[PATCH 5.4 05/51] powerpc/bpf: Fix BPF_MOD when imm == 1
From: Greg Kroah-Hartman
Date: Mon Nov 01 2021 - 05:29:05 EST
From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
commit 8bbc9d822421d9ac8ff9ed26a3713c9afc69d6c8 upstream.
Only ignore the operation if dividing by 1.
Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF")
Signed-off-by: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
Tested-by: Johan Almbladh <johan.almbladh@xxxxxxxxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Acked-by: Song Liu <songliubraving@xxxxxx>
Acked-by: Johan Almbladh <johan.almbladh@xxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/c674ca18c3046885602caebb326213731c675d06.1633464148.git.naveen.n.rao@xxxxxxxxxxxxxxxxxx
[cascardo: use PPC_LI instead of EMIT(PPC_RAW_LI)]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/net/bpf_jit_comp64.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -408,8 +408,14 @@ static int bpf_jit_build_body(struct bpf
case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */
if (imm == 0)
return -EINVAL;
- else if (imm == 1)
- goto bpf_alu32_trunc;
+ if (imm == 1) {
+ if (BPF_OP(code) == BPF_DIV) {
+ goto bpf_alu32_trunc;
+ } else {
+ PPC_LI(dst_reg, 0);
+ break;
+ }
+ }
PPC_LI32(b2p[TMP_REG_1], imm);
switch (BPF_CLASS(code)) {