diff options
| author | Jiong Wang <jiong.wang@netronome.com> | 2019-02-22 22:36:04 +0000 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2019-02-23 00:07:47 +0100 |
| commit | f036ebd9bfbe1e91a3d855e85e05fc5ff156b641 (patch) | |
| tree | b676669c186253e4a40026c2f70da6b88b5bf933 | |
| parent | 71c190249f0ced5b26377ea6bf829ab3af77a40c (diff) | |
| download | lwn-f036ebd9bfbe1e91a3d855e85e05fc5ff156b641.tar.gz lwn-f036ebd9bfbe1e91a3d855e85e05fc5ff156b641.zip | |
nfp: bpf: fix ALU32 high bits clearance bug
NFP BPF JIT compiler is doing a couple of small optimizations when jitting
ALU imm instructions, some of these optimizations could save code-gen, for
example:
A & -1 = A
A | 0 = A
A ^ 0 = A
However, for ALU32, high 32-bit of the 64-bit register should still be
cleared according to ISA semantics.
Fixes: cd7df56ed3e6 ("nfp: add BPF to NFP code translator")
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
| -rw-r--r-- | drivers/net/ethernet/netronome/nfp/bpf/jit.c | 17 |
1 files changed, 6 insertions, 11 deletions
diff --git a/drivers/net/ethernet/netronome/nfp/bpf/jit.c b/drivers/net/ethernet/netronome/nfp/bpf/jit.c index a09696540171..0a868c829b90 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/jit.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/jit.c @@ -1291,15 +1291,10 @@ wrp_alu64_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, static int wrp_alu32_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta, - enum alu_op alu_op, bool skip) + enum alu_op alu_op) { const struct bpf_insn *insn = &meta->insn; - if (skip) { - meta->skip = true; - return 0; - } - wrp_alu_imm(nfp_prog, insn->dst_reg * 2, alu_op, insn->imm); wrp_immed(nfp_prog, reg_both(insn->dst_reg * 2 + 1), 0); @@ -2309,7 +2304,7 @@ static int xor_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int xor_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR, !meta->insn.imm); + return wrp_alu32_imm(nfp_prog, meta, ALU_OP_XOR); } static int and_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) @@ -2319,7 +2314,7 @@ static int and_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int and_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - return wrp_alu32_imm(nfp_prog, meta, ALU_OP_AND, !~meta->insn.imm); + return wrp_alu32_imm(nfp_prog, meta, ALU_OP_AND); } static int or_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) @@ -2329,7 +2324,7 @@ static int or_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int or_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - return wrp_alu32_imm(nfp_prog, meta, ALU_OP_OR, !meta->insn.imm); + return wrp_alu32_imm(nfp_prog, meta, ALU_OP_OR); } static int add_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) @@ -2339,7 +2334,7 @@ static int add_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int add_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - return wrp_alu32_imm(nfp_prog, meta, ALU_OP_ADD, !meta->insn.imm); + return wrp_alu32_imm(nfp_prog, meta, ALU_OP_ADD); } static int sub_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) @@ -2349,7 +2344,7 @@ static int sub_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) static int sub_imm(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) { - return wrp_alu32_imm(nfp_prog, meta, ALU_OP_SUB, !meta->insn.imm); + return wrp_alu32_imm(nfp_prog, meta, ALU_OP_SUB); } static int mul_reg(struct nfp_prog *nfp_prog, struct nfp_insn_meta *meta) |