From 68d0021fe7231eec0fb84cd110cf62a6e782b72d Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Tue, 24 Sep 2024 21:28:04 +0200 Subject: wifi: cfg80211: Add wiphy_delayed_work_pending() Add wiphy_delayed_work_pending() to check if any delayed work timer is pending, that can be used to be sure that wiphy_delayed_work_queue() won't postpone an already pending delayed work. Signed-off-by: Remi Pommarel Link: https://patch.msgid.link/20240924192805.13859-2-repk@triplefau.lt [fix return value kernel-doc] Signed-off-by: Johannes Berg --- include/net/cfg80211.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'include') diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 69ec1eb41a09..941dc62f3027 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -6129,6 +6129,50 @@ void wiphy_delayed_work_cancel(struct wiphy *wiphy, void wiphy_delayed_work_flush(struct wiphy *wiphy, struct wiphy_delayed_work *dwork); +/** + * wiphy_delayed_work_pending - Find out whether a wiphy delayable + * work item is currently pending. + * + * @wiphy: the wiphy, for debug purposes + * @dwork: the delayed work in question + * + * Return: true if timer is pending, false otherwise + * + * How wiphy_delayed_work_queue() works is by setting a timer which + * when it expires calls wiphy_work_queue() to queue the wiphy work. + * Because wiphy_delayed_work_queue() uses mod_timer(), if it is + * called twice and the second call happens before the first call + * deadline, the work will rescheduled for the second deadline and + * won't run before that. + * + * wiphy_delayed_work_pending() can be used to detect if calling + * wiphy_work_delayed_work_queue() would start a new work schedule + * or delayed a previous one. As seen below it cannot be used to + * detect precisely if the work has finished to execute nor if it + * is currently executing. + * + * CPU0 CPU1 + * wiphy_delayed_work_queue(wk) + * mod_timer(wk->timer) + * wiphy_delayed_work_pending(wk) -> true + * + * [...] + * expire_timers(wk->timer) + * detach_timer(wk->timer) + * wiphy_delayed_work_pending(wk) -> false + * wk->timer->function() | + * wiphy_work_queue(wk) | delayed work pending + * list_add_tail() | returns false but + * queue_work(cfg80211_wiphy_work) | wk->func() has not + * | been run yet + * [...] | + * cfg80211_wiphy_work() | + * wk->func() V + * + */ +bool wiphy_delayed_work_pending(struct wiphy *wiphy, + struct wiphy_delayed_work *dwork); + /** * enum ieee80211_ap_reg_power - regulatory power for an Access Point * -- cgit v1.2.3 From 57be3d3562ca4aa62b8047bc681028cc402af8ce Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Fri, 4 Oct 2024 14:14:44 -0600 Subject: wifi: radiotap: Avoid -Wflex-array-member-not-at-end warnings -Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. So, in order to avoid ending up with a flexible-array member in the middle of multiple other structs, we use the `__struct_group()` helper to create a new tagged `struct ieee80211_radiotap_header_fixed`. This structure groups together all the members of the flexible `struct ieee80211_radiotap_header` except the flexible array. As a result, the array is effectively separated from the rest of the members without modifying the memory layout of the flexible structure. We then change the type of the middle struct members currently causing trouble from `struct ieee80211_radiotap_header` to `struct ieee80211_radiotap_header_fixed`. We also want to ensure that in case new members need to be added to the flexible structure, they are always included within the newly created tagged struct. For this, we use `static_assert()`. This ensures that the memory layout for both the flexible structure and the new tagged struct is the same after any changes. This approach avoids having to implement `struct ieee80211_radiotap_header_fixed` as a completely separate structure, thus preventing having to maintain two independent but basically identical structures, closing the door to potential bugs in the future. So, with these changes, fix the following warnings: drivers/net/wireless/ath/wil6210/txrx.c:309:50: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/intel/ipw2x00/ipw2100.c:2521:50: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/intel/ipw2x00/ipw2200.h:1146:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/intel/ipw2x00/libipw.h:595:36: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/marvell/libertas/radiotap.h:34:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/marvell/libertas/radiotap.h:5:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/microchip/wilc1000/mon.c:10:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/microchip/wilc1000/mon.c:15:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/virtual/mac80211_hwsim.c:758:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/net/wireless/virtual/mac80211_hwsim.c:767:42: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Signed-off-by: Gustavo A. R. Silva Link: https://patch.msgid.link/ZwBMtBZKcrzwU7l4@kspp Signed-off-by: Johannes Berg --- include/net/ieee80211_radiotap.h | 43 ++++++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 19 deletions(-) (limited to 'include') diff --git a/include/net/ieee80211_radiotap.h b/include/net/ieee80211_radiotap.h index 91762faecc13..1458d3695005 100644 --- a/include/net/ieee80211_radiotap.h +++ b/include/net/ieee80211_radiotap.h @@ -24,25 +24,27 @@ * struct ieee80211_radiotap_header - base radiotap header */ struct ieee80211_radiotap_header { - /** - * @it_version: radiotap version, always 0 - */ - uint8_t it_version; - - /** - * @it_pad: padding (or alignment) - */ - uint8_t it_pad; - - /** - * @it_len: overall radiotap header length - */ - __le16 it_len; - - /** - * @it_present: (first) present word - */ - __le32 it_present; + __struct_group(ieee80211_radiotap_header_fixed, hdr, __packed, + /** + * @it_version: radiotap version, always 0 + */ + uint8_t it_version; + + /** + * @it_pad: padding (or alignment) + */ + uint8_t it_pad; + + /** + * @it_len: overall radiotap header length + */ + __le16 it_len; + + /** + * @it_present: (first) present word + */ + __le32 it_present; + ); /** * @it_optional: all remaining presence bitmaps @@ -50,6 +52,9 @@ struct ieee80211_radiotap_header { __le32 it_optional[]; } __packed; +static_assert(offsetof(struct ieee80211_radiotap_header, it_optional) == sizeof(struct ieee80211_radiotap_header_fixed), + "struct member likely outside of __struct_group()"); + /* version is always 0 */ #define PKTHDR_RADIOTAP_VERSION 0 -- cgit v1.2.3