[PATCH bpf-next] bpf: Simplify expression for identify bpf mem type
From: Jianlin Lv <hidden>
Date: 2021-03-17 12:52:49
Also in:
bpf, linux-api, lkml
Subsystem:
bpf jit for nfp nics, bpf [core], bpf [general] (safe dynamic programs and tools), netronome ethernet drivers, networking drivers, the rest · Maintainers:
Jakub Kicinski, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Andrew Lunn, "David S. Miller", Eric Dumazet, Paolo Abeni, Linus Torvalds
Added BPF_SIZE_MASK macro as mask of size modifier that help to reduce the evaluation of expressions in if statements, and remove BPF_SIZE_MASK in netronome driver. Signed-off-by: Jianlin Lv <redacted> --- drivers/net/ethernet/netronome/nfp/bpf/main.h | 2 -- include/uapi/linux/bpf.h | 1 + kernel/bpf/verifier.c | 12 ++++-------- 3 files changed, 5 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/main.h b/drivers/net/ethernet/netronome/nfp/bpf/main.h
index d0e17eebddd9..8b1c2509ce46 100644
--- a/drivers/net/ethernet/netronome/nfp/bpf/main.h
+++ b/drivers/net/ethernet/netronome/nfp/bpf/main.h@@ -346,8 +346,6 @@ struct nfp_insn_meta { struct list_head l; }; -#define BPF_SIZE_MASK 0x18 - static inline u8 mbpf_class(const struct nfp_insn_meta *meta) { return BPF_CLASS(meta->insn.code);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 2d3036e292a9..5d77675e7112 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -21,6 +21,7 @@ #define BPF_DW 0x18 /* double word (64-bit) */ #define BPF_ATOMIC 0xc0 /* atomic memory ops - op type in immediate */ #define BPF_XADD 0xc0 /* exclusive add - legacy name */ +#define BPF_SIZE_MASK 0x18 /* mask of size modifier */ /* alu/jmp fields */ #define BPF_MOV 0xb0 /* mov reg to reg */
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index f9096b049cd6..9755bb4d7de4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -11384,15 +11384,11 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) for (i = 0; i < insn_cnt; i++, insn++) { bpf_convert_ctx_access_t convert_ctx_access; - if (insn->code == (BPF_LDX | BPF_MEM | BPF_B) || - insn->code == (BPF_LDX | BPF_MEM | BPF_H) || - insn->code == (BPF_LDX | BPF_MEM | BPF_W) || - insn->code == (BPF_LDX | BPF_MEM | BPF_DW)) + /* opcode: BPF_MEM | <size> | BPF_LDX */ + if ((insn->code & ~BPF_SIZE_MASK) == (BPF_LDX | BPF_MEM)) type = BPF_READ; - else if (insn->code == (BPF_STX | BPF_MEM | BPF_B) || - insn->code == (BPF_STX | BPF_MEM | BPF_H) || - insn->code == (BPF_STX | BPF_MEM | BPF_W) || - insn->code == (BPF_STX | BPF_MEM | BPF_DW)) + /* opcode: BPF_MEM | <size> | BPF_STX */ + else if ((insn->code & ~BPF_SIZE_MASK) == (BPF_STX | BPF_MEM)) type = BPF_WRITE; else continue;
--
2.25.1