Re: [PATCH 5/9] powerpc/bpf: Fix BPF_MOD when imm == 1
From: Song Liu <song@kernel.org>
Date: 2021-10-01 21:55:24
Also in:
bpf
On Fri, Oct 1, 2021 at 2:16 PM Naveen N. Rao [off-list ref] wrote:
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 <redacted>Acked-by: Song Liu <redacted>
quoted hunk ↗ jump to hunk
--- 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 3351a866ef6207..ffb7a2877a8469 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c@@ -391,8 +391,14 @@ int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, struct codegen_context * 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