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| author | Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> | 2021-10-05 23:25:23 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-10-07 11:52:26 +0300 |
| commit | 5855c4c1f415ca3ba1046e77c0b3d3dfc96c9025 (patch) | |
| tree | 3f5123b46a801ca6e58a4eff17c6520b90a3b756 | |
| parent | 8bbc9d822421d9ac8ff9ed26a3713c9afc69d6c8 (diff) | |
| download | linux-5855c4c1f415ca3ba1046e77c0b3d3dfc96c9025.tar.xz | |
powerpc/bpf: Fix BPF_SUB when imm == 0x80000000
We aren't handling subtraction involving an immediate value of
0x80000000 properly. Fix the same.
Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fold in fix from Naveen to use imm <= 32768]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fc4b1276eb10761fd7ce0814c8dd089da2815251.1633464148.git.naveen.n.rao@linux.vnet.ibm.com
| -rw-r--r-- | arch/powerpc/net/bpf_jit_comp64.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index d67f6d62e2e1..2ea1c3f6e287 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -330,18 +330,25 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * EMIT(PPC_RAW_SUB(dst_reg, dst_reg, src_reg)); goto bpf_alu32_trunc; case BPF_ALU | BPF_ADD | BPF_K: /* (u32) dst += (u32) imm */ - case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_ADD | BPF_K: /* dst += imm */ + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm >= -32768 && imm < 32768) { + EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm))); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + EMIT(PPC_RAW_ADD(dst_reg, dst_reg, b2p[TMP_REG_1])); + } + goto bpf_alu32_trunc; + case BPF_ALU | BPF_SUB | BPF_K: /* (u32) dst -= (u32) imm */ case BPF_ALU64 | BPF_SUB | BPF_K: /* dst -= imm */ - if (BPF_OP(code) == BPF_SUB) - imm = -imm; - if (imm) { - if (imm >= -32768 && imm < 32768) - EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(imm))); - else { - PPC_LI32(b2p[TMP_REG_1], imm); - EMIT(PPC_RAW_ADD(dst_reg, dst_reg, b2p[TMP_REG_1])); - } + if (!imm) { + goto bpf_alu32_trunc; + } else if (imm > -32768 && imm <= 32768) { + EMIT(PPC_RAW_ADDI(dst_reg, dst_reg, IMM_L(-imm))); + } else { + PPC_LI32(b2p[TMP_REG_1], imm); + EMIT(PPC_RAW_SUB(dst_reg, dst_reg, b2p[TMP_REG_1])); } goto bpf_alu32_trunc; case BPF_ALU | BPF_MUL | BPF_X: /* (u32) dst *= (u32) src */ |