From: Tian Tao <tiantao6(a)hisilicon.com>
[ Upstream commit 7d614ab2f20503ed8766363d41f8607337571adf ]
fixed the below warning:
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c:84:2-8: WARNING: NULL check
before some freeing functions is not needed.
Signed-off-by: Tian Tao <tiantao6(a)hisilicon.com>
Acked-by: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Lucas Stach <l.stach(a)pengutronix.de>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index f24dd21c2363..9e657a096f45 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -77,8 +77,7 @@ static void etnaviv_gem_prime_release(struct etnaviv_gem_object *etnaviv_obj)
/* Don't drop the pages for imported dmabuf, as they are not
* ours, just free the array we allocated:
*/
- if (etnaviv_obj->pages)
- kvfree(etnaviv_obj->pages);
+ kvfree(etnaviv_obj->pages);
drm_prime_gem_destroy(&etnaviv_obj->base, etnaviv_obj->sgt);
}
--
2.30.2
From: Tian Tao <tiantao6(a)hisilicon.com>
[ Upstream commit 7d614ab2f20503ed8766363d41f8607337571adf ]
fixed the below warning:
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c:84:2-8: WARNING: NULL check
before some freeing functions is not needed.
Signed-off-by: Tian Tao <tiantao6(a)hisilicon.com>
Acked-by: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Lucas Stach <l.stach(a)pengutronix.de>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index b390dd4d60b7..d741b1d735f7 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -80,8 +80,7 @@ static void etnaviv_gem_prime_release(struct etnaviv_gem_object *etnaviv_obj)
/* Don't drop the pages for imported dmabuf, as they are not
* ours, just free the array we allocated:
*/
- if (etnaviv_obj->pages)
- kvfree(etnaviv_obj->pages);
+ kvfree(etnaviv_obj->pages);
drm_prime_gem_destroy(&etnaviv_obj->base, etnaviv_obj->sgt);
}
--
2.30.2
xfrm_bydst_resize() calls synchronize_rcu() while holding
hash_resize_mutex. But then on PREEMPT_RT configurations,
xfrm_policy_lookup_bytype() may acquire that mutex while running in an
RCU read side critical section. This results in a deadlock.
In fact the scope of hash_resize_mutex is way beyond the purpose of
xfrm_policy_lookup_bytype() to just fetch a coherent and stable policy
for a given destination/direction, along with other details.
The lower level net->xfrm.xfrm_policy_lock, which among other things
protects per destination/direction references to policy entries, is
enough to serialize and benefit from priority inheritance against the
write side. As a bonus, it makes it officially a per network namespace
synchronization business where a policy table resize on namespace A
shouldn't block a policy lookup on namespace B.
Fixes: 77cc278f7b20 (xfrm: policy: Use sequence counters with associated lock)
Cc: stable(a)vger.kernel.org
Cc: Ahmed S. Darwish <a.darwish(a)linutronix.de>
Cc: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Cc: Varad Gautam <varad.gautam(a)suse.com>
Cc: Steffen Klassert <steffen.klassert(a)secunet.com>
Cc: Herbert Xu <herbert(a)gondor.apana.org.au>
Cc: David S. Miller <davem(a)davemloft.net>
Signed-off-by: Frederic Weisbecker <frederic(a)kernel.org>
---
include/net/netns/xfrm.h | 1 +
net/xfrm/xfrm_policy.c | 17 ++++++++---------
2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/include/net/netns/xfrm.h b/include/net/netns/xfrm.h
index e816b6a3ef2b..9b376b87bd54 100644
--- a/include/net/netns/xfrm.h
+++ b/include/net/netns/xfrm.h
@@ -74,6 +74,7 @@ struct netns_xfrm {
#endif
spinlock_t xfrm_state_lock;
seqcount_spinlock_t xfrm_state_hash_generation;
+ seqcount_spinlock_t xfrm_policy_hash_generation;
spinlock_t xfrm_policy_lock;
struct mutex xfrm_cfg_mutex;
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index ce500f847b99..46a6d15b66d6 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -155,7 +155,6 @@ static struct xfrm_policy_afinfo const __rcu *xfrm_policy_afinfo[AF_INET6 + 1]
__read_mostly;
static struct kmem_cache *xfrm_dst_cache __ro_after_init;
-static __read_mostly seqcount_mutex_t xfrm_policy_hash_generation;
static struct rhashtable xfrm_policy_inexact_table;
static const struct rhashtable_params xfrm_pol_inexact_params;
@@ -585,7 +584,7 @@ static void xfrm_bydst_resize(struct net *net, int dir)
return;
spin_lock_bh(&net->xfrm.xfrm_policy_lock);
- write_seqcount_begin(&xfrm_policy_hash_generation);
+ write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
odst = rcu_dereference_protected(net->xfrm.policy_bydst[dir].table,
lockdep_is_held(&net->xfrm.xfrm_policy_lock));
@@ -596,7 +595,7 @@ static void xfrm_bydst_resize(struct net *net, int dir)
rcu_assign_pointer(net->xfrm.policy_bydst[dir].table, ndst);
net->xfrm.policy_bydst[dir].hmask = nhashmask;
- write_seqcount_end(&xfrm_policy_hash_generation);
+ write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
synchronize_rcu();
@@ -1245,7 +1244,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
} while (read_seqretry(&net->xfrm.policy_hthresh.lock, seq));
spin_lock_bh(&net->xfrm.xfrm_policy_lock);
- write_seqcount_begin(&xfrm_policy_hash_generation);
+ write_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
/* make sure that we can insert the indirect policies again before
* we start with destructive action.
@@ -1354,7 +1353,7 @@ static void xfrm_hash_rebuild(struct work_struct *work)
out_unlock:
__xfrm_policy_inexact_flush(net);
- write_seqcount_end(&xfrm_policy_hash_generation);
+ write_seqcount_end(&net->xfrm.xfrm_policy_hash_generation);
spin_unlock_bh(&net->xfrm.xfrm_policy_lock);
mutex_unlock(&hash_resize_mutex);
@@ -2095,9 +2094,9 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
rcu_read_lock();
retry:
do {
- sequence = read_seqcount_begin(&xfrm_policy_hash_generation);
+ sequence = read_seqcount_begin(&net->xfrm.xfrm_policy_hash_generation);
chain = policy_hash_direct(net, daddr, saddr, family, dir);
- } while (read_seqcount_retry(&xfrm_policy_hash_generation, sequence));
+ } while (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence));
ret = NULL;
hlist_for_each_entry_rcu(pol, chain, bydst) {
@@ -2128,7 +2127,7 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
}
skip_inexact:
- if (read_seqcount_retry(&xfrm_policy_hash_generation, sequence))
+ if (read_seqcount_retry(&net->xfrm.xfrm_policy_hash_generation, sequence))
goto retry;
if (ret && !xfrm_pol_hold_rcu(ret))
@@ -4084,6 +4083,7 @@ static int __net_init xfrm_net_init(struct net *net)
/* Initialize the per-net locks here */
spin_lock_init(&net->xfrm.xfrm_state_lock);
spin_lock_init(&net->xfrm.xfrm_policy_lock);
+ seqcount_spinlock_init(&net->xfrm.xfrm_policy_hash_generation, &net->xfrm.xfrm_policy_lock);
mutex_init(&net->xfrm.xfrm_cfg_mutex);
rv = xfrm_statistics_init(net);
@@ -4128,7 +4128,6 @@ void __init xfrm_init(void)
{
register_pernet_subsys(&xfrm_net_ops);
xfrm_dev_init();
- seqcount_mutex_init(&xfrm_policy_hash_generation, &hash_resize_mutex);
xfrm_input_init();
#ifdef CONFIG_XFRM_ESPINTCP
--
2.25.1