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Diffstat (limited to 'arch/arm64/net/bpf_jit_comp.c')
-rw-r--r--arch/arm64/net/bpf_jit_comp.c54
1 files changed, 36 insertions, 18 deletions
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index a44e5293c6f5..cf3c7d4a1b58 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -1,7 +1,7 @@
/*
* BPF JIT compiler for ARM64
*
- * Copyright (C) 2014 Zi Shen Lim <zlim.lnx@gmail.com>
+ * Copyright (C) 2014-2015 Zi Shen Lim <zlim.lnx@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -225,6 +225,17 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
u8 jmp_cond;
s32 jmp_offset;
+#define check_imm(bits, imm) do { \
+ if ((((imm) > 0) && ((imm) >> (bits))) || \
+ (((imm) < 0) && (~(imm) >> (bits)))) { \
+ pr_info("[%2d] imm=%d(0x%x) out of range\n", \
+ i, imm, imm); \
+ return -EINVAL; \
+ } \
+} while (0)
+#define check_imm19(imm) check_imm(19, imm)
+#define check_imm26(imm) check_imm(26, imm)
+
switch (code) {
/* dst = src */
case BPF_ALU | BPF_MOV | BPF_X:
@@ -258,15 +269,33 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx)
break;
case BPF_ALU | BPF_DIV | BPF_X:
case BPF_ALU64 | BPF_DIV | BPF_X:
- emit(A64_UDIV(is64, dst, dst, src), ctx);
- break;
case BPF_ALU | BPF_MOD | BPF_X:
case BPF_ALU64 | BPF_MOD | BPF_X:
- ctx->tmp_used = 1;
- emit(A64_UDIV(is64, tmp, dst, src), ctx);
- emit(A64_MUL(is64, tmp, tmp, src), ctx);
- emit(A64_SUB(is64, dst, dst, tmp), ctx);
+ {
+ const u8 r0 = bpf2a64[BPF_REG_0];
+
+ /* if (src == 0) return 0 */
+ jmp_offset = 3; /* skip ahead to else path */
+ check_imm19(jmp_offset);
+ emit(A64_CBNZ(is64, src, jmp_offset), ctx);
+ emit(A64_MOVZ(1, r0, 0, 0), ctx);
+ jmp_offset = epilogue_offset(ctx);
+ check_imm26(jmp_offset);
+ emit(A64_B(jmp_offset), ctx);
+ /* else */
+ switch (BPF_OP(code)) {
+ case BPF_DIV:
+ emit(A64_UDIV(is64, dst, dst, src), ctx);
+ break;
+ case BPF_MOD:
+ ctx->tmp_used = 1;
+ emit(A64_UDIV(is64, tmp, dst, src), ctx);
+ emit(A64_MUL(is64, tmp, tmp, src), ctx);
+ emit(A64_SUB(is64, dst, dst, tmp), ctx);
+ break;
+ }
break;
+ }
case BPF_ALU | BPF_LSH | BPF_X:
case BPF_ALU64 | BPF_LSH | BPF_X:
emit(A64_LSLV(is64, dst, dst, src), ctx);
@@ -393,17 +422,6 @@ emit_bswap_uxt:
emit(A64_ASR(is64, dst, dst, imm), ctx);
break;
-#define check_imm(bits, imm) do { \
- if ((((imm) > 0) && ((imm) >> (bits))) || \
- (((imm) < 0) && (~(imm) >> (bits)))) { \
- pr_info("[%2d] imm=%d(0x%x) out of range\n", \
- i, imm, imm); \
- return -EINVAL; \
- } \
-} while (0)
-#define check_imm19(imm) check_imm(19, imm)
-#define check_imm26(imm) check_imm(26, imm)
-
/* JUMP off */
case BPF_JMP | BPF_JA:
jmp_offset = bpf2a64_offset(i + off, i, ctx);