Re: [PATCH 2.6.20] kobject net ifindex + rename

From: Jarek Poplawski
Date: Wed Feb 28 2007 - 04:31:23 EST


On 28-02-2007 02:27, Jean Tourrilhes wrote:
> Hi all,
...
> Patch for 2.6.20 is attached. The patch was tested on a system
> running the hotplug scripts, and on another system running udev.
>
> Have fun...
>
> Jean
>
> Signed-off-by: Jean Tourrilhes <jt@xxxxxxxxxx>
>
> ---------------------------------------------------------
...
> diff -u -p linux/net/core/net-sysfs.j1.c linux/net/core/net-sysfs.c
> --- linux/net/core/net-sysfs.j1.c 2007-02-27 15:01:08.000000000 -0800
> +++ linux/net/core/net-sysfs.c 2007-02-27 15:06:49.000000000 -0800
> @@ -412,6 +412,17 @@ static int netdev_uevent(struct class_de
> if ((size <= 0) || (i >= num_envp))
> return -ENOMEM;
>
> + /* pass ifindex to uevent.
> + * ifindex is useful as it won't change (interface name may change)
> + * and is what RtNetlink uses natively. */
> + envp[i++] = buf;
> + n = snprintf(buf, size, "IFINDEX=%d", dev->ifindex) + 1;
> + buf += n;
> + size -= n;
> +
> + if ((size <= 0) || (i >= num_envp))

Btw.:
1. if size == 10 and snprintf returns 9 (without NULL)
then n == 10 (with NULL), so isn't it enough (here and above):

if ((size < 0) || (i >= num_envp))

2. shouldn't there be (here and above):

envp[--i] = NULL;

> + return -ENOMEM;
> +
> envp[i] = NULL;
> return 0;
> }
...
> diff -u -p linux/drivers/base/class.j1.c linux/drivers/base/class.c
> --- linux/drivers/base/class.j1.c 2007-02-26 18:38:10.000000000 -0800
> +++ linux/drivers/base/class.c 2007-02-27 15:52:37.000000000 -0800
> @@ -841,6 +841,8 @@ int class_device_rename(struct class_dev
> {
> int error = 0;
> char *old_class_name = NULL, *new_class_name = NULL;
> + char *devname_string = NULL;
> + char *envp[2];
>
> class_dev = class_device_get(class_dev);
> if (!class_dev)
> @@ -849,6 +851,15 @@ int class_device_rename(struct class_dev
> pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
> new_name);
>
> + devname_string = kmalloc(strlen(class_dev->class_id) + 15, GFP_KERNEL);
> + if (!devname_string) {
> + class_device_put(class_dev);
> + return -ENOMEM;
> + }
> + sprintf(devname_string, "INTERFACE_OLD=%s", class_dev->class_id);
> + envp[0] = devname_string;
> + envp[1] = NULL;
> +
> #ifdef CONFIG_SYSFS_DEPRECATED
> if (class_dev->dev)
> old_class_name = make_class_name(class_dev->class->name,
> @@ -868,8 +879,16 @@ int class_device_rename(struct class_dev
> sysfs_remove_link(&class_dev->dev->kobj, old_class_name);
> }
> #endif
> +
> + /* This function is only used for network interface.
> + * Some hotplug package track interfaces by their name and
> + * therefore want to know when the name is changed by the user. */
> + if(!error)
> + kobject_uevent_env(&class_dev->kobj, KOBJ_RENAME, envp);
> +
> class_device_put(class_dev);
>
> + kfree(devname_string);

Maybe I miss something, but it seems kobject_uevent_env copies
pointers from envp instead of buffers' contents.

Regards,
Jarek P.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/