From patchwork Tue Nov 23 04:56:17 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 12633429 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 316CEC433FE for ; Tue, 23 Nov 2021 04:56:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232042AbhKWE73 (ORCPT ); Mon, 22 Nov 2021 23:59:29 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:39686 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232196AbhKWE73 (ORCPT ); Mon, 22 Nov 2021 23:59:29 -0500 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1AN1AAvB032287 for ; Mon, 22 Nov 2021 20:56:21 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=a78C0wwhT21pTsAPYqJfGkREY3KHax2NpA1BpwS6jbI=; b=RZSiXQw9rWwDu+/3zi4slA/ooYK7dHSD0EjOWSDEAK7hr70dj+UPuAoEr1TvAIEhulRQ QnYqsQ+ka7B0zBG45pqj4W2HlxJ3jkFtT/c6CpmzLM3Syhb8iMFiNiuGii0hI2ZT79In oK6Z3pT2ZTkY7+5HVbkV8Ag11OLId4XFWWc= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3cgpcy0vkx-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 22 Nov 2021 20:56:21 -0800 Received: from intmgw001.25.frc3.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::4) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Mon, 22 Nov 2021 20:56:18 -0800 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 8CF322CD4951; Mon, 22 Nov 2021 20:56:17 -0800 (PST) From: Yonghong Song To: Arnaldo Carvalho de Melo , CC: Alexei Starovoitov , Andrii Nakryiko , , Daniel Borkmann , Subject: [PATCH dwarves v2 1/4] libbpf: sync with latest libbpf repo Date: Mon, 22 Nov 2021 20:56:17 -0800 Message-ID: <20211123045617.1387921-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211123045612.1387544-1-yhs@fb.com> References: <20211123045612.1387544-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-FB-Source: Intern X-Proofpoint-ORIG-GUID: BZMBDavH62mhYOQZB2sYUhMHBndNLU0N X-Proofpoint-GUID: BZMBDavH62mhYOQZB2sYUhMHBndNLU0N X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-23_01,2021-11-22_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxlogscore=791 suspectscore=0 spamscore=0 clxscore=1015 phishscore=0 priorityscore=1501 impostorscore=0 lowpriorityscore=0 mlxscore=0 bulkscore=0 adultscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111230025 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Sync up to commit 94a49850c5ee ("Makefile: enforce gnu89 standard"). This is needed to support BTF_KIND_TYPE_TAG. Signed-off-by: Yonghong Song --- lib/bpf | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/bpf b/lib/bpf index f05791d..94a4985 160000 --- a/lib/bpf +++ b/lib/bpf @@ -1 +1 @@ -Subproject commit f05791d8cfcbbf9092b4099b9d011bb72e241ef8 +Subproject commit 94a49850c5ee61ea02dfcbabf48013391e8cecdf From patchwork Tue Nov 23 04:56:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 12633431 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 95771C433FE for ; Tue, 23 Nov 2021 04:56:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232503AbhKWE7f (ORCPT ); Mon, 22 Nov 2021 23:59:35 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:29760 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S232317AbhKWE7e (ORCPT ); Mon, 22 Nov 2021 23:59:34 -0500 Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.16.1.2/8.16.1.2) with SMTP id 1AN13biX000986 for ; Mon, 22 Nov 2021 20:56:27 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=B92FYu3iv8rxoXs4iB9B5OsX82GG7G5AdWNm2hiQIRg=; b=aThqZyHAHszBSvbL6pFdEZz8soe39GQ509MSwMG2/pRbfVJfvy//T0PQQdUyecVt2A1P PpChZAYawqjh113PYtVeX9kMWj2VPhF0ROt1oGoYvuNPzMbygtu/qZ8aJZxfQRJ+UxKj mXEuhOLe2rvik1avRDUAXKqYGHO8aeNbU/E= Received: from maileast.thefacebook.com ([163.114.130.16]) by m0001303.ppops.net with ESMTP id 3cgpa40x0j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 22 Nov 2021 20:56:27 -0800 Received: from intmgw001.06.ash9.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Mon, 22 Nov 2021 20:56:26 -0800 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id CEE8C2CD498A; Mon, 22 Nov 2021 20:56:22 -0800 (PST) From: Yonghong Song To: Arnaldo Carvalho de Melo , CC: Alexei Starovoitov , Andrii Nakryiko , , Daniel Borkmann , Subject: [PATCH dwarves v2 2/4] dutil: move DW_TAG_LLVM_annotation definition to dutil.h Date: Mon, 22 Nov 2021 20:56:22 -0800 Message-ID: <20211123045622.1388411-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211123045612.1387544-1-yhs@fb.com> References: <20211123045612.1387544-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-FB-Source: Intern X-Proofpoint-ORIG-GUID: woYeUHtJt0iDOuV3YqvuSoJ7PTt-4B26 X-Proofpoint-GUID: woYeUHtJt0iDOuV3YqvuSoJ7PTt-4B26 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-23_01,2021-11-22_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 spamscore=0 priorityscore=1501 mlxscore=0 malwarescore=0 adultscore=0 phishscore=0 impostorscore=0 bulkscore=0 clxscore=1015 mlxlogscore=667 suspectscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111230024 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Move DW_TAG_LLVM_annotation definition from dwarf_load.c to dutil.h as it will be used later for btf_encoder.c. There is no functionality change for this patch. Signed-off-by: Yonghong Song --- dutil.h | 4 ++++ dwarf_loader.c | 4 ---- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/dutil.h b/dutil.h index 25691ea..e45bba0 100644 --- a/dutil.h +++ b/dutil.h @@ -31,6 +31,10 @@ #define roundup(x,y) ((((x) + ((y) - 1)) / (y)) * (y)) +#ifndef DW_TAG_LLVM_annotation +#define DW_TAG_LLVM_annotation 0x6000 +#endif + static inline __attribute__((const)) bool is_power_of_2(unsigned long n) { return (n != 0 && ((n & (n - 1)) == 0)); diff --git a/dwarf_loader.c b/dwarf_loader.c index cf005da..1b07a62 100644 --- a/dwarf_loader.c +++ b/dwarf_loader.c @@ -52,10 +52,6 @@ #define DW_OP_addrx 0xa1 #endif -#ifndef DW_TAG_LLVM_annotation -#define DW_TAG_LLVM_annotation 0x6000 -#endif - static pthread_mutex_t libdw__lock = PTHREAD_MUTEX_INITIALIZER; static uint32_t hashtags__bits = 12; From patchwork Tue Nov 23 04:56:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 12633433 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 236C2C433F5 for ; Tue, 23 Nov 2021 04:56:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232317AbhKWE7i (ORCPT ); Mon, 22 Nov 2021 23:59:38 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:36912 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232196AbhKWE7i (ORCPT ); Mon, 22 Nov 2021 23:59:38 -0500 Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.1.2/8.16.1.2) with SMTP id 1AN3n3A8014424 for ; Mon, 22 Nov 2021 20:56:31 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : content-type : content-transfer-encoding : mime-version; s=facebook; bh=55V/t2dsIVBsr/m39srW2ScG3rrwc17lYoziGXY7zWI=; b=SbtNZoqKbJc+1hd/ouCf721rNzis60gWVsSX6MccPdwpnLf5MwfC6Ltp3uljzAxMyJHE V/IA2l9EtSe/gMUEd9Vr60FQqYbIsI7ZjeBPRnav7LiNoPVMYk3uIoMrPM09AaK2/Mg/ YJMbT7BsX9/Pq59LoEIoj1CXxRn2ali/izM= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 3cgrqj870a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 22 Nov 2021 20:56:30 -0800 Received: from intmgw001.25.frc3.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Mon, 22 Nov 2021 20:56:30 -0800 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 1E5EE2CD49DD; Mon, 22 Nov 2021 20:56:28 -0800 (PST) From: Yonghong Song To: Arnaldo Carvalho de Melo , CC: Alexei Starovoitov , Andrii Nakryiko , , Daniel Borkmann , Subject: [PATCH dwarves v2 3/4] dwarf_loader: support btf_type_tag attribute Date: Mon, 22 Nov 2021 20:56:28 -0800 Message-ID: <20211123045628.1388788-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211123045612.1387544-1-yhs@fb.com> References: <20211123045612.1387544-1-yhs@fb.com> X-FB-Internal: Safe X-FB-Source: Intern X-Proofpoint-GUID: lwkXQhDyVrsXospbJ-lmd750N5MJ0cKC X-Proofpoint-ORIG-GUID: lwkXQhDyVrsXospbJ-lmd750N5MJ0cKC X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-23_01,2021-11-22_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 suspectscore=0 phishscore=0 clxscore=1015 impostorscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 priorityscore=1501 malwarescore=0 lowpriorityscore=0 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111230025 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org LLVM patches ([1] for clang, [2] and [3] for BPF backend) added support for btf_type_tag attributes. The following is an example: [$ ~] cat t.c #define __tag1 __attribute__((btf_type_tag("tag1"))) #define __tag2 __attribute__((btf_type_tag("tag2"))) int __tag1 * __tag1 __tag2 *g __attribute__((section(".data..percpu"))); [$ ~] clang -O2 -g -c t.c [$ ~] llvm-dwarfdump --debug-info t.o t.o: file format elf64-x86-64 ... 0x0000001e: DW_TAG_variable DW_AT_name ("g") DW_AT_type (0x00000033 "int **") DW_AT_external (true) DW_AT_decl_file ("/home/yhs/t.c") DW_AT_decl_line (3) DW_AT_location (DW_OP_addr 0x0) 0x00000033: DW_TAG_pointer_type DW_AT_type (0x0000004b "int *") 0x00000038: DW_TAG_LLVM_annotation DW_AT_name ("btf_type_tag") DW_AT_const_value ("tag1") 0x00000041: DW_TAG_LLVM_annotation DW_AT_name ("btf_type_tag") DW_AT_const_value ("tag2") 0x0000004a: NULL 0x0000004b: DW_TAG_pointer_type DW_AT_type (0x0000005a "int") 0x00000050: DW_TAG_LLVM_annotation DW_AT_name ("btf_type_tag") DW_AT_const_value ("tag1") 0x00000059: NULL 0x0000005a: DW_TAG_base_type DW_AT_name ("int") DW_AT_encoding (DW_ATE_signed) DW_AT_byte_size (0x04) 0x00000061: NULL From the above example, you can see that DW_TAG_pointer_type may contain one or more DW_TAG_LLVM_annotation btf_type_tag tags. If DW_TAG_LLVM_annotation tags are present inside DW_TAG_pointer_type, for BTF encoding, pahole will need to follow [3] to generate a type chain like var -> ptr -> tag2 -> tag1 -> ptr -> tag1 -> int This patch implemented dwarf_loader support. If a pointer type contains DW_TAG_LLVM_annotation tags, a new type btf_type_tag_ptr_type will be created which will store the pointer tag itself and all DW_TAG_LLVM_annotation tags. During recoding stage, the type chain will be formed properly based on the above example. An option "--skip_encoding_btf_type_tag" is added to disable this new functionality. [1] https://reviews.llvm.org/D111199 [2] https://reviews.llvm.org/D113222 [3] https://reviews.llvm.org/D113496 --- dwarf_loader.c | 136 +++++++++++++++++++++++++++++++++++++++++++++++-- dwarves.h | 33 +++++++++++- pahole.c | 8 +++ 3 files changed, 173 insertions(+), 4 deletions(-) diff --git a/dwarf_loader.c b/dwarf_loader.c index 1b07a62..e30b03c 100644 --- a/dwarf_loader.c +++ b/dwarf_loader.c @@ -1206,6 +1206,89 @@ static struct tag *die__create_new_tag(Dwarf_Die *die, struct cu *cu) return tag; } +static struct btf_type_tag_ptr_type *die__create_new_btf_type_tag_ptr_type(Dwarf_Die *die, struct cu *cu) +{ + struct btf_type_tag_ptr_type *tag; + + tag = tag__alloc_with_spec(cu, sizeof(struct btf_type_tag_ptr_type)); + if (tag == NULL) + return NULL; + + tag__init(&tag->tag, cu, die); + tag->tag.has_btf_type_tag = true; + INIT_LIST_HEAD(&tag->tags); + return tag; +} + +static struct btf_type_tag_type *die__create_new_btf_type_tag_type(Dwarf_Die *die, struct cu *cu, + struct conf_load *conf) +{ + struct btf_type_tag_type *tag; + + tag = tag__alloc_with_spec(cu, sizeof(struct btf_type_tag_type)); + if (tag == NULL) + return NULL; + + tag__init(&tag->tag, cu, die); + tag->value = attr_string(die, DW_AT_const_value, conf); + return tag; +} + +static struct tag *die__create_new_pointer_tag(Dwarf_Die *die, struct cu *cu, + struct conf_load *conf) +{ + struct btf_type_tag_ptr_type *tag = NULL; + struct btf_type_tag_type *annot; + Dwarf_Die *cdie, child; + const char *name; + uint32_t id; + + /* If no child tags or skipping btf_type_tag encoding, just create a new tag + * and return + */ + if (!dwarf_haschildren(die) || dwarf_child(die, &child) != 0 || + conf->skip_encoding_btf_type_tag) + return tag__new(die, cu); + + /* Otherwise, check DW_TAG_LLVM_annotation child tags */ + cdie = &child; + do { + if (dwarf_tag(cdie) != DW_TAG_LLVM_annotation) + continue; + + /* Only check btf_type_tag annotations */ + name = attr_string(cdie, DW_AT_name, conf); + if (strcmp(name, "btf_type_tag") != 0) + continue; + + if (tag == NULL) { + /* Create a btf_type_tag_ptr type. */ + tag = die__create_new_btf_type_tag_ptr_type(die, cu); + if (!tag) + return NULL; + } + + /* Create a btf_type_tag type for this annotation. */ + annot = die__create_new_btf_type_tag_type(cdie, cu, conf); + if (annot == NULL) + return NULL; + + if (cu__table_add_tag(cu, &annot->tag, &id) < 0) + return NULL; + + struct dwarf_tag *dtag = annot->tag.priv; + dtag->small_id = id; + cu__hash(cu, &annot->tag); + + /* For a list of DW_TAG_LLVM_annotation like tag1 -> tag2 -> tag3, + * the tag->tags contains tag3 -> tag2 -> tag1. + */ + list_add(&annot->node, &tag->tags); + } while (dwarf_siblingof(cdie, cdie) == 0); + + return tag ? &tag->tag : tag__new(die, cu); +} + static struct tag *die__create_new_ptr_to_member_type(Dwarf_Die *die, struct cu *cu) { @@ -1903,12 +1986,13 @@ static struct tag *__die__process_tag(Dwarf_Die *die, struct cu *cu, case DW_TAG_const_type: case DW_TAG_imported_declaration: case DW_TAG_imported_module: - case DW_TAG_pointer_type: case DW_TAG_reference_type: case DW_TAG_restrict_type: case DW_TAG_unspecified_type: case DW_TAG_volatile_type: tag = die__create_new_tag(die, cu); break; + case DW_TAG_pointer_type: + tag = die__create_new_pointer_tag(die, cu, conf); break; case DW_TAG_ptr_to_member_type: tag = die__create_new_ptr_to_member_type(die, cu); break; case DW_TAG_enumeration_type: @@ -2192,6 +2276,45 @@ static void lexblock__recode_dwarf_types(struct lexblock *tag, struct cu *cu) } } +static void dwarf_cu__recode_btf_type_tag_ptr(struct btf_type_tag_ptr_type *tag, + uint32_t pointee_type) +{ + struct btf_type_tag_type *annot; + struct dwarf_tag *annot_dtag; + struct tag *prev_tag; + + /* Given source like + * int tag1 tag2 tag3 *p; + * the tag->tags contains tag3 -> tag2 -> tag1, the final type chain looks like: + * pointer -> tag3 -> tag2 -> tag1 -> pointee + * + * Basically it means + * - '*' applies to "int tag1 tag2 tag3" + * - tag3 applies to "int tag1 tag2" + * - tag2 applies to "int tag1" + * - tag1 applies to "int" + * + * This also makes final source code (format c) easier as we can do + * emit for "tag3 -> tag2 -> tag1 -> int" + * emit '*' + * + * For 'tag3 -> tag2 -> tag1 -> int": + * emit for "tag2 -> tag1 -> int" + * emit tag3 + * + * Eventually we can get the source code like + * int tag1 tag2 tag3 *p; + * and this matches the user/kernel code. + */ + prev_tag = &tag->tag; + list_for_each_entry(annot, &tag->tags, node) { + annot_dtag = annot->tag.priv; + prev_tag->type = annot_dtag->small_id; + prev_tag = &annot->tag; + } + prev_tag->type = pointee_type; +} + static int tag__recode_dwarf_type(struct tag *tag, struct cu *cu) { struct dwarf_tag *dtag = tag->priv; @@ -2301,7 +2424,10 @@ static int tag__recode_dwarf_type(struct tag *tag, struct cu *cu) } if (dtag->type.off == 0) { - tag->type = 0; /* void */ + if (tag->tag != DW_TAG_pointer_type || !tag->has_btf_type_tag) + tag->type = 0; /* void */ + else + dwarf_cu__recode_btf_type_tag_ptr(tag__btf_type_tag_ptr(tag), 0); return 0; } @@ -2313,7 +2439,11 @@ check_type: return 0; } out: - tag->type = dtype->small_id; + if (tag->tag != DW_TAG_pointer_type || !tag->has_btf_type_tag) + tag->type = dtype->small_id; + else + dwarf_cu__recode_btf_type_tag_ptr(tag__btf_type_tag_ptr(tag), dtype->small_id); + return 0; } diff --git a/dwarves.h b/dwarves.h index 0d3e204..4425d3c 100644 --- a/dwarves.h +++ b/dwarves.h @@ -63,6 +63,7 @@ struct conf_load { bool ptr_table_stats; bool skip_encoding_btf_decl_tag; bool skip_missing; + bool skip_encoding_btf_type_tag; uint8_t hashtable_bits; uint8_t max_hashtable_bits; uint16_t kabi_prefix_len; @@ -413,6 +414,7 @@ struct tag { uint16_t tag; bool visited; bool top_level; + bool has_btf_type_tag; uint16_t recursivity_level; void *priv; }; @@ -533,7 +535,8 @@ static inline int tag__is_tag_type(const struct tag *tag) tag->tag == DW_TAG_restrict_type || tag->tag == DW_TAG_subroutine_type || tag->tag == DW_TAG_unspecified_type || - tag->tag == DW_TAG_volatile_type; + tag->tag == DW_TAG_volatile_type || + tag->tag == DW_TAG_LLVM_annotation; } static inline const char *tag__decl_file(const struct tag *tag, @@ -606,6 +609,34 @@ struct llvm_annotation { struct list_head node; }; +/** struct btf_type_tag_type - representing a btf_type_tag annotation + * + * @tag - DW_TAG_LLVM_annotation tag + * @value - btf_type_tag value string + * @node - list_head node + */ +struct btf_type_tag_type { + struct tag tag; + const char *value; + struct list_head node; +}; + +/** The struct btf_type_tag_ptr_type - type containing both pointer type and + * its btf_type_tag annotations + * + * @tag - pointer type tag + * @tags - btf_type_tag annotations for the pointer type + */ +struct btf_type_tag_ptr_type { + struct tag tag; + struct list_head tags; +}; + +static inline struct btf_type_tag_ptr_type *tag__btf_type_tag_ptr(struct tag *tag) +{ + return (struct btf_type_tag_ptr_type *)tag; +} + /** struct namespace - base class for enums, structs, unions, typedefs, etc * * @tags - class_member, enumerators, etc diff --git a/pahole.c b/pahole.c index 5fc1cca..f3a51cb 100644 --- a/pahole.c +++ b/pahole.c @@ -1126,6 +1126,7 @@ ARGP_PROGRAM_VERSION_HOOK_DEF = dwarves_print_version; #define ARGP_devel_stats 330 #define ARGP_skip_encoding_btf_decl_tag 331 #define ARGP_skip_missing 332 +#define ARGP_skip_encoding_btf_type_tag 333 static const struct argp_option pahole__options[] = { { @@ -1506,6 +1507,11 @@ static const struct argp_option pahole__options[] = { .key = ARGP_skip_missing, .doc = "skip missing types passed to -C rather than stop", }, + { + .name = "skip_encoding_btf_type_tag", + .key = ARGP_skip_encoding_btf_type_tag, + .doc = "Do not encode TAGs in BTF." + }, { .name = NULL, } @@ -1658,6 +1664,8 @@ static error_t pahole__options_parser(int key, char *arg, conf_load.skip_encoding_btf_decl_tag = true; break; case ARGP_skip_missing: conf_load.skip_missing = true; break; + case ARGP_skip_encoding_btf_type_tag: + conf_load.skip_encoding_btf_type_tag = true; break; default: return ARGP_ERR_UNKNOWN; } From patchwork Tue Nov 23 04:56:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yonghong Song X-Patchwork-Id: 12633435 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 8E623C433F5 for ; Tue, 23 Nov 2021 04:56:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232196AbhKWE7r (ORCPT ); Mon, 22 Nov 2021 23:59:47 -0500 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:39858 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232662AbhKWE7q (ORCPT ); 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Mon, 22 Nov 2021 20:56:38 -0800 Received: by devbig309.ftw3.facebook.com (Postfix, from userid 128203) id 5A5FD2CD4A37; Mon, 22 Nov 2021 20:56:33 -0800 (PST) From: Yonghong Song To: Arnaldo Carvalho de Melo , CC: Alexei Starovoitov , Andrii Nakryiko , , Daniel Borkmann , Subject: [PATCH dwarves v2 4/4] btf_encoder: support btf_type_tag attribute Date: Mon, 22 Nov 2021 20:56:33 -0800 Message-ID: <20211123045633.1389158-1-yhs@fb.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20211123045612.1387544-1-yhs@fb.com> References: <20211123045612.1387544-1-yhs@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-FB-Source: Intern X-Proofpoint-ORIG-GUID: EHdqsVkg0LkZ-YtIwoJUZlV3aEPkiSA0 X-Proofpoint-GUID: EHdqsVkg0LkZ-YtIwoJUZlV3aEPkiSA0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.0.607.475 definitions=2021-11-23_01,2021-11-22_02,2020-04-07_01 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 clxscore=1015 lowpriorityscore=0 bulkscore=0 priorityscore=1501 impostorscore=0 suspectscore=0 spamscore=0 adultscore=0 malwarescore=0 phishscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2111230025 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The following is an example. [$ ~] cat t.c #define __tag1 __attribute__((btf_type_tag("tag1"))) #define __tag2 __attribute__((btf_type_tag("tag2"))) int __tag1 * __tag1 __tag2 *g __attribute__((section(".data..percpu"))); [$ ~] clang -O2 -g -c t.c [$ ~] pahole -JV t.o Found per-CPU symbol 'g' at address 0x0 Found 1 per-CPU variables! File t.o: [1] TYPE_TAG tag1 type_id=5 [2] TYPE_TAG tag2 type_id=1 [3] PTR (anon) type_id=2 [4] TYPE_TAG tag1 type_id=6 [5] PTR (anon) type_id=4 [6] INT int size=4 nr_bits=32 encoding=SIGNED search cu 't.c' for percpu global variables. Variable 'g' from CU 't.c' at address 0x0 encoded [7] VAR g type=3 linkage=1 [8] DATASEC .data..percpu size=8 vlen=1 type=7 offset=0 size=8 [$ ~] You can see for the source int __tag1 * __tag1 __tag2 *g __attribute__((section(".data..percpu"))); the following type chain is generated: var -> ptr -> tag2 -> tag1 -> ptr -> tag1 -> int The following shows pahole option "--skip_encoding_btf_type_tag" can prevent BTF_KIND_TYPE_TAG generation. [$ ~] pahole -JV t.o --skip_encoding_btf_type_tag Found per-CPU symbol 'g' at address 0x0 Found 1 per-CPU variables! File t.o: [1] PTR (anon) type_id=2 [2] PTR (anon) type_id=3 [3] INT int size=4 nr_bits=32 encoding=SIGNED search cu 't.c' for percpu global variables. Variable 'g' from CU 't.c' at address 0x0 encoded [4] VAR g type=1 linkage=1 [5] DATASEC .data..percpu size=8 vlen=1 type=4 offset=0 size=8 [$ ~] Signed-off-by: Yonghong Song --- btf_encoder.c | 7 +++++++ dwarves.h | 5 +++++ 2 files changed, 12 insertions(+) diff --git a/btf_encoder.c b/btf_encoder.c index 117656e..9d015f3 100644 --- a/btf_encoder.c +++ b/btf_encoder.c @@ -143,6 +143,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_DATASEC] = "DATASEC", [BTF_KIND_FLOAT] = "FLOAT", [BTF_KIND_DECL_TAG] = "DECL_TAG", + [BTF_KIND_TYPE_TAG] = "TYPE_TAG", }; static const char *btf__printable_name(const struct btf *btf, uint32_t offset) @@ -393,6 +394,9 @@ static int32_t btf_encoder__add_ref_type(struct btf_encoder *encoder, uint16_t k case BTF_KIND_TYPEDEF: id = btf__add_typedef(btf, name, type); break; + case BTF_KIND_TYPE_TAG: + id = btf__add_type_tag(btf, name, type); + break; case BTF_KIND_FWD: id = btf__add_fwd(btf, name, kind_flag); break; @@ -862,6 +866,9 @@ static int btf_encoder__encode_tag(struct btf_encoder *encoder, struct tag *tag, case DW_TAG_typedef: name = namespace__name(tag__namespace(tag)); return btf_encoder__add_ref_type(encoder, BTF_KIND_TYPEDEF, ref_type_id, name, false); + case DW_TAG_LLVM_annotation: + name = tag__btf_type_tag(tag)->value; + return btf_encoder__add_ref_type(encoder, BTF_KIND_TYPE_TAG, ref_type_id, name, false); case DW_TAG_structure_type: case DW_TAG_union_type: case DW_TAG_class_type: diff --git a/dwarves.h b/dwarves.h index 4425d3c..52d162d 100644 --- a/dwarves.h +++ b/dwarves.h @@ -637,6 +637,11 @@ static inline struct btf_type_tag_ptr_type *tag__btf_type_tag_ptr(struct tag *ta return (struct btf_type_tag_ptr_type *)tag; } +static inline struct btf_type_tag_type *tag__btf_type_tag(struct tag *tag) +{ + return (struct btf_type_tag_type *)tag; +} + /** struct namespace - base class for enums, structs, unions, typedefs, etc * * @tags - class_member, enumerators, etc