From patchwork Tue Mar 15 14:02:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12781469 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 4AF77C433EF for ; Tue, 15 Mar 2022 14:02:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349014AbiCOOD6 (ORCPT ); Tue, 15 Mar 2022 10:03:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349017AbiCOODz (ORCPT ); Tue, 15 Mar 2022 10:03:55 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 531BE5469B; Tue, 15 Mar 2022 07:02:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E36E861685; Tue, 15 Mar 2022 14:02:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A864C340E8; Tue, 15 Mar 2022 14:02:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1647352962; bh=gYl4Kdz77UQE5JD3kUI4FvgjNtnkg0CruIjvyq/cUEQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gIykNzyR/1l/mQrXCe7Qiz1hbCWb986Y5AWpAQYS4EpFO+wHWBDx4TGtlKnkPTKmv DaVMA7zO4LCirp2Qu+Lz7ml2vVsdxlEy7uvocsRzALwfySfAfEINpec9jt9eva7Z+W XZ3bJxXiVE7RibfK0UYuSYoCso6wFPI4t1PUtHIeWnMPbfqmIlpvie4H9hTrd8Gk9b 5c5gJKDpP0Mc66Nn1AlzfX6tExsvdtWuFi4ZYJC1Pr0G0pWt/Iu6t8rgOnqfMrbBZ4 XXwsI55sOSs7S9IejouR5zNjcSdJQiUJJ+QINpTYSCd9uksJZkVT4vCR4ZBTkm2Bfe kyFm2dyAyCLlQ== From: Masami Hiramatsu To: Jiri Olsa , Alexei Starovoitov , Andrii Nakryiko Cc: Daniel Borkmann , Andrii Nakryiko , Masami Hiramatsu , netdev@vger.kernel.org, bpf@vger.kernel.org, lkml , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Steven Rostedt , "Naveen N . Rao" , Anil S Keshavamurthy , "David S . Miller" Subject: [PATCH v12 bpf-next 12/12] fprobe: Add a selftest for fprobe Date: Tue, 15 Mar 2022 23:02:35 +0900 Message-Id: <164735295554.1084943.18347620679928750960.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <164735281449.1084943.12438881786173547153.stgit@devnote2> References: <164735281449.1084943.12438881786173547153.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add a KUnit based selftest for fprobe interface. Signed-off-by: Masami Hiramatsu --- Changes in v11: - Build selftest only if KUNIT=y. Changes in v9: - Rename fprobe_target* to fprobe_selftest_target*. - Find the correct expected ip by ftrace_location_range(). - Since the ftrace_location_range() is not exposed to module, make this test only for embedded. - Add entry only test. - Reset the fprobe structure before reuse it. --- lib/Kconfig.debug | 12 ++++ lib/Makefile | 2 + lib/test_fprobe.c | 174 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 188 insertions(+) create mode 100644 lib/test_fprobe.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 72ca4684beda..b0bf0d224b2c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2118,6 +2118,18 @@ config KPROBES_SANITY_TEST Say N if you are unsure. +config FPROBE_SANITY_TEST + bool "Self test for fprobe" + depends on DEBUG_KERNEL + depends on FPROBE + depends on KUNIT=y + help + This option will enable testing the fprobe when the system boot. + A series of tests are made to verify that the fprobe is functioning + properly. + + Say N if you are unsure. + config BACKTRACE_SELF_TEST tristate "Self test for the backtrace code" depends on DEBUG_KERNEL diff --git a/lib/Makefile b/lib/Makefile index 300f569c626b..154008764b16 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -103,6 +103,8 @@ obj-$(CONFIG_TEST_HMM) += test_hmm.o obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o obj-$(CONFIG_TEST_REF_TRACKER) += test_ref_tracker.o +CFLAGS_test_fprobe.o += $(CC_FLAGS_FTRACE) +obj-$(CONFIG_FPROBE_SANITY_TEST) += test_fprobe.o # # CFLAGS for compiling floating point code inside the kernel. x86/Makefile turns # off the generation of FPU/SSE* instructions for kernel proper but FPU_FLAGS diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c new file mode 100644 index 000000000000..ed70637a2ffa --- /dev/null +++ b/lib/test_fprobe.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * test_fprobe.c - simple sanity test for fprobe + */ + +#include +#include +#include +#include + +#define div_factor 3 + +static struct kunit *current_test; + +static u32 rand1, entry_val, exit_val; + +/* Use indirect calls to avoid inlining the target functions */ +static u32 (*target)(u32 value); +static u32 (*target2)(u32 value); +static unsigned long target_ip; +static unsigned long target2_ip; + +static noinline u32 fprobe_selftest_target(u32 value) +{ + return (value / div_factor); +} + +static noinline u32 fprobe_selftest_target2(u32 value) +{ + return (value / div_factor) + 1; +} + +static notrace void fp_entry_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs) +{ + KUNIT_EXPECT_FALSE(current_test, preemptible()); + /* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */ + if (ip != target_ip) + KUNIT_EXPECT_EQ(current_test, ip, target2_ip); + entry_val = (rand1 / div_factor); +} + +static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip, struct pt_regs *regs) +{ + unsigned long ret = regs_return_value(regs); + + KUNIT_EXPECT_FALSE(current_test, preemptible()); + if (ip != target_ip) { + KUNIT_EXPECT_EQ(current_test, ip, target2_ip); + KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor) + 1); + } else + KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor)); + KUNIT_EXPECT_EQ(current_test, entry_val, (rand1 / div_factor)); + exit_val = entry_val + div_factor; +} + +/* Test entry only (no rethook) */ +static void test_fprobe_entry(struct kunit *test) +{ + struct fprobe fp_entry = { + .entry_handler = fp_entry_handler, + }; + + current_test = test; + + /* Before register, unregister should be failed. */ + KUNIT_EXPECT_NE(test, 0, unregister_fprobe(&fp_entry)); + KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp_entry, "fprobe_selftest_target*", NULL)); + + entry_val = 0; + exit_val = 0; + target(rand1); + KUNIT_EXPECT_NE(test, 0, entry_val); + KUNIT_EXPECT_EQ(test, 0, exit_val); + + entry_val = 0; + exit_val = 0; + target2(rand1); + KUNIT_EXPECT_NE(test, 0, entry_val); + KUNIT_EXPECT_EQ(test, 0, exit_val); + + KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp_entry)); +} + +static void test_fprobe(struct kunit *test) +{ + struct fprobe fp = { + .entry_handler = fp_entry_handler, + .exit_handler = fp_exit_handler, + }; + + current_test = test; + KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp, "fprobe_selftest_target*", NULL)); + + entry_val = 0; + exit_val = 0; + target(rand1); + KUNIT_EXPECT_NE(test, 0, entry_val); + KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val); + + entry_val = 0; + exit_val = 0; + target2(rand1); + KUNIT_EXPECT_NE(test, 0, entry_val); + KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val); + + KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp)); +} + +static void test_fprobe_syms(struct kunit *test) +{ + static const char *syms[] = {"fprobe_selftest_target", "fprobe_selftest_target2"}; + struct fprobe fp = { + .entry_handler = fp_entry_handler, + .exit_handler = fp_exit_handler, + }; + + current_test = test; + KUNIT_EXPECT_EQ(test, 0, register_fprobe_syms(&fp, syms, 2)); + + entry_val = 0; + exit_val = 0; + target(rand1); + KUNIT_EXPECT_NE(test, 0, entry_val); + KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val); + + entry_val = 0; + exit_val = 0; + target2(rand1); + KUNIT_EXPECT_NE(test, 0, entry_val); + KUNIT_EXPECT_EQ(test, entry_val + div_factor, exit_val); + + KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp)); +} + +static unsigned long get_ftrace_location(void *func) +{ + unsigned long size, addr = (unsigned long)func; + + if (!kallsyms_lookup_size_offset(addr, &size, NULL) || !size) + return 0; + + return ftrace_location_range(addr, addr + size - 1); +} + +static int fprobe_test_init(struct kunit *test) +{ + do { + rand1 = prandom_u32(); + } while (rand1 <= div_factor); + + target = fprobe_selftest_target; + target2 = fprobe_selftest_target2; + target_ip = get_ftrace_location(target); + target2_ip = get_ftrace_location(target2); + + return 0; +} + +static struct kunit_case fprobe_testcases[] = { + KUNIT_CASE(test_fprobe_entry), + KUNIT_CASE(test_fprobe), + KUNIT_CASE(test_fprobe_syms), + {} +}; + +static struct kunit_suite fprobe_test_suite = { + .name = "fprobe_test", + .init = fprobe_test_init, + .test_cases = fprobe_testcases, +}; + +kunit_test_suites(&fprobe_test_suite); + +MODULE_LICENSE("GPL");