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Код Задачи Пакеты Проекты Релизы Вики Активность

regulatory: use RCU to protect last_request 

This will allow making freq_reg_info() lock-free.

Acked-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2012-12-06 16:29:25 +01:00
Родитель 458f4f9e96
Коммит c492db370c
2 изменённых файлов: 111 добавлений и 90 удалений
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2
include/net/regulatory.h
Просмотреть файл

@ -36,6 +36,7 @@ enum environment_cap {
/**
* struct regulatory_request - used to keep track of regulatory requests
*
* @rcu_head: RCU head struct used to free the request
* @wiphy_idx: this is set if this request's initiator is
* %REGDOM_SET_BY_COUNTRY_IE or %REGDOM_SET_BY_DRIVER. This
* can be used by the wireless core to deal with conflicts
@ -73,6 +74,7 @@ enum environment_cap {
* @list: used to insert into the reg_requests_list linked list
*/
struct regulatory_request {
struct rcu_head rcu_head;
int wiphy_idx;
enum nl80211_reg_initiator initiator;
enum nl80211_user_reg_hint_type user_reg_hint_type;

199
net/wireless/reg.c
Просмотреть файл

@ -82,7 +82,8 @@ static struct regulatory_request core_request_world = {
};
/* Receipt of information from last regulatory request */
static struct regulatory_request *last_request = &core_request_world;
static struct regulatory_request __rcu *last_request =
(void __rcu *)&core_request_world;
/* To trigger userspace events */
static struct platform_device *reg_pdev;
@ -102,7 +103,7 @@ const struct ieee80211_regdomain __rcu *cfg80211_regdomain;
* Protects static reg.c components:
* - cfg80211_regdomain (if not used with RCU)
* - cfg80211_world_regdom
* - last_request
* - last_request (if not used with RCU)
* - reg_num_devs_support_basehint
*/
static DEFINE_MUTEX(reg_mutex);
@ -137,6 +138,12 @@ static void rcu_free_regdom(const struct ieee80211_regdomain *r)
kfree_rcu((struct ieee80211_regdomain *)r, rcu_head);
}
static struct regulatory_request *get_last_request(void)
{
return rcu_dereference_protected(last_request,
lockdep_is_held(&reg_mutex));
}
/* Used to queue up regulatory hints */
static LIST_HEAD(reg_requests_list);
static spinlock_t reg_requests_lock;
@ -206,6 +213,7 @@ static void reset_regdomains(bool full_reset,
const struct ieee80211_regdomain *new_regdom)
{
const struct ieee80211_regdomain *r;
struct regulatory_request *lr;
assert_reg_lock();
@ -228,9 +236,10 @@ static void reset_regdomains(bool full_reset,
if (!full_reset)
return;
if (last_request != &core_request_world)
kfree(last_request);
last_request = &core_request_world;
lr = get_last_request();
if (lr != &core_request_world && lr)
kfree_rcu(lr, rcu_head);
rcu_assign_pointer(last_request, &core_request_world);
}
/*
@ -239,9 +248,11 @@ static void reset_regdomains(bool full_reset,
*/
static void update_world_regdomain(const struct ieee80211_regdomain *rd)
{
WARN_ON(!last_request);
struct regulatory_request *lr;
assert_reg_lock();
lr = get_last_request();
WARN_ON(!lr);
reset_regdomains(false, rd);
@ -448,15 +459,12 @@ static int call_crda(const char *alpha2)
static bool reg_is_valid_request(const char *alpha2)
{
assert_reg_lock();
struct regulatory_request *lr = get_last_request();
if (!last_request)
if (!lr || lr->processed)
return false;
if (last_request->processed)
return false;
return alpha2_equal(last_request->alpha2, alpha2);
return alpha2_equal(lr->alpha2, alpha2);
}
/* Sanity check on a regulatory rule */
@ -746,15 +754,14 @@ int freq_reg_info(struct wiphy *wiphy, u32 center_freq,
const struct ieee80211_reg_rule **reg_rule)
{
const struct ieee80211_regdomain *regd;
assert_reg_lock();
struct regulatory_request *lr = get_last_request();
/*
* Follow the driver's regulatory domain, if present, unless a country
* IE has been processed or a user wants to help complaince further
*/
if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
last_request->initiator != NL80211_REGDOM_SET_BY_USER &&
if (lr->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
lr->initiator != NL80211_REGDOM_SET_BY_USER &&
wiphy->regd)
regd = get_wiphy_regdom(wiphy);
else
@ -828,8 +835,9 @@ static void handle_channel(struct wiphy *wiphy,
const struct ieee80211_power_rule *power_rule = NULL;
const struct ieee80211_freq_range *freq_range = NULL;
struct wiphy *request_wiphy = NULL;
struct regulatory_request *lr = get_last_request();
request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
flags = chan->orig_flags;
@ -862,7 +870,7 @@ static void handle_channel(struct wiphy *wiphy,
if (freq_range->max_bandwidth_khz < MHZ_TO_KHZ(40))
bw_flags = IEEE80211_CHAN_NO_HT40;
if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
request_wiphy && request_wiphy == wiphy &&
request_wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY) {
/*
@ -927,7 +935,7 @@ bool reg_last_request_cell_base(void)
bool val;
mutex_lock(&reg_mutex);
val = reg_request_cell_base(last_request);
val = reg_request_cell_base(get_last_request());
mutex_unlock(&reg_mutex);
return val;
@ -938,10 +946,12 @@ bool reg_last_request_cell_base(void)
static enum reg_request_treatment
reg_ignore_cell_hint(struct regulatory_request *pending_request)
{
struct regulatory_request *lr = get_last_request();
if (!reg_num_devs_support_basehint)
return REG_REQ_IGNORE;
if (reg_request_cell_base(last_request) &&
if (reg_request_cell_base(lr) &&
!regdom_changes(pending_request->alpha2))
return REG_REQ_ALREADY_SET;
@ -969,7 +979,9 @@ static bool reg_dev_ignore_cell_hint(struct wiphy *wiphy)
static bool ignore_reg_update(struct wiphy *wiphy,
enum nl80211_reg_initiator initiator)
{
if (!last_request) {
struct regulatory_request *lr = get_last_request();
if (!lr) {
REG_DBG_PRINT("Ignoring regulatory request %s since last_request is not set\n",
reg_initiator_name(initiator));
return true;
@ -988,13 +1000,13 @@ static bool ignore_reg_update(struct wiphy *wiphy,
*/
if (wiphy->flags & WIPHY_FLAG_STRICT_REGULATORY && !wiphy->regd &&
initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
!is_world_regdom(last_request->alpha2)) {
!is_world_regdom(lr->alpha2)) {
REG_DBG_PRINT("Ignoring regulatory request %s since the driver requires its own regulatory domain to be set first\n",
reg_initiator_name(initiator));
return true;
}
if (reg_request_cell_base(last_request))
if (reg_request_cell_base(lr))
return reg_dev_ignore_cell_hint(wiphy);
return false;
@ -1080,12 +1092,12 @@ static bool reg_is_world_roaming(struct wiphy *wiphy)
{
const struct ieee80211_regdomain *cr = get_cfg80211_regdom();
const struct ieee80211_regdomain *wr = get_wiphy_regdom(wiphy);
struct regulatory_request *lr = get_last_request();
if (is_world_regdom(cr->alpha2) || (wr && is_world_regdom(wr->alpha2)))
return true;
if (last_request &&
last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
if (lr && lr->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE &&
wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY)
return true;
@ -1184,13 +1196,12 @@ static void wiphy_update_regulatory(struct wiphy *wiphy,
enum nl80211_reg_initiator initiator)
{
enum ieee80211_band band;
assert_reg_lock();
struct regulatory_request *lr = get_last_request();
if (ignore_reg_update(wiphy, initiator))
return;
last_request->dfs_region = get_cfg80211_regdom()->dfs_region;
lr->dfs_region = get_cfg80211_regdom()->dfs_region;
for (band = 0; band < IEEE80211_NUM_BANDS; band++)
handle_band(wiphy, initiator, wiphy->bands[band]);
@ -1199,7 +1210,7 @@ static void wiphy_update_regulatory(struct wiphy *wiphy,
reg_process_ht_flags(wiphy);
if (wiphy->reg_notifier)
wiphy->reg_notifier(wiphy, last_request);
wiphy->reg_notifier(wiphy, lr);
}
static void update_all_wiphy_regulatory(enum nl80211_reg_initiator initiator)
@ -1220,7 +1231,7 @@ static void update_all_wiphy_regulatory(enum nl80211_reg_initiator initiator)
if (initiator == NL80211_REGDOM_SET_BY_CORE &&
wiphy->flags & WIPHY_FLAG_CUSTOM_REGULATORY &&
wiphy->reg_notifier)
wiphy->reg_notifier(wiphy, last_request);
wiphy->reg_notifier(wiphy, get_last_request());
}
}
@ -1300,28 +1311,28 @@ get_reg_request_treatment(struct wiphy *wiphy,
struct regulatory_request *pending_request)
{
struct wiphy *last_wiphy = NULL;
struct regulatory_request *lr = get_last_request();
/* All initial requests are respected */
if (!last_request)
if (!lr)
return REG_REQ_OK;
switch (pending_request->initiator) {
case NL80211_REGDOM_SET_BY_CORE:
return REG_REQ_OK;
case NL80211_REGDOM_SET_BY_COUNTRY_IE:
if (reg_request_cell_base(last_request)) {
if (reg_request_cell_base(lr)) {
/* Trust a Cell base station over the AP's country IE */
if (regdom_changes(pending_request->alpha2))
return REG_REQ_IGNORE;
return REG_REQ_ALREADY_SET;
}
last_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
last_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
if (unlikely(!is_an_alpha2(pending_request->alpha2)))
return -EINVAL;
if (last_request->initiator ==
NL80211_REGDOM_SET_BY_COUNTRY_IE) {
if (lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
if (last_wiphy != wiphy) {
/*
* Two cards with two APs claiming different
@ -1343,7 +1354,7 @@ get_reg_request_treatment(struct wiphy *wiphy,
}
return 0;
case NL80211_REGDOM_SET_BY_DRIVER:
if (last_request->initiator == NL80211_REGDOM_SET_BY_CORE) {
if (lr->initiator == NL80211_REGDOM_SET_BY_CORE) {
if (regdom_changes(pending_request->alpha2))
return REG_REQ_OK;
return REG_REQ_ALREADY_SET;
@ -1354,7 +1365,7 @@ get_reg_request_treatment(struct wiphy *wiphy,
* back in or if you add a new device for which the previously
* loaded card also agrees on the regulatory domain.
*/
if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER &&
!regdom_changes(pending_request->alpha2))
return REG_REQ_ALREADY_SET;
@ -1363,26 +1374,26 @@ get_reg_request_treatment(struct wiphy *wiphy,
if (reg_request_cell_base(pending_request))
return reg_ignore_cell_hint(pending_request);
if (reg_request_cell_base(last_request))
if (reg_request_cell_base(lr))
return REG_REQ_IGNORE;
if (last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)
if (lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)
return REG_REQ_INTERSECT;
/*
* If the user knows better the user should set the regdom
* to their country before the IE is picked up
*/
if (last_request->initiator == NL80211_REGDOM_SET_BY_USER &&
last_request->intersect)
if (lr->initiator == NL80211_REGDOM_SET_BY_USER &&
lr->intersect)
return REG_REQ_IGNORE;
/*
* Process user requests only after previous user/driver/core
* requests have been processed
*/
if ((last_request->initiator == NL80211_REGDOM_SET_BY_CORE ||
last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
last_request->initiator == NL80211_REGDOM_SET_BY_USER) &&
regdom_changes(last_request->alpha2))
if ((lr->initiator == NL80211_REGDOM_SET_BY_CORE ||
lr->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
lr->initiator == NL80211_REGDOM_SET_BY_USER) &&
regdom_changes(lr->alpha2))
return REG_REQ_IGNORE;
if (!regdom_changes(pending_request->alpha2))
@ -1397,15 +1408,16 @@ get_reg_request_treatment(struct wiphy *wiphy,
static void reg_set_request_processed(void)
{
bool need_more_processing = false;
struct regulatory_request *lr = get_last_request();
last_request->processed = true;
lr->processed = true;
spin_lock(&reg_requests_lock);
if (!list_empty(&reg_requests_list))
need_more_processing = true;
spin_unlock(&reg_requests_lock);
if (last_request->initiator == NL80211_REGDOM_SET_BY_USER)
if (lr->initiator == NL80211_REGDOM_SET_BY_USER)
cancel_delayed_work(&reg_timeout);
if (need_more_processing)
@ -1432,6 +1444,7 @@ __regulatory_hint(struct wiphy *wiphy,
const struct ieee80211_regdomain *regd;
bool intersect = false;
enum reg_request_treatment treatment;
struct regulatory_request *lr;
treatment = get_reg_request_treatment(wiphy, pending_request);
@ -1472,18 +1485,20 @@ __regulatory_hint(struct wiphy *wiphy,
}
new_request:
if (last_request != &core_request_world)
kfree(last_request);
lr = get_last_request();
if (lr != &core_request_world && lr)
kfree_rcu(lr, rcu_head);
last_request = pending_request;
last_request->intersect = intersect;
last_request->processed = false;
pending_request->intersect = intersect;
pending_request->processed = false;
rcu_assign_pointer(last_request, pending_request);
lr = pending_request;
pending_request = NULL;
if (last_request->initiator == NL80211_REGDOM_SET_BY_USER) {
user_alpha2[0] = last_request->alpha2[0];
user_alpha2[1] = last_request->alpha2[1];
if (lr->initiator == NL80211_REGDOM_SET_BY_USER) {
user_alpha2[0] = lr->alpha2[0];
user_alpha2[1] = lr->alpha2[1];
}
/* When r == REG_REQ_INTERSECT we do need to call CRDA */
@ -1494,13 +1509,13 @@ new_request:
* inform userspace we have processed the request
*/
if (treatment == REG_REQ_ALREADY_SET) {
nl80211_send_reg_change_event(last_request);
nl80211_send_reg_change_event(lr);
reg_set_request_processed();
}
return treatment;
}
if (call_crda(last_request->alpha2))
if (call_crda(lr->alpha2))
return REG_REQ_IGNORE;
return REG_REQ_OK;
}
@ -1543,13 +1558,14 @@ static void reg_process_hint(struct regulatory_request *reg_request,
*/
static void reg_process_pending_hints(void)
{
struct regulatory_request *reg_request;
struct regulatory_request *reg_request, *lr;
mutex_lock(&cfg80211_mutex);
mutex_lock(&reg_mutex);
lr = get_last_request();
/* When last_request->processed becomes true this will be rescheduled */
if (last_request && !last_request->processed) {
if (lr && !lr->processed) {
REG_DBG_PRINT("Pending regulatory request, waiting for it to be processed...\n");
goto out;
}
@ -1702,11 +1718,12 @@ void regulatory_hint_11d(struct wiphy *wiphy, enum ieee80211_band band,
{
char alpha2[2];
enum environment_cap env = ENVIRON_ANY;
struct regulatory_request *request;
struct regulatory_request *request, *lr;
mutex_lock(&reg_mutex);
lr = get_last_request();
if (unlikely(!last_request))
if (unlikely(!lr))
goto out;
/* IE len must be evenly divisible by 2 */
@ -1729,8 +1746,8 @@ void regulatory_hint_11d(struct wiphy *wiphy, enum ieee80211_band band,
* We leave conflict resolution to the workqueue, where can hold
* cfg80211_mutex.
*/
if (last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
last_request->wiphy_idx != WIPHY_IDX_INVALID)
if (lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE &&
lr->wiphy_idx != WIPHY_IDX_INVALID)
goto out;
request = kzalloc(sizeof(struct regulatory_request), GFP_KERNEL);
@ -2021,13 +2038,12 @@ static void print_dfs_region(u8 dfs_region)
static void print_regdomain(const struct ieee80211_regdomain *rd)
{
struct regulatory_request *lr = get_last_request();
if (is_intersected_alpha2(rd->alpha2)) {
if (last_request->initiator ==
NL80211_REGDOM_SET_BY_COUNTRY_IE) {
if (lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE) {
struct cfg80211_registered_device *rdev;
rdev = cfg80211_rdev_by_wiphy_idx(
last_request->wiphy_idx);
rdev = cfg80211_rdev_by_wiphy_idx(lr->wiphy_idx);
if (rdev) {
pr_info("Current regulatory domain updated by AP to: %c%c\n",
rdev->country_ie_alpha2[0],
@ -2042,7 +2058,7 @@ static void print_regdomain(const struct ieee80211_regdomain *rd)
if (is_unknown_alpha2(rd->alpha2))
pr_info("Regulatory domain changed to driver built-in settings (unknown country)\n");
else {
if (reg_request_cell_base(last_request))
if (reg_request_cell_base(lr))
pr_info("Regulatory domain changed to country: %c%c by Cell Station\n",
rd->alpha2[0], rd->alpha2[1]);
else
@ -2067,11 +2083,10 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
const struct ieee80211_regdomain *regd;
const struct ieee80211_regdomain *intersected_rd = NULL;
struct wiphy *request_wiphy;
struct regulatory_request *lr = get_last_request();
/* Some basic sanity checks first */
assert_reg_lock();
if (!reg_is_valid_request(rd->alpha2))
return -EINVAL;
@ -2089,7 +2104,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
* rd is non static (it means CRDA was present and was used last)
* and the pending request came in from a country IE
*/
if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
if (lr->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
/*
* If someone else asked us to change the rd lets only bother
* checking if the alpha2 changes if CRDA was already called
@ -2111,16 +2126,16 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
return -EINVAL;
}
request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
if (!request_wiphy &&
(last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)) {
(lr->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
lr->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)) {
schedule_delayed_work(&reg_timeout, 0);
return -ENODEV;
}
if (!last_request->intersect) {
if (last_request->initiator != NL80211_REGDOM_SET_BY_DRIVER) {
if (!lr->intersect) {
if (lr->initiator != NL80211_REGDOM_SET_BY_DRIVER) {
reset_regdomains(false, rd);
return 0;
}
@ -2148,7 +2163,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
/* Intersection requires a bit more work */
if (last_request->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
if (lr->initiator != NL80211_REGDOM_SET_BY_COUNTRY_IE) {
intersected_rd = regdom_intersect(rd, get_cfg80211_regdom());
if (!intersected_rd)
return -EINVAL;
@ -2158,7 +2173,7 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
* However if a driver requested this specific regulatory
* domain we keep it for its private use
*/
if (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER)
if (lr->initiator == NL80211_REGDOM_SET_BY_DRIVER)
rcu_assign_pointer(request_wiphy->regd, rd);
else
kfree(rd);
@ -2181,9 +2196,11 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
*/
int set_regdom(const struct ieee80211_regdomain *rd)
{
struct regulatory_request *lr;
int r;
mutex_lock(&reg_mutex);
lr = get_last_request();
/* Note that this doesn't update the wiphys, this is done below */
r = __set_regdom(rd);
@ -2196,18 +2213,17 @@ int set_regdom(const struct ieee80211_regdomain *rd)
}
/* This would make this whole thing pointless */
if (WARN_ON(!last_request->intersect &&
rd != get_cfg80211_regdom())) {
if (WARN_ON(!lr->intersect && rd != get_cfg80211_regdom())) {
r = -EINVAL;
goto out;
}
/* update all wiphys now with the new established regulatory domain */
update_all_wiphy_regulatory(last_request->initiator);
update_all_wiphy_regulatory(lr->initiator);
print_regdomain(get_cfg80211_regdom());
nl80211_send_reg_change_event(last_request);
nl80211_send_reg_change_event(lr);
reg_set_request_processed();
@ -2220,10 +2236,11 @@ int set_regdom(const struct ieee80211_regdomain *rd)
#ifdef CONFIG_HOTPLUG
int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
if (last_request && !last_request->processed) {
struct regulatory_request *lr = get_last_request();
if (lr && !lr->processed) {
if (add_uevent_var(env, "COUNTRY=%c%c",
last_request->alpha2[0],
last_request->alpha2[1]))
lr->alpha2[0], lr->alpha2[1]))
return -ENOMEM;
}
@ -2252,8 +2269,10 @@ void wiphy_regulatory_register(struct wiphy *wiphy)
void wiphy_regulatory_deregister(struct wiphy *wiphy)
{
struct wiphy *request_wiphy = NULL;
struct regulatory_request *lr;
mutex_lock(&reg_mutex);
lr = get_last_request();
if (!reg_dev_ignore_cell_hint(wiphy))
reg_num_devs_support_basehint--;
@ -2261,14 +2280,14 @@ void wiphy_regulatory_deregister(struct wiphy *wiphy)
rcu_free_regdom(get_wiphy_regdom(wiphy));
rcu_assign_pointer(wiphy->regd, NULL);
if (last_request)
request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
if (lr)
request_wiphy = wiphy_idx_to_wiphy(lr->wiphy_idx);
if (!request_wiphy || request_wiphy != wiphy)
goto out;
last_request->wiphy_idx = WIPHY_IDX_INVALID;
last_request->country_ie_env = ENVIRON_ANY;
lr->wiphy_idx = WIPHY_IDX_INVALID;
lr->country_ie_env = ENVIRON_ANY;
out:
mutex_unlock(&reg_mutex);
}