From e90a7ecde5f361a7044e169fe6000036ceb69794 Mon Sep 17 00:00:00 2001 From: "Naveen N. Rao" Date: Thu, 13 Jun 2019 00:21:40 +0530 Subject: [PATCH] powerpc/bpf: use unsigned division instruction for 64-bit operations commit 758f2046ea040773ae8ea7f72dd3bbd8fa984501 upstream. BPF_ALU64 div/mod operations are currently using signed division, unlike BPF_ALU32 operations. Fix the same. DIV64 and MOD64 overflow tests pass with this fix. Fixes: 156d0e290e969c ("powerpc/ebpf/jit: Implement JIT compiler for extended BPF") Cc: stable@vger.kernel.org # v4.8+ Signed-off-by: Naveen N. Rao Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/ppc-opcode.h | 1 + arch/powerpc/net/bpf_jit.h | 2 +- arch/powerpc/net/bpf_jit_comp64.c | 8 ++++---- 3 files changed, 6 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h index 48e8f1f..b706759 100644 --- a/arch/powerpc/include/asm/ppc-opcode.h +++ b/arch/powerpc/include/asm/ppc-opcode.h @@ -261,6 +261,7 @@ #define PPC_INST_MULLI 0x1c000000 #define PPC_INST_DIVWU 0x7c000396 #define PPC_INST_DIVD 0x7c0003d2 +#define PPC_INST_DIVDU 0x7c000392 #define PPC_INST_RLWINM 0x54000000 #define PPC_INST_RLWIMI 0x50000000 #define PPC_INST_RLDICL 0x78000000 diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h index 7b1d172..83e5b25 100644 --- a/arch/powerpc/net/bpf_jit.h +++ b/arch/powerpc/net/bpf_jit.h @@ -116,7 +116,7 @@ ___PPC_RA(a) | IMM_L(i)) #define PPC_DIVWU(d, a, b) EMIT(PPC_INST_DIVWU | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) -#define PPC_DIVD(d, a, b) EMIT(PPC_INST_DIVD | ___PPC_RT(d) | \ +#define PPC_DIVDU(d, a, b) EMIT(PPC_INST_DIVDU | ___PPC_RT(d) | \ ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_AND(d, a, b) EMIT(PPC_INST_AND | ___PPC_RA(d) | \ ___PPC_RS(a) | ___PPC_RB(b)) diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index e7d78f9..9f0810c 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -419,12 +419,12 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, PPC_LI(b2p[BPF_REG_0], 0); PPC_JMP(exit_addr); if (BPF_OP(code) == BPF_MOD) { - PPC_DIVD(b2p[TMP_REG_1], dst_reg, src_reg); + PPC_DIVDU(b2p[TMP_REG_1], dst_reg, src_reg); PPC_MULD(b2p[TMP_REG_1], src_reg, b2p[TMP_REG_1]); PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); } else - PPC_DIVD(dst_reg, dst_reg, src_reg); + PPC_DIVDU(dst_reg, dst_reg, src_reg); break; case BPF_ALU | BPF_MOD | BPF_K: /* (u32) dst %= (u32) imm */ case BPF_ALU | BPF_DIV | BPF_K: /* (u32) dst /= (u32) imm */ @@ -452,7 +452,7 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, break; case BPF_ALU64: if (BPF_OP(code) == BPF_MOD) { - PPC_DIVD(b2p[TMP_REG_2], dst_reg, + PPC_DIVDU(b2p[TMP_REG_2], dst_reg, b2p[TMP_REG_1]); PPC_MULD(b2p[TMP_REG_1], b2p[TMP_REG_1], @@ -460,7 +460,7 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32 *image, PPC_SUB(dst_reg, dst_reg, b2p[TMP_REG_1]); } else - PPC_DIVD(dst_reg, dst_reg, + PPC_DIVDU(dst_reg, dst_reg, b2p[TMP_REG_1]); break; } -- 2.7.4