bpf: Simplify insn rewrite on BPF_WRITE __sk_buff->tstamp
authorMartin KaFai Lau <kafai@fb.com>
Wed, 9 Mar 2022 09:05:02 +0000 (01:05 -0800)
committerDaniel Borkmann <daniel@iogearbox.net>
Thu, 10 Mar 2022 21:57:05 +0000 (22:57 +0100)
commit9d90db97e4d4537c82a5ee476b1c13553e487f28
tree5272251f183d4a30a00f500ae407adce4319384e
parent539de9328e3ab444efe51ddc7416ce2a3f0f23b2
bpf: Simplify insn rewrite on BPF_WRITE __sk_buff->tstamp

BPF_JMP32_IMM(BPF_JSET) is used to save a BPF_ALU32_IMM(BPF_AND).

The skb->tc_at_ingress and skb->mono_delivery_time are at the same
offset, so only one BPF_LDX_MEM(BPF_B) is needed.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220309090502.3711982-1-kafai@fb.com
net/core/filter.c