[PATCH 5.10 73/83] powerpc/bpf: Fix BPF_MOD when imm == 1
From: Greg Kroah-Hartman
Date: Mon Oct 11 2021 - 09:59:05 EST
From: Naveen N. Rao <naveen.n.rao@xxxxxxxxxxxxxxxxxx>
[ Upstream commit 8bbc9d822421d9ac8ff9ed26a3713c9afc69d6c8 ]
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
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/powerpc/net/bpf_jit_comp64.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
index 658ca2bab13c..e79f9eae2bc0 100644
--- 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_prog *fp, u32 *image,
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 {
+ EMIT(PPC_RAW_LI(dst_reg, 0));
+ break;
+ }
+ }
PPC_LI32(b2p[TMP_REG_1], imm);
switch (BPF_CLASS(code)) {
--
2.33.0