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: sta...@vger.kernel.org # v4.8+
Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
---
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 23f7ed796f38..49d65cd08ee0 100644
--- a/arch/powerpc/include/asm/ppc-opcode.h
+++ b/arch/powerpc/include/asm/ppc-opcode.h
@@ -342,6 +342,7 @@
#define PPC_INST_MADDLD 0x10000033
#define PPC_INST_DIVWU 0x7c000396
#define PPC_INST_DIVD 0x7c0003d2
+#define PPC_INST_DIVDU 0x7c000392
#define PPC_INST_RLWINM 0x54000000
#define PPC_INST_RLWINM_DOT 0x54000001
#define PPC_INST_RLWIMI 0x50000000
diff --git a/arch/powerpc/net/bpf_jit.h b/arch/powerpc/net/bpf_jit.h
index dcac37745b05..1e932898d430 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 0ebd946f178b..b0fa4723d6fb 100644
--- a/arch/powerpc/net/bpf_jit_comp64.c
+++ b/arch/powerpc/net/bpf_jit_comp64.c
@@ -399,12 +399,12 @@ static int bpf_jit_build_body(struct bpf_prog *fp, u32
*image,
case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */
case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */
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 */
@@ -432,7 +432,7 @@ 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],
@@ -440,7 +440,7 @@ 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;
}
--
2.21.0
