From patchwork Mon Sep 27 14:59:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 12520109 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE4B6C4332F for ; Mon, 27 Sep 2021 15:00:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDC4660EE2 for ; Mon, 27 Sep 2021 15:00:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235093AbhI0PC1 (ORCPT ); Mon, 27 Sep 2021 11:02:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235045AbhI0PCL (ORCPT ); Mon, 27 Sep 2021 11:02:11 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DAEDC06177E; Mon, 27 Sep 2021 08:00:24 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id t11so11957422plq.11; Mon, 27 Sep 2021 08:00:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=6sE66zJDQq6Lg7OPKq9GTbHJbssrncUby2t9sXV4jV0=; b=j1MCkFk8k9bEQGFlS9+bxiPDO3hJoj1e1W8CNhMrOu8PQzl0WpSHF4tB7GqK8+8wiA hsi+0knUDFzEC35D0w8SR2MNXykthUaqnTBxy/ser1SXzPZfjnud5zi5tDz4QDanN5PF o9bK6zPQLJwDDQC0MUvJf3C/911uLNjSEXFUxy5zwAxrKlYLnMO5exlyzeMl30WEETeX bJ9h9cXeQRMiuoc1UoUNW4U16XkPbeg+ZpckPhI9O97RSbzeeAYXiggVXUaAoymY4qIS 3ztST6NvN3qVP89/UZZ8IB6p7cBjYpMJQMXKMKXUKUKnGHDWMCymviOrScyueRRlpHXg iQHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=6sE66zJDQq6Lg7OPKq9GTbHJbssrncUby2t9sXV4jV0=; b=4I3bYkF7syFNab0ODKCLEWHNajEalRAQcuOUjzwacddmP8VcZFA4zTLMJNB2J5wQSB Qs4qN8YLjw4KV2NL8fOCoN2gqMJl84n6bhqqQFHzg519WPnbKvl5IdmKKPi1AUHQufck U4M2YMCePq1+taGBxz1aAzMrmRA/giszXyjayJ+cSEezfgyDx2ZTXcyqNnSEYnYYQBwS pb8Z1FYWrC8pEZRGC8PinTZt5IwtPkrN+F8lMP4O1M1xSz3aiHtg5y2wjnvo6NTrgO5Q y3cwxB6RbFG0kqoCy6Z8ADlUsM/z6Dq616yG7d5rKXVHkqKiZ9VzhyWyWpx/tIPJvcRp 5Hew== X-Gm-Message-State: AOAM5323suzoEgujo551nxMvr5dVjKChjkOKbXuDAz5c7HVwc+a7J9L7 APX1s5Tcreg0U86g8AO7ZnjHmEAtSUk= X-Google-Smtp-Source: ABdhPJz0+IynyrqPKFQURhpnDbt1eqb8eO7ClZwaHvv6bDK5yJZDkwKEd2FJf0U/ebyAnNzLnSwhcA== X-Received: by 2002:a17:902:e88a:b0:13c:9ca3:f724 with SMTP id w10-20020a170902e88a00b0013c9ca3f724mr471451plg.10.1632754823929; Mon, 27 Sep 2021 08:00:23 -0700 (PDT) Received: from localhost ([2405:201:6014:d058:a28d:3909:6ed5:29e7]) by smtp.gmail.com with ESMTPSA id 2sm19738272pjt.23.2021.09.27.08.00.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Sep 2021 08:00:23 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Kumar Kartikeya Dwivedi , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , Jesper Dangaard Brouer , =?utf-8?q?Toke_H=C3=B8iland-J?= =?utf-8?q?=C3=B8rgensen?= , netdev@vger.kernel.org Subject: [PATCH bpf-next v5 12/12] bpf: selftests: Add selftests for module kfunc support Date: Mon, 27 Sep 2021 20:29:41 +0530 Message-Id: <20210927145941.1383001-13-memxor@gmail.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927145941.1383001-1-memxor@gmail.com> References: <20210927145941.1383001-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=11846; h=from:subject; bh=CtSiGElH/UrODUZz0IPrVPwlgUYMWrvlaeteZpqX6go=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBhUdxPC+iDwZJfOAzoI3NkCTxafmbnxTReN+vX9+W5 XEwpXnuJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCYVHcTwAKCRBM4MiGSL8Ryvg/D/ 9X2R3KXoAS4e9BQ3w1PDkgYDBZuAJUxk+jEJZsal5WLFvnneImm2ywSGcKofqfjPugMh8ozw+k1EDt RGe6/4b5HG2VlLV/fVJnM1FT9UMUeofhjaKV5sP+8u8LXEXB8uAzR1INp0WYvwnUqEWLjH9nVv3dDa lZsIEVtTAzz/svR8wTAlGB+M7hfVPJZaZyQJn4YHq+N6+x7TlPro6F/F449xtiYwzdaoib5zbfyq17 jnDSplpds3MK9Eu0UXnVPFpoDGxAg0FETfGnj2EzWx4pvDP8MQv/XIpbR41UrDjlrbjuJY9Z1uGKzp x6CADcBbINz0fSGXkv4gwwU2tZnpf1CviTzZqIW8YVa93KRR3BN0LwyAKecd5OMT/7GmF82dmQ5uqT SKwyOOuMl6xr9WQe7FIC3KwSWuPjqxdTzJs2OzmxYt6ZVjJOR/r96OSHv45WXtSwbGSFEBP4uiFrmV 0VXuWwTAubL9i0Qzsy5saMnksvCKeo2cEGx7BniOD4jIVAH3Dx4P3Cd5s/PCz7rg+122cT4EP34sDg 9sTv9DikF4eQmA+Ba1P1KrR1Gb7RAN+7ArrQHH2Czux9F/9maHJ93wWCYBacf9fgOk6DYHllRTaxvK C1KoyRz8CCJMyoI/DH0MGMYz05UfilHM3hsG8DdWpGvg7NGeZzmT4qAQuHpQ== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This adds selftests that tests the success and failure path for modules kfuncs (in presence of invalid kfunc calls) for both libbpf and gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can add module BTF ID set from bpf_testmod. This also introduces a couple of test cases to verifier selftests for validating whether we get an error or not depending on if invalid kfunc call remains after elimination of unreachable instructions. Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/btf.h | 2 + kernel/bpf/btf.c | 2 + net/bpf/test_run.c | 5 +- tools/testing/selftests/bpf/Makefile | 8 ++-- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 23 +++++++++- .../selftests/bpf/prog_tests/ksyms_module.c | 29 ++++++------ .../bpf/prog_tests/ksyms_module_libbpf.c | 28 +++++++++++ .../selftests/bpf/progs/test_ksyms_module.c | 46 ++++++++++++++----- tools/testing/selftests/bpf/verifier/calls.c | 23 ++++++++++ 9 files changed, 135 insertions(+), 31 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/ksyms_module_libbpf.c diff --git a/include/linux/btf.h b/include/linux/btf.h index 8dc65ff02bd6..4075cc24b88a 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -270,7 +270,9 @@ static inline void unregister_kfunc_btf_id_set(struct kfunc_btf_id_list *l, THIS_MODULE } extern struct kfunc_btf_id_list bpf_tcp_ca_kfunc_list; +extern struct kfunc_btf_id_list prog_test_kfunc_list; DECLARE_CHECK_KFUNC_CALLBACK(tcp_ca); +DECLARE_CHECK_KFUNC_CALLBACK(prog_test); #endif diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 423744378fc8..2d84b739ec22 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6397,3 +6397,5 @@ EXPORT_SYMBOL_GPL(unregister_kfunc_btf_id_set); DEFINE_KFUNC_BTF_ID_LIST(bpf_tcp_ca_kfunc_list); DEFINE_CHECK_KFUNC_CALLBACK(tcp_ca, bpf_tcp_ca_kfunc_list); +DEFINE_KFUNC_BTF_ID_LIST(prog_test_kfunc_list); +DEFINE_CHECK_KFUNC_CALLBACK(prog_test, prog_test_kfunc_list); diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index fe5c34f414a2..e2b5f71af37e 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -2,6 +2,7 @@ /* Copyright (c) 2017 Facebook */ #include +#include #include #include #include @@ -243,7 +244,9 @@ BTF_SET_END(test_sk_kfunc_ids) bool bpf_prog_test_check_kfunc_call(u32 kfunc_id, struct module *owner) { - return btf_id_set_contains(&test_sk_kfunc_ids, kfunc_id); + if (btf_id_set_contains(&test_sk_kfunc_ids, kfunc_id)) + return true; + return __bpf_prog_test_check_kfunc_call(kfunc_id, owner); } static void *bpf_test_init(const union bpf_attr *kattr, u32 size, diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index e1ce73be7a5b..df461699932d 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -174,6 +174,7 @@ $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_tes $(Q)$(RM) bpf_testmod/bpf_testmod.ko # force re-compilation $(Q)$(MAKE) $(submake_extras) -C bpf_testmod $(Q)cp bpf_testmod/bpf_testmod.ko $@ + $(Q)$(RESOLVE_BTFIDS) -b $(VMLINUX_BTF) bpf_testmod.ko $(OUTPUT)/test_stub.o: test_stub.c $(BPFOBJ) $(call msg,CC,,$@) @@ -315,8 +316,9 @@ LINKED_SKELS := test_static_linked.skel.h linked_funcs.skel.h \ linked_vars.skel.h linked_maps.skel.h LSKELS := kfunc_call_test.c fentry_test.c fexit_test.c fexit_sleep.c \ - test_ksyms_module.c test_ringbuf.c atomics.c trace_printk.c \ - trace_vprintk.c + test_ringbuf.c atomics.c trace_printk.c trace_vprintk.c +# Generate both light skeleton and libbpf skeleton for these +LSKELS_EXTRA := test_ksyms_module.c SKEL_BLACKLIST += $$(LSKELS) test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o @@ -346,7 +348,7 @@ TRUNNER_BPF_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o, $$(TRUNNER_BPF_SRCS) TRUNNER_BPF_SKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.skel.h, \ $$(filter-out $(SKEL_BLACKLIST) $(LINKED_BPF_SRCS),\ $$(TRUNNER_BPF_SRCS))) -TRUNNER_BPF_LSKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.lskel.h, $$(LSKELS)) +TRUNNER_BPF_LSKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.lskel.h, $$(LSKELS) $$(LSKELS_EXTRA)) TRUNNER_BPF_SKELS_LINKED := $$(addprefix $$(TRUNNER_OUTPUT)/,$(LINKED_SKELS)) TEST_GEN_FILES += $$(TRUNNER_BPF_OBJS) diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index 50fc5561110a..b892948dc134 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -1,5 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2020 Facebook */ +#include +#include #include #include #include @@ -13,6 +15,12 @@ DEFINE_PER_CPU(int, bpf_testmod_ksym_percpu) = 123; +noinline void +bpf_testmod_test_mod_kfunc(int i) +{ + *(int *)this_cpu_ptr(&bpf_testmod_ksym_percpu) = i; +} + noinline int bpf_testmod_loop_test(int n) { int i, sum = 0; @@ -71,13 +79,26 @@ static struct bin_attribute bin_attr_bpf_testmod_file __ro_after_init = { .write = bpf_testmod_test_write, }; +BTF_SET_START(bpf_testmod_kfunc_ids) +BTF_ID(func, bpf_testmod_test_mod_kfunc) +BTF_SET_END(bpf_testmod_kfunc_ids) + +static DEFINE_KFUNC_BTF_ID_SET(&bpf_testmod_kfunc_ids, bpf_testmod_kfunc_btf_set); + static int bpf_testmod_init(void) { - return sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + int ret; + + ret = sysfs_create_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); + if (ret) + return ret; + register_kfunc_btf_id_set(&prog_test_kfunc_list, &bpf_testmod_kfunc_btf_set); + return 0; } static void bpf_testmod_exit(void) { + unregister_kfunc_btf_id_set(&prog_test_kfunc_list, &bpf_testmod_kfunc_btf_set); return sysfs_remove_bin_file(kernel_kobj, &bin_attr_bpf_testmod_file); } diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c index 2cd5cded543f..831447878d7b 100644 --- a/tools/testing/selftests/bpf/prog_tests/ksyms_module.c +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_module.c @@ -2,30 +2,29 @@ /* Copyright (c) 2021 Facebook */ #include -#include -#include +#include #include "test_ksyms_module.lskel.h" -static int duration; - void test_ksyms_module(void) { - struct test_ksyms_module* skel; + struct test_ksyms_module *skel; + int retval; int err; - skel = test_ksyms_module__open_and_load(); - if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + if (!env.has_testmod) { + test__skip(); return; + } - err = test_ksyms_module__attach(skel); - if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + skel = test_ksyms_module__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_ksyms_module__open_and_load")) + return; + err = bpf_prog_test_run(skel->progs.load.prog_fd, 1, &pkt_v4, sizeof(pkt_v4), + NULL, NULL, (__u32 *)&retval, NULL); + if (!ASSERT_OK(err, "bpf_prog_test_run")) goto cleanup; - - usleep(1); - - ASSERT_EQ(skel->bss->triggered, true, "triggered"); - ASSERT_EQ(skel->bss->out_mod_ksym_global, 123, "global_ksym_val"); - + ASSERT_EQ(retval, 0, "retval"); + ASSERT_EQ(skel->bss->out_bpf_testmod_ksym, 42, "bpf_testmod_ksym"); cleanup: test_ksyms_module__destroy(skel); } diff --git a/tools/testing/selftests/bpf/prog_tests/ksyms_module_libbpf.c b/tools/testing/selftests/bpf/prog_tests/ksyms_module_libbpf.c new file mode 100644 index 000000000000..e6343ef63af9 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/ksyms_module_libbpf.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "test_ksyms_module.skel.h" + +void test_ksyms_module_libbpf(void) +{ + struct test_ksyms_module *skel; + int retval, err; + + if (!env.has_testmod) { + test__skip(); + return; + } + + skel = test_ksyms_module__open_and_load(); + if (!ASSERT_OK_PTR(skel, "test_ksyms_module__open")) + return; + err = bpf_prog_test_run(bpf_program__fd(skel->progs.load), 1, &pkt_v4, + sizeof(pkt_v4), NULL, NULL, (__u32 *)&retval, NULL); + if (!ASSERT_OK(err, "bpf_prog_test_run")) + goto cleanup; + ASSERT_EQ(retval, 0, "retval"); + ASSERT_EQ(skel->bss->out_bpf_testmod_ksym, 42, "bpf_testmod_ksym"); +cleanup: + test_ksyms_module__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_ksyms_module.c b/tools/testing/selftests/bpf/progs/test_ksyms_module.c index d6a0b3086b90..5fc50deef3b4 100644 --- a/tools/testing/selftests/bpf/progs/test_ksyms_module.c +++ b/tools/testing/selftests/bpf/progs/test_ksyms_module.c @@ -2,24 +2,48 @@ /* Copyright (c) 2021 Facebook */ #include "vmlinux.h" - #include +#define X_0(x) +#define X_1(x) x X_0(x) +#define X_2(x) x X_1(x) +#define X_3(x) x X_2(x) +#define X_4(x) x X_3(x) +#define X_5(x) x X_4(x) +#define X_6(x) x X_5(x) +#define X_7(x) x X_6(x) +#define X_8(x) x X_7(x) +#define X_9(x) x X_8(x) +#define X_10(x) x X_9(x) +#define REPEAT_256(Y) X_2(X_10(X_10(Y))) X_5(X_10(Y)) X_6(Y) + extern const int bpf_testmod_ksym_percpu __ksym; +extern void bpf_testmod_test_mod_kfunc(int i) __ksym; +extern void bpf_testmod_invalid_mod_kfunc(void) __ksym __weak; -int out_mod_ksym_global = 0; -bool triggered = false; +int out_bpf_testmod_ksym = 0; +const volatile int x = 0; -SEC("raw_tp/sys_enter") -int handler(const void *ctx) +SEC("classifier") +int load(struct __sk_buff *skb) { - int *val; - __u32 cpu; - - val = (int *)bpf_this_cpu_ptr(&bpf_testmod_ksym_percpu); - out_mod_ksym_global = *val; - triggered = true; + /* This will be kept by clang, but removed by verifier. Since it is + * marked as __weak, libbpf and gen_loader don't error out if BTF ID + * is not found for it, instead imm and off is set to 0 for it. + */ + if (x) + bpf_testmod_invalid_mod_kfunc(); + bpf_testmod_test_mod_kfunc(42); + out_bpf_testmod_ksym = *(int *)bpf_this_cpu_ptr(&bpf_testmod_ksym_percpu); + return 0; +} +SEC("classifier") +int load_256(struct __sk_buff *skb) +{ + /* this will fail if kfunc doesn't reuse its own btf fd index */ + REPEAT_256(bpf_testmod_test_mod_kfunc(42);); + bpf_testmod_test_mod_kfunc(42); return 0; } diff --git a/tools/testing/selftests/bpf/verifier/calls.c b/tools/testing/selftests/bpf/verifier/calls.c index 336a749673d1..d7b74eb28333 100644 --- a/tools/testing/selftests/bpf/verifier/calls.c +++ b/tools/testing/selftests/bpf/verifier/calls.c @@ -1,3 +1,26 @@ +{ + "calls: invalid kfunc call not eliminated", + .insns = { + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = REJECT, + .errstr = "invalid kernel function call not eliminated in verifier pass", +}, +{ + "calls: invalid kfunc call unreachable", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_JMP_IMM(BPF_JGT, BPF_REG_0, 0, 2), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = ACCEPT, +}, { "calls: basic sanity", .insns = {