[PATCH 06/17] net: convert sock.sk_wmem_alloc from atomic_t to refcount_t

From: Elena Reshetova
Date: Thu Mar 16 2017 - 11:32:31 EST

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@xxxxxxxxx>
Signed-off-by: Hans Liljestrand <ishkamiel@xxxxxxxxx>
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: David Windsor <dwindsor@xxxxxxxxx>
---
drivers/atm/fore200e.c | 12 +-----------
drivers/atm/he.c | 2 +-
drivers/atm/idt77252.c | 4 ++--
include/linux/atmdev.h | 2 +-
include/net/sock.h | 8 ++++----
net/atm/br2684.c | 2 +-
net/atm/clip.c | 2 +-
net/atm/common.c | 10 +++++-----
net/atm/lec.c | 4 ++--
net/atm/mpc.c | 4 ++--
net/atm/pppoatm.c | 2 +-
net/atm/raw.c | 2 +-
net/atm/signaling.c | 2 +-
net/caif/caif_socket.c | 2 +-
net/core/datagram.c | 2 +-
net/core/skbuff.c | 2 +-
net/core/sock.c | 26 +++++++++++++-------------
net/ipv4/af_inet.c | 2 +-
net/ipv4/esp4.c | 2 +-
net/ipv4/ip_output.c | 6 +++---
net/ipv4/tcp.c | 4 ++--
net/ipv4/tcp_offload.c | 2 +-
net/ipv4/tcp_output.c | 13 ++++++-------
net/ipv6/esp6.c | 2 +-
net/ipv6/ip6_output.c | 4 ++--
net/kcm/kcmproc.c | 2 +-
net/key/af_key.c | 2 +-
net/netlink/af_netlink.c | 2 +-
net/packet/af_packet.c | 4 ++--
net/phonet/socket.c | 2 +-
net/rds/tcp_send.c | 2 +-
net/rxrpc/af_rxrpc.c | 4 ++--
net/sched/sch_atm.c | 2 +-
net/sctp/output.c | 2 +-
net/sctp/proc.c | 2 +-
net/sctp/socket.c | 4 ++--
net/unix/af_unix.c | 6 +++---
37 files changed, 73 insertions(+), 84 deletions(-)

diff --git a/drivers/atm/fore200e.c b/drivers/atm/fore200e.c
index 637c3e6..b770d18 100644
--- a/drivers/atm/fore200e.c
+++ b/drivers/atm/fore200e.c
@@ -924,12 +924,7 @@ fore200e_tx_irq(struct fore200e* fore200e)
else {
dev_kfree_skb_any(entry->skb);
}
-#if 1
- /* race fixed by the above incarnation mechanism, but... */
- if (atomic_read(&sk_atm(vcc)->sk_wmem_alloc) < 0) {
- atomic_set(&sk_atm(vcc)->sk_wmem_alloc, 0);
- }
-#endif
+
/* check error condition */
if (*entry->status & STATUS_ERROR)
atomic_inc(&vcc->stats->tx_err);
@@ -1130,13 +1125,9 @@ fore200e_push_rpd(struct fore200e* fore200e, struct atm_vcc* vcc, struct rpd* rp
return -ENOMEM;
}

- ASSERT(atomic_read(&sk_atm(vcc)->sk_wmem_alloc) >= 0);
-
vcc->push(vcc, skb);
atomic_inc(&vcc->stats->rx);

- ASSERT(atomic_read(&sk_atm(vcc)->sk_wmem_alloc) >= 0);
-
return 0;
}

@@ -1572,7 +1563,6 @@ fore200e_send(struct atm_vcc *vcc, struct sk_buff *skb)
unsigned long flags;

ASSERT(vcc);
- ASSERT(atomic_read(&sk_atm(vcc)->sk_wmem_alloc) >= 0);
ASSERT(fore200e);
ASSERT(fore200e_vcc);

diff --git a/drivers/atm/he.c b/drivers/atm/he.c
index 3617659..fc1bbdb 100644
--- a/drivers/atm/he.c
+++ b/drivers/atm/he.c
@@ -2395,7 +2395,7 @@ he_close(struct atm_vcc *vcc)
* TBRQ, the host issues the close command to the adapter.
*/

- while (((tx_inuse = atomic_read(&sk_atm(vcc)->sk_wmem_alloc)) > 1) &&
+ while (((tx_inuse = refcount_read(&sk_atm(vcc)->sk_wmem_alloc)) > 1) &&
(retry < MAX_RETRY)) {
msleep(sleep);
if (sleep < 250)
diff --git a/drivers/atm/idt77252.c b/drivers/atm/idt77252.c
index 5ec1095..20eda87 100644
--- a/drivers/atm/idt77252.c
+++ b/drivers/atm/idt77252.c
@@ -724,7 +724,7 @@ push_on_scq(struct idt77252_dev *card, struct vc_map *vc, struct sk_buff *skb)
struct sock *sk = sk_atm(vcc);

vc->estimator->cells += (skb->len + 47) / 48;
- if (atomic_read(&sk->sk_wmem_alloc) >
+ if (refcount_read(&sk->sk_wmem_alloc) >
(sk->sk_sndbuf >> 1)) {
u32 cps = vc->estimator->maxcps;

@@ -2012,7 +2012,7 @@ idt77252_send_oam(struct atm_vcc *vcc, void *cell, int flags)
atomic_inc(&vcc->stats->tx_err);
return -ENOMEM;
}
- atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);

memcpy(skb_put(skb, 52), cell, 52);

diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h
index c1da539..4d97a89 100644
--- a/include/linux/atmdev.h
+++ b/include/linux/atmdev.h
@@ -254,7 +254,7 @@ static inline void atm_return(struct atm_vcc *vcc,int truesize)

static inline int atm_may_send(struct atm_vcc *vcc,unsigned int size)
{
- return (size + atomic_read(&sk_atm(vcc)->sk_wmem_alloc)) <
+ return (size + refcount_read(&sk_atm(vcc)->sk_wmem_alloc)) <
sk_atm(vcc)->sk_sndbuf;
}

diff --git a/include/net/sock.h b/include/net/sock.h
index c519de7..24dcdba 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -388,7 +388,7 @@ struct sock {

/* ===== cache line for TX ===== */
int sk_wmem_queued;
- atomic_t sk_wmem_alloc;
+ refcount_t sk_wmem_alloc;
unsigned long sk_tsq_flags;
struct sk_buff *sk_send_head;
struct sk_buff_head sk_write_queue;
@@ -1916,7 +1916,7 @@ static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *fro
*/
static inline int sk_wmem_alloc_get(const struct sock *sk)
{
- return atomic_read(&sk->sk_wmem_alloc) - 1;
+ return refcount_read(&sk->sk_wmem_alloc) - 1;
}

/**
@@ -2060,7 +2060,7 @@ static inline unsigned long sock_wspace(struct sock *sk)
int amt = 0;

if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
- amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
+ amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
if (amt < 0)
amt = 0;
}
@@ -2141,7 +2141,7 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
*/
static inline bool sock_writeable(const struct sock *sk)
{
- return atomic_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
+ return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
}

static inline gfp_t gfp_any(void)
diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index fca84e1..4e11119 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -252,7 +252,7 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,

ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
- atomic_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
ATM_SKB(skb)->atm_options = atmvcc->atm_options;
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
diff --git a/net/atm/clip.c b/net/atm/clip.c
index 33e0940..e2e1318 100644
--- a/net/atm/clip.c
+++ b/net/atm/clip.c
@@ -381,7 +381,7 @@ static netdev_tx_t clip_start_xmit(struct sk_buff *skb,
memcpy(here, llc_oui, sizeof(llc_oui));
((__be16 *) here)[3] = skb->protocol;
}
- atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
ATM_SKB(skb)->atm_options = vcc->atm_options;
entry->vccs->last_use = jiffies;
pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
diff --git a/net/atm/common.c b/net/atm/common.c
index 9613381..e58d938 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -75,7 +75,7 @@ static struct sk_buff *alloc_tx(struct atm_vcc *vcc, unsigned int size)
while (!(skb = alloc_skb(size, GFP_KERNEL)))
schedule();
pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
- atomic_add(skb->truesize, &sk->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
return skb;
}

@@ -85,9 +85,9 @@ static void vcc_sock_destruct(struct sock *sk)
printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.\n",
__func__, atomic_read(&sk->sk_rmem_alloc));

- if (atomic_read(&sk->sk_wmem_alloc))
+ if (refcount_read(&sk->sk_wmem_alloc))
printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.\n",
- __func__, atomic_read(&sk->sk_wmem_alloc));
+ __func__, refcount_read(&sk->sk_wmem_alloc));
}

static void vcc_def_wakeup(struct sock *sk)
@@ -106,7 +106,7 @@ static inline int vcc_writable(struct sock *sk)
struct atm_vcc *vcc = atm_sk(sk);

return (vcc->qos.txtp.max_sdu +
- atomic_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
+ refcount_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
}

static void vcc_write_space(struct sock *sk)
@@ -161,7 +161,7 @@ int vcc_create(struct net *net, struct socket *sock, int protocol, int family, i
memset(&vcc->local, 0, sizeof(struct sockaddr_atmsvc));
memset(&vcc->remote, 0, sizeof(struct sockaddr_atmsvc));
vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
- atomic_set(&sk->sk_wmem_alloc, 1);
+ refcount_set(&sk->sk_wmem_alloc, 1);
atomic_set(&sk->sk_rmem_alloc, 0);
vcc->push = NULL;
vcc->pop = NULL;
diff --git a/net/atm/lec.c b/net/atm/lec.c
index 09cfe87..7554571 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -181,7 +181,7 @@ lec_send(struct atm_vcc *vcc, struct sk_buff *skb)
ATM_SKB(skb)->vcc = vcc;
ATM_SKB(skb)->atm_options = vcc->atm_options;

- atomic_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
if (vcc->send(vcc, skb) < 0) {
dev->stats.tx_dropped++;
return;
@@ -345,7 +345,7 @@ static int lec_atm_send(struct atm_vcc *vcc, struct sk_buff *skb)
int i;
char *tmp; /* FIXME */

- atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc));
mesg = (struct atmlec_msg *)skb->data;
tmp = skb->data;
tmp += sizeof(struct atmlec_msg);
diff --git a/net/atm/mpc.c b/net/atm/mpc.c
index a190800..680a4b9 100644
--- a/net/atm/mpc.c
+++ b/net/atm/mpc.c
@@ -555,7 +555,7 @@ static int send_via_shortcut(struct sk_buff *skb, struct mpoa_client *mpc)
sizeof(struct llc_snap_hdr));
}

- atomic_add(skb->truesize, &sk_atm(entry->shortcut)->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk_atm(entry->shortcut)->sk_wmem_alloc);
ATM_SKB(skb)->atm_options = entry->shortcut->atm_options;
entry->shortcut->send(entry->shortcut, skb);
entry->packets_fwded++;
@@ -911,7 +911,7 @@ static int msg_from_mpoad(struct atm_vcc *vcc, struct sk_buff *skb)

struct mpoa_client *mpc = find_mpc_by_vcc(vcc);
struct k_message *mesg = (struct k_message *)skb->data;
- atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc));

if (mpc == NULL) {
pr_info("no mpc found\n");
diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
index c4e0984..21d9d34 100644
--- a/net/atm/pppoatm.c
+++ b/net/atm/pppoatm.c
@@ -350,7 +350,7 @@ static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
return 1;
}

- atomic_add(skb->truesize, &sk_atm(ATM_SKB(skb)->vcc)->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk_atm(ATM_SKB(skb)->vcc)->sk_wmem_alloc);
ATM_SKB(skb)->atm_options = ATM_SKB(skb)->vcc->atm_options;
pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
diff --git a/net/atm/raw.c b/net/atm/raw.c
index 2e17e97..821c079 100644
--- a/net/atm/raw.c
+++ b/net/atm/raw.c
@@ -35,7 +35,7 @@ static void atm_pop_raw(struct atm_vcc *vcc, struct sk_buff *skb)

pr_debug("(%d) %d -= %d\n",
vcc->vci, sk_wmem_alloc_get(sk), skb->truesize);
- atomic_sub(skb->truesize, &sk->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
dev_kfree_skb_any(skb);
sk->sk_write_space(sk);
}
diff --git a/net/atm/signaling.c b/net/atm/signaling.c
index adb6e3d..ca59496 100644
--- a/net/atm/signaling.c
+++ b/net/atm/signaling.c
@@ -67,7 +67,7 @@ static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb)
struct sock *sk;

msg = (struct atmsvc_msg *) skb->data;
- atomic_sub(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc));
vcc = *(struct atm_vcc **) &msg->vcc;
pr_debug("%d (0x%lx)\n", (int)msg->type, (unsigned long)vcc);
sk = sk_atm(vcc);
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index adcad34..0ea2616 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -1009,7 +1009,7 @@ static const struct proto_ops caif_stream_ops = {
static void caif_sock_destructor(struct sock *sk)
{
struct caifsock *cf_sk = container_of(sk, struct caifsock, sk);
- caif_assert(!atomic_read(&sk->sk_wmem_alloc));
+ caif_assert(!refcount_read(&sk->sk_wmem_alloc));
caif_assert(sk_unhashed(sk));
caif_assert(!sk->sk_socket);
if (!sock_flag(sk, SOCK_DEAD)) {
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 281e5d6..d0702d0 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -595,7 +595,7 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from)
skb->data_len += copied;
skb->len += copied;
skb->truesize += truesize;
- atomic_add(truesize, &skb->sk->sk_wmem_alloc);
+ refcount_add(truesize, &skb->sk->sk_wmem_alloc);
while (copied) {
int size = min_t(int, copied, PAGE_SIZE - start);
skb_fill_page_desc(skb, frag++, pages[n], start, size);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6911269..e81a27f 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2985,7 +2985,7 @@ int skb_append_datato_frags(struct sock *sk, struct sk_buff *skb,
get_page(pfrag->page);

skb->truesize += copy;
- atomic_add(copy, &sk->sk_wmem_alloc);
+ refcount_add(copy, &sk->sk_wmem_alloc);
skb->len += copy;
skb->data_len += copy;
offset += copy;
diff --git a/net/core/sock.c b/net/core/sock.c
index f6fd79f..e830ddc 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1404,7 +1404,7 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
if (likely(sk->sk_net_refcnt))
get_net(net);
sock_net_set(sk, net);
- atomic_set(&sk->sk_wmem_alloc, 1);
+ refcount_set(&sk->sk_wmem_alloc, 1);

mem_cgroup_sk_alloc(sk);
cgroup_sk_alloc(&sk->sk_cgrp_data);
@@ -1428,7 +1428,7 @@ static void __sk_destruct(struct rcu_head *head)
sk->sk_destruct(sk);

filter = rcu_dereference_check(sk->sk_filter,
- atomic_read(&sk->sk_wmem_alloc) == 0);
+ refcount_read(&sk->sk_wmem_alloc) == 0);
if (filter) {
sk_filter_uncharge(sk, filter);
RCU_INIT_POINTER(sk->sk_filter, NULL);
@@ -1473,7 +1473,7 @@ void sk_free(struct sock *sk)
* some packets are still in some tx queue.
* If not null, sock_wfree() will call __sk_free(sk) later
*/
- if (atomic_dec_and_test(&sk->sk_wmem_alloc))
+ if (refcount_dec_and_test(&sk->sk_wmem_alloc))
__sk_free(sk);
}
EXPORT_SYMBOL(sk_free);
@@ -1509,7 +1509,7 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
/*
* sk_wmem_alloc set to one (see sk_free() and sock_wfree())
*/
- atomic_set(&newsk->sk_wmem_alloc, 1);
+ refcount_set(&newsk->sk_wmem_alloc, 1);
atomic_set(&newsk->sk_omem_alloc, 0);
skb_queue_head_init(&newsk->sk_receive_queue);
skb_queue_head_init(&newsk->sk_write_queue);
@@ -1638,7 +1638,7 @@ void sock_wfree(struct sk_buff *skb)
* Keep a reference on sk_wmem_alloc, this will be released
* after sk_write_space() call
*/
- atomic_sub(len - 1, &sk->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(len - 1, &sk->sk_wmem_alloc));
sk->sk_write_space(sk);
len = 1;
}
@@ -1646,7 +1646,7 @@ void sock_wfree(struct sk_buff *skb)
* if sk_wmem_alloc reaches 0, we must finish what sk_free()
* could not do because of in-flight packets
*/
- if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
+ if (refcount_sub_and_test(len, &sk->sk_wmem_alloc))
__sk_free(sk);
}
EXPORT_SYMBOL(sock_wfree);
@@ -1658,7 +1658,7 @@ void __sock_wfree(struct sk_buff *skb)
{
struct sock *sk = skb->sk;

- if (atomic_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
+ if (refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc))
__sk_free(sk);
}

@@ -1680,7 +1680,7 @@ void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
* is enough to guarantee sk_free() wont free this sock until
* all in-flight packets are completed
*/
- atomic_add(skb->truesize, &sk->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
}
EXPORT_SYMBOL(skb_set_owner_w);

@@ -1708,7 +1708,7 @@ void skb_orphan_partial(struct sk_buff *skb)
|| skb->destructor == tcp_wfree
#endif
) {
- atomic_sub(skb->truesize - 1, &skb->sk->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize - 1, &skb->sk->sk_wmem_alloc));
skb->truesize = 1;
} else {
skb_orphan(skb);
@@ -1767,7 +1767,7 @@ EXPORT_SYMBOL(sock_i_ino);
struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
gfp_t priority)
{
- if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
+ if (force || refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
struct sk_buff *skb = alloc_skb(size, priority);
if (skb) {
skb_set_owner_w(skb, sk);
@@ -1842,7 +1842,7 @@ static long sock_wait_for_wmem(struct sock *sk, long timeo)
break;
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
- if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
+ if (refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
break;
if (sk->sk_shutdown & SEND_SHUTDOWN)
break;
@@ -2145,7 +2145,7 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
if (sk->sk_type == SOCK_STREAM) {
if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
return 1;
- } else if (atomic_read(&sk->sk_wmem_alloc) <
+ } else if (refcount_read(&sk->sk_wmem_alloc) <
prot->sysctl_wmem[0])
return 1;
}
@@ -2411,7 +2411,7 @@ static void sock_def_write_space(struct sock *sk)
/* Do not wake up a writer until he can make "significant"
* progress. --DaveM
*/
- if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
+ if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
wq = rcu_dereference(sk->sk_wq);
if (skwq_has_sleeper(wq))
wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 5091f46..4d89969 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -150,7 +150,7 @@ void inet_sock_destruct(struct sock *sk)
}

WARN_ON(atomic_read(&sk->sk_rmem_alloc));
- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));
WARN_ON(sk->sk_wmem_queued);
WARN_ON(sk->sk_forward_alloc);

diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index b1e2444..d02afc2 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -337,7 +337,7 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb)
skb->data_len += tailen;
skb->truesize += tailen;
if (sk)
- atomic_add(tailen, &sk->sk_wmem_alloc);
+ refcount_add(tailen, &sk->sk_wmem_alloc);

skb_push(skb, -skb_network_offset(skb));

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 737ce82..a2ea706 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1036,7 +1036,7 @@ static int __ip_append_data(struct sock *sk,
(flags & MSG_DONTWAIT), &err);
} else {
skb = NULL;
- if (atomic_read(&sk->sk_wmem_alloc) <=
+ if (refcount_read(&sk->sk_wmem_alloc) <=
2 * sk->sk_sndbuf)
skb = sock_wmalloc(sk,
alloclen + hh_len + 15, 1,
@@ -1144,7 +1144,7 @@ static int __ip_append_data(struct sock *sk,
skb->len += copy;
skb->data_len += copy;
skb->truesize += copy;
- atomic_add(copy, &sk->sk_wmem_alloc);
+ refcount_add(copy, &sk->sk_wmem_alloc);
}
offset += copy;
length -= copy;
@@ -1368,7 +1368,7 @@ ssize_t ip_append_page(struct sock *sk, struct flowi4 *fl4, struct page *page,
skb->len += len;
skb->data_len += len;
skb->truesize += len;
- atomic_add(len, &sk->sk_wmem_alloc);
+ refcount_add(len, &sk->sk_wmem_alloc);
offset += len;
size -= len;
}
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 3354a61..1f82de5 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -644,7 +644,7 @@ static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
return skb->len < size_goal &&
sysctl_tcp_autocorking &&
skb != tcp_write_queue_head(sk) &&
- atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
+ refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
}

static void tcp_push(struct sock *sk, int flags, int mss_now,
@@ -672,7 +672,7 @@ static void tcp_push(struct sock *sk, int flags, int mss_now,
/* It is possible TX completion already happened
* before we set TSQ_THROTTLED.
*/
- if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
+ if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
return;
}

diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index bc68da3..11f69bb 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -152,7 +152,7 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
swap(gso_skb->sk, skb->sk);
swap(gso_skb->destructor, skb->destructor);
sum_truesize += skb->truesize;
- atomic_add(sum_truesize - gso_skb->truesize,
+ refcount_add(sum_truesize - gso_skb->truesize,
&skb->sk->sk_wmem_alloc);
}

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 22548b5..7cd1283 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -863,12 +863,11 @@ void tcp_wfree(struct sk_buff *skb)
struct sock *sk = skb->sk;
struct tcp_sock *tp = tcp_sk(sk);
unsigned long flags, nval, oval;
- int wmem;

/* Keep one reference on sk_wmem_alloc.
* Will be released by sk_free() from here or tcp_tasklet_func()
*/
- wmem = atomic_sub_return(skb->truesize - 1, &sk->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(skb->truesize - 1, &sk->sk_wmem_alloc));

/* If this softirq is serviced by ksoftirqd, we are likely under stress.
* Wait until our queues (qdisc + devices) are drained.
@@ -877,7 +876,7 @@ void tcp_wfree(struct sk_buff *skb)
* - chance for incoming ACK (processed by another cpu maybe)
* to migrate this flow (skb->ooo_okay will be eventually set)
*/
- if (wmem >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current)
+ if (refcount_read(&sk->sk_wmem_alloc) >= SKB_TRUESIZE(1) && this_cpu_ksoftirqd() == current)
goto out;

for (oval = READ_ONCE(sk->sk_tsq_flags);; oval = nval) {
@@ -981,7 +980,7 @@ static int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, int clone_it,
skb->sk = sk;
skb->destructor = skb_is_tcp_pure_ack(skb) ? __sock_wfree : tcp_wfree;
skb_set_hash_from_sk(skb, sk);
- atomic_add(skb->truesize, &sk->sk_wmem_alloc);
+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);

skb_set_dst_pending_confirm(skb, sk->sk_dst_pending_confirm);

@@ -2101,7 +2100,7 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
limit = min_t(u32, limit, sysctl_tcp_limit_output_bytes);
limit <<= factor;

- if (atomic_read(&sk->sk_wmem_alloc) > limit) {
+ if (refcount_read(&sk->sk_wmem_alloc) > limit) {
/* Always send the 1st or 2nd skb in write queue.
* No need to wait for TX completion to call us back,
* after softirq/tasklet schedule.
@@ -2117,7 +2116,7 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb,
* test again the condition.
*/
smp_mb__after_atomic();
- if (atomic_read(&sk->sk_wmem_alloc) > limit)
+ if (refcount_read(&sk->sk_wmem_alloc) > limit)
return true;
}
return false;
@@ -2735,7 +2734,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs)
/* Do not sent more than we queued. 1/4 is reserved for possible
* copying overhead: fragmentation, tunneling, mangling etc.
*/
- if (atomic_read(&sk->sk_wmem_alloc) >
+ if (refcount_read(&sk->sk_wmem_alloc) >
min_t(u32, sk->sk_wmem_queued + (sk->sk_wmem_queued >> 2),
sk->sk_sndbuf))
return -EAGAIN;
diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c
index ff54faa..b8f127e 100644
--- a/net/ipv6/esp6.c
+++ b/net/ipv6/esp6.c
@@ -317,7 +317,7 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb)
skb->data_len += tailen;
skb->truesize += tailen;
if (sk)
- atomic_add(tailen, &sk->sk_wmem_alloc);
+ refcount_add(tailen, &sk->sk_wmem_alloc);

skb_push(skb, -skb_network_offset(skb));

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 528b3c1..42a2f73 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1464,7 +1464,7 @@ static int __ip6_append_data(struct sock *sk,
(flags & MSG_DONTWAIT), &err);
} else {
skb = NULL;
- if (atomic_read(&sk->sk_wmem_alloc) <=
+ if (refcount_read(&sk->sk_wmem_alloc) <=
2 * sk->sk_sndbuf)
skb = sock_wmalloc(sk,
alloclen + hh_len, 1,
@@ -1577,7 +1577,7 @@ static int __ip6_append_data(struct sock *sk,
skb->len += copy;
skb->data_len += copy;
skb->truesize += copy;
- atomic_add(copy, &sk->sk_wmem_alloc);
+ refcount_add(copy, &sk->sk_wmem_alloc);
}
offset += copy;
length -= copy;
diff --git a/net/kcm/kcmproc.c b/net/kcm/kcmproc.c
index bf75c92..c343ac6 100644
--- a/net/kcm/kcmproc.c
+++ b/net/kcm/kcmproc.c
@@ -162,7 +162,7 @@ static void kcm_format_psock(struct kcm_psock *psock, struct seq_file *seq,
psock->sk->sk_receive_queue.qlen,
atomic_read(&psock->sk->sk_rmem_alloc),
psock->sk->sk_write_queue.qlen,
- atomic_read(&psock->sk->sk_wmem_alloc));
+ refcount_read(&psock->sk->sk_wmem_alloc));

if (psock->done)
seq_puts(seq, "Done ");
diff --git a/net/key/af_key.c b/net/key/af_key.c
index 9d96b82..ba00bd3 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -104,7 +104,7 @@ static void pfkey_sock_destruct(struct sock *sk)
}

WARN_ON(atomic_read(&sk->sk_rmem_alloc));
- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));

atomic_dec(&net_pfkey->socks_nr);
}
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7dac4a9..9332b24 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -341,7 +341,7 @@ static void netlink_sock_destruct(struct sock *sk)
}

WARN_ON(atomic_read(&sk->sk_rmem_alloc));
- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));
WARN_ON(nlk_sk(sk)->groups);
}

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a0dbe7c..82eb052 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1320,7 +1320,7 @@ static void packet_sock_destruct(struct sock *sk)
skb_queue_purge(&sk->sk_error_queue);

WARN_ON(atomic_read(&sk->sk_rmem_alloc));
- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));

if (!sock_flag(sk, SOCK_DEAD)) {
pr_err("Attempt to release alive packet socket: %p\n", sk);
@@ -2482,7 +2482,7 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb,
skb->data_len = to_write;
skb->len += to_write;
skb->truesize += to_write;
- atomic_add(to_write, &po->sk.sk_wmem_alloc);
+ refcount_add(to_write, &po->sk.sk_wmem_alloc);

while (likely(to_write)) {
nr_frags = skb_shinfo(skb)->nr_frags;
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index a6c8da3..27b0b13 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -360,7 +360,7 @@ static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
return POLLHUP;

if (sk->sk_state == TCP_ESTABLISHED &&
- atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
+ refcount_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf &&
atomic_read(&pn->tx_credits))
mask |= POLLOUT | POLLWRNORM | POLLWRBAND;

diff --git a/net/rds/tcp_send.c b/net/rds/tcp_send.c
index dcf4742..592e68b 100644
--- a/net/rds/tcp_send.c
+++ b/net/rds/tcp_send.c
@@ -208,7 +208,7 @@ void rds_tcp_write_space(struct sock *sk)
tc->t_last_seen_una = rds_tcp_snd_una(tc);
rds_send_path_drop_acked(cp, rds_tcp_snd_una(tc), rds_tcp_is_acked);

- if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf)
+ if ((refcount_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf)
queue_delayed_work(rds_wq, &cp->cp_send_w, 0);

out:
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index 7fb59c3..b473ac2 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -56,7 +56,7 @@ static void rxrpc_sock_destructor(struct sock *);
*/
static inline int rxrpc_writable(struct sock *sk)
{
- return atomic_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
+ return refcount_read(&sk->sk_wmem_alloc) < (size_t) sk->sk_sndbuf;
}

/*
@@ -665,7 +665,7 @@ static void rxrpc_sock_destructor(struct sock *sk)

rxrpc_purge_queue(&sk->sk_receive_queue);

- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));
WARN_ON(!sk_unhashed(sk));
WARN_ON(sk->sk_socket);

diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index 2209c2d..2b0778b 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -491,7 +491,7 @@ static void sch_atm_dequeue(unsigned long data)
ATM_SKB(skb)->vcc = flow->vcc;
memcpy(skb_push(skb, flow->hdr_len), flow->hdr,
flow->hdr_len);
- atomic_add(skb->truesize,
+ refcount_add(skb->truesize,
&sk_atm(flow->vcc)->sk_wmem_alloc);
/* atm.atm_options are already set by atm_tc_enqueue */
flow->vcc->send(flow->vcc, skb);
diff --git a/net/sctp/output.c b/net/sctp/output.c
index 71ce6b9..6574281 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -392,7 +392,7 @@ static void sctp_packet_set_owner_w(struct sk_buff *skb, struct sock *sk)
* therefore only reserve a single byte to keep socket around until
* the packet has been transmitted.
*/
- atomic_inc(&sk->sk_wmem_alloc);
+ refcount_inc(&sk->sk_wmem_alloc);
}

static int sctp_packet_pack(struct sctp_packet *packet,
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 206377f..25cd840 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -365,7 +365,7 @@ static int sctp_assocs_seq_show(struct seq_file *seq, void *v)
assoc->c.sinit_num_ostreams, assoc->max_retrans,
assoc->init_retries, assoc->shutdown_retries,
assoc->rtx_data_chunks,
- atomic_read(&sk->sk_wmem_alloc),
+ refcount_read(&sk->sk_wmem_alloc),
sk->sk_wmem_queued,
sk->sk_sndbuf,
sk->sk_rcvbuf);
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index c1120d5..67dfec1 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -164,7 +164,7 @@ static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
sizeof(struct sk_buff) +
sizeof(struct sctp_chunk);

- atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
+ refcount_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
sk->sk_wmem_queued += chunk->skb->truesize;
sk_mem_charge(sk, chunk->skb->truesize);
}
@@ -7539,7 +7539,7 @@ static void sctp_wfree(struct sk_buff *skb)
sizeof(struct sk_buff) +
sizeof(struct sctp_chunk);

- atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
+ WARN_ON(refcount_sub_and_test(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc));

/*
* This undoes what is done via sctp_set_owner_w and sk_mem_charge
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index a48d403..a74339e 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -442,7 +442,7 @@ static int unix_dgram_peer_wake_me(struct sock *sk, struct sock *other)
static int unix_writable(const struct sock *sk)
{
return sk->sk_state != TCP_LISTEN &&
- (atomic_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
+ (refcount_read(&sk->sk_wmem_alloc) << 2) <= sk->sk_sndbuf;
}

static void unix_write_space(struct sock *sk)
@@ -487,7 +487,7 @@ static void unix_sock_destructor(struct sock *sk)

skb_queue_purge(&sk->sk_receive_queue);

- WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(refcount_read(&sk->sk_wmem_alloc));
WARN_ON(!sk_unhashed(sk));
WARN_ON(sk->sk_socket);
if (!sock_flag(sk, SOCK_DEAD)) {
@@ -2024,7 +2024,7 @@ static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
skb->len += size;
skb->data_len += size;
skb->truesize += size;
- atomic_add(size, &sk->sk_wmem_alloc);
+ refcount_add(size, &sk->sk_wmem_alloc);

if (newskb) {
err = unix_scm_to_skb(&scm, skb, false);
--
2.7.4