From patchwork Sat Oct 3 02:19:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 11814891 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 306F36CB for ; Sat, 3 Oct 2020 02:19:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11F052074B for ; Sat, 3 Oct 2020 02:19:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="BKglzgri" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725801AbgJCCTH (ORCPT ); Fri, 2 Oct 2020 22:19:07 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:38862 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725536AbgJCCTH (ORCPT ); Fri, 2 Oct 2020 22:19:07 -0400 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.0.42/8.16.0.42) with SMTP id 0932CDmF000965 for ; Fri, 2 Oct 2020 19:19:06 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=facebook; bh=NOWjPhkMde+qKCxOunFWPTDpqcuSgcVCE4Bvgmb1gyQ=; b=BKglzgrihw3J/m1e63Of/eI3fxFOqXaK1xU5mFBEg6fnEdwQSWzr8GNK/g/OSKoVf3uv uE5pOqMEBfBAr/fxfbLChG3YlveL/mAUalkamOBebWGJL1IAi+vAAtTo7oQVIGrCt8LB Z5GHTGhRO+Xy8bCkC88ff5ol8Qn6z/iA5ws= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0001303.ppops.net with ESMTP id 33w05ndq04-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Fri, 02 Oct 2020 19:19:05 -0700 Received: from intmgw001.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Fri, 2 Oct 2020 19:19:05 -0700 Received: by devbig003.ftw2.facebook.com (Postfix, from userid 128203) id BD76E3705C29; Fri, 2 Oct 2020 19:19:04 -0700 (PDT) From: Yonghong Song To: , CC: Alexei Starovoitov , Daniel Borkmann , Subject: [PATCH bpf-next 1/2] samples/bpf: change Makefile to cope with latest llvm Date: Fri, 2 Oct 2020 19:19:04 -0700 Message-ID: <20201003021904.1468678-1-yhs@fb.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-10-02_14:2020-10-02,2020-10-02 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=0 priorityscore=1501 mlxlogscore=999 impostorscore=0 spamscore=0 bulkscore=0 lowpriorityscore=0 clxscore=1015 mlxscore=0 malwarescore=0 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2010030019 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org With latest llvm trunk, bpf programs under samples/bpf directory, if using CORE, may experience the following errors: LLVM ERROR: Cannot select: intrinsic %llvm.preserve.struct.access.index PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace. Stack dump: 0. Program arguments: llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o 1. Running pass 'Function Pass Manager' on module ''. 2. Running pass 'BPF DAG->DAG Pattern Instruction Selection' on function '@bpf_prog1' #0 0x000000000183c26c llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x183c26c) ... #7 0x00000000017c375e (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x17c375e) #8 0x00000000016a75c5 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16a75c5) #9 0x00000000016ab4f8 llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*, unsigned int) (/data/users/yhs/work/llvm-project/llvm/build.cur/install/bin/llc+0x16ab4f8) ... Aborted (core dumped) | llc -march=bpf -filetype=obj -o samples/bpf/test_probe_write_user_kern.o The reason is due to llvm change https://reviews.llvm.org/D87153 where the CORE relocation global generation is moved from the beginning of target dependent optimization (llc) to the beginning of target independent optimization (opt). Since samples/bpf programs did not use vmlinux.h and its clang compilation uses native architecture, we need to adjust arch triple at opt level to do CORE relocation global generation properly. Otherwise, the above error will appear. This patch fixed the issue by introduce opt and llvm-dis to compilation chain, which will do proper CORE relocation global generation as well as O2 level optimization. Tested with llvm10, llvm11 and trunk/llvm12. Signed-off-by: Yonghong Song Acked-by: Andrii Nakryiko --- samples/bpf/Makefile | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 4f1ed0e3cf9f..79c5fdea63d2 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -211,6 +211,8 @@ TPROGLDLIBS_xsk_fwd += -pthread # make M=samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang LLC ?= llc CLANG ?= clang +OPT ?= opt +LLVM_DIS ?= llvm-dis LLVM_OBJCOPY ?= llvm-objcopy BTF_PAHOLE ?= pahole @@ -314,7 +316,9 @@ $(obj)/%.o: $(src)/%.c -Wno-address-of-packed-member -Wno-tautological-compare \ -Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \ -I$(srctree)/samples/bpf/ -include asm_goto_workaround.h \ - -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@ + -O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \ + $(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \ + $(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@ ifeq ($(DWARF2BTF),y) $(BTF_PAHOLE) -J $@ endif