diff options
| author | Johannes Berg <johannes.berg@intel.com> | 2021-01-22 18:19:43 +0300 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2021-01-26 13:55:50 +0300 |
| commit | a05829a7222e9d10c416dd2dbbf3929fe6646b89 (patch) | |
| tree | 87d6d74e56da555ca3976d42fa94589f917b23ce /net/wireless/debugfs.c | |
| parent | 2fe8ef106238b274c505c480ecf00d8765abf0d8 (diff) | |
| download | linux-a05829a7222e9d10c416dd2dbbf3929fe6646b89.tar.xz | |
cfg80211: avoid holding the RTNL when calling the driver
Currently, _everything_ in cfg80211 holds the RTNL, and if you
have a slow USB device (or a few) you can get some bad lock
contention on that.
Fix that by re-adding a mutex to each wiphy/rdev as we had at
some point, so we have locking for the wireless_dev lists and
all the other things in there, and also so that drivers still
don't have to worry too much about it (they still won't get
parallel calls for a single device).
Then, we can restrict the RTNL to a few cases where we add or
remove interfaces and really need the added protection. Some
of the global list management still also uses the RTNL, since
we need to have it anyway for netdev management, but we only
hold the RTNL for very short periods of time here.
Link: https://lore.kernel.org/r/20210122161942.81df9f5e047a.I4a8e1a60b18863ea8c5e6d3a0faeafb2d45b2f40@changeid
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> [marvell driver issues]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/debugfs.c')
| -rw-r--r-- | net/wireless/debugfs.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/net/wireless/debugfs.c b/net/wireless/debugfs.c index 76b845f68ac8..aab43469a2f0 100644 --- a/net/wireless/debugfs.c +++ b/net/wireless/debugfs.c @@ -73,8 +73,6 @@ static ssize_t ht40allow_map_read(struct file *file, if (!buf) return -ENOMEM; - rtnl_lock(); - for (band = 0; band < NUM_NL80211_BANDS; band++) { sband = wiphy->bands[band]; if (!sband) @@ -84,8 +82,6 @@ static ssize_t ht40allow_map_read(struct file *file, buf, buf_size, offset); } - rtnl_unlock(); - r = simple_read_from_buffer(user_buf, count, ppos, buf, offset); kfree(buf); |