From: Eliad Peller <[email protected]> If drv_start() fails during hw_restart, all the running interfaces are being closed/stopped, which results in drv_stop() being called, although the driver was never started successfully.
This might cause drivers to perform operations on uninitialized memory (as they assume it was initialized on drv_start) Consider the local->started flag, and call the driver's stop() op only if drv_start() succeeded before. Move drv_start() and drv_stop() to driver-ops.c, as they are no longer simple wrappers. Signed-off-by: Eliad Peller <[email protected]> Signed-off-by: Emmanuel Grumbach <[email protected]> --- net/mac80211/driver-ops.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ net/mac80211/driver-ops.h | 32 ++------------------------------ net/mac80211/util.c | 3 ++- 3 files changed, 48 insertions(+), 31 deletions(-) diff --git a/net/mac80211/driver-ops.c b/net/mac80211/driver-ops.c index a1d5431..9f97343 100644 --- a/net/mac80211/driver-ops.c +++ b/net/mac80211/driver-ops.c @@ -1,4 +1,6 @@ /* + * Copyright 2015 Intel Deutschland GmbH + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. @@ -8,6 +10,48 @@ #include "trace.h" #include "driver-ops.h" +int drv_start(struct ieee80211_local *local) +{ + int ret; + + might_sleep(); + + if (WARN_ON(local->started)) + return -EALREADY; + + trace_drv_start(local); + local->started = true; + /* allow rx frames */ + smp_mb(); + ret = local->ops->start(&local->hw); + trace_drv_return_int(local, ret); + + if (ret) + local->started = false; + + return ret; +} + +void drv_stop(struct ieee80211_local *local) +{ + might_sleep(); + + if (WARN_ON(!local->started)) + return; + + trace_drv_stop(local); + local->ops->stop(&local->hw); + trace_drv_return_void(local); + + /* sync away all work on the tasklet before clearing started */ + tasklet_disable(&local->tasklet); + tasklet_enable(&local->tasklet); + + barrier(); + + local->started = false; +} + int drv_add_interface(struct ieee80211_local *local, struct ieee80211_sub_if_data *sdata) { diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h index 3098709..f82cfab 100644 --- a/net/mac80211/driver-ops.h +++ b/net/mac80211/driver-ops.h @@ -66,36 +66,8 @@ static inline int drv_get_et_sset_count(struct ieee80211_sub_if_data *sdata, return rv; } -static inline int drv_start(struct ieee80211_local *local) -{ - int ret; - - might_sleep(); - - trace_drv_start(local); - local->started = true; - smp_mb(); - ret = local->ops->start(&local->hw); - trace_drv_return_int(local, ret); - return ret; -} - -static inline void drv_stop(struct ieee80211_local *local) -{ - might_sleep(); - - trace_drv_stop(local); - local->ops->stop(&local->hw); - trace_drv_return_void(local); - - /* sync away all work on the tasklet before clearing started */ - tasklet_disable(&local->tasklet); - tasklet_enable(&local->tasklet); - - barrier(); - - local->started = false; -} +int drv_start(struct ieee80211_local *local); +void drv_stop(struct ieee80211_local *local); #ifdef CONFIG_PM static inline int drv_suspend(struct ieee80211_local *local, diff --git a/net/mac80211/util.c b/net/mac80211/util.c index e936acd..c51ff91 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1665,7 +1665,6 @@ static void ieee80211_handle_reconfig_failure(struct ieee80211_local *local) local->resuming = false; local->suspended = false; - local->started = false; local->in_reconfig = false; /* scheduled scan clearly can't be running any more, but tell @@ -1764,6 +1763,8 @@ int ieee80211_reconfig(struct ieee80211_local *local) if (suspended && local->in_reconfig && !reconfig_due_to_wowlan) cancel_work_sync(&local->restart_work); + local->started = false; + /* * Upon resume hardware can sometimes be goofy due to * various platform / driver / bus issues, so restarting -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
