net/tls: sleeping function from invalid context

HW unhash within mutex for registered tls devices cause sleep
when called from tcp_set_state for TCP_CLOSE. Release lock and
re-acquire after function call with ref count incr/dec.
defined kref and fp release for tls_device to ensure device
is not released outside lock.

BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:748
in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/7
INFO: lockdep is turned off.
CPU: 7 PID: 0 Comm: swapper/7 Tainted: G        W  O
Call Trace:
 <IRQ>
 dump_stack+0x5e/0x8b
 ___might_sleep+0x222/0x260
 __mutex_lock+0x5c/0xa50
 ? vprintk_emit+0x1f3/0x440
 ? kmem_cache_free+0x22d/0x2a0
 ? tls_hw_unhash+0x2f/0x80
 ? printk+0x52/0x6e
 ? tls_hw_unhash+0x2f/0x80
 tls_hw_unhash+0x2f/0x80
 tcp_set_state+0x5f/0x180
 tcp_done+0x2e/0xe0
 tcp_rcv_state_process+0x92c/0xdd3
 ? lock_acquire+0xf5/0x1f0
 ? tcp_v4_rcv+0xa7c/0xbe0
 ? tcp_v4_do_rcv+0x70/0x1e0

Signed-off-by: Atul Gupta <atul.gupta@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/crypto/chelsio/chtls/chtls_main.c b/drivers/crypto/chelsio/chtls/chtls_main.c
index f472c51..db40ab6 100644 (file)
--- a/drivers/crypto/chelsio/chtls/chtls_main.c
+++ b/drivers/crypto/chelsio/chtls/chtls_main.c
@@ -149,6 +149,30 @@ static void chtls_destroy_hash(struct tls_device *dev, struct sock *sk)
                chtls_stop_listen(sk);
 }
 
+static void chtls_free_uld(struct chtls_dev *cdev)
+{
+       int i;
+
+       tls_unregister_device(&cdev->tlsdev);
+       kvfree(cdev->kmap.addr);
+       idr_destroy(&cdev->hwtid_idr);
+       for (i = 0; i < (1 << RSPQ_HASH_BITS); i++)
+               kfree_skb(cdev->rspq_skb_cache[i]);
+       kfree(cdev->lldi);
+       kfree_skb(cdev->askb);
+       kfree(cdev);
+}
+
+static inline void chtls_dev_release(struct kref *kref)
+{
+       struct chtls_dev *cdev;
+       struct tls_device *dev;
+
+       dev = container_of(kref, struct tls_device, kref);
+       cdev = to_chtls_dev(dev);
+       chtls_free_uld(cdev);
+}
+
 static void chtls_register_dev(struct chtls_dev *cdev)
 {
        struct tls_device *tlsdev = &cdev->tlsdev;
@@ -159,15 +183,12 @@ static void chtls_register_dev(struct chtls_dev *cdev)
        tlsdev->feature = chtls_inline_feature;
        tlsdev->hash = chtls_create_hash;
        tlsdev->unhash = chtls_destroy_hash;
-       tls_register_device(&cdev->tlsdev);
+       tlsdev->release = chtls_dev_release;
+       kref_init(&tlsdev->kref);
+       tls_register_device(tlsdev);
        cdev->cdev_state = CHTLS_CDEV_STATE_UP;
 }
 
-static void chtls_unregister_dev(struct chtls_dev *cdev)
-{
-       tls_unregister_device(&cdev->tlsdev);
-}
-
 static void process_deferq(struct work_struct *task_param)
 {
        struct chtls_dev *cdev = container_of(task_param,
@@ -262,28 +283,16 @@ out:
        return NULL;
 }
 
-static void chtls_free_uld(struct chtls_dev *cdev)
-{
-       int i;
-
-       chtls_unregister_dev(cdev);
-       kvfree(cdev->kmap.addr);
-       idr_destroy(&cdev->hwtid_idr);
-       for (i = 0; i < (1 << RSPQ_HASH_BITS); i++)
-               kfree_skb(cdev->rspq_skb_cache[i]);
-       kfree(cdev->lldi);
-       kfree_skb(cdev->askb);
-       kfree(cdev);
-}
-
 static void chtls_free_all_uld(void)
 {
        struct chtls_dev *cdev, *tmp;
 
        mutex_lock(&cdev_mutex);
        list_for_each_entry_safe(cdev, tmp, &cdev_list, list) {
-               if (cdev->cdev_state == CHTLS_CDEV_STATE_UP)
-                       chtls_free_uld(cdev);
+               if (cdev->cdev_state == CHTLS_CDEV_STATE_UP) {
+                       list_del(&cdev->list);
+                       kref_put(&cdev->tlsdev.kref, cdev->tlsdev.release);
+               }
        }
        mutex_unlock(&cdev_mutex);
 }
@@ -304,7 +313,7 @@ static int chtls_uld_state_change(void *handle, enum cxgb4_state new_state)
                mutex_lock(&cdev_mutex);
                list_del(&cdev->list);
                mutex_unlock(&cdev_mutex);
-               chtls_free_uld(cdev);
+               kref_put(&cdev->tlsdev.kref, cdev->tlsdev.release);
                break;
        default:
                break;

diff --git a/include/net/tls.h b/include/net/tls.h
index bab5627..3cbcd12 100644 (file)
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -76,6 +76,10 @@
  *
  * void (*unhash)(struct tls_device *device, struct sock *sk);
  *     This function cleans listen state set by Inline TLS driver
+ *
+ * void (*release)(struct kref *kref);
+ *     Release the registered device and allocated resources
+ * @kref: Number of reference to tls_device
  */
 struct tls_device {
        char name[TLS_DEVICE_NAME_MAX];
@@ -83,6 +87,8 @@ struct tls_device {
        int  (*feature)(struct tls_device *device);
        int  (*hash)(struct tls_device *device, struct sock *sk);
        void (*unhash)(struct tls_device *device, struct sock *sk);
+       void (*release)(struct kref *kref);
+       struct kref kref;
 };
 
 enum {

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index 4920803..1428bd7 100644 (file)
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -56,7 +56,7 @@ enum {
 static struct proto *saved_tcpv6_prot;
 static DEFINE_MUTEX(tcpv6_prot_mutex);
 static LIST_HEAD(device_list);
-static DEFINE_MUTEX(device_mutex);
+static DEFINE_SPINLOCK(device_spinlock);
 static struct proto tls_prots[TLS_NUM_PROTS][TLS_NUM_CONFIG][TLS_NUM_CONFIG];
 static struct proto_ops tls_sw_proto_ops;
 
@@ -555,7 +555,7 @@ static int tls_hw_prot(struct sock *sk)
        struct tls_device *dev;
        int rc = 0;
 
-       mutex_lock(&device_mutex);
+       spin_lock_bh(&device_spinlock);
        list_for_each_entry(dev, &device_list, dev_list) {
                if (dev->feature && dev->feature(dev)) {
                        ctx = create_ctx(sk);
@@ -573,7 +573,7 @@ static int tls_hw_prot(struct sock *sk)
                }
        }
 out:
-       mutex_unlock(&device_mutex);
+       spin_unlock_bh(&device_spinlock);
        return rc;
 }
 
@@ -582,12 +582,17 @@ static void tls_hw_unhash(struct sock *sk)
        struct tls_context *ctx = tls_get_ctx(sk);
        struct tls_device *dev;
 
-       mutex_lock(&device_mutex);
+       spin_lock_bh(&device_spinlock);
        list_for_each_entry(dev, &device_list, dev_list) {
-               if (dev->unhash)
+               if (dev->unhash) {
+                       kref_get(&dev->kref);
+                       spin_unlock_bh(&device_spinlock);
                        dev->unhash(dev, sk);
+                       kref_put(&dev->kref, dev->release);
+                       spin_lock_bh(&device_spinlock);
+               }
        }
-       mutex_unlock(&device_mutex);
+       spin_unlock_bh(&device_spinlock);
        ctx->unhash(sk);
 }
 
@@ -598,12 +603,17 @@ static int tls_hw_hash(struct sock *sk)
        int err;
 
        err = ctx->hash(sk);
-       mutex_lock(&device_mutex);
+       spin_lock_bh(&device_spinlock);
        list_for_each_entry(dev, &device_list, dev_list) {
-               if (dev->hash)
+               if (dev->hash) {
+                       kref_get(&dev->kref);
+                       spin_unlock_bh(&device_spinlock);
                        err |= dev->hash(dev, sk);
+                       kref_put(&dev->kref, dev->release);
+                       spin_lock_bh(&device_spinlock);
+               }
        }
-       mutex_unlock(&device_mutex);
+       spin_unlock_bh(&device_spinlock);
 
        if (err)
                tls_hw_unhash(sk);
@@ -699,17 +709,17 @@ out:
 
 void tls_register_device(struct tls_device *device)
 {
-       mutex_lock(&device_mutex);
+       spin_lock_bh(&device_spinlock);
        list_add_tail(&device->dev_list, &device_list);
-       mutex_unlock(&device_mutex);
+       spin_unlock_bh(&device_spinlock);
 }
 EXPORT_SYMBOL(tls_register_device);
 
 void tls_unregister_device(struct tls_device *device)
 {
-       mutex_lock(&device_mutex);
+       spin_lock_bh(&device_spinlock);
        list_del(&device->dev_list);
-       mutex_unlock(&device_mutex);
+       spin_unlock_bh(&device_spinlock);
 }
 EXPORT_SYMBOL(tls_unregister_device);