[PATCH] vdev: fix name comparison in find_vdev

[PATCH] vdev: fix name comparison in find_vdev

[Nachiketa Prachanda]

Use strcmp to compare device names as the strncmp in original code
causes find_vdev to return -EEXIST  for names that are prefix
of another. The creation of interfaces fails unpredictably based
on the order of their creation. An easy way hit this bug is to create
eth_vhost1 after eth_vhost11.

Signed-off-by: Nachiketa Prachanda <nprachan@vyatta.att-mail.com>

Fixes: dda987315ca2 ("vdev: make virtual bus use its device struct")
Cc: jblunck@infradead.org
Cc: stable@dpdk.org
---
 drivers/bus/vdev/vdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index e4bc724..7eae319 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -188,7 +188,7 @@ find_vdev(const char *name)
 	TAILQ_FOREACH(dev, &vdev_device_list, next) {
 		const char *devname = rte_vdev_device_name(dev);
 
-		if (!strncmp(devname, name, strlen(name)))
+		if (!strcmp(devname, name))
 			return dev;
 	}
 
-- 
2.7.4

Re: [PATCH] vdev: fix name comparison in find_vdev

[Tan, Jianfeng]

Hi,


On 3/10/2018 6:28 AM, Nachiketa Prachanda wrote:
> Use strcmp to compare device names as the strncmp in original code
> causes find_vdev to return -EEXIST  for names that are prefix
> of another. The creation of interfaces fails unpredictably based
> on the order of their creation. An easy way hit this bug is to create
> eth_vhost1 after eth_vhost11.
>
> Signed-off-by: Nachiketa Prachanda <nprachan@vyatta.att-mail.com>

Except a nit bellow:

Acked-by: Jianfeng Tan <jianfeng.tan@intel.com>

>
> Fixes: dda987315ca2 ("vdev: make virtual bus use its device struct")
> Cc: jblunck@infradead.org
> Cc: stable@dpdk.org

AFAIK, we usually put above line before Signed-off-by.

> ---
>   drivers/bus/vdev/vdev.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
> index e4bc724..7eae319 100644
> --- a/drivers/bus/vdev/vdev.c
> +++ b/drivers/bus/vdev/vdev.c
> @@ -188,7 +188,7 @@ find_vdev(const char *name)
>   	TAILQ_FOREACH(dev, &vdev_device_list, next) {
>   		const char *devname = rte_vdev_device_name(dev);
>   
> -		if (!strncmp(devname, name, strlen(name)))
> +		if (!strcmp(devname, name))
>   			return dev;
>   	}
>   

[PATCH v2] vdev: fix name comparison in find_vdev

[Nachiketa Prachanda]

Use strcmp to compare device names as the strncmp in original code
causes find_vdev to return -EEXIST  for names that are prefix
of another. The creation of interfaces fails unpredictably based
on the order of their creation. An easy way hit this bug is to create
eth_vhost1 after eth_vhost11.

Fixes: dda987315ca2 ("vdev: make virtual bus use its device struct")
Cc: jblunck@infradead.org
Cc: stable@dpdk.org

Signed-off-by: Nachiketa Prachanda <nprachan@vyatta.att-mail.com>
Acked-by: Jianfeng Tan <jianfeng.tan@intel.com>
---

Notes:
     V2: No changes
    
     Move Signed-off-by line after Fixes.

 drivers/bus/vdev/vdev.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/bus/vdev/vdev.c b/drivers/bus/vdev/vdev.c
index e4bc724..7eae319 100644
--- a/drivers/bus/vdev/vdev.c
+++ b/drivers/bus/vdev/vdev.c
@@ -188,7 +188,7 @@ find_vdev(const char *name)
 	TAILQ_FOREACH(dev, &vdev_device_list, next) {
 		const char *devname = rte_vdev_device_name(dev);
 
-		if (!strncmp(devname, name, strlen(name)))
+		if (!strcmp(devname, name))
 			return dev;
 	}
 
-- 
2.7.4

Re: [dpdk-stable] [PATCH v2] vdev: fix name comparison in find_vdev

[Thomas Monjalon]

12/03/2018 17:54, Nachiketa Prachanda:
> Use strcmp to compare device names as the strncmp in original code
> causes find_vdev to return -EEXIST  for names that are prefix
> of another. The creation of interfaces fails unpredictably based
> on the order of their creation. An easy way hit this bug is to create
> eth_vhost1 after eth_vhost11.
> 
> Fixes: dda987315ca2 ("vdev: make virtual bus use its device struct")
> Cc: jblunck@infradead.org
> Cc: stable@dpdk.org
> 
> Signed-off-by: Nachiketa Prachanda <nprachan@vyatta.att-mail.com>
> Acked-by: Jianfeng Tan <jianfeng.tan@intel.com>

Applied, thanks