From 30d3d94cc3d507a23dcb09e5c365464e4aa9f580 Mon Sep 17 00:00:00 2001 From: Zi Shen Lim Date: Tue, 16 Sep 2014 21:29:23 +0100 Subject: [PATCH] arm64: bpf: add 'load 64-bit immediate' instruction Commit 02ab695bb37e (net: filter: add "load 64-bit immediate" eBPF instruction) introduced a new eBPF instruction. Let's add support for this for arm64 as well. Our arm64 eBPF JIT compiler now passes the new "load 64-bit immediate" test case introduced in the same commit 02ab695bb37e. Signed-off-by: Zi Shen Lim Cc: Will Deacon Cc: David S. Miller Cc: Alexei Starovoitov Signed-off-by: Catalin Marinas --- arch/arm64/net/bpf_jit_comp.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 80cc76972798..618d2cdc2f1b 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -205,6 +205,12 @@ static void build_epilogue(struct jit_ctx *ctx) emit(A64_RET(A64_LR), ctx); } +/* JITs an eBPF instruction. + * Returns: + * 0 - successfully JITed an 8-byte eBPF instruction. + * >0 - successfully JITed a 16-byte eBPF instruction. + * <0 - failed to JIT. + */ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) { const u8 code = insn->code; @@ -464,6 +470,27 @@ static int build_insn(const struct bpf_insn *insn, struct jit_ctx *ctx) emit(A64_B(jmp_offset), ctx); break; + /* dst = imm64 */ + case BPF_LD | BPF_IMM | BPF_DW: + { + const struct bpf_insn insn1 = insn[1]; + u64 imm64; + + if (insn1.code != 0 || insn1.src_reg != 0 || + insn1.dst_reg != 0 || insn1.off != 0) { + /* Note: verifier in BPF core must catch invalid + * instructions. + */ + pr_err_once("Invalid BPF_LD_IMM64 instruction\n"); + return -EINVAL; + } + + imm64 = (u64)insn1.imm << 32 | imm; + emit_a64_mov_i64(dst, imm64, ctx); + + return 1; + } + /* LDX: dst = *(size *)(src + off) */ case BPF_LDX | BPF_MEM | BPF_W: case BPF_LDX | BPF_MEM | BPF_H: @@ -615,6 +642,10 @@ static int build_body(struct jit_ctx *ctx) ctx->offset[i] = ctx->idx; ret = build_insn(insn, ctx); + if (ret > 0) { + i++; + continue; + } if (ret) return ret; } -- GitLab