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| author | Yonghong Song <yonghong.song@linux.dev> | 2023-07-27 18:12:19 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2023-07-27 18:52:33 -0700 |
| commit | ec0e2da95f72d4a46050a4d994e4fe471474fd80 (patch) | |
| tree | f61640998fc71caa7506d67a1bd2668ca1adcce6 /kernel/bpf/verifier.c | |
| parent | 0845c3db7bf5c4ceb7100bcd8fd594d9ccf3c29a (diff) | |
| download | lwn-ec0e2da95f72d4a46050a4d994e4fe471474fd80.tar.gz lwn-ec0e2da95f72d4a46050a4d994e4fe471474fd80.zip | |
bpf: Support new signed div/mod instructions.
Add interpreter/jit support for new signed div/mod insns.
The new signed div/mod instructions are encoded with
unsigned div/mod instructions plus insn->off == 1.
Also add basic verifier support to ensure new insns get
accepted.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230728011219.3714605-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a3dcaeed8217..c0aceedfcb9c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13237,7 +13237,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) } else { /* all other ALU ops: and, sub, xor, add, ... */ if (BPF_SRC(insn->code) == BPF_X) { - if (insn->imm != 0 || insn->off != 0) { + if (insn->imm != 0 || insn->off > 1 || + (insn->off == 1 && opcode != BPF_MOD && opcode != BPF_DIV)) { verbose(env, "BPF_ALU uses reserved fields\n"); return -EINVAL; } @@ -13246,7 +13247,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) if (err) return err; } else { - if (insn->src_reg != BPF_REG_0 || insn->off != 0) { + if (insn->src_reg != BPF_REG_0 || insn->off > 1 || + (insn->off == 1 && opcode != BPF_MOD && opcode != BPF_DIV)) { verbose(env, "BPF_ALU uses reserved fields\n"); return -EINVAL; } |