Skip to content

Commit

Permalink
wifi: mac80211: use wiphy locked debugfs for sdata/link
Browse files Browse the repository at this point in the history 
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: Johannes Berg <johannes.berg@intel.com>
  • Loading branch information
Johannes Berg committed Nov 27, 2023
1 parent 3d529cd commit 4ded3bf
Showing 1 changed file with 105 additions and 45 deletions.
150 changes: 105 additions & 45 deletions net/mac80211/debugfs_netdev.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
};

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 ret;
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);
}

struct ieee80211_if_write_link_data {
ssize_t (*write)(struct ieee80211_link_data *, const char *, int);
struct ieee80211_link_data *link;
};

if (ret >= 0)
ret = simple_read_from_buffer(userbuf, count, ppos, buf, 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 ret;
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) \
Expand Down Expand Up @@ -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); \
}
Expand All @@ -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); \
}
Expand Down Expand Up @@ -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); \
}
Expand All @@ -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); \
}
Expand Down

0 comments on commit 4ded3bf

Please sign in to comment.