diff options
Diffstat (limited to 'arch/powerpc/net/bpf_jit_comp64.c')
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 96 |
1 files changed, 69 insertions, 27 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 594c54931e20..29ee306d6302 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -360,6 +360,7 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * u32 size = BPF_SIZE(code); u32 tmp1_reg = bpf_to_ppc(TMP_REG_1); u32 tmp2_reg = bpf_to_ppc(TMP_REG_2); + u32 save_reg, ret_reg; s16 off = insn[i].off; s32 imm = insn[i].imm; bool func_addr_fixed; @@ -777,42 +778,83 @@ emit_clear: * BPF_STX ATOMIC (atomic ops) */ case BPF_STX | BPF_ATOMIC | BPF_W: - if (imm != BPF_ADD) { - pr_err_ratelimited( - "eBPF filter atomic op code %02x (@%d) unsupported\n", - code, i); - return -ENOTSUPP; - } - - /* *(u32 *)(dst + off) += src */ + case BPF_STX | BPF_ATOMIC | BPF_DW: + save_reg = tmp2_reg; + ret_reg = src_reg; - /* Get EA into TMP_REG_1 */ - EMIT(PPC_RAW_ADDI(tmp1_reg, dst_reg, off)); + /* Get offset into TMP_REG_1 */ + EMIT(PPC_RAW_LI(tmp1_reg, off)); tmp_idx = ctx->idx * 4; /* load value from memory into TMP_REG_2 */ - EMIT(PPC_RAW_LWARX(tmp2_reg, 0, tmp1_reg, 0)); - /* add value from src_reg into this */ - EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg)); - /* store result back */ - EMIT(PPC_RAW_STWCX(tmp2_reg, 0, tmp1_reg)); - /* we're done if this succeeded */ - PPC_BCC_SHORT(COND_NE, tmp_idx); - break; - case BPF_STX | BPF_ATOMIC | BPF_DW: - if (imm != BPF_ADD) { + if (size == BPF_DW) + EMIT(PPC_RAW_LDARX(tmp2_reg, tmp1_reg, dst_reg, 0)); + else + EMIT(PPC_RAW_LWARX(tmp2_reg, tmp1_reg, dst_reg, 0)); + + /* Save old value in _R0 */ + if (imm & BPF_FETCH) + EMIT(PPC_RAW_MR(_R0, tmp2_reg)); + + switch (imm) { + case BPF_ADD: + case BPF_ADD | BPF_FETCH: + EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_AND: + case BPF_AND | BPF_FETCH: + EMIT(PPC_RAW_AND(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_OR: + case BPF_OR | BPF_FETCH: + EMIT(PPC_RAW_OR(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_XOR: + case BPF_XOR | BPF_FETCH: + EMIT(PPC_RAW_XOR(tmp2_reg, tmp2_reg, src_reg)); + break; + case BPF_CMPXCHG: + /* + * Return old value in BPF_REG_0 for BPF_CMPXCHG & + * in src_reg for other cases. + */ + ret_reg = bpf_to_ppc(BPF_REG_0); + + /* Compare with old value in BPF_R0 */ + if (size == BPF_DW) + EMIT(PPC_RAW_CMPD(bpf_to_ppc(BPF_REG_0), tmp2_reg)); + else + EMIT(PPC_RAW_CMPW(bpf_to_ppc(BPF_REG_0), tmp2_reg)); + /* Don't set if different from old value */ + PPC_BCC_SHORT(COND_NE, (ctx->idx + 3) * 4); + fallthrough; + case BPF_XCHG: + save_reg = src_reg; + break; + default: pr_err_ratelimited( "eBPF filter atomic op code %02x (@%d) unsupported\n", code, i); - return -ENOTSUPP; + return -EOPNOTSUPP; } - /* *(u64 *)(dst + off) += src */ - EMIT(PPC_RAW_ADDI(tmp1_reg, dst_reg, off)); - tmp_idx = ctx->idx * 4; - EMIT(PPC_RAW_LDARX(tmp2_reg, 0, tmp1_reg, 0)); - EMIT(PPC_RAW_ADD(tmp2_reg, tmp2_reg, src_reg)); - EMIT(PPC_RAW_STDCX(tmp2_reg, 0, tmp1_reg)); + /* store new value */ + if (size == BPF_DW) + EMIT(PPC_RAW_STDCX(save_reg, tmp1_reg, dst_reg)); + else + EMIT(PPC_RAW_STWCX(save_reg, tmp1_reg, dst_reg)); + /* we're done if this succeeded */ PPC_BCC_SHORT(COND_NE, tmp_idx); + + if (imm & BPF_FETCH) { + EMIT(PPC_RAW_MR(ret_reg, _R0)); + /* + * Skip unnecessary zero-extension for 32-bit cmpxchg. + * For context, see commit 39491867ace5. + */ + if (size != BPF_DW && imm == BPF_CMPXCHG && + insn_is_zext(&insn[i + 1])) + addrs[++i] = ctx->idx * 4; + } break; /* |