提交 70e33bec 编写于 作者: P Peter Zijlstra 提交者: openeuler-sync-bot

locking/rwsem: Better collate rwsem_read_trylock()

mainline inclusion
from mainline-v5.11-rc1
commit 3379116a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7A0N9
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3379116a0ca965b00e6522c7ea3f16c9dbd8f9f9

--------------------------------

All users of rwsem_read_trylock() do rwsem_set_reader_owned(sem) on
success, move it into rwsem_read_trylock() proper.
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201207090243.GE3040@hirez.programming.kicks-ass.netSigned-off-by: NYang Yingliang <yangyingliang@huawei.com>
(cherry picked from commit aa6c618f)
上级 1ad25d9d
......@@ -273,9 +273,16 @@ static inline void rwsem_set_nonspinnable(struct rw_semaphore *sem)
static inline bool rwsem_read_trylock(struct rw_semaphore *sem)
{
long cnt = atomic_long_add_return_acquire(RWSEM_READER_BIAS, &sem->count);
if (WARN_ON_ONCE(cnt < 0))
rwsem_set_nonspinnable(sem);
return !(cnt & RWSEM_READ_FAILED_MASK);
if (!(cnt & RWSEM_READ_FAILED_MASK)) {
rwsem_set_reader_owned(sem);
return true;
}
return false;
}
/*
......@@ -1340,8 +1347,6 @@ static inline void __down_read(struct rw_semaphore *sem)
if (!rwsem_read_trylock(sem)) {
rwsem_down_read_slowpath(sem, TASK_UNINTERRUPTIBLE);
DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
} else {
rwsem_set_reader_owned(sem);
}
}
......@@ -1351,8 +1356,6 @@ static inline int __down_read_interruptible(struct rw_semaphore *sem)
if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE)))
return -EINTR;
DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
} else {
rwsem_set_reader_owned(sem);
}
return 0;
}
......@@ -1363,8 +1366,6 @@ static inline int __down_read_killable(struct rw_semaphore *sem)
if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_KILLABLE)))
return -EINTR;
DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
} else {
rwsem_set_reader_owned(sem);
}
return 0;
}
......
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