diff mbox series

[net-next,v4] NFC: nci: Allow to create multiple virtual nci devices

Message ID 20221115100017.787929-1-dvyukov@google.com (mailing list archive)
State Accepted
Commit b2e44aac91b25abbed57d785089c4b7af926a7bd
Delegated to: Netdev Maintainers
Headers show
Series [net-next,v4] NFC: nci: Allow to create multiple virtual nci devices | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 3 of 3 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch warning CHECK: Alignment should match open parenthesis CHECK: struct mutex definition without comment
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Dmitry Vyukov Nov. 15, 2022, 10 a.m. UTC 
The current virtual nci driver is great for testing and fuzzing.
But it allows to create at most one "global" device which does not allow
to run parallel tests and harms fuzzing isolation and reproducibility.
Restructure the driver to allow creation of multiple independent devices.
This should be backwards compatible for existing tests.

Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: Bongsu Jeon <bongsu.jeon@samsung.com>
Cc: Bongsu Jeon <bongsu.jeon@samsung.com>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org

---
Changes in v4:
 - add Reviewed-by tag
 - rebase onto currnet net-next

Changes in v3:
 - free vdev in virtual_ncidev_close()

Changes in v2:
 - check return value of skb_clone()
 - rebase onto currnet net-next
---
 drivers/nfc/virtual_ncidev.c | 147 +++++++++++++++++------------------
 1 file changed, 71 insertions(+), 76 deletions(-)


base-commit: f12ed9c04804eec4f1819097a0fd0b4800adac2f

Comments

patchwork-bot+netdevbpf@kernel.org Nov. 17, 2022, 1 p.m. UTC | #1 
Hello:

This patch was applied to netdev/net-next.git (master)
by Paolo Abeni <pabeni@redhat.com>:

On Tue, 15 Nov 2022 11:00:17 +0100 you wrote:
> The current virtual nci driver is great for testing and fuzzing.
> But it allows to create at most one "global" device which does not allow
> to run parallel tests and harms fuzzing isolation and reproducibility.
> Restructure the driver to allow creation of multiple independent devices.
> This should be backwards compatible for existing tests.
> 
> Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
> Reviewed-by: Bongsu Jeon <bongsu.jeon@samsung.com>
> Cc: Bongsu Jeon <bongsu.jeon@samsung.com>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: netdev@vger.kernel.org
> 
> [...]

Here is the summary with links:
  - [net-next,v4] NFC: nci: Allow to create multiple virtual nci devices
    https://git.kernel.org/netdev/net-next/c/b2e44aac91b2

You are awesome, thank you!
diff mbox series

Patch

diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c
index 85c06dbb2c449..bb76c7c7cc822 100644
--- a/drivers/nfc/virtual_ncidev.c
+++ b/drivers/nfc/virtual_ncidev.c
@@ -13,12 +13,6 @@ 
 #include <linux/wait.h>
 #include <net/nfc/nci_core.h>
 
-enum virtual_ncidev_mode {
-	virtual_ncidev_enabled,
-	virtual_ncidev_disabled,
-	virtual_ncidev_disabling,
-};
-
 #define IOCTL_GET_NCIDEV_IDX    0
 #define VIRTUAL_NFC_PROTOCOLS	(NFC_PROTO_JEWEL_MASK | \
 				 NFC_PROTO_MIFARE_MASK | \
@@ -27,12 +21,12 @@  enum virtual_ncidev_mode {
 				 NFC_PROTO_ISO14443_B_MASK | \
 				 NFC_PROTO_ISO15693_MASK)
 
-static enum virtual_ncidev_mode state;
-static DECLARE_WAIT_QUEUE_HEAD(wq);
-static struct miscdevice miscdev;
-static struct sk_buff *send_buff;
-static struct nci_dev *ndev;
-static DEFINE_MUTEX(nci_mutex);
+struct virtual_nci_dev {
+	struct nci_dev *ndev;
+	struct mutex mtx;
+	struct sk_buff *send_buff;
+	struct wait_queue_head wq;
+};
 
 static int virtual_nci_open(struct nci_dev *ndev)
 {
@@ -41,31 +35,34 @@  static int virtual_nci_open(struct nci_dev *ndev)
 
 static int virtual_nci_close(struct nci_dev *ndev)
 {
-	mutex_lock(&nci_mutex);
-	kfree_skb(send_buff);
-	send_buff = NULL;
-	mutex_unlock(&nci_mutex);
+	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
+
+	mutex_lock(&vdev->mtx);
+	kfree_skb(vdev->send_buff);
+	vdev->send_buff = NULL;
+	mutex_unlock(&vdev->mtx);
 
 	return 0;
 }
 
 static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb)
 {
-	mutex_lock(&nci_mutex);
-	if (state != virtual_ncidev_enabled) {
-		mutex_unlock(&nci_mutex);
+	struct virtual_nci_dev *vdev = nci_get_drvdata(ndev);
+
+	mutex_lock(&vdev->mtx);
+	if (vdev->send_buff) {
+		mutex_unlock(&vdev->mtx);
 		kfree_skb(skb);
-		return 0;
+		return -1;
 	}
-
-	if (send_buff) {
-		mutex_unlock(&nci_mutex);
+	vdev->send_buff = skb_copy(skb, GFP_KERNEL);
+	if (!vdev->send_buff) {
+		mutex_unlock(&vdev->mtx);
 		kfree_skb(skb);
 		return -1;
 	}
-	send_buff = skb_copy(skb, GFP_KERNEL);
-	mutex_unlock(&nci_mutex);
-	wake_up_interruptible(&wq);
+	mutex_unlock(&vdev->mtx);
+	wake_up_interruptible(&vdev->wq);
 	consume_skb(skb);
 
 	return 0;
@@ -80,29 +77,30 @@  static const struct nci_ops virtual_nci_ops = {
 static ssize_t virtual_ncidev_read(struct file *file, char __user *buf,
 				   size_t count, loff_t *ppos)
 {
+	struct virtual_nci_dev *vdev = file->private_data;
 	size_t actual_len;
 
-	mutex_lock(&nci_mutex);
-	while (!send_buff) {
-		mutex_unlock(&nci_mutex);
-		if (wait_event_interruptible(wq, send_buff))
+	mutex_lock(&vdev->mtx);
+	while (!vdev->send_buff) {
+		mutex_unlock(&vdev->mtx);
+		if (wait_event_interruptible(vdev->wq, vdev->send_buff))
 			return -EFAULT;
-		mutex_lock(&nci_mutex);
+		mutex_lock(&vdev->mtx);
 	}
 
-	actual_len = min_t(size_t, count, send_buff->len);
+	actual_len = min_t(size_t, count, vdev->send_buff->len);
 
-	if (copy_to_user(buf, send_buff->data, actual_len)) {
-		mutex_unlock(&nci_mutex);
+	if (copy_to_user(buf, vdev->send_buff->data, actual_len)) {
+		mutex_unlock(&vdev->mtx);
 		return -EFAULT;
 	}
 
-	skb_pull(send_buff, actual_len);
-	if (send_buff->len == 0) {
-		consume_skb(send_buff);
-		send_buff = NULL;
+	skb_pull(vdev->send_buff, actual_len);
+	if (vdev->send_buff->len == 0) {
+		consume_skb(vdev->send_buff);
+		vdev->send_buff = NULL;
 	}
-	mutex_unlock(&nci_mutex);
+	mutex_unlock(&vdev->mtx);
 
 	return actual_len;
 }
@@ -111,6 +109,7 @@  static ssize_t virtual_ncidev_write(struct file *file,
 				    const char __user *buf,
 				    size_t count, loff_t *ppos)
 {
+	struct virtual_nci_dev *vdev = file->private_data;
 	struct sk_buff *skb;
 
 	skb = alloc_skb(count, GFP_KERNEL);
@@ -122,63 +121,58 @@  static ssize_t virtual_ncidev_write(struct file *file,
 		return -EFAULT;
 	}
 
-	nci_recv_frame(ndev, skb);
+	nci_recv_frame(vdev->ndev, skb);
 	return count;
 }
 
 static int virtual_ncidev_open(struct inode *inode, struct file *file)
 {
 	int ret = 0;
+	struct virtual_nci_dev *vdev;
 
-	mutex_lock(&nci_mutex);
-	if (state != virtual_ncidev_disabled) {
-		mutex_unlock(&nci_mutex);
-		return -EBUSY;
-	}
-
-	ndev = nci_allocate_device(&virtual_nci_ops, VIRTUAL_NFC_PROTOCOLS,
-				   0, 0);
-	if (!ndev) {
-		mutex_unlock(&nci_mutex);
+	vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
+	if (!vdev)
+		return -ENOMEM;
+	vdev->ndev = nci_allocate_device(&virtual_nci_ops,
+		VIRTUAL_NFC_PROTOCOLS, 0, 0);
+	if (!vdev->ndev) {
+		kfree(vdev);
 		return -ENOMEM;
 	}
 
-	ret = nci_register_device(ndev);
+	mutex_init(&vdev->mtx);
+	init_waitqueue_head(&vdev->wq);
+	file->private_data = vdev;
+	nci_set_drvdata(vdev->ndev, vdev);
+
+	ret = nci_register_device(vdev->ndev);
 	if (ret < 0) {
-		nci_free_device(ndev);
-		mutex_unlock(&nci_mutex);
+		nci_free_device(vdev->ndev);
+		mutex_destroy(&vdev->mtx);
+		kfree(vdev);
 		return ret;
 	}
-	state = virtual_ncidev_enabled;
-	mutex_unlock(&nci_mutex);
 
 	return 0;
 }
 
 static int virtual_ncidev_close(struct inode *inode, struct file *file)
 {
-	mutex_lock(&nci_mutex);
-
-	if (state == virtual_ncidev_enabled) {
-		state = virtual_ncidev_disabling;
-		mutex_unlock(&nci_mutex);
+	struct virtual_nci_dev *vdev = file->private_data;
 
-		nci_unregister_device(ndev);
-		nci_free_device(ndev);
-
-		mutex_lock(&nci_mutex);
-	}
-
-	state = virtual_ncidev_disabled;
-	mutex_unlock(&nci_mutex);
+	nci_unregister_device(vdev->ndev);
+	nci_free_device(vdev->ndev);
+	mutex_destroy(&vdev->mtx);
+	kfree(vdev);
 
 	return 0;
 }
 
-static long virtual_ncidev_ioctl(struct file *flip, unsigned int cmd,
+static long virtual_ncidev_ioctl(struct file *file, unsigned int cmd,
 				 unsigned long arg)
 {
-	const struct nfc_dev *nfc_dev = ndev->nfc_dev;
+	struct virtual_nci_dev *vdev = file->private_data;
+	const struct nfc_dev *nfc_dev = vdev->ndev->nfc_dev;
 	void __user *p = (void __user *)arg;
 
 	if (cmd != IOCTL_GET_NCIDEV_IDX)
@@ -199,14 +193,15 @@  static const struct file_operations virtual_ncidev_fops = {
 	.unlocked_ioctl = virtual_ncidev_ioctl
 };
 
+static struct miscdevice miscdev = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "virtual_nci",
+	.fops = &virtual_ncidev_fops,
+	.mode = 0600,
+};
+
 static int __init virtual_ncidev_init(void)
 {
-	state = virtual_ncidev_disabled;
-	miscdev.minor = MISC_DYNAMIC_MINOR;
-	miscdev.name = "virtual_nci";
-	miscdev.fops = &virtual_ncidev_fops;
-	miscdev.mode = 0600;
-
 	return misc_register(&miscdev);
 }