From patchwork Tue Jan 4 01:42:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 12702891 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A2D4C433FE for ; Tue, 4 Jan 2022 01:27:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231731AbiADB1Y (ORCPT ); Mon, 3 Jan 2022 20:27:24 -0500 Received: from szxga08-in.huawei.com ([45.249.212.255]:31065 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229617AbiADB1X (ORCPT ); Mon, 3 Jan 2022 20:27:23 -0500 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4JSZdS28Xsz1DKM0; Tue, 4 Jan 2022 09:23:56 +0800 (CST) Received: from huawei.com (10.175.124.27) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Tue, 4 Jan 2022 09:27:20 +0800 From: Hou Tao To: Alexei Starovoitov CC: Martin KaFai Lau , Yonghong Song , Daniel Borkmann , Andrii Nakryiko , "David S . Miller" , Jakub Kicinski , , , , Zi Shen Lim , Catalin Marinas , Will Deacon , Subject: [PATCH bpf] bpf, arm64: calculate offset as byte-offset for bpf line info Date: Tue, 4 Jan 2022 09:42:36 +0800 Message-ID: <20220104014236.1512639-1-houtao1@huawei.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500025.china.huawei.com (7.185.36.35) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net The bpf line info for arm64 is broken due to two reasons: (1) insn_to_jit_off passed to bpf_prog_fill_jited_linfo() is calculated in instruction granularity instead of bytes granularity. (2) insn_to_jit_off only considers the body itself and ignores prologue before the body. So fix it by calculating offset as byte-offset and do build_prologue() first in the first JIT pass. Fixes: 37ab566c178d ("bpf: arm64: Enable arm64 jit to provide bpf_line_info") Signed-off-by: Hou Tao --- arch/arm64/net/bpf_jit_comp.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 148ca51325bb..d7a6d4b523c9 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -24,6 +24,8 @@ #include "bpf_jit.h" +#define INSN_SZ (sizeof(u32)) + #define TMP_REG_1 (MAX_BPF_JIT_REG + 0) #define TMP_REG_2 (MAX_BPF_JIT_REG + 1) #define TCALL_CNT (MAX_BPF_JIT_REG + 2) @@ -154,10 +156,11 @@ static inline int bpf2a64_offset(int bpf_insn, int off, bpf_insn++; /* * Whereas arm64 branch instructions encode the offset - * from the branch itself, so we must subtract 1 from the + * from the branch itself, so we must subtract 4 from the * instruction offset. */ - return ctx->offset[bpf_insn + off] - (ctx->offset[bpf_insn] - 1); + return (ctx->offset[bpf_insn + off] - + (ctx->offset[bpf_insn] - INSN_SZ)) / INSN_SZ; } static void jit_fill_hole(void *area, unsigned int size) @@ -955,13 +958,14 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass) const struct bpf_insn *insn = &prog->insnsi[i]; int ret; + /* BPF line info needs byte-offset instead of insn-offset */ if (ctx->image == NULL) - ctx->offset[i] = ctx->idx; + ctx->offset[i] = ctx->idx * INSN_SZ; ret = build_insn(insn, ctx, extra_pass); if (ret > 0) { i++; if (ctx->image == NULL) - ctx->offset[i] = ctx->idx; + ctx->offset[i] = ctx->idx * INSN_SZ; continue; } if (ret) @@ -973,7 +977,7 @@ static int build_body(struct jit_ctx *ctx, bool extra_pass) * instruction (end of program) */ if (ctx->image == NULL) - ctx->offset[i] = ctx->idx; + ctx->offset[i] = ctx->idx * INSN_SZ; return 0; } @@ -1058,15 +1062,18 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) goto out_off; } - /* 1. Initial fake pass to compute ctx->idx. */ - - /* Fake pass to fill in ctx->offset. */ - if (build_body(&ctx, extra_pass)) { + /* + * 1. Initial fake pass to compute ctx->idx and ctx->offset. + * + * BPF line info needs ctx->offset[i] to be the byte offset + * of instruction[i] in jited image, so build prologue first. + */ + if (build_prologue(&ctx, was_classic)) { prog = orig_prog; goto out_off; } - if (build_prologue(&ctx, was_classic)) { + if (build_body(&ctx, extra_pass)) { prog = orig_prog; goto out_off; }