From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-y-111.mailbox.org (mout-y-111.mailbox.org [91.198.250.236]) (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 C869F3E00A1; Mon, 6 Jul 2026 07:57:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.198.250.236 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783324654; cv=none; b=i9/uqDjApAJutTddy0hixnEIBoFL7UasKmmmQ1I0PE+Bp9wXjMfALqwbhcRGSxmsZXXTdJhcwSxy7FeF4TvR5zHkZha4HbF5sSSOvG+ja61m4gWaoTtlBMjbUkrMV1ZqLejG0O0mpNv4ZLp+MOq6jbOL7oee7m1ugR/1NjAmu7A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783324654; c=relaxed/simple; bh=uO0yuH0cgFlwuh+60ouE/XunglpmQTZB7vngb53hITQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=nwO2X2C1S+YFVHVSU3uP52haF3szEMgb3wYy8wy5ek+sT75QAC4LoH7rqcsTmx76x+F5LoOQAYUDh8m6tE4g7LrVS89yUyMZPjQ0dkC6zoJz3yyn27T7Tdn6iTE7Z1tqAT6SDnmquunXGK2bvDcwOJRhN73ECnu15A9SGxNpGZI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mavick.dev; spf=pass smtp.mailfrom=mavick.dev; arc=none smtp.client-ip=91.198.250.236 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mavick.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mavick.dev Received: from smtp2.mailbox.org (smtp2.mailbox.org [10.196.197.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange x25519 server-signature RSA-PSS (4096 bits) server-digest SHA512) (No client certificate requested) by mout-y-111.mailbox.org (Postfix) with ESMTPS id 4gt66q2QHkzMlf3; Sun, 05 Jul 2026 01:20:35 +0200 (CEST) From: Eugene Mavick Date: Sun, 05 Jul 2026 07:19:23 +0800 Subject: [PATCH 4/4] kunit: add test for ref_trace_final_put Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260705-refcount-final-put-trace-v1-4-cdd0014626a9@mavick.dev> References: <20260705-refcount-final-put-trace-v1-0-cdd0014626a9@mavick.dev> In-Reply-To: <20260705-refcount-final-put-trace-v1-0-cdd0014626a9@mavick.dev> To: Will Deacon , Peter Zijlstra , Boqun Feng , Mark Rutland , Gary Guo , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Andrew Morton , Dennis Zhou , Tejun Heo , Christoph Lameter Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-mm@kvack.org, Eugene Mavick X-Developer-Signature: v=1; a=openpgp-sha256; l=5737; i=m@mavick.dev; h=from:subject:message-id; bh=uO0yuH0cgFlwuh+60ouE/XunglpmQTZB7vngb53hITQ=; b=owGbwMvMwCU2V/5U3e1aE3/G02pJDFmeU5kCI4JSjJN+yF3Tt2GQiRXUT953vzjuu9nCtDJOg YoZRuYdpSwMYlwMsmKKLDVZCe4ZK2clGh+d1AMzh5UJZAgDF6cATMTmOyPDet/XZc0fq6Y8e7i8 p1yb76Vkc929VUW20Vf7Jm3YfOMvJyPDhgNNDx+mah2q3f19hrbBxbCJDbnLnCINH2+Udn97Saq WAQA= X-Developer-Key: i=m@mavick.dev; a=openpgp; fpr=7C6A604768A99A6133C5928C9D1FCA7EDB7D344F Add a KUnit test suite for the ref_trace_final_put tracepoint. The test registers a probe function and triggers both refcount_t and percpu_ref final put paths, verifying that the tracepoint fires correctly and that the recorded fields match expected values. Signed-off-by: Eugene Mavick --- MAINTAINERS | 1 + lib/Kconfig | 10 ++++ lib/tests/Makefile | 1 + lib/tests/ref_trace_kunit.c | 138 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 150 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 8dab37726b9d..7c387ed746ee 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -4213,6 +4213,7 @@ F: include/*/atomic*.h F: include/linux/ref_trace.h F: include/linux/refcount.h F: lib/ref_trace.h +F: lib/tests/ref_trace_kunit.c F: scripts/atomic/ F: rust/kernel/sync/atomic.rs F: rust/kernel/sync/atomic/ diff --git a/lib/Kconfig b/lib/Kconfig index 00a9509636c1..c29b2ccb3c31 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -52,6 +52,16 @@ config PACKING_KUNIT_TEST When in doubt, say N. +config REF_TRACE_KUNIT_TEST + bool "ref_trace kunit test" if !KUNIT_ALL_TESTS + depends on KUNIT && FTRACE + default KUNIT_ALL_TESTS + help + This option enables the KUnit test suite for the ref_trace_final_put + tracepoint. + + If unsure, say N + config BITREVERSE tristate diff --git a/lib/tests/Makefile b/lib/tests/Makefile index 7e9c2fa52e35..828a030ad8c7 100644 --- a/lib/tests/Makefile +++ b/lib/tests/Makefile @@ -57,5 +57,6 @@ obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o obj-$(CONFIG_UTIL_MACROS_KUNIT) += util_macros_kunit.o obj-$(CONFIG_RATELIMIT_KUNIT_TEST) += test_ratelimit.o obj-$(CONFIG_UUID_KUNIT_TEST) += uuid_kunit.o +obj-$(CONFIG_REF_TRACE_KUNIT_TEST) += ref_trace_kunit.o obj-$(CONFIG_TEST_RUNTIME_MODULE) += module/ diff --git a/lib/tests/ref_trace_kunit.c b/lib/tests/ref_trace_kunit.c new file mode 100644 index 000000000000..2ece6c840fe0 --- /dev/null +++ b/lib/tests/ref_trace_kunit.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include +#include + +struct data { + unsigned long caller; + const char *fn; + const void *obj; + int *flag; + struct kunit *test; +}; + +struct data refc_chk; +struct data pcpu_chk; + +//called when tracepoint fires +static void probe( + void *ignore, + unsigned long caller, + const char *fn, + const void *obj) +{ + struct data *chk_val; + + char func_name[KSYM_SYMBOL_LEN]; + + sprint_symbol_no_offset(func_name, caller); + + if (!strcmp(func_name, "test_refcount")) { + chk_val = &refc_chk; + KUNIT_EXPECT_FALSE(chk_val->test, memcmp(obj, chk_val->obj, sizeof(refcount_t))); + } else if (!strcmp(func_name, "test_percpu")) { + chk_val = &pcpu_chk; + KUNIT_EXPECT_FALSE(chk_val->test, memcmp( + obj, chk_val->obj, sizeof(struct percpu_ref))); + } else { + //non test function origin trace events + return; + } + + struct kunit *test = chk_val->test; + int *flag = chk_val->flag; + + //ensure past flag writes are done before reading + KUNIT_EXPECT_EQ(test, 1, smp_load_acquire(flag)); + KUNIT_EXPECT_EQ(test, caller, chk_val->caller); + + smp_store_release(flag, 0); //signal probe completion +} + + + +static void test_refcount(struct kunit *test) +{ + refcount_t refc; + int flag_addr = 0; + + refc_chk.caller = (unsigned long)&test_refcount; + refc_chk.fn = "__refcount_sub_and_test"; + refc_chk.obj = &refc; + refc_chk.flag = &flag_addr; + refc_chk.test = test; + + int *flag = refc_chk.flag; + + KUNIT_EXPECT_FALSE(test, register_trace_ref_trace_final_put(probe, NULL)); + + refcount_set(&refc, 2); + + KUNIT_EXPECT_FALSE(test, refcount_dec_and_test(&refc)); + + smp_store_release(flag, 1); //signal final put can happen + + KUNIT_EXPECT_TRUE(test, refcount_dec_and_test(&refc)); + + wait_var_event(flag, smp_load_acquire(flag)); //wait for probe completion + unregister_trace_ref_trace_final_put(probe, NULL); +} + +static void dummy_release(struct percpu_ref *ref) {} + +static void test_percpu(struct kunit *test) +{ + struct percpu_ref pcpu_ref; + + int flag_addr = 1; + + pcpu_chk.caller = (unsigned long)&test_percpu; + pcpu_chk.fn = "percpu_ref_put_many"; + pcpu_chk.obj = &pcpu_ref; + pcpu_chk.flag = &flag_addr; + pcpu_chk.test = test; + + int *flag = pcpu_chk.flag; + + KUNIT_EXPECT_FALSE(test, register_trace_ref_trace_final_put(probe, NULL)); + + KUNIT_EXPECT_FALSE(test, percpu_ref_init(&pcpu_ref, dummy_release, 0, GFP_KERNEL)); + + percpu_ref_get(&pcpu_ref); + percpu_ref_get(&pcpu_ref); + + percpu_ref_put(&pcpu_ref); + percpu_ref_put(&pcpu_ref); + + percpu_ref_switch_to_atomic_sync(&pcpu_ref); + + smp_store_release(flag, 1); //signal final put can happen + + percpu_ref_put(&pcpu_ref); + + wait_var_event(flag, smp_load_acquire(flag)); //wait for probe completion + unregister_trace_ref_trace_final_put(probe, NULL); + percpu_ref_exit(&pcpu_ref); +} + +static struct kunit_case __refdata ref_trace_test_cases[] = { + KUNIT_CASE(test_refcount), + KUNIT_CASE(test_percpu), + {} +}; + +static struct kunit_suite ref_trace_test_suite = { + .name = "ref-trace", + .test_cases = ref_trace_test_cases, +}; + +kunit_test_suites(&ref_trace_test_suite); + +MODULE_AUTHOR("Eugene Mavick "); +MODULE_DESCRIPTION("KUnit test for ref_trace"); +MODULE_LICENSE("GPL"); -- 2.51.2