From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from akranes.kaiser.cx (akranes.kaiser.cx [152.53.16.207]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EB9A3FCB31; Thu, 7 May 2026 13:46:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=152.53.16.207 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778161598; cv=none; b=b9XjadFM5F+jQXMgR7bBe226cKSE/hUP7dJZwNFtSyY9E6FKgFTaFdBEZoR6e0ZCMpY3fz7BcLE3cfX9tVnZ2aleXktZg6NzWxXkn0u4JgtYXxtYkJarTV+ogPcQFTLVBigxMwCcSq+95joMpSuC8pxHr3D3VGOlkTnfr209E5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778161598; c=relaxed/simple; bh=mI6M/OEib7vV2K5kAkNiO/eUM83xzR+mIzT6SbHH0wc=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=e1LLOFmwpPhBjOi1E4IW/irkMCb0vlykblRQ8AJgp6MoWRMEnV+MXCU7dHve0YIWAgLl9EDrCpHCopxx1Ibnqz+DJu8cLtBMlwvLesLhkxJ6sgiku5pJ2uL7ZNrii17U8piL6Cn0MPvgKdZtDg01g+ajb8VQKp8Yga7cPaAlVZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kaiser.cx; spf=pass smtp.mailfrom=kaiser.cx; arc=none smtp.client-ip=152.53.16.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=kaiser.cx Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kaiser.cx Received: from ipservice-092-208-105-007.092.208.pools.vodafone-ip.de ([92.208.105.7] helo=nb282.user.codasip.com) by akranes.kaiser.cx with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wKz3f-00000000dxS-45zL; Thu, 07 May 2026 15:46:32 +0200 From: Martin Kaiser To: Naveen N Rao , Masami Hiramatsu Cc: Steven Rostedt , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, Martin Kaiser Subject: [PATCH] test_kprobes: clear kprobes between test runs Date: Thu, 7 May 2026 15:44:33 +0200 Message-ID: <20260507134615.1010905-1-martin@kaiser.cx> X-Mailer: git-send-email 2.43.7 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Running the kprobes sanity tests twice makes all tests fail and eventually crashes the kernel. [root@martin-riscv-1 ~]# echo 1 > /sys/kernel/debug/kunit/kprobes_test/run ... # Totals: pass:5 fail:0 skip:0 total:5 ok 1 kprobes_test [root@martin-riscv-1 ~]# echo 1 > /sys/kernel/debug/kunit/kprobes_test/run ... # test_kprobe: EXPECTATION FAILED at lib/tests/test_kprobes.c:64 Expected 0 == register_kprobe(&kp), but register_kprobe(&kp) == -22 (0xffffffffffffffea) ... Unable to handle kernel paging request ... The testsuite defines several kprobes and kretprobes as static variables that are preserved across test runs. After register_kprobe and unregister_kprobe, a kprobe contains some leftover data that must be cleared before the kprobe can be registered again. The tests are setting symbol_name to define the probe location. Address and flags must be cleared. The existing code clears some of the probes between subsequent tests, but not between two test runs. The leftover data from a previous test run makes the registrations fail in the next run. Move the cleanups for all kprobes into kprobes_test_init, this function is called before each single test (including the first test of a test run). Signed-off-by: Martin Kaiser --- lib/tests/test_kprobes.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/lib/tests/test_kprobes.c b/lib/tests/test_kprobes.c index b7582010125c..06e729e4de05 100644 --- a/lib/tests/test_kprobes.c +++ b/lib/tests/test_kprobes.c @@ -12,6 +12,12 @@ #define div_factor 3 +#define KP_CLEAR(_kp) \ +do { \ + (_kp).addr = NULL; \ + (_kp).flags = 0; \ +} while (0) + static u32 rand1, preh_val, posth_val; static u32 (*target)(u32 value); static u32 (*recursed_target)(u32 value); @@ -125,10 +131,6 @@ static void test_kprobes(struct kunit *test) current_test = test; - /* addr and flags should be cleard for reusing kprobe. */ - kp.addr = NULL; - kp.flags = 0; - KUNIT_EXPECT_EQ(test, 0, register_kprobes(kps, 2)); preh_val = 0; posth_val = 0; @@ -226,9 +228,6 @@ static void test_kretprobes(struct kunit *test) struct kretprobe *rps[2] = {&rp, &rp2}; current_test = test; - /* addr and flags should be cleard for reusing kprobe. */ - rp.kp.addr = NULL; - rp.kp.flags = 0; KUNIT_EXPECT_EQ(test, 0, register_kretprobes(rps, 2)); krph_val = 0; @@ -290,8 +289,6 @@ static void test_stacktrace_on_kretprobe(struct kunit *test) unsigned long myretaddr = (unsigned long)__builtin_return_address(0); current_test = test; - rp3.kp.addr = NULL; - rp3.kp.flags = 0; /* * Run the stacktrace_driver() to record correct return address in @@ -352,8 +349,6 @@ static void test_stacktrace_on_nested_kretprobe(struct kunit *test) struct kretprobe *rps[2] = {&rp3, &rp4}; current_test = test; - rp3.kp.addr = NULL; - rp3.kp.flags = 0; //KUNIT_ASSERT_NE(test, myretaddr, stacktrace_driver()); @@ -367,6 +362,18 @@ static void test_stacktrace_on_nested_kretprobe(struct kunit *test) static int kprobes_test_init(struct kunit *test) { + KP_CLEAR(kp); + KP_CLEAR(kp2); + KP_CLEAR(kp_missed); +#ifdef CONFIG_KRETPROBES + KP_CLEAR(rp.kp); + KP_CLEAR(rp2.kp); +#ifdef CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE + KP_CLEAR(rp3.kp); + KP_CLEAR(rp4.kp); +#endif +#endif + target = kprobe_target; target2 = kprobe_target2; recursed_target = kprobe_recursed_target; -- 2.43.7