diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 0c5269415090..5fb69a85d967 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5400,15 +5400,37 @@ static int fixup_bpf_calls(struct bpf_verifier_env *env) int i, cnt, delta = 0; for (i = 0; i < insn_cnt; i++, insn++) { - if (insn->code == (BPF_ALU | BPF_MOD | BPF_X) || + if (insn->code == (BPF_ALU64 | BPF_MOD | BPF_X) || + insn->code == (BPF_ALU64 | BPF_DIV | BPF_X) || + insn->code == (BPF_ALU | BPF_MOD | BPF_X) || insn->code == (BPF_ALU | BPF_DIV | BPF_X)) { - /* due to JIT bugs clear upper 32-bits of src register - * before div/mod operation - */ - insn_buf[0] = BPF_MOV32_REG(insn->src_reg, insn->src_reg); - insn_buf[1] = *insn; - cnt = 2; - new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + bool is64 = BPF_CLASS(insn->code) == BPF_ALU64; + struct bpf_insn mask_and_div[] = { + BPF_MOV32_REG(insn->src_reg, insn->src_reg), + /* Rx div 0 -> 0 */ + BPF_JMP_IMM(BPF_JNE, insn->src_reg, 0, 2), + BPF_ALU32_REG(BPF_XOR, insn->dst_reg, insn->dst_reg), + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + *insn, + }; + struct bpf_insn mask_and_mod[] = { + BPF_MOV32_REG(insn->src_reg, insn->src_reg), + /* Rx mod 0 -> Rx */ + BPF_JMP_IMM(BPF_JEQ, insn->src_reg, 0, 1), + *insn, + }; + struct bpf_insn *patchlet; + + if (insn->code == (BPF_ALU64 | BPF_DIV | BPF_X) || + insn->code == (BPF_ALU | BPF_DIV | BPF_X)) { + patchlet = mask_and_div + (is64 ? 1 : 0); + cnt = ARRAY_SIZE(mask_and_div) - (is64 ? 1 : 0); + } else { + patchlet = mask_and_mod + (is64 ? 1 : 0); + cnt = ARRAY_SIZE(mask_and_mod) - (is64 ? 1 : 0); + } + + new_prog = bpf_patch_insn_data(env, i + delta, patchlet, cnt); if (!new_prog) return -ENOMEM; |