diff mbox series

[net-next,05/27] skbuff: drop null check from skb_zcopy

Message ID 62db530f5b9875c820c97d4b6b2f30b511d94468.1648981571.git.asml.silence@gmail.com (mailing list archive)
State Deferred
Delegated to: Netdev Maintainers
Headers show
Series net and/or udp optimisations | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5854 this patch: 5854
netdev/cc_maintainers warning 6 maintainers not CCed: petrm@nvidia.com pabeni@redhat.com yoshfuji@linux-ipv6.org dsahern@kernel.org imagedong@tencent.com keescook@chromium.org
netdev/build_clang success Errors and warnings before: 1149 this patch: 1149
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5992 this patch: 5992
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 66 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Pavel Begunkov April 3, 2022, 1:06 p.m. UTC 
skb_zcopy() is used all around the networkong code including generic
paths. Many callers pass only a non-null skb, so we can remove it from
there and fix up several callers that would be affected. It removes
extra checks from zerocopy paths but also sheds some bytes from the
binary.

   text    data     bss     dec     hex filename
8521472       0       0 8521472  820700 arch/x86/boot/bzImage
8521056       0       0 8521056  820560 arch/x86/boot/bzImage
delta=416B

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 include/linux/skbuff.h | 2 +-
 net/core/dev.c         | 2 +-
 net/core/skbuff.c      | 3 ++-
 net/ipv4/ip_output.c   | 7 +++++--
 net/ipv4/tcp.c         | 5 ++++-
 net/ipv6/ip6_output.c  | 7 +++++--
 6 files changed, 18 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index f5de5c9cc3da..10f94b1909da 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -1649,7 +1649,7 @@  static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb)
 
 static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
 {
-	bool is_zcopy = skb && skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
+	bool is_zcopy = skb_shinfo(skb)->flags & SKBFL_ZEROCOPY_ENABLE;
 
 	return is_zcopy ? skb_uarg(skb) : NULL;
 }
diff --git a/net/core/dev.c b/net/core/dev.c
index 8a5109479dbe..4842a398f08d 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2286,7 +2286,7 @@  void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
 	}
 out_unlock:
 	if (pt_prev) {
-		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
+		if (!skb2 || !skb_orphan_frags_rx(skb2, GFP_ATOMIC))
 			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
 		else
 			kfree_skb(skb2);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 10bde7c6db44..7680314038b4 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -893,7 +893,8 @@  EXPORT_SYMBOL(skb_dump);
  */
 void skb_tx_error(struct sk_buff *skb)
 {
-	skb_zcopy_clear(skb, true);
+	if (skb)
+		skb_zcopy_clear(skb, true);
 }
 EXPORT_SYMBOL(skb_tx_error);
 
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index f864b8c48e42..ab10b1f94669 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1018,10 +1018,13 @@  static int __ip_append_data(struct sock *sk,
 		csummode = CHECKSUM_PARTIAL;
 
 	if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) {
-		uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb));
+		if (skb)
+			uarg = skb_zcopy(skb);
+		extra_uref = !uarg; /* only ref on new uarg */
+
+		uarg = msg_zerocopy_realloc(sk, length, uarg);
 		if (!uarg)
 			return -ENOBUFS;
-		extra_uref = !skb_zcopy(skb);	/* only ref on new uarg */
 		if (rt->dst.dev->features & NETIF_F_SG &&
 		    csummode == CHECKSUM_PARTIAL) {
 			paged = true;
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index cf18fbcbf123..add71b703520 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1205,7 +1205,10 @@  int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
 
 	if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) {
 		skb = tcp_write_queue_tail(sk);
-		uarg = msg_zerocopy_realloc(sk, size, skb_zcopy(skb));
+		if (skb)
+			uarg = skb_zcopy(skb);
+
+		uarg = msg_zerocopy_realloc(sk, size, uarg);
 		if (!uarg) {
 			err = -ENOBUFS;
 			goto out_err;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index e9b039f56637..f1ada6f2af7d 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1520,10 +1520,13 @@  static int __ip6_append_data(struct sock *sk,
 		csummode = CHECKSUM_PARTIAL;
 
 	if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) {
-		uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb));
+		if (skb)
+			uarg = skb_zcopy(skb);
+		extra_uref = !uarg; /* only ref on new uarg */
+
+		uarg = msg_zerocopy_realloc(sk, length, uarg);
 		if (!uarg)
 			return -ENOBUFS;
-		extra_uref = !skb_zcopy(skb);	/* only ref on new uarg */
 		if (rt->dst.dev->features & NETIF_F_SG &&
 		    csummode == CHECKSUM_PARTIAL) {
 			paged = true;