Hi there,
John W. Linville schrieb:
> From: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> --- /dev/null
> +++ b/net/wireless/core.c
> @@ -0,0 +1,209 @@
> +/*
> + * This is the linux wireless configuration interface.
> + *
> + * Copyright 2006, 2007 Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/if.h>
> +#include <linux/module.h>
> +#include <linux/err.h>
> +#include <linux/mutex.h>
> +#include <linux/list.h>
> +#include <linux/nl80211.h>
> +#include <linux/debugfs.h>
> +#include <linux/notifier.h>
> +#include <linux/device.h>
> +#include <net/genetlink.h>
> +#include <net/cfg80211.h>
> +#include <net/wireless.h>
> +#include "core.h"
> +#include "sysfs.h"
> +
> +/* name for sysfs, %d is appended */
> +#define PHY_NAME "phy"
> +
> +MODULE_AUTHOR("Johannes Berg");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("wireless configuration support");
> +
> +/* RCU might be appropriate here since we usually
> + * only read the list, and that can happen quite
> + * often because we need to do it for each command */
> +LIST_HEAD(cfg80211_drv_list);
> +DEFINE_MUTEX(cfg80211_drv_mutex);
> +static int wiphy_counter;
> +
> +/* for debugfs */
> +static struct dentry *ieee80211_debugfs_dir;
> +
> +/* exported functions */
> +
> +struct wiphy *wiphy_new(struct cfg80211_ops *ops, int sizeof_priv)
> +{
> + struct cfg80211_registered_device *drv;
> + int alloc_size;
> +
> + alloc_size = sizeof(*drv) + sizeof_priv;
> +
> + drv = kzalloc(alloc_size, GFP_KERNEL);
> + if (!drv)
> + return NULL;
> +
> + drv->ops = ops;
> +
> + mutex_lock(&cfg80211_drv_mutex);
> +
> + if (unlikely(wiphy_counter<0)) {
mutex_unlock(&cfg80211_drv_mutex);
> + /* ugh, wrapped! */
> + kfree(drv);
> + return NULL;
> + }
> + drv->idx = wiphy_counter;
> +
> + /* give it a proper name */
> + snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE,
> + PHY_NAME "%d", drv->idx);
> +
> + /* now increase counter for the next time */
> + wiphy_counter++;
> + mutex_unlock(&cfg80211_drv_mutex);
Since drv and its contents are not visible to anyone yet,
I suggest the following code flow for that:
mutex_lock(&cfg80211_drv_mutex);
drv->idx = wiphy_counter;
/* increase counter for the next time, if id didn't wrap */
if (drv->idx >= 0)
wiphy_counter++;
mutex_unlock(&cfg80211_drv_mutex);
if (drv->idx < 0) {
kfree(drv);
return NULL;
}
/* give it a proper name */
snprintf(drv->wiphy.dev.bus_id, BUS_ID_SIZE,
PHY_NAME "%d", drv->idx);
[enqueue to all lists here]
Rest looks good so far.
Regards
Ingo Oeser
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