Merge branch 'futexes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip (bd453cd4) · Commits · e / devices / android_kernel_xiaomi_markw

kernel/futex.c

+24 −21

Original line number	Diff line number	Diff line
		@@ -284,6 +284,25 @@ void put_futex_key(int fshared, union futex_key *key)
		drop_futex_key_refs(key);
		}

		/*
		* fault_in_user_writeable - fault in user address and verify RW access
		* @uaddr: pointer to faulting user space address
		*
		* Slow path to fixup the fault we just took in the atomic write
		* access to @uaddr.
		*
		* We have no generic implementation of a non destructive write to the
		* user address. We know that we faulted in the atomic pagefault
		* disabled section so we can as well avoid the #PF overhead by
		* calling get_user_pages() right away.
		*/
		static int fault_in_user_writeable(u32 __user *uaddr)
		{
		int ret = get_user_pages(current, current->mm, (unsigned long)uaddr,
		sizeof(*uaddr), 1, 0, NULL, NULL);
		return ret < 0 ? ret : 0;
		}

		/**
		* futex_top_waiter() - Return the highest priority waiter on a futex
		* @hb: the hash bucket the futex_q's reside in
		@@ -896,7 +915,6 @@ retry:
		retry_private:
		op_ret = futex_atomic_op_inuser(op, uaddr2);
		if (unlikely(op_ret < 0)) {
		u32 dummy;

		double_unlock_hb(hb1, hb2);

		@@ -914,7 +932,7 @@ retry_private:
		goto out_put_keys;
		}

		ret = get_user(dummy, uaddr2);
		ret = fault_in_user_writeable(uaddr2);
		if (ret)
		goto out_put_keys;

		@@ -1204,7 +1222,7 @@ retry_private:
		double_unlock_hb(hb1, hb2);
		put_futex_key(fshared, &key2);
		put_futex_key(fshared, &key1);
		ret = get_user(curval2, uaddr2);
		ret = fault_in_user_writeable(uaddr2);
		if (!ret)
		goto retry;
		goto out;
		@@ -1482,7 +1500,7 @@ retry:
		handle_fault:
		spin_unlock(q->lock_ptr);

		ret = get_user(uval, uaddr);
		ret = fault_in_user_writeable(uaddr);

		spin_lock(q->lock_ptr);

		@@ -1807,7 +1825,6 @@ static int futex_lock_pi(u32 __user *uaddr, int fshared,
		{
		struct hrtimer_sleeper timeout, *to = NULL;
		struct futex_hash_bucket *hb;
		u32 uval;
		struct futex_q q;
		int res, ret;

		@@ -1909,16 +1926,9 @@ out:
		return ret != -EINTR ? ret : -ERESTARTNOINTR;

		uaddr_faulted:
		/*
		* We have to r/w (int __user )uaddr, and we have to modify it
		* atomically. Therefore, if we continue to fault after get_user()
		* below, we need to handle the fault ourselves, while still holding
		* the mmap_sem. This can occur if the uaddr is under contention as
		* we have to drop the mmap_sem in order to call get_user().
		*/
		queue_unlock(&q, hb);

		ret = get_user(uval, uaddr);
		ret = fault_in_user_writeable(uaddr);
		if (ret)
		goto out_put_key;

		@@ -2013,17 +2023,10 @@ out:
		return ret;

		pi_faulted:
		/*
		* We have to r/w (int __user )uaddr, and we have to modify it
		* atomically. Therefore, if we continue to fault after get_user()
		* below, we need to handle the fault ourselves, while still holding
		* the mmap_sem. This can occur if the uaddr is under contention as
		* we have to drop the mmap_sem in order to call get_user().
		*/
		spin_unlock(&hb->lock);
		put_futex_key(fshared, &key);

		ret = get_user(uval, uaddr);
		ret = fault_in_user_writeable(uaddr);
		if (!ret)
		goto retry;