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Diffstat (limited to 'target/linux/generic/backport-4.14/080-net-convert-sock.sk_wmem_alloc-from-atomic_t-to-refc.patch')
-rw-r--r--target/linux/generic/backport-4.14/080-net-convert-sock.sk_wmem_alloc-from-atomic_t-to-refc.patch172
1 files changed, 0 insertions, 172 deletions
diff --git a/target/linux/generic/backport-4.14/080-net-convert-sock.sk_wmem_alloc-from-atomic_t-to-refc.patch b/target/linux/generic/backport-4.14/080-net-convert-sock.sk_wmem_alloc-from-atomic_t-to-refc.patch
deleted file mode 100644
index 06d00886f1..0000000000
--- a/target/linux/generic/backport-4.14/080-net-convert-sock.sk_wmem_alloc-from-atomic_t-to-refc.patch
+++ /dev/null
@@ -1,172 +0,0 @@
-From 9bbe60a67be5a1c6f79b3c9be5003481a50529ff Mon Sep 17 00:00:00 2001
-From: David Woodhouse <dwmw2@infradead.org>
-Date: Sat, 16 Jun 2018 11:55:44 +0100
-Subject: atm: Preserve value of skb->truesize when accounting to vcc
-MIME-Version: 1.0
-Content-Type: text/plain; charset=UTF-8
-Content-Transfer-Encoding: 8bit
-
-ATM accounts for in-flight TX packets in sk_wmem_alloc of the VCC on
-which they are to be sent. But it doesn't take ownership of those
-packets from the sock (if any) which originally owned them. They should
-remain owned by their actual sender until they've left the box.
-
-There's a hack in pskb_expand_head() to avoid adjusting skb->truesize
-for certain skbs, precisely to avoid messing up sk_wmem_alloc
-accounting. Ideally that hack would cover the ATM use case too, but it
-doesn't — skbs which aren't owned by any sock, for example PPP control
-frames, still get their truesize adjusted when the low-level ATM driver
-adds headroom.
-
-This has always been an issue, it seems. The truesize of a packet
-increases, and sk_wmem_alloc on the VCC goes negative. But this wasn't
-for normal traffic, only for control frames. So I think we just got away
-with it, and we probably needed to send 2GiB of LCP echo frames before
-the misaccounting would ever have caused a problem and caused
-atm_may_send() to start refusing packets.
-
-Commit 14afee4b609 ("net: convert sock.sk_wmem_alloc from atomic_t to
-refcount_t") did exactly what it was intended to do, and turned this
-mostly-theoretical problem into a real one, causing PPPoATM to fail
-immediately as sk_wmem_alloc underflows and atm_may_send() *immediately*
-starts refusing to allow new packets.
-
-The least intrusive solution to this problem is to stash the value of
-skb->truesize that was accounted to the VCC, in a new member of the
-ATM_SKB(skb) structure. Then in atm_pop_raw() subtract precisely that
-value instead of the then-current value of skb->truesize.
-
-Fixes: 158f323b9868 ("net: adjust skb->truesize in pskb_expand_head()")
-Signed-off-by: David Woodhouse <dwmw2@infradead.org>
-Tested-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
-Signed-off-by: David S. Miller <davem@davemloft.net>
----
- include/linux/atmdev.h | 15 +++++++++++++++
- net/atm/br2684.c | 3 +--
- net/atm/clip.c | 3 +--
- net/atm/common.c | 3 +--
- net/atm/lec.c | 3 +--
- net/atm/mpc.c | 3 +--
- net/atm/pppoatm.c | 3 +--
- net/atm/raw.c | 4 ++--
- 8 files changed, 23 insertions(+), 14 deletions(-)
-
---- a/include/linux/atmdev.h
-+++ b/include/linux/atmdev.h
-@@ -214,6 +214,7 @@ struct atmphy_ops {
- struct atm_skb_data {
- struct atm_vcc *vcc; /* ATM VCC */
- unsigned long atm_options; /* ATM layer options */
-+ unsigned int acct_truesize; /* truesize accounted to vcc */
- };
-
- #define VCC_HTABLE_SIZE 32
-@@ -241,6 +242,20 @@ void vcc_insert_socket(struct sock *sk);
-
- void atm_dev_release_vccs(struct atm_dev *dev);
-
-+static inline void atm_account_tx(struct atm_vcc *vcc, struct sk_buff *skb)
-+{
-+ /*
-+ * Because ATM skbs may not belong to a sock (and we don't
-+ * necessarily want to), skb->truesize may be adjusted,
-+ * escaping the hack in pskb_expand_head() which avoids
-+ * doing so for some cases. So stash the value of truesize
-+ * at the time we accounted it, and atm_pop_raw() can use
-+ * that value later, in case it changes.
-+ */
-+ refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
-+ ATM_SKB(skb)->acct_truesize = skb->truesize;
-+ ATM_SKB(skb)->atm_options = vcc->atm_options;
-+}
-
- static inline void atm_force_charge(struct atm_vcc *vcc,int truesize)
- {
---- a/net/atm/br2684.c
-+++ b/net/atm/br2684.c
-@@ -252,8 +252,7 @@ static int br2684_xmit_vcc(struct sk_buf
-
- ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
- pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
-- refcount_add(skb->truesize, &sk_atm(atmvcc)->sk_wmem_alloc);
-- ATM_SKB(skb)->atm_options = atmvcc->atm_options;
-+ atm_account_tx(atmvcc, skb);
- dev->stats.tx_packets++;
- dev->stats.tx_bytes += skb->len;
-
---- a/net/atm/clip.c
-+++ b/net/atm/clip.c
-@@ -381,8 +381,7 @@ static netdev_tx_t clip_start_xmit(struc
- memcpy(here, llc_oui, sizeof(llc_oui));
- ((__be16 *) here)[3] = skb->protocol;
- }
-- refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
-- ATM_SKB(skb)->atm_options = vcc->atm_options;
-+ atm_account_tx(vcc, skb);
- entry->vccs->last_use = jiffies;
- pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, vcc, vcc->dev);
- old = xchg(&entry->vccs->xoff, 1); /* assume XOFF ... */
---- a/net/atm/common.c
-+++ b/net/atm/common.c
-@@ -630,10 +630,9 @@ int vcc_sendmsg(struct socket *sock, str
- goto out;
- }
- pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
-- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-+ atm_account_tx(vcc, skb);
-
- skb->dev = NULL; /* for paths shared with net_device interfaces */
-- ATM_SKB(skb)->atm_options = vcc->atm_options;
- if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) {
- kfree_skb(skb);
- error = -EFAULT;
---- a/net/atm/lec.c
-+++ b/net/atm/lec.c
-@@ -182,9 +182,8 @@ lec_send(struct atm_vcc *vcc, struct sk_
- struct net_device *dev = skb->dev;
-
- ATM_SKB(skb)->vcc = vcc;
-- ATM_SKB(skb)->atm_options = vcc->atm_options;
-+ atm_account_tx(vcc, skb);
-
-- refcount_add(skb->truesize, &sk_atm(vcc)->sk_wmem_alloc);
- if (vcc->send(vcc, skb) < 0) {
- dev->stats.tx_dropped++;
- return;
---- a/net/atm/mpc.c
-+++ b/net/atm/mpc.c
-@@ -555,8 +555,7 @@ static int send_via_shortcut(struct sk_b
- sizeof(struct llc_snap_hdr));
- }
-
-- refcount_add(skb->truesize, &sk_atm(entry->shortcut)->sk_wmem_alloc);
-- ATM_SKB(skb)->atm_options = entry->shortcut->atm_options;
-+ atm_account_tx(entry->shortcut, skb);
- entry->shortcut->send(entry->shortcut, skb);
- entry->packets_fwded++;
- mpc->in_ops->put(entry);
---- a/net/atm/pppoatm.c
-+++ b/net/atm/pppoatm.c
-@@ -350,8 +350,7 @@ static int pppoatm_send(struct ppp_chann
- return 1;
- }
-
-- refcount_add(skb->truesize, &sk_atm(ATM_SKB(skb)->vcc)->sk_wmem_alloc);
-- ATM_SKB(skb)->atm_options = ATM_SKB(skb)->vcc->atm_options;
-+ atm_account_tx(vcc, skb);
- pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
- skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
- ret = ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
---- a/net/atm/raw.c
-+++ b/net/atm/raw.c
-@@ -35,8 +35,8 @@ static void atm_pop_raw(struct atm_vcc *
- struct sock *sk = sk_atm(vcc);
-
- pr_debug("(%d) %d -= %d\n",
-- vcc->vci, sk_wmem_alloc_get(sk), skb->truesize);
-- WARN_ON(refcount_sub_and_test(skb->truesize, &sk->sk_wmem_alloc));
-+ vcc->vci, sk_wmem_alloc_get(sk), ATM_SKB(skb)->acct_truesize);
-+ WARN_ON(refcount_sub_and_test(ATM_SKB(skb)->acct_truesize, &sk->sk_wmem_alloc));
- dev_kfree_skb_any(skb);
- sk->sk_write_space(sk);
- }
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-02 06:30:42 +0000