[PATCH 0/9] UML vector network driver: Adjustments for three function implementations

[PATCH 0/9] UML vector network driver: Adjustments for three function implementations

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 16:06:16 +0100

Some update suggestions were taken into account
from static source code analysis.

Markus Elfring (9):
  Delete unnecessary code in user_init_raw_fds()
  Less checks in user_init_raw_fds() after error detection
  Adjust an error message in user_init_socket_fds()
  Delete an unnecessary check before kfree() in user_init_socket_fds()
  Delete two unnecessary checks before freeaddrinfo() in user_init_socket_fds()
  Less checks in user_init_socket_fds() after error detection
  Adjust an error message in user_init_tap_fds()
  Less checks in user_init_tap_fds() after error detection
  Delete an unnecessary variable initialisation in user_init_tap_fds()

 arch/um/drivers/vector_user.c | 133 +++++++++++++++++++-----------------------
 1 file changed, 60 insertions(+), 73 deletions(-)

-- 
2.16.2

[PATCH 1/9] um/drivers/vector_user: Delete unnecessary code in user_init_raw_fds()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 11:36:18 +0100

* One condition check could never be reached with a non-null pointer
  at the end of this function. Thus remove the corresponding statement.

* Delete an initialisation for the local variable "result"
  which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 4291f1a5d342..d6a6207d4061 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -211,7 +211,7 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
 	struct sockaddr_ll sock;
 	int err = -ENOMEM;
 	char *iface;
-	struct vector_fds *result = NULL;
+	struct vector_fds *result;
 	int optval = 1;
 
 
@@ -276,8 +276,6 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
 		os_close_file(rxfd);
 	if (txfd >= 0)
 		os_close_file(txfd);
-	if (result != NULL)
-		kfree(result);
 	return NULL;
 }
 
-- 
2.16.2

[PATCH 2/9] um/drivers/vector_user: Less checks in user_init_raw_fds() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 11:40:14 +0100

Up to two checks could be repeated by the user_init_raw_fds() function
during error handling even if the relevant properties can be determined
for the involved variables before by source code analysis.

* Adjust jump targets so that an extra check can be omitted at the end.

* Delete an initialisation for the local variable "rxfd"
  which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 61 ++++++++++++++++++++-----------------------
 1 file changed, 28 insertions(+), 33 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index d6a6207d4061..037cd85ee424 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -207,54 +207,46 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
 {
 	struct ifreq ifr;
-	int rxfd = -1, txfd = -1;
+	int rxfd, txfd = -1;
 	struct sockaddr_ll sock;
-	int err = -ENOMEM;
-	char *iface;
 	struct vector_fds *result;
 	int optval = 1;
+	int err;
+	char *iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
 
-
-	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
-	if (iface == NULL)
-		goto cleanup;
+	if (!iface) {
+		err = -ENOMEM;
+		goto report_failure;
+	}
 
 	rxfd = socket(AF_PACKET, SOCK_RAW, ETH_P_ALL);
-	if (rxfd == -1) {
-		err = -errno;
-		goto cleanup;
-	}
+	if (rxfd == -1)
+		goto set_error_code;
+
 	txfd = socket(AF_PACKET, SOCK_RAW, 0); /* Turn off RX on this fd */
-	if (txfd == -1) {
-		err = -errno;
-		goto cleanup;
-	}
+	if (txfd == -1)
+		goto set_error_code;
+
 	memset(&ifr, 0, sizeof(ifr));
 	strncpy((char *)&ifr.ifr_name, iface, sizeof(ifr.ifr_name) - 1);
-	if (ioctl(rxfd, SIOCGIFINDEX, (void *) &ifr) < 0) {
-		err = -errno;
-		goto cleanup;
-	}
+	if (ioctl(rxfd, SIOCGIFINDEX, (void *) &ifr) < 0)
+		goto set_error_code;
 
 	sock.sll_family = AF_PACKET;
 	sock.sll_protocol = htons(ETH_P_ALL);
 	sock.sll_ifindex = ifr.ifr_ifindex;
 
-	if (bind(rxfd,
-		(struct sockaddr *) &sock, sizeof(struct sockaddr_ll)) < 0) {
-		err = -errno;
-		goto cleanup;
-	}
+	if (bind(rxfd, (struct sockaddr *)&sock, sizeof(struct sockaddr_ll))
+	    < 0)
+		goto set_error_code;
 
 	sock.sll_family = AF_PACKET;
 	sock.sll_protocol = htons(ETH_P_IP);
 	sock.sll_ifindex = ifr.ifr_ifindex;
 
-	if (bind(txfd,
-		(struct sockaddr *) &sock, sizeof(struct sockaddr_ll)) < 0) {
-		err = -errno;
-		goto cleanup;
-	}
+	if (bind(txfd, (struct sockaddr *)&sock, sizeof(struct sockaddr_ll))
+	    < 0)
+		goto set_error_code;
 
 	if (setsockopt(txfd,
 		SOL_PACKET, PACKET_QDISC_BYPASS,
@@ -270,12 +262,15 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
 		result->remote_addr_size = 0;
 	}
 	return result;
-cleanup:
-	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
-	if (rxfd >= 0)
-		os_close_file(rxfd);
+
+set_error_code:
+	err = -errno;
+	os_close_file(rxfd);
+
 	if (txfd >= 0)
 		os_close_file(txfd);
+report_failure:
+	printk(UM_KERN_ERR "%s: init failed: %d", __func__, err);
 	return NULL;
 }
 
-- 
2.16.2

[PATCH 3/9] um/drivers/vector_user: Adjust an error message in user_init_socket_fds()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 13:53:08 +0100

* Adjust an error message at the end of this function.

* Delete the local variable "err" which became unnecessary
  with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 037cd85ee424..9cc4651990e3 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -305,7 +305,6 @@ bool uml_tap_enable_vnet_headers(int fd)
 
 static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 {
-	int err = -ENOMEM;
 	int fd = -1, gairet;
 	struct addrinfo srchints;
 	struct addrinfo dsthints;
@@ -419,7 +418,7 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 cleanup:
 	if (gairesult != NULL)
 		freeaddrinfo(gairesult);
-	printk(UM_KERN_ERR "user_init_socket: init failed, error %d", err);
+
 	if (fd >= 0)
 		os_close_file(fd);
 	if (result != NULL) {
@@ -427,6 +426,8 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 			kfree(result->remote_addr);
 		kfree(result);
 	}
+
+	printk(UM_KERN_ERR "%s: init failed: %d", __func__, -ENOMEM);
 	return NULL;
 }
 
-- 
2.16.2

[PATCH 4/9] um/drivers/vector_user: Delete an unnecessary check before kfree() in user_init_socket_fds()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 14:00:09 +0100

The kfree() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 9cc4651990e3..e831bd85cad4 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -422,8 +422,7 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 	if (fd >= 0)
 		os_close_file(fd);
 	if (result != NULL) {
-		if (result->remote_addr != NULL)
-			kfree(result->remote_addr);
+		kfree(result->remote_addr);
 		kfree(result);
 	}
 
-- 
2.16.2

[PATCH 5/9] um/drivers/vector_user: Delete two unnecessary checks before freeaddrinfo() in user_init_socket_fds()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 14:20:46 +0100

The implementation returns from this function if a null pointer
was detected in the local variable "gairesult". Thus the check
before two calls of the function "freeaddrinfo" is not needed.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index e831bd85cad4..2dee1e183387 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -384,9 +384,7 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 		goto cleanup;
 	}
 
-	if (gairesult != NULL)
-		freeaddrinfo(gairesult);
-
+	freeaddrinfo(gairesult);
 	gairesult = NULL;
 
 	gairet = getaddrinfo(dst, dstport, &dsthints, &gairesult);
@@ -416,8 +414,7 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 	freeaddrinfo(gairesult);
 	return result;
 cleanup:
-	if (gairesult != NULL)
-		freeaddrinfo(gairesult);
+	freeaddrinfo(gairesult);
 
 	if (fd >= 0)
 		os_close_file(fd);
-- 
2.16.2

[PATCH 6/9] um/drivers/vector_user: Less checks in user_init_socket_fds() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 14:56:38 +0100

Two checks could be repeated by the user_init_socket_fds() function
during error handling even if the relevant properties can be determined
for the involved variables before by source code analysis.

* Adjust jump targets.

* Delete two sanity checks and a call of the function "kfree"
  which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 2dee1e183387..4c265262a369 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -375,13 +375,13 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 			"socket_open : could not open socket, error = %d",
 			-errno
 		);
-		goto cleanup;
+		goto free_info;
 	}
 	if (bind(fd,
 		(struct sockaddr *) gairesult->ai_addr,
 		gairesult->ai_addrlen)) {
 		printk(UM_KERN_ERR L2TPV3_BIND_FAIL, errno);
-		goto cleanup;
+		goto close_file;
 	}
 
 	freeaddrinfo(gairesult);
@@ -403,7 +403,8 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 		result->remote_addr = uml_kmalloc(
 			gairesult->ai_addrlen, UM_GFP_KERNEL);
 		if (result->remote_addr == NULL)
-			goto cleanup;
+			goto free_result;
+
 		result->remote_addr_size = gairesult->ai_addrlen;
 		memcpy(
 			result->remote_addr,
@@ -413,16 +414,13 @@ static struct vector_fds *user_init_socket_fds(struct arglist *ifspec, int id)
 	}
 	freeaddrinfo(gairesult);
 	return result;
-cleanup:
-	freeaddrinfo(gairesult);
-
-	if (fd >= 0)
-		os_close_file(fd);
-	if (result != NULL) {
-		kfree(result->remote_addr);
-		kfree(result);
-	}
 
+free_result:
+	kfree(result);
+close_file:
+	os_close_file(fd);
+free_info:
+	freeaddrinfo(gairesult);
 	printk(UM_KERN_ERR "%s: init failed: %d", __func__, -ENOMEM);
 	return NULL;
 }
-- 
2.16.2

[PATCH 7/9] um/drivers/vector_user: Adjust an error message in user_init_tap_fds()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 15:10:05 +0100

Adjust an error message at the end of this function so that its name
will be automatically determined as a parameter.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 4c265262a369..5e78723c34d4 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -192,7 +192,6 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	}
 	return result;
 tap_cleanup:
-	printk(UM_KERN_ERR "user_init_tap: init failed, error %d", err);
 	if (result != NULL) {
 		if (result->rx_fd >= 0)
 			os_close_file(result->rx_fd);
@@ -200,6 +199,8 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 			os_close_file(result->tx_fd);
 		kfree(result);
 	}
+
+	printk(UM_KERN_ERR "%s: init failed: %d", __func__, err);
 	return NULL;
 }
 
-- 
2.16.2

[PATCH 8/9] um/drivers/vector_user: Less checks in user_init_tap_fds() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 15:43:31 +0100

Three checks could be repeated by the user_init_tap_fds() function
during error handling even if the relevant properties can be determined
for the involved variables before by source code analysis.

* Adjust jump targets.

* Delete three sanity checks and an initialisation (for the local
  variable "result") which became unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 5e78723c34d4..bd625034a0f0 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -123,18 +123,18 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	struct sockaddr_ll sock;
 	int err = -ENOMEM, offload;
 	char *iface;
-	struct vector_fds *result = NULL;
+	struct vector_fds *result;
 
 	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);
 	if (iface == NULL) {
 		printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");
-		goto tap_cleanup;
+		goto report_failure;
 	}
 
 	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
 	if (result == NULL) {
 		printk(UM_KERN_ERR "uml_tap: failed to allocate file descriptors\n");
-		goto tap_cleanup;
+		goto report_failure;
 	}
 	result->rx_fd = -1;
 	result->tx_fd = -1;
@@ -146,7 +146,7 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	fd = open(PATH_NET_TUN, O_RDWR);
 	if (fd < 0) {
 		printk(UM_KERN_ERR "uml_tap: failed to open tun device\n");
-		goto tap_cleanup;
+		goto free_result;
 	}
 	result->tx_fd = fd;
 	memset(&ifr, 0, sizeof(ifr));
@@ -156,7 +156,7 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	err = ioctl(fd, TUNSETIFF, (void *) &ifr);
 	if (err != 0) {
 		printk(UM_KERN_ERR "uml_tap: failed to select tap interface\n");
-		goto tap_cleanup;
+		goto close_tx_fd;
 	}
 
 	offload = TUN_F_CSUM | TUN_F_TSO4 | TUN_F_TSO6;
@@ -168,7 +168,7 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	if (fd == -1) {
 		printk(UM_KERN_ERR
 			"uml_tap: failed to create socket: %i\n", -errno);
-		goto tap_cleanup;
+		goto close_tx_fd;
 	}
 	result->rx_fd = fd;
 	memset(&ifr, 0, sizeof(ifr));
@@ -176,7 +176,7 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 	if (ioctl(fd, SIOCGIFINDEX, (void *) &ifr) < 0) {
 		printk(UM_KERN_ERR
 			"uml_tap: failed to set interface: %i\n", -errno);
-		goto tap_cleanup;
+		goto close_rx_fd;
 	}
 
 	sock.sll_family = AF_PACKET;
@@ -188,18 +188,17 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 		printk(UM_KERN_ERR
 			"user_init_tap: failed to bind raw pair, err %d\n",
 				-errno);
-		goto tap_cleanup;
+		goto close_rx_fd;
 	}
 	return result;
-tap_cleanup:
-	if (result != NULL) {
-		if (result->rx_fd >= 0)
-			os_close_file(result->rx_fd);
-		if (result->tx_fd >= 0)
-			os_close_file(result->tx_fd);
-		kfree(result);
-	}
 
+close_rx_fd:
+	os_close_file(result->rx_fd);
+close_tx_fd:
+	os_close_file(result->tx_fd);
+free_result:
+	kfree(result);
+report_failure:
 	printk(UM_KERN_ERR "%s: init failed: %d", __func__, err);
 	return NULL;
 }
-- 
2.16.2

[PATCH 9/9] um/drivers/vector_user: Delete an unnecessary variable initialisation in user_init_tap_fds()

[SF Markus Elfring]

From: Markus Elfring <elfring@users.sourceforge.net>
Date: Sun, 11 Mar 2018 15:50:29 +0100

The local variable "fd" will eventually be set to an appropriate value
a bit later. Thus omit the explicit initialisation at the beginning.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
 arch/um/drivers/vector_user.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index bd625034a0f0..3bd510eded58 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -119,9 +119,8 @@ struct arglist *uml_parse_vector_ifspec(char *arg)
 static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
 {
 	struct ifreq ifr;
-	int fd = -1;
 	struct sockaddr_ll sock;
-	int err = -ENOMEM, offload;
+	int err = -ENOMEM, fd, offload;
 	char *iface;
 	struct vector_fds *result;
 
-- 
2.16.2

Re: [PATCH 1/9] um/drivers/vector_user: Delete unnecessary code in user_init_raw_fds()

[Anton Ivanov]

Thanks, well noted.

It still does not fix it completely though.

Re-reading the code it will leak a fd if the malloc for result fails. 
That return result; there should be inside the conditional falling back 
to cleanup if the alloc fails.

A.


On 03/11/18 15:16, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@users.sourceforge.net>
> Date: Sun, 11 Mar 2018 11:36:18 +0100
>
> * One condition check could never be reached with a non-null pointer
>    at the end of this function. Thus remove the corresponding statement.
>
> * Delete an initialisation for the local variable "result"
>    which became unnecessary with this refactoring.
>
> Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
> ---
>   arch/um/drivers/vector_user.c | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> index 4291f1a5d342..d6a6207d4061 100644
> --- a/arch/um/drivers/vector_user.c
> +++ b/arch/um/drivers/vector_user.c
> @@ -211,7 +211,7 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
>   	struct sockaddr_ll sock;
>   	int err = -ENOMEM;
>   	char *iface;
> -	struct vector_fds *result = NULL;
> +	struct vector_fds *result;
>   	int optval = 1;
>   
>   
> @@ -276,8 +276,6 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
>   		os_close_file(rxfd);
>   	if (txfd >= 0)
>   		os_close_file(txfd);
> -	if (result != NULL)
> -		kfree(result);
>   	return NULL;
>   }
>   

-- 
Anton R. Ivanov

Cambridge Greys Limited, England and Wales company No 10273661
http://www.cambridgegreys.com/

Re: [2/9] um/drivers/vector_user: Less checks in user_init_raw_fds() after error detection

[SF Markus Elfring]

> +set_error_code:
> +	err = -errno;
> +	os_close_file(rxfd);

I have taken another look at this change idea.
Now I notice that I should have preserved a sanity check there.

	if (rxfd >= 0)
		os_close_file(rxfd);


Regards,
Markus

Re: [0/9] UML vector network driver: Adjustments for three function implementations

[SF Markus Elfring]

> Date: Sun, 11 Mar 2018 16:06:16 +0100
> 
> Some update suggestions were taken into account
> from static source code analysis.
…
>   Delete unnecessary code in user_init_raw_fds()
>   Less checks in user_init_raw_fds() after error detection
>   Adjust an error message in user_init_socket_fds()
>   Delete an unnecessary check before kfree() in user_init_socket_fds()
>   Delete two unnecessary checks before freeaddrinfo() in user_init_socket_fds()
>   Less checks in user_init_socket_fds() after error detection
>   Adjust an error message in user_init_tap_fds()
>   Less checks in user_init_tap_fds() after error detection
>   Delete an unnecessary variable initialisation in user_init_tap_fds()
…

Would you like to pick any idea up from this patch series?
	
Regards,
Markus