agp: Remove the BKL from agp_open (55e858c8) · Commits · 戴 / test

- Remove the BKL from agp_open - Perform a few clean-ups. Analysis: --------- int minor is local to the function. The following are protected by agp_fe.agp_mutex struct agp_file_private *priv; struct agp_client *client; Call-outs: kzalloc should be safe to call under the mutex_lock agp_find_client_by_pid: - agp_mmap calls that under agp_fe.agp_mutex which we hold in agp_open - agpioc_reserve_wrap calls it without any locking what-so-ever. - Is that an error? Or is that okay because it has pid that is a unique handle? agp_insert_file_private: - This function only manipulates struct agp_file_private, once again while agp_fe.agp_mutex is held Signed-off-by:

John Kacur <jkacur@redhat.com> Acked-by:

David Airlie <airlied@linux.ie> LKML-Reference: <alpine.LFD.2.00.0910112216060.12574@localhost.localdomain> Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

drivers/char/agp/frontend.c

+11 −17

Original line number	Diff line number	Diff line
		@@ -676,25 +676,25 @@ static int agp_open(struct inode inode, struct file file)
		int minor = iminor(inode);
		struct agp_file_private *priv;
		struct agp_client *client;
		int rc = -ENXIO;

		lock_kernel();
		mutex_lock(&(agp_fe.agp_mutex));

		if (minor != AGPGART_MINOR)
		goto err_out;
		return -ENXIO;

		mutex_lock(&(agp_fe.agp_mutex));

		priv = kzalloc(sizeof(struct agp_file_private), GFP_KERNEL);
		if (priv == NULL)
		goto err_out_nomem;
		if (priv == NULL) {
		mutex_unlock(&(agp_fe.agp_mutex));
		return -ENOMEM;
		}

		set_bit(AGP_FF_ALLOW_CLIENT, &priv->access_flags);
		priv->my_pid = current->pid;

		if (capable(CAP_SYS_RAWIO)) {
		if (capable(CAP_SYS_RAWIO))
		/* Root priv, can be controller */
		set_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags);
		}

		client = agp_find_client_by_pid(current->pid);

		if (client != NULL) {
		@@ -704,16 +704,10 @@ static int agp_open(struct inode inode, struct file file)
		file->private_data = (void *) priv;
		agp_insert_file_private(priv);
		DBG("private=%p, client=%p", priv, client);
		mutex_unlock(&(agp_fe.agp_mutex));
		unlock_kernel();
		return 0;

		err_out_nomem:
		rc = -ENOMEM;
		err_out:
		mutex_unlock(&(agp_fe.agp_mutex));
		unlock_kernel();
		return rc;

		return 0;
		}

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