From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68630C433ED for ; Wed, 14 Apr 2021 20:03:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4933160E08 for ; Wed, 14 Apr 2021 20:03:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353729AbhDNUDd convert rfc822-to-8bit (ORCPT ); Wed, 14 Apr 2021 16:03:33 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:7008 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353727AbhDNUDM (ORCPT ); Wed, 14 Apr 2021 16:03:12 -0400 Received: from pps.filterd (m0148460.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 13EJshfN007328 for ; Wed, 14 Apr 2021 13:02:50 -0700 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 37wv5jbns4-13 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 14 Apr 2021 13:02:50 -0700 Received: from intmgw001.37.frc1.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Wed, 14 Apr 2021 13:02:28 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 7E1772ED1A84; Wed, 14 Apr 2021 13:02:27 -0700 (PDT) From: Andrii Nakryiko To: , , , CC: , Subject: [PATCH bpf-next 16/17] selftests/bpf: add global variables linking selftest Date: Wed, 14 Apr 2021 13:01:45 -0700 Message-ID: <20210414200146.2663044-17-andrii@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210414200146.2663044-1-andrii@kernel.org> References: <20210414200146.2663044-1-andrii@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: wS6PbcfnYbY4PAdnfWPapoFLWNDyFCTZ X-Proofpoint-GUID: wS6PbcfnYbY4PAdnfWPapoFLWNDyFCTZ X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-04-14_12:2021-04-14,2021-04-14 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxlogscore=999 bulkscore=0 spamscore=0 adultscore=0 priorityscore=1501 lowpriorityscore=0 malwarescore=0 mlxscore=0 clxscore=1015 phishscore=0 suspectscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104060000 definitions=main-2104140127 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Add selftest validating various aspects of statically linking global variables: - correct resolution of extern variables across .bss, .data, and .rodata sections; - correct handling of weak definitions; - correct de-duplication of repeating special externs (.kconfig, .ksyms). Signed-off-by: Andrii Nakryiko --- tools/testing/selftests/bpf/Makefile | 3 +- .../selftests/bpf/prog_tests/linked_vars.c | 43 +++++++++++++ .../selftests/bpf/progs/linked_vars1.c | 60 ++++++++++++++++++ .../selftests/bpf/progs/linked_vars2.c | 61 +++++++++++++++++++ 4 files changed, 166 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/linked_vars.c create mode 100644 tools/testing/selftests/bpf/progs/linked_vars1.c create mode 100644 tools/testing/selftests/bpf/progs/linked_vars2.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index c5d25aef1074..a690fd125c6d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -303,10 +303,11 @@ endef SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c -LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h +LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h linked_vars.skel.h test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o linked_funcs.skel.h-deps := linked_funcs1.o linked_funcs2.o +linked_vars.skel.h-deps := linked_vars1.o linked_vars2.o LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps))) diff --git a/tools/testing/selftests/bpf/prog_tests/linked_vars.c b/tools/testing/selftests/bpf/prog_tests/linked_vars.c new file mode 100644 index 000000000000..4122ec330039 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/linked_vars.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include +#include +#include "linked_vars.skel.h" + +void test_linked_vars(void) +{ + int err; + struct linked_vars* skel; + + skel = linked_vars__open(); + if (!ASSERT_OK_PTR(skel, "skel_open")) + return; + + skel->bss->input_bss1 = 1000; + skel->bss->input_bss2 = 2000; + skel->bss->input_bss_weak = 3000; + + err = linked_vars__load(skel); + if (!ASSERT_OK(err, "skel_load")) + goto cleanup; + + err = linked_vars__attach(skel); + if (!ASSERT_OK(err, "skel_attach")) + goto cleanup; + + /* trigger */ + syscall(SYS_getpgid); + + ASSERT_EQ(skel->bss->output_bss1, 1000 + 2000 + 3000, "output_bss1"); + ASSERT_EQ(skel->bss->output_bss2, 1000 + 2000 + 3000, "output_bss2"); + /* 10 comes from "winner" input_data_weak in first obj file */ + ASSERT_EQ(skel->bss->output_data1, 1 + 2 + 10, "output_bss1"); + ASSERT_EQ(skel->bss->output_data2, 1 + 2 + 10, "output_bss2"); + /* 10 comes from "winner" input_rodata_weak in first obj file */ + ASSERT_EQ(skel->bss->output_rodata1, 11 + 22 + 100 , "output_weak1"); + ASSERT_EQ(skel->bss->output_rodata2, 11 + 22 + 100 , "output_weak2"); + +cleanup: + linked_vars__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/linked_vars1.c b/tools/testing/selftests/bpf/progs/linked_vars1.c new file mode 100644 index 000000000000..e3865047ed5d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/linked_vars1.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include "vmlinux.h" +#include +#include + +extern int LINUX_KERNEL_VERSION __kconfig; +/* this weak extern will be strict due to the other file's strong extern */ +extern bool CONFIG_BPF_SYSCALL __kconfig __weak; +extern const void bpf_link_fops __ksym __weak; +/* make sure special extern funcs are handled as well */ +/* extern int bpf_kfunc_call_test2(struct sock *, __u32, __u32) __ksym; */ + +/* static name conflicts are not handled by BPF skeleton well yet */ +/* static volatile int input_bss_static = 0; */ + +int input_bss1 = 0; +int input_data1 = 1; +const volatile int input_rodata1 = 11; + +int input_bss_weak __weak = 0; +/* these two definitions should win */ +int input_data_weak __weak = 10; +const volatile int input_rodata_weak __weak = 100; + +extern int input_bss2; +extern int input_data2; +extern const int input_rodata2; + +int output_bss1 = 0; +int output_data1 = 0; +int output_rodata1 = 0; + +long output_sink1 = 0; + +static __noinline int get_bss_res(void) +{ + /* just make sure all the relocations work against .text as well */ + return /*input_bss_static +*/ input_bss1 + input_bss2 + input_bss_weak; +} + +SEC("raw_tp/sys_enter") +int BPF_PROG(handler1) +{ + output_bss1 = get_bss_res(); + output_data1 = input_data1 + input_data2 + input_data_weak; + output_rodata1 = input_rodata1 + input_rodata2 + input_rodata_weak; + + /* make sure we actually use above special externs, otherwise compiler + * will optimize them out + */ + output_sink1 = LINUX_KERNEL_VERSION + + CONFIG_BPF_SYSCALL + + (long)&bpf_link_fops; + /* + (long)&bpf_kfunc_call_test2; */ + return 0; +} + +char LICENSE[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/linked_vars2.c b/tools/testing/selftests/bpf/progs/linked_vars2.c new file mode 100644 index 000000000000..18880b54bc29 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/linked_vars2.c @@ -0,0 +1,61 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2021 Facebook */ + +#include "vmlinux.h" +#include +#include + +extern int LINUX_KERNEL_VERSION __kconfig; +/* when an extern is defined as both strong and weak, resulting symbol will be strong */ +extern bool CONFIG_BPF_SYSCALL __kconfig; +extern const void __start_BTF __ksym; +/* make sure special extern funcs are handled as well */ +/*extern int bpf_kfunc_call_test2(struct sock *, __u32, __u32) __ksym;*/ + +/* static naming conflicts are not handled by BPF skeleton yet */ +/* static volatile int input_bss_static = 0; */ + +int input_bss2 = 0; +int input_data2 = 2; +const volatile int input_rodata2 = 22; + +int input_bss_weak __weak = 0; +/* these two weak variables should lose */ +int input_data_weak __weak = 20; +const volatile int input_rodata_weak __weak = 200; + +extern int input_bss1; +extern int input_data1; +extern const int input_rodata1; + +int output_bss2 = 0; +int output_data2 = 0; +int output_rodata2 = 0; + +int output_sink2 = 0; + +static __noinline int get_data_res(void) +{ + /* just make sure all the relocations work against .text as well */ + return input_data1 + input_data2 + input_data_weak; +} + +SEC("raw_tp/sys_enter") +int BPF_PROG(handler2) +{ + output_bss2 = /*input_bss_static +*/ input_bss1 + input_bss2 + input_bss_weak; + output_data2 = get_data_res(); + output_rodata2 = input_rodata1 + input_rodata2 + input_rodata_weak; + + /* make sure we actually use above special externs, otherwise compiler + * will optimize them out + */ + output_sink2 = LINUX_KERNEL_VERSION + + CONFIG_BPF_SYSCALL + + (long)&__start_BTF; + /*+ (long)&bpf_kfunc_call_test2;*/ + + return 0; +} + +char LICENSE[] SEC("license") = "GPL"; -- 2.30.2