Commit c9985d09 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: sock_ops: Change some members of sock_ops_kern from u32 to u8 



A later 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 later
patch can still fit everything in a cacheline.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200820190058.2885640-1-kafai@fb.com
parent 331fca43

include/linux/filter.h

+2 −2
Original line number Diff line number Diff line
@@ -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

net/core/filter.c

+10 −5
Original line number Diff line number Diff line
@@ -8465,17 +8465,22 @@ 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);

CRA Git | Maintained and supported by SUSTech CRA and CCSE