diff options
Diffstat (limited to 'net/mac80211/scan.c')
| -rw-r--r-- | net/mac80211/scan.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index bc061f629674..b822dce97867 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -345,6 +345,13 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, if (local->scan_req) return -EBUSY; + if (!list_empty(&local->work_list)) { + /* wait for the work to finish/time out */ + local->scan_req = req; + local->scan_sdata = sdata; + return 0; + } + if (local->ops->hw_scan) { u8 *ies; @@ -364,29 +371,33 @@ static int __ieee80211_start_scan(struct ieee80211_sub_if_data *sdata, local->hw_scan_req->ie = ies; local->hw_scan_band = 0; + + /* + * After allocating local->hw_scan_req, we must + * go through until ieee80211_prep_hw_scan(), so + * anything that might be changed here and leave + * this function early must not go after this + * allocation. + */ } local->scan_req = req; local->scan_sdata = sdata; - if (!list_empty(&local->work_list)) { - /* wait for the work to finish/time out */ - return 0; - } - if (local->ops->hw_scan) __set_bit(SCAN_HW_SCANNING, &local->scanning); else __set_bit(SCAN_SW_SCANNING, &local->scanning); + /* * Kicking off the scan need not be protected, * only the scan variable stuff, since now * local->scan_req is assigned and other callers * will abort their scan attempts. * - * This avoids getting a scan_mtx -> iflist_mtx - * dependency, so that the scan completed calls - * have more locking freedom. + * This avoids too many locking dependencies + * so that the scan completed calls have more + * locking freedom. */ ieee80211_recalc_idle(local); |