From: Kui-Feng Lee <sinquersw@gmail.com>
To: Eduard Zingerman <eddyz87@gmail.com>,
thinker.li@gmail.com, bpf@vger.kernel.org, ast@kernel.org,
martin.lau@linux.dev, song@kernel.org, kernel-team@meta.com,
andrii@kernel.org, drosen@google.com
Cc: kuifeng@meta.com
Subject: Re: [PATCH bpf-next v6 10/10] selftests/bpf: test case for register_bpf_struct_ops().
Date: Fri, 27 Oct 2023 00:09:00 -0700 [thread overview]
Message-ID: <82ef06b9-d0e3-4ad2-8c00-cc458cc1796a@gmail.com> (raw)
In-Reply-To: <5b3609f3-bc40-4fc3-b591-d124432dc4d9@gmail.com>
On 10/26/23 21:55, Kui-Feng Lee wrote:
>
>
> On 10/26/23 13:31, Eduard Zingerman wrote:
>> On Sat, 2023-10-21 at 22:03 -0700, thinker.li@gmail.com wrote:
>>> From: Kui-Feng Lee <thinker.li@gmail.com>
>>>
>>> Create a new struct_ops type called bpf_testmod_ops within the
>>> bpf_testmod
>>> module. When a struct_ops object is registered, the bpf_testmod
>>> module will
>>> invoke test_2 from the module.
>>>
>>> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
>>
>> Hello,
>>
>> Sorry for the late response, was moving through the patch-set very
>> slowly.
>> Please note that CI currently fails for this series [0], reported
>> error is:
>>
>> testing_helpers.c:13:10: fatal error: 'rcu_tasks_trace_gp.skel.h' file
>> not found
>> 13 | #include "rcu_tasks_trace_gp.skel.h"
>> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Thank! I will fix this dependency issue.
>
>>
>> I get the same error when try to run tests locally (after full clean).
>> On the other hand it looks like `kern_sync_rcu_tasks_trace` changes
>> are not really necessary, when I undo these changes but keep changes in:
>>
>> - .../selftests/bpf/bpf_testmod/bpf_testmod.c
>> - .../selftests/bpf/bpf_testmod/bpf_testmod.h
>> - .../bpf/prog_tests/test_struct_ops_module.c
>> - .../selftests/bpf/progs/struct_ops_module.c
>>
>> struct_ops_module/regular_load test still passes.
>>
>
> The test will pass even without this change.
> But, the test harness may complain by showing warnings.
> You may see an additional warning message without this change.
One thing forgot to mentioned. The test harness may fail to unload
the bpf_testmod module.
>
>> Regarding assertion:
>>
>>> + ASSERT_EQ(skel->bss->test_2_result, 7, "test_2_result");
>>
>> Could you please leave a comment explaining why the value is 7?
>> I don't understand what invokes 'test_2' but changing it to 8
>> forces test to fail, so something does call 'test_2' :)
>
> It is called by bpf_dummy_reg() in bpf_testmod.c.
> I will add a comment here.
>
>>
>> Also, when running test_maps I get the following error:
>>
>> libbpf: bpf_map_create_opts has non-zero extra bytes
>> map_create_opts(317):FAIL:bpf_map_create() error:Invalid argument
>> (name=hash_of_maps)
>
> It looks like a padding issue. I will check it.
>
>>
>> [0]
>> https://patchwork.kernel.org/project/netdevbpf/patch/20231022050335.2579051-11-thinker.li@gmail.com/
>> (look for 'Logs for x86_64-gcc / build / build for x86_64 with
>> gcc ')
>>
>>> ---
>>> tools/testing/selftests/bpf/Makefile | 2 +
>>> .../selftests/bpf/bpf_testmod/bpf_testmod.c | 59 +++++++++++++++++++
>>> .../selftests/bpf/bpf_testmod/bpf_testmod.h | 5 ++
>>> .../bpf/prog_tests/test_struct_ops_module.c | 38 ++++++++++++
>>> .../selftests/bpf/progs/struct_ops_module.c | 30 ++++++++++
>>> tools/testing/selftests/bpf/testing_helpers.c | 35 +++++++++++
>>> 6 files changed, 169 insertions(+)
>>> create mode 100644
>>> tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
>>> create mode 100644
>>> tools/testing/selftests/bpf/progs/struct_ops_module.c
>>>
>>> diff --git a/tools/testing/selftests/bpf/Makefile
>>> b/tools/testing/selftests/bpf/Makefile
>>> index caede9b574cb..dd7ff14e1fdf 100644
>>> --- a/tools/testing/selftests/bpf/Makefile
>>> +++ b/tools/testing/selftests/bpf/Makefile
>>> @@ -706,6 +706,8 @@ $(OUTPUT)/uprobe_multi: uprobe_multi.c
>>> $(call msg,BINARY,,$@)
>>> $(Q)$(CC) $(CFLAGS) $(LDFLAGS) $^ $(LDLIBS) -o $@
>>> +$(OUTPUT)/testing_helpers.o: $(OUTPUT)/rcu_tasks_trace_gp.skel.h
>>> +
>>> EXTRA_CLEAN := $(TEST_CUSTOM_PROGS) $(SCRATCH_DIR)
>>> $(HOST_SCRATCH_DIR) \
>>> prog_tests/tests.h map_tests/tests.h verifier/tests.h \
>>> feature bpftool \
>>> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>>> index cefc5dd72573..f1a20669d884 100644
>>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>>> @@ -1,5 +1,6 @@
>>> // SPDX-License-Identifier: GPL-2.0
>>> /* Copyright (c) 2020 Facebook */
>>> +#include <linux/bpf.h>
>>> #include <linux/btf.h>
>>> #include <linux/btf_ids.h>
>>> #include <linux/error-injection.h>
>>> @@ -517,11 +518,66 @@ BTF_ID_FLAGS(func,
>>> bpf_kfunc_call_test_static_unused_arg)
>>> BTF_ID_FLAGS(func, bpf_kfunc_call_test_offset)
>>> BTF_SET8_END(bpf_testmod_check_kfunc_ids)
>>> +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
>>> +
>>> +DEFINE_STRUCT_OPS_VALUE_TYPE(bpf_testmod_ops);
>>> +
>>> +static int bpf_testmod_ops_init(struct btf *btf)
>>> +{
>>> + return 0;
>>> +}
>>> +
>>> +static bool bpf_testmod_ops_is_valid_access(int off, int size,
>>> + enum bpf_access_type type,
>>> + const struct bpf_prog *prog,
>>> + struct bpf_insn_access_aux *info)
>>> +{
>>> + return bpf_tracing_btf_ctx_access(off, size, type, prog, info);
>>> +}
>>> +
>>> +static int bpf_testmod_ops_init_member(const struct btf_type *t,
>>> + const struct btf_member *member,
>>> + void *kdata, const void *udata)
>>> +{
>>> + return 0;
>>> +}
>>> +
>>> static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = {
>>> .owner = THIS_MODULE,
>>> .set = &bpf_testmod_check_kfunc_ids,
>>> };
>>> +static const struct bpf_verifier_ops bpf_testmod_verifier_ops = {
>>> + .is_valid_access = bpf_testmod_ops_is_valid_access,
>>> +};
>>> +
>>> +static int bpf_dummy_reg(void *kdata)
>>> +{
>>> + struct bpf_testmod_ops *ops = kdata;
>>> + int r;
>>> +
>>> + BTF_STRUCT_OPS_TYPE_EMIT(bpf_testmod_ops);
>>> + r = ops->test_2(4, 3);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static void bpf_dummy_unreg(void *kdata)
>>> +{
>>> +}
>>> +
>>> +struct bpf_struct_ops bpf_bpf_testmod_ops = {
>>> + .verifier_ops = &bpf_testmod_verifier_ops,
>>> + .init = bpf_testmod_ops_init,
>>> + .init_member = bpf_testmod_ops_init_member,
>>> + .reg = bpf_dummy_reg,
>>> + .unreg = bpf_dummy_unreg,
>>> + .name = "bpf_testmod_ops",
>>> + .owner = THIS_MODULE,
>>> +};
>>> +
>>> +#endif /* CONFIG_DEBUG_INFO_BTF_MODULES */
>>> +
>>> extern int bpf_fentry_test1(int a);
>>> static int bpf_testmod_init(void)
>>> @@ -532,6 +588,9 @@ static int bpf_testmod_init(void)
>>> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS,
>>> &bpf_testmod_kfunc_set);
>>> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING,
>>> &bpf_testmod_kfunc_set);
>>> ret = ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SYSCALL,
>>> &bpf_testmod_kfunc_set);
>>> +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES
>>> + ret = ret ?: register_bpf_struct_ops(&bpf_bpf_testmod_ops);
>>> +#endif
>>> if (ret < 0)
>>> return ret;
>>> if (bpf_fentry_test1(0) < 0)
>>> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>>> index f32793efe095..ca5435751c79 100644
>>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
>>> @@ -28,4 +28,9 @@ struct bpf_iter_testmod_seq {
>>> int cnt;
>>> };
>>> +struct bpf_testmod_ops {
>>> + int (*test_1)(void);
>>> + int (*test_2)(int a, int b);
>>> +};
>>> +
>>> #endif /* _BPF_TESTMOD_H */
>>> diff --git
>>> a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
>>> b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
>>> new file mode 100644
>>> index 000000000000..7261fc6c377a
>>> --- /dev/null
>>> +++ b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
>>> @@ -0,0 +1,38 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
>>> +#include <test_progs.h>
>>> +#include <time.h>
>>> +
>>> +#include "rcu_tasks_trace_gp.skel.h"
>>> +#include "struct_ops_module.skel.h"
>>> +
>>> +static void test_regular_load(void)
>>> +{
>>> + struct struct_ops_module *skel;
>>> + struct bpf_link *link;
>>> + DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts);
>>> + int err;
>>> +
>>> + skel = struct_ops_module__open_opts(&opts);
>>> + if (!ASSERT_OK_PTR(skel, "struct_ops_module_open"))
>>> + return;
>>> + err = struct_ops_module__load(skel);
>>> + if (!ASSERT_OK(err, "struct_ops_module_load"))
>>> + return;
>>> +
>>> + link = bpf_map__attach_struct_ops(skel->maps.testmod_1);
>>> + ASSERT_OK_PTR(link, "attach_test_mod_1");
>>> +
>>> + ASSERT_EQ(skel->bss->test_2_result, 7, "test_2_result");
>>> +
>>> + bpf_link__destroy(link);
>>> +
>>> + struct_ops_module__destroy(skel);
>>> +}
>>> +
>>> +void serial_test_struct_ops_module(void)
>>> +{
>>> + if (test__start_subtest("regular_load"))
>>> + test_regular_load();
>>> +}
>>> +
>>> diff --git a/tools/testing/selftests/bpf/progs/struct_ops_module.c
>>> b/tools/testing/selftests/bpf/progs/struct_ops_module.c
>>> new file mode 100644
>>> index 000000000000..cb305d04342f
>>> --- /dev/null
>>> +++ b/tools/testing/selftests/bpf/progs/struct_ops_module.c
>>> @@ -0,0 +1,30 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
>>> +#include <vmlinux.h>
>>> +#include <bpf/bpf_helpers.h>
>>> +#include <bpf/bpf_tracing.h>
>>> +#include "../bpf_testmod/bpf_testmod.h"
>>> +
>>> +char _license[] SEC("license") = "GPL";
>>> +
>>> +int test_2_result = 0;
>>> +
>>> +SEC("struct_ops/test_1")
>>> +int BPF_PROG(test_1)
>>> +{
>>> + return 0xdeadbeef;
>>> +}
>>> +
>>> +SEC("struct_ops/test_2")
>>> +int BPF_PROG(test_2, int a, int b)
>>> +{
>>> + test_2_result = a + b;
>>> + return a + b;
>>> +}
>>> +
>>> +SEC(".struct_ops.link")
>>> +struct bpf_testmod_ops testmod_1 = {
>>> + .test_1 = (void *)test_1,
>>> + .test_2 = (void *)test_2,
>>> +};
>>> +
>>> diff --git a/tools/testing/selftests/bpf/testing_helpers.c
>>> b/tools/testing/selftests/bpf/testing_helpers.c
>>> index 8d994884c7b4..05870cd62458 100644
>>> --- a/tools/testing/selftests/bpf/testing_helpers.c
>>> +++ b/tools/testing/selftests/bpf/testing_helpers.c
>>> @@ -10,6 +10,7 @@
>>> #include "test_progs.h"
>>> #include "testing_helpers.h"
>>> #include <linux/membarrier.h>
>>> +#include "rcu_tasks_trace_gp.skel.h"
>>> int parse_num_list(const char *s, bool **num_set, int *num_set_len)
>>> {
>>> @@ -380,10 +381,44 @@ int load_bpf_testmod(bool verbose)
>>> return 0;
>>> }
>>> +/* This function will trigger call_rcu_tasks_trace() in the kernel */
>>> +static int kern_sync_rcu_tasks_trace(void)
>>> +{
>>> + struct rcu_tasks_trace_gp *rcu;
>>> + time_t start;
>>> + long gp_seq;
>>> + LIBBPF_OPTS(bpf_test_run_opts, opts);
>>> +
>>> + rcu = rcu_tasks_trace_gp__open_and_load();
>>> + if (IS_ERR(rcu))
>>> + return -EFAULT;
>>> + if (rcu_tasks_trace_gp__attach(rcu))
>>> + return -EFAULT;
>>> +
>>> + gp_seq = READ_ONCE(rcu->bss->gp_seq);
>>> +
>>> + if
>>> (bpf_prog_test_run_opts(bpf_program__fd(rcu->progs.do_call_rcu_tasks_trace),
>>> + &opts))
>>> + return -EFAULT;
>>> + if (opts.retval != 0)
>>> + return -EFAULT;
>>> +
>>> + start = time(NULL);
>>> + while ((start + 2) > time(NULL) &&
>>> + gp_seq == READ_ONCE(rcu->bss->gp_seq))
>>> + sched_yield();
>>> +
>>> + rcu_tasks_trace_gp__destroy(rcu);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> /*
>>> * Trigger synchronize_rcu() in kernel.
>>> */
>>> int kern_sync_rcu(void)
>>> {
>>> + if (kern_sync_rcu_tasks_trace())
>>> + return -EFAULT;
>>> return syscall(__NR_membarrier, MEMBARRIER_CMD_SHARED, 0, 0);
>>> }
>>
next prev parent reply other threads:[~2023-10-27 7:09 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-22 5:03 [PATCH bpf-next v6 00/10] Registrating struct_ops types from modules thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 01/10] bpf: refactory struct_ops type initialization to a function thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 02/10] bpf, net: introduce bpf_struct_ops_desc thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 03/10] bpf: add struct_ops_tab to btf thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 04/10] bpf: hold module for bpf_struct_ops_map thinker.li
2023-10-26 21:11 ` Eduard Zingerman
2023-10-27 4:35 ` Kui-Feng Lee
2023-10-22 5:03 ` [PATCH bpf-next v6 05/10] bpf: validate value_type thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 06/10] bpf: pass attached BTF to the bpf_struct_ops subsystem thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 07/10] bpf, net: switch to dynamic registration thinker.li
2023-10-22 6:46 ` kernel test robot
2023-10-26 21:02 ` Eduard Zingerman
2023-10-27 4:39 ` Kui-Feng Lee
2023-10-27 21:32 ` Kui-Feng Lee
2023-10-27 22:02 ` Eduard Zingerman
2023-10-22 5:03 ` [PATCH bpf-next v6 08/10] libbpf: Find correct module BTFs for struct_ops maps and progs thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 09/10] bpf: export btf_ctx_access to modules thinker.li
2023-10-22 5:03 ` [PATCH bpf-next v6 10/10] selftests/bpf: test case for register_bpf_struct_ops() thinker.li
2023-10-22 7:08 ` kernel test robot
2023-10-26 20:31 ` Eduard Zingerman
2023-10-27 4:55 ` Kui-Feng Lee
2023-10-27 7:09 ` Kui-Feng Lee [this message]
2023-10-27 14:13 ` Eduard Zingerman
2023-10-29 2:34 ` Kui-Feng Lee
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