nouveau] |other info that might help us debug this: | Possible unsafe locking scenario: | CPU0 | ---- | lock(reservation_ww_class_mutex); | lock(reservation_ww_class_mutex); | | *** DEADLOCK *** | | May be due to missing lock nesting notation | |3 locks held by Xorg/4298: | #0: (&cli->mutex){+.+.+.}, at: [<ffffffffa02b597b>] nouveau_abi16_get+0x2b/0x100 [nouveau] | #1: (reservation_ww_class_acquire){+.+...}, at: [<ffffffffa0160cd2>] drm_ioctl+0x4d2/0x610 [drm] | #2: (reservation_ww_class_mutex){+.+.+.}, at: [<ffffffffa02b4270>] nouveau_gem_ioctl_pushbuf+0x870/0x19f0 [nouveau] Cc: stable-rt@vger.kernel.org Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/locking/rtmutex.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 74a824523d3a..1794fae96a2a 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -2238,7 +2238,7 @@ __ww_mutex_lock_interruptible(struct ww_mutex *lock, struct ww_acquire_ctx *ww_c
might_sleep();
- mutex_acquire(&lock->base.dep_map, 0, 0, _RET_IP_);
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
ret = rt_mutex_slowlock(&lock->base.lock, TASK_INTERRUPTIBLE, NULL, 0, ww_ctx);
if (ret)
mutex_release(&lock->base.dep_map, 1, _RET_IP_);
@@ -2256,8 +2256,7 @@ __ww_mutex_lock(struct ww_mutex *lock, struct ww_acquire_ctx *ww_ctx)
might_sleep();
- mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map,
- _RET_IP_);
+ mutex_acquire_nest(&lock->base.dep_map, 0, 0, &ww_ctx->dep_map, _RET_IP_);
ret = rt_mutex_slowlock(&lock->base.lock, TASK_UNINTERRUPTIBLE, NULL, 0, ww_ctx);
if (ret)
mutex_release(&lock->base.dep_map, 1, _RET_IP_);