From: Eugene Mavick <[email protected]> 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 <[email protected]> --- 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 <linux/kernel.h> +#include <kunit/test.h> +#include <linux/wait_bit.h> +#include <linux/instruction_pointer.h> +#include <linux/kallsyms.h> +#include <linux/percpu-refcount.h> +#include <linux/refcount.h> +#include <trace/events/ref_trace.h> + +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 <[email protected]>"); +MODULE_DESCRIPTION("KUnit test for ref_trace"); +MODULE_LICENSE("GPL"); -- 2.51.2
