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authorArnd Bergmann <arnd@arndb.de>2016-01-26 23:05:31 +0100
committerJohannes Berg <johannes.berg@intel.com>2016-02-24 09:04:28 +0100
commit0ef049dc1167fe834d0ad5d63f89eddc5c70f6e4 (patch)
treea6c3d5acd8a3f163271b0b867f3d7d3dfb238adb /net/mac80211
parent89f774e6c41efdcede9d4b37867af5aabcc835d5 (diff)
downloadop-kernel-dev-0ef049dc1167fe834d0ad5d63f89eddc5c70f6e4.zip
op-kernel-dev-0ef049dc1167fe834d0ad5d63f89eddc5c70f6e4.tar.gz
mac80211: avoid excessive stack usage in sta_info
When CONFIG_OPTIMIZE_INLINING is set, the sta_info_insert_finish function consumes more stack than normally, exceeding the 1024 byte limit on ARM: net/mac80211/sta_info.c: In function 'sta_info_insert_finish': net/mac80211/sta_info.c:561:1: error: the frame size of 1080 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] It turns out that there are two functions that put a 'struct station_info' on the stack: __sta_info_destroy_part2 and sta_info_insert_finish, and this structure alone requires up to 792 bytes. Hoping that both are called rarely enough, this replaces the on-stack structure with a dynamic allocation, which unfortunately requires some suboptimal error handling for out-of-memory. The __sta_info_destroy_part2 function is actually affected by the stack usage twice because it calls cfg80211_del_sta_sinfo(), which has another instance of struct station_info on its stack. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 98b6218388e3 ("mac80211/cfg80211: add station events") Fixes: 6f7a8d26e266 ("mac80211: send statistics with delete station event") Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211')
-rw-r--r--net/mac80211/sta_info.c24
1 files changed, 16 insertions, 8 deletions
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 7e007cf..b28e7a2 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -498,11 +498,17 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
{
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
- struct station_info sinfo;
+ struct station_info *sinfo;
int err = 0;
lockdep_assert_held(&local->sta_mtx);
+ sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL);
+ if (!sinfo) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+
/* check if STA exists already */
if (sta_info_get_bss(sdata, sta->sta.addr)) {
err = -EEXIST;
@@ -533,10 +539,9 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU)
ieee80211_sta_debugfs_add(sta);
rate_control_add_sta_debugfs(sta);
- memset(&sinfo, 0, sizeof(sinfo));
- sinfo.filled = 0;
- sinfo.generation = local->sta_generation;
- cfg80211_new_sta(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL);
+ sinfo->generation = local->sta_generation;
+ cfg80211_new_sta(sdata->dev, sta->sta.addr, sinfo, GFP_KERNEL);
+ kfree(sinfo);
sta_dbg(sdata, "Inserted STA %pM\n", sta->sta.addr);
@@ -897,7 +902,7 @@ static void __sta_info_destroy_part2(struct sta_info *sta)
{
struct ieee80211_local *local = sta->local;
struct ieee80211_sub_if_data *sdata = sta->sdata;
- struct station_info sinfo = {};
+ struct station_info *sinfo;
int ret;
/*
@@ -935,8 +940,11 @@ static void __sta_info_destroy_part2(struct sta_info *sta)
sta_dbg(sdata, "Removed STA %pM\n", sta->sta.addr);
- sta_set_sinfo(sta, &sinfo);
- cfg80211_del_sta_sinfo(sdata->dev, sta->sta.addr, &sinfo, GFP_KERNEL);
+ sinfo = kzalloc(sizeof(*sinfo), GFP_KERNEL);
+ if (sinfo)
+ sta_set_sinfo(sta, sinfo);
+ cfg80211_del_sta_sinfo(sdata->dev, sta->sta.addr, sinfo, GFP_KERNEL);
+ kfree(sinfo);
rate_control_remove_sta_debugfs(sta);
ieee80211_sta_debugfs_remove(sta);
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