Commit 4ded3bfe authored by Johannes Berg's avatar Johannes Berg
Browse files

wifi: mac80211: use wiphy locked debugfs for sdata/link 



The debugfs files for netdevs (sdata) and links are removed
with the wiphy mutex held, which may deadlock. Use the new
wiphy locked debugfs to avoid that.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 3d529cd1

net/mac80211/debugfs_netdev.c

+105 −45
Original line number Diff line number Diff line
@@ -22,88 +22,148 @@ 
#include "debugfs_netdev.h"

#include "driver-ops.h"



struct ieee80211_if_read_sdata_data {

	ssize_t (*format)(const struct ieee80211_sub_if_data *, char *, int);

	struct ieee80211_sub_if_data *sdata;

};



static ssize_t ieee80211_if_read_sdata_handler(struct wiphy *wiphy,

					       struct file *file,

					       char *buf,

					       size_t bufsize,

					       void *data)

{

	struct ieee80211_if_read_sdata_data *d = data;



	return d->format(d->sdata, buf, bufsize);

}



static ssize_t ieee80211_if_read_sdata(

	struct ieee80211_sub_if_data *sdata,

	struct file *file,

	char __user *userbuf,

	size_t count, loff_t *ppos,

	ssize_t (*format)(const struct ieee80211_sub_if_data *sdata, char *, int))

{

	struct ieee80211_sub_if_data *sdata = file->private_data;

	struct ieee80211_if_read_sdata_data data = {

		.format = format,

		.sdata = sdata,

	};

	char buf[200];

	ssize_t ret = -EINVAL;



	wiphy_lock(sdata->local->hw.wiphy);

	ret = (*format)(sdata, buf, sizeof(buf));

	wiphy_unlock(sdata->local->hw.wiphy);

	return wiphy_locked_debugfs_read(sdata->local->hw.wiphy,

					 file, buf, sizeof(buf),

					 userbuf, count, ppos,

					 ieee80211_if_read_sdata_handler,

					 &data);

}



	if (ret >= 0)

		ret = simple_read_from_buffer(userbuf, count, ppos, buf, ret);

struct ieee80211_if_write_sdata_data {

	ssize_t (*write)(struct ieee80211_sub_if_data *, const char *, int);

	struct ieee80211_sub_if_data *sdata;

};



	return ret;

static ssize_t ieee80211_if_write_sdata_handler(struct wiphy *wiphy,

						struct file *file,

						char *buf,

						size_t count,

						void *data)

{

	struct ieee80211_if_write_sdata_data *d = data;



	return d->write(d->sdata, buf, count);

}



static ssize_t ieee80211_if_write_sdata(

	struct ieee80211_sub_if_data *sdata,

	struct file *file,

	const char __user *userbuf,

	size_t count, loff_t *ppos,

	ssize_t (*write)(struct ieee80211_sub_if_data *sdata, const char *, int))

{

	struct ieee80211_sub_if_data *sdata = file->private_data;

	struct ieee80211_if_write_sdata_data data = {

		.write = write,

		.sdata = sdata,

	};

	char buf[64];

	ssize_t ret;



	if (count >= sizeof(buf))

		return -E2BIG;

	return wiphy_locked_debugfs_write(sdata->local->hw.wiphy,

					  file, buf, sizeof(buf),

					  userbuf, count,

					  ieee80211_if_write_sdata_handler,

					  &data);

}



	if (copy_from_user(buf, userbuf, count))

		return -EFAULT;

	buf[count] = '\0';

struct ieee80211_if_read_link_data {

	ssize_t (*format)(const struct ieee80211_link_data *, char *, int);

	struct ieee80211_link_data *link;

};



	wiphy_lock(sdata->local->hw.wiphy);

	ret = (*write)(sdata, buf, count);

	wiphy_unlock(sdata->local->hw.wiphy);

static ssize_t ieee80211_if_read_link_handler(struct wiphy *wiphy,

					      struct file *file,

					      char *buf,

					      size_t bufsize,

					      void *data)

{

	struct ieee80211_if_read_link_data *d = data;



	return ret;

	return d->format(d->link, buf, bufsize);

}



static ssize_t ieee80211_if_read_link(

	struct ieee80211_link_data *link,

	struct file *file,

	char __user *userbuf,

	size_t count, loff_t *ppos,

	ssize_t (*format)(const struct ieee80211_link_data *link, char *, int))

{

	struct ieee80211_link_data *link = file->private_data;

	struct ieee80211_if_read_link_data data = {

		.format = format,

		.link = link,

	};

	char buf[200];

	ssize_t ret = -EINVAL;



	wiphy_lock(link->sdata->local->hw.wiphy);

	ret = (*format)(link, buf, sizeof(buf));

	wiphy_unlock(link->sdata->local->hw.wiphy);

	return wiphy_locked_debugfs_read(link->sdata->local->hw.wiphy,

					 file, buf, sizeof(buf),

					 userbuf, count, ppos,

					 ieee80211_if_read_link_handler,

					 &data);

}



	if (ret >= 0)

		ret = simple_read_from_buffer(userbuf, count, ppos, buf, ret);

struct ieee80211_if_write_link_data {

	ssize_t (*write)(struct ieee80211_link_data *, const char *, int);

	struct ieee80211_link_data *link;

};



	return ret;

static ssize_t ieee80211_if_write_link_handler(struct wiphy *wiphy,

					       struct file *file,

					       char *buf,

					       size_t count,

					       void *data)

{

	struct ieee80211_if_write_sdata_data *d = data;



	return d->write(d->sdata, buf, count);

}



static ssize_t ieee80211_if_write_link(

	struct ieee80211_link_data *link,

	struct file *file,

	const char __user *userbuf,

	size_t count, loff_t *ppos,

	ssize_t (*write)(struct ieee80211_link_data *link, const char *, int))

{

	struct ieee80211_link_data *link = file->private_data;

	struct ieee80211_if_write_link_data data = {

		.write = write,

		.link = link,

	};

	char buf[64];

	ssize_t ret;



	if (count >= sizeof(buf))

		return -E2BIG;



	if (copy_from_user(buf, userbuf, count))

		return -EFAULT;

	buf[count] = '\0';



	wiphy_lock(link->sdata->local->hw.wiphy);

	ret = (*write)(link, buf, count);

	wiphy_unlock(link->sdata->local->hw.wiphy);



	return ret;

	return wiphy_locked_debugfs_write(link->sdata->local->hw.wiphy,

					  file, buf, sizeof(buf),

					  userbuf, count,

					  ieee80211_if_write_link_handler,

					  &data);

}



#define IEEE80211_IF_FMT(name, type, field, format_string)		\
@@ -173,7 +233,7 @@ static ssize_t ieee80211_if_read_##name(struct file *file, \ 
					char __user *userbuf,		\

					size_t count, loff_t *ppos)	\

{									\

	return ieee80211_if_read_sdata(file->private_data,		\

	return ieee80211_if_read_sdata(file,				\

				       userbuf, count, ppos,		\

				       ieee80211_if_fmt_##name);	\

}
@@ -183,7 +243,7 @@ static ssize_t ieee80211_if_write_##name(struct file *file, \ 
					 const char __user *userbuf,	\

					 size_t count, loff_t *ppos)	\

{									\

	return ieee80211_if_write_sdata(file->private_data, userbuf,	\

	return ieee80211_if_write_sdata(file, userbuf,			\

					count, ppos,			\

					ieee80211_if_parse_##name);	\

}
@@ -211,7 +271,7 @@ static ssize_t ieee80211_if_read_##name(struct file *file, \ 
					char __user *userbuf,		\

					size_t count, loff_t *ppos)	\

{									\

	return ieee80211_if_read_link(file->private_data,		\

	return ieee80211_if_read_link(file,				\

				      userbuf, count, ppos,		\

				      ieee80211_if_fmt_##name);	\

}
@@ -221,7 +281,7 @@ static ssize_t ieee80211_if_write_##name(struct file *file, \ 
					 const char __user *userbuf,	\

					 size_t count, loff_t *ppos)	\

{									\

	return ieee80211_if_write_link(file->private_data, userbuf,	\

	return ieee80211_if_write_link(file, userbuf,			\

				       count, ppos,			\

				       ieee80211_if_parse_##name);	\

}