From patchwork Mon May 23 15:20:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 12859166 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 DE24BC433F5 for ; Mon, 23 May 2022 15:21:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237681AbiEWPUy (ORCPT ); Mon, 23 May 2022 11:20:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48670 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237734AbiEWPUx (ORCPT ); Mon, 23 May 2022 11:20:53 -0400 Received: from mx0a-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1AA75DA7F for ; Mon, 23 May 2022 08:20:51 -0700 (PDT) Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.17.1.5/8.17.1.5) with ESMTP id 24N8qlTw026927 for ; Mon, 23 May 2022 08:20:50 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : content-type : content-transfer-encoding : mime-version; s=facebook; bh=LKRfxk7fSTHvRbAUg+0bXFDqYlW0I8BK8H9263ZIg/8=; b=dTM3qJ2oCWrQQ7lS9YbpYPic8w1AtO6pGBeiZCclimhpU8YqTKIyyhLs8fElq/U3CHl5 oOoHIUCro+4wfcFA1r3QGN2ZV0Pw9sU8qi4sUHEE9W151YL9Yamcrg1IrloVCb5R1F/E bj3y4WkXSfZgJEnAcsAgGUDLZHrNqFb36fI= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0089730.ppops.net (PPS) with ESMTPS id 3g6uk7huxk-3 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 23 May 2022 08:20:50 -0700 Received: from twshared24024.25.frc3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::e) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.28; Mon, 23 May 2022 08:20:50 -0700 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 057AEAB381DD; Mon, 23 May 2022 08:20:44 -0700 (PDT) From: Yonghong Song To: CC: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , , Mykola Lysenko Subject: [PATCH bpf-next] selftests/bpf: fix btf_dump/btf_dump due to recent clang change Date: Mon, 23 May 2022 08:20:44 -0700 Message-ID: <20220523152044.3905809-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 X-FB-Internal: Safe X-Proofpoint-ORIG-GUID: F3LjnVWdr03UxwImI31bGn-1huIVM9Ul X-Proofpoint-GUID: F3LjnVWdr03UxwImI31bGn-1huIVM9Ul X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.874,Hydra:6.0.486,FMLib:17.11.64.514 definitions=2022-05-23_06,2022-05-23_01,2022-02-23_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Latest llvm-project upstream had a change of behavior related to qualifiers on function return type ([1]). This caused selftests btf_dump/btf_dump failure. The following example shows what changed. $ cat t.c typedef const char * const (* const (* const fn_ptr_arr2_t[5])())(char * (*)(int)); struct t { int a; fn_ptr_arr2_t l; }; int foo(struct t *arg) { return arg->a; } Compiled with latest upstream llvm15, $ clang -O2 -g -target bpf -S -emit-llvm t.c The related generated debuginfo IR looks like: !16 = !DIDerivedType(tag: DW_TAG_typedef, name: "fn_ptr_arr2_t", file: !1, line: 1, baseType: !17) !17 = !DICompositeType(tag: DW_TAG_array_type, baseType: !18, size: 320, elements: !32) !18 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !19) !19 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !20, size: 64) !20 = !DISubroutineType(types: !21) !21 = !{!22, null} !22 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !23, size: 64) !23 = !DISubroutineType(types: !24) !24 = !{!25, !28} !25 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !26, size: 64) !26 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !27) !27 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char) You can see two intermediate const qualifier to pointer are dropped in debuginfo IR. With llvm14, we have following debuginfo IR: !16 = !DIDerivedType(tag: DW_TAG_typedef, name: "fn_ptr_arr2_t", file: !1, line: 1, baseType: !17) !17 = !DICompositeType(tag: DW_TAG_array_type, baseType: !18, size: 320, elements: !34) !18 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !19) !19 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !20, size: 64) !20 = !DISubroutineType(types: !21) !21 = !{!22, null} !22 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !23) !23 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !24, size: 64) !24 = !DISubroutineType(types: !25) !25 = !{!26, !30} !26 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !27) !27 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !28, size: 64) !28 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !29) !29 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char) All const qualifiers are preserved. To adapt the selftest to both old and new llvm, this patch removed the intermediate const qualifier in const-to-ptr types, to make the test succeed again. [1] https://reviews.llvm.org/D125919 Reported-by: Mykola Lysenko Signed-off-by: Yonghong Song --- tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c index 1c7105fcae3c..4ee4748133fe 100644 --- a/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c +++ b/tools/testing/selftests/bpf/progs/btf_dump_test_case_syntax.c @@ -94,7 +94,7 @@ typedef void (* (*signal_t)(int, void (*)(int)))(int); typedef char * (*fn_ptr_arr1_t[10])(int **); -typedef char * (* const (* const fn_ptr_arr2_t[5])())(char * (*)(int)); +typedef char * (* (* const fn_ptr_arr2_t[5])())(char * (*)(int)); struct struct_w_typedefs { int_t a;