This patch adds missing rcu_assign_pointer()/rcu_dereference() to used rcu
pointers. There was already a previous commit c5d99d2b35da ("ieee802154:
hwsim: fix rcu address annotation"), but there was more which was
pointed out on my side by using newest sparse version.
Cc: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
Fixes: f25da51fdc38 ("ieee802154: hwsim: add replacement for fakelb")
Signed-off-by: Alexander Aring <aring@xxxxxxxxxxxx>
---
After I installed finally the newest sparse version I found more what kbuild
was pointed out.
I hope I did it right, not sure if I really need rcu functionality in these
case because protection by mutex but I make sparse silent.
At some places the resource isn't a shared resource at this moment.
Anyway in my case I want to use this driver to create easily multi-hop
scenarios, if somebody report things (or I hit it) which smells like some
memory in this area - I will try and help to fix it.
Newest sparse version from git is happy now and I hope kbuild bot as well.
I tested this patch with RPOVE_RCU enabled and tried to update these settings
while heavy loading in rcu protected xmit hotpath is occured, without any
issues so far.
Sorry again.
drivers/net/ieee802154/mac802154_hwsim.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
index f4e92054f7df..53f39435321e 100644
--- a/drivers/net/ieee802154/mac802154_hwsim.c
+++ b/drivers/net/ieee802154/mac802154_hwsim.c
@@ -22,6 +22,7 @@
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/platform_device.h>
+#include <linux/rtnetlink.h>
#include <linux/netdevice.h>
#include <linux/device.h>
#include <linux/spinlock.h>
@@ -110,7 +111,7 @@ static int hwsim_hw_channel(struct ieee802154_hw *hw, u8 page, u8 channel)
pib->page = page;
pib->channel = channel;
- pib_old = phy->pib;
+ pib_old = rtnl_dereference(phy->pib);
rcu_assign_pointer(phy->pib, pib);
kfree_rcu(pib_old, rcu);
return 0;
@@ -406,7 +407,7 @@ static struct hwsim_edge *hwsim_alloc_edge(struct hwsim_phy *endpoint, u8 lqi)
}
einfo->lqi = 0xff;
- e->info = einfo;
+ rcu_assign_pointer(e->info, einfo);
e->endpoint = endpoint;
return e;
@@ -414,7 +415,13 @@ static struct hwsim_edge *hwsim_alloc_edge(struct hwsim_phy *endpoint, u8 lqi)
static void hwsim_free_edge(struct hwsim_edge *e)
{
- kfree_rcu(e->info, rcu);
+ struct hwsim_edge_info *einfo;
+
+ rcu_read_lock();
+ einfo = rcu_dereference(e->info);
+ rcu_read_unlock();
+
+ kfree_rcu(einfo, rcu);
kfree_rcu(e, rcu);
}
@@ -796,7 +803,7 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
goto err_pib;
}
- phy->pib = pib;
+ rcu_assign_pointer(phy->pib, pib);
phy->idx = idx;
INIT_LIST_HEAD(&phy->edges);
@@ -829,10 +836,17 @@ static int hwsim_add_one(struct genl_info *info, struct device *dev,
static void hwsim_del(struct hwsim_phy *phy)
{
+ struct hwsim_pib *pib;
+
hwsim_edge_unsubscribe_me(phy);
list_del(&phy->list);
- kfree_rcu(phy->pib, rcu);
+
+ rcu_read_lock();
+ pib = rcu_dereference(phy->pib);
+ rcu_read_unlock();
+
+ kfree_rcu(pib, rcu);
ieee802154_unregister_hw(phy->hw);
ieee802154_free_hw(phy->hw);
--
2.11.0
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