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: Martin KaFai Lau <kafai@xxxxxx>
---
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 0a355b005bf4..c427dfa5f908 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 075ab71b985c..1608f4b3987f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -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);
--
2.24.1
