Hi,
On Sat, Apr 8, 2023 at 4:22 AM Chen Aotian <chenaotian2@xxxxxxx> wrote:
>
> After replacing e->info, it is necessary to free the old einfo.
>
> Fixes: f25da51fdc38 ("ieee802154: hwsim: add replacement for fakelb")
> Reviewed-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> Signed-off-by: Chen Aotian <chenaotian2@xxxxxxx>
> ---
>
> V1 -> V2:
> * Using rcu_replace_pointer() is better then rcu_dereference()
> and rcu_assign_pointer().
>
> drivers/net/ieee802154/mac802154_hwsim.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ieee802154/mac802154_hwsim.c b/drivers/net/ieee802154/mac802154_hwsim.c
> index 8445c2189..6ffcadb9d 100644
> --- a/drivers/net/ieee802154/mac802154_hwsim.c
> +++ b/drivers/net/ieee802154/mac802154_hwsim.c
> @@ -685,7 +685,7 @@ static int hwsim_del_edge_nl(struct sk_buff *msg, struct genl_info *info)
> static int hwsim_set_edge_lqi(struct sk_buff *msg, struct genl_info *info)
> {
> struct nlattr *edge_attrs[MAC802154_HWSIM_EDGE_ATTR_MAX + 1];
> - struct hwsim_edge_info *einfo;
> + struct hwsim_edge_info *einfo, *einfo_old;
> struct hwsim_phy *phy_v0;
> struct hwsim_edge *e;
> u32 v0, v1;
> @@ -723,8 +723,10 @@ static int hwsim_set_edge_lqi(struct sk_buff *msg, struct genl_info *info)
> list_for_each_entry_rcu(e, &phy_v0->edges, list) {
> if (e->endpoint->idx == v1) {
> einfo->lqi = lqi;
> - rcu_assign_pointer(e->info, einfo);
> + einfo_old = rcu_replace_pointer(e->info, einfo,
> + lock_is_held(&hwsim_phys_lock));
I think lockdep_is_held() should be correct here.
- Alex
