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From: Martin KaFai Lau <kafai@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Eric Dumazet <edumazet@google.com>, <kernel-team@fb.com>,
	Lawrence Brakmo <brakmo@fb.com>,
	Neal Cardwell <ncardwell@google.com>, <netdev@vger.kernel.org>,
	Yuchung Cheng <ycheng@google.com>
Subject: [PATCH bpf-next 03/10] bpf: sock_ops: Change some members of sock_ops_kern from u32 to u8
Date: Fri, 26 Jun 2020 10:55:20 -0700	[thread overview]
Message-ID: <20200626175520.1460850-1-kafai@fb.com> (raw)
In-Reply-To: <20200626175501.1459961-1-kafai@fb.com>

A latter patch needs to add a few pointers and a few u8 to
sock_ops_kern.  Hence, this patch saves some spaces by moving
some of the existing members from u32 to u8 so that the latter
patch can still fit everything in a cacheline.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
---
 include/linux/filter.h |  4 ++--
 net/core/filter.c      | 15 ++++++++++-----
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index 259377723603..aae52cbda670 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -1236,13 +1236,13 @@ struct bpf_sock_addr_kern {
 
 struct bpf_sock_ops_kern {
 	struct	sock *sk;
-	u32	op;
 	union {
 		u32 args[4];
 		u32 reply;
 		u32 replylong[4];
 	};
-	u32	is_fullsock;
+	u8	op;
+	u8	is_fullsock;
 	u64	temp;			/* temp and everything after is not
 					 * initialized to 0 before calling
 					 * the BPF program. New fields that
diff --git a/net/core/filter.c b/net/core/filter.c
index 19dbcc8448d8..1dd07972c5c7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -8355,17 +8355,22 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
 		return insn - insn_buf;
 
 	switch (si->off) {
-	case offsetof(struct bpf_sock_ops, op) ...
+	case offsetof(struct bpf_sock_ops, op):
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(struct bpf_sock_ops_kern,
+						       op),
+				      si->dst_reg, si->src_reg,
+				      offsetof(struct bpf_sock_ops_kern, op));
+		break;
+
+	case offsetof(struct bpf_sock_ops, replylong[0]) ...
 	     offsetof(struct bpf_sock_ops, replylong[3]):
-		BUILD_BUG_ON(sizeof_field(struct bpf_sock_ops, op) !=
-			     sizeof_field(struct bpf_sock_ops_kern, op));
 		BUILD_BUG_ON(sizeof_field(struct bpf_sock_ops, reply) !=
 			     sizeof_field(struct bpf_sock_ops_kern, reply));
 		BUILD_BUG_ON(sizeof_field(struct bpf_sock_ops, replylong) !=
 			     sizeof_field(struct bpf_sock_ops_kern, replylong));
 		off = si->off;
-		off -= offsetof(struct bpf_sock_ops, op);
-		off += offsetof(struct bpf_sock_ops_kern, op);
+		off -= offsetof(struct bpf_sock_ops, replylong[0]);
+		off += offsetof(struct bpf_sock_ops_kern, replylong[0]);
 		if (type == BPF_WRITE)
 			*insn++ = BPF_STX_MEM(BPF_W, si->dst_reg, si->src_reg,
 					      off);
-- 
2.24.1


  parent reply	other threads:[~2020-06-26 17:55 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-26 17:55 [PATCH bpf-next 00/10] BPF TCP header options Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 01/10] tcp: Use a struct to represent a saved_syn Martin KaFai Lau
2020-06-27 17:41   ` Eric Dumazet
2020-06-30 23:24     ` Martin KaFai Lau
2020-06-30 23:35       ` Eric Dumazet
2020-06-26 17:55 ` [PATCH bpf-next 02/10] tcp: bpf: Parse BPF experimental header option Martin KaFai Lau
2020-06-27 16:44   ` Eric Dumazet
2020-06-27 17:17   ` Eric Dumazet
2020-06-28 23:44     ` Martin KaFai Lau
2020-06-29  0:45     ` Martin KaFai Lau
2020-06-26 17:55 ` Martin KaFai Lau [this message]
2020-06-26 17:55 ` [PATCH bpf-next 04/10] bpf: tcp: Allow bpf prog to write and parse BPF TCP " Martin KaFai Lau
2020-06-28 18:24   ` Alexei Starovoitov
2020-06-29  0:34     ` Martin KaFai Lau
2020-07-02  5:31       ` Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 05/10] bpf: selftests: A few improvements to network_helpers.c Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 06/10] bpf: selftests: Add fastopen_connect to network_helpers Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 07/10] bpf: selftests: Restore netns after each test Martin KaFai Lau
2020-06-26 22:45   ` Andrii Nakryiko
2020-06-27  0:23     ` Martin KaFai Lau
2020-06-27 20:31       ` Andrii Nakryiko
2020-06-29 18:00         ` Martin KaFai Lau
2020-06-29 18:13           ` Andrii Nakryiko
2020-06-29 18:24             ` Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 08/10] bpf: selftests: tcp header options Martin KaFai Lau
2020-06-26 17:55 ` [PATCH bpf-next 09/10] tcp: bpf: Add TCP_BPF_DELACK_MAX and TCP_BPF_RTO_MIN to bpf_setsockopt Martin KaFai Lau
2020-06-27 17:30   ` Eric Dumazet
2020-06-26 17:56 ` [PATCH bpf-next 10/10] bpf: selftest: Add test for TCP_BPF_DELACK_MAX and TCP_BPF_RTO_MIN Martin KaFai Lau

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