From: Kui-Feng Lee <sinquersw@gmail.com>
To: Martin KaFai Lau <martin.lau@linux.dev>,
Kui-Feng Lee <thinker.li@gmail.com>
Cc: bpf@vger.kernel.org, ast@kernel.org, song@kernel.org,
kernel-team@meta.com, andrii@kernel.org, kuifeng@meta.com
Subject: Re: [PATCH bpf-next v2 4/6] selftests/bpf: test struct_ops with epoll
Date: Wed, 8 May 2024 17:22:07 -0700 [thread overview]
Message-ID: <696c9521-74df-48f1-a1d8-bf2c49a55319@gmail.com> (raw)
In-Reply-To: <de29eee0-9a69-4f97-b77e-83294dc8ed6f@linux.dev>
On 5/8/24 16:34, Martin KaFai Lau wrote:
> On 5/6/24 10:55 PM, Kui-Feng Lee wrote:
>> Verify whether a user space program is informed through epoll with
>> EPOLLHUP
>> when a struct_ops object is detached.
>>
>> Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
>> ---
>> .../selftests/bpf/bpf_testmod/bpf_testmod.c | 13 +++++
>> .../bpf/bpf_testmod/bpf_testmod_kfunc.h | 1 +
>> .../bpf/prog_tests/test_struct_ops_module.c | 57 +++++++++++++++++++
>> .../selftests/bpf/progs/struct_ops_detach.c | 31 ++++++++++
>> 4 files changed, 102 insertions(+)
>> create mode 100644
>> tools/testing/selftests/bpf/progs/struct_ops_detach.c
>>
>> diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> index e24a18bfee14..c89a6414c69f 100644
>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
>> @@ -10,6 +10,7 @@
>> #include <linux/percpu-defs.h>
>> #include <linux/sysfs.h>
>> #include <linux/tracepoint.h>
>> +#include <linux/workqueue.h>
>> #include "bpf_testmod.h"
>> #include "bpf_testmod_kfunc.h"
>> @@ -498,6 +499,9 @@ __bpf_kfunc void bpf_kfunc_call_test_sleepable(void)
>> {
>> }
>> +static DEFINE_MUTEX(detach_mutex);
>> +static struct bpf_link *link_to_detach;
>> +
>> BTF_KFUNCS_START(bpf_testmod_check_kfunc_ids)
>> BTF_ID_FLAGS(func, bpf_testmod_test_mod_kfunc)
>> BTF_ID_FLAGS(func, bpf_kfunc_call_test1)
>> @@ -577,11 +581,20 @@ static int bpf_dummy_reg(void *kdata, struct
>> bpf_link *link)
>> if (ops->test_2)
>> ops->test_2(4, ops->data);
>> + mutex_lock(&detach_mutex);
>> + if (!link_to_detach)
>> + link_to_detach = link;
>> + mutex_unlock(&detach_mutex);
>> +
>> return 0;
>> }
>> static void bpf_dummy_unreg(void *kdata, struct bpf_link *link)
>> {
>> + mutex_lock(&detach_mutex);
>> + if (link == link_to_detach)
>> + link_to_detach = NULL;
>> + mutex_unlock(&detach_mutex);
>
> The reg/unreg changes should belong to the next patch.
Sure!
>
>> }
>> static int bpf_testmod_test_1(void)
>> diff --git
>> a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
>> b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
>> index ce5cd763561c..9f9b60880fd3 100644
>> --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
>> +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h
>> @@ -105,6 +105,7 @@ void bpf_kfunc_call_test_fail1(struct
>> prog_test_fail1 *p);
>> void bpf_kfunc_call_test_fail2(struct prog_test_fail2 *p);
>> void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p);
>> void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len);
>> +int bpf_dummy_do_link_detach(void) __ksym;
>
> The kfunc is not added in this patch either.
Sure!
>
>> void bpf_kfunc_common_test(void) __ksym;
>> #endif /* _BPF_TESTMOD_KFUNC_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
>> index bd39586abd5a..f39455b81664 100644
>> --- a/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
>> +++ b/tools/testing/selftests/bpf/prog_tests/test_struct_ops_module.c
>> @@ -2,8 +2,12 @@
>> /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
>> #include <test_progs.h>
>> #include <time.h>
>> +#include <network_helpers.h>
>
> What is needed from network_herlpers.h?
>
>> +
>> +#include <sys/epoll.h>
>> #include "struct_ops_module.skel.h"
>> +#include "struct_ops_detach.skel.h"
>> static void check_map_info(struct bpf_map_info *info)
>> {
>> @@ -174,6 +178,57 @@ static void test_struct_ops_incompatible(void)
>> struct_ops_module__destroy(skel);
>> }
>> +/* Detach a link from a user space program */
>> +static void test_detach_link(void)
>> +{
>> + struct epoll_event ev, events[2];
>> + struct struct_ops_detach *skel;
>> + struct bpf_link *link = NULL;
>> + int fd, epollfd = -1, nfds;
>> + int err;
>> +
>> + skel = struct_ops_detach__open_and_load();
>> + if (!ASSERT_OK_PTR(skel, "struct_ops_detach__open_and_load"))
>> + return;
>> +
>> + link = bpf_map__attach_struct_ops(skel->maps.testmod_do_detach);
>> + if (!ASSERT_OK_PTR(link, "attach_struct_ops"))
>> + goto cleanup;
>> +
>> + fd = bpf_link__fd(link);
>> + if (!ASSERT_GE(fd, 0, "link_fd"))
>> + goto cleanup;
>> +
>> + epollfd = epoll_create1(0);
>> + if (!ASSERT_GE(epollfd, 0, "epoll_create1"))
>> + goto cleanup;
>> +
>> + ev.events = EPOLLHUP;
>> + ev.data.fd = fd;
>> + err = epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &ev);
>> + if (!ASSERT_OK(err, "epoll_ctl"))
>> + goto cleanup;
>> +
>> + err = bpf_link__detach(link);
>> + if (!ASSERT_OK(err, "detach_link"))
>> + goto cleanup;
>> +
>> + /* Wait for EPOLLHUP */
>> + nfds = epoll_wait(epollfd, events, 2, 500);
>> + if (!ASSERT_EQ(nfds, 1, "epoll_wait"))
>> + goto cleanup;
>> +
>> + if (!ASSERT_EQ(events[0].data.fd, fd, "epoll_wait_fd"))
>> + goto cleanup;
>> + if (!ASSERT_TRUE(events[0].events & EPOLLHUP, "events[0].events"))
>> + goto cleanup;
>> +
>> +cleanup:
>> + close(epollfd);
>
> Better check epollfd since it is init to -1. There are cases that
> epollfd is -1 here.
Ok! Although close(-1) doesn't cause any issue, it makes sense doing
check before calling it.
>
>> + bpf_link__destroy(link);
>> + struct_ops_detach__destroy(skel);
>> +}
>> +
>> void serial_test_struct_ops_module(void)
>> {
>> if (test__start_subtest("test_struct_ops_load"))
>> @@ -182,5 +237,7 @@ void serial_test_struct_ops_module(void)
>> test_struct_ops_not_zeroed();
>> if (test__start_subtest("test_struct_ops_incompatible"))
>> test_struct_ops_incompatible();
>> + if (test__start_subtest("test_detach_link"))
>> + test_detach_link();
>> }
>> diff --git a/tools/testing/selftests/bpf/progs/struct_ops_detach.c
>> b/tools/testing/selftests/bpf/progs/struct_ops_detach.c
>> new file mode 100644
>> index 000000000000..aeb355b3bea3
>> --- /dev/null
>> +++ b/tools/testing/selftests/bpf/progs/struct_ops_detach.c
>> @@ -0,0 +1,31 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
>> +#include <vmlinux.h>
>> +#include <bpf/bpf_helpers.h>
>> +#include <bpf/bpf_tracing.h>
>> +#include "../bpf_testmod/bpf_testmod.h"
>> +#include "../bpf_testmod/bpf_testmod_kfunc.h"
>
> The _kfunc.h should not be needed in this patch either.
Sure!
>
>> +
>> +char _license[] SEC("license") = "GPL";
>> +
>> +int test_1_result = 0;
>> +int test_2_result = 0;
>
> Are these global vars tested? If not, can the test_1 and test_2 programs
> be removed? or some of them is not optional?
Yes, they are optional. I will remove these functions.
>
>> +
>> +SEC("struct_ops/test_1")
>> +int BPF_PROG(test_1)
>> +{
>> + test_1_result = 0xdeadbeef;
>> + return 0;
>> +}
>> +
>> +SEC("struct_ops/test_2")
>> +void BPF_PROG(test_2, int a, int b)
>> +{
>> + test_2_result = a + b;
>> +}
>> +
>> +SEC(".struct_ops.link")
>> +struct bpf_testmod_ops testmod_do_detach = {
>> + .test_1 = (void *)test_1,
>> + .test_2 = (void *)test_2,
>> +};
>
next prev parent reply other threads:[~2024-05-09 0:22 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 5:55 [PATCH bpf-next v2 0/6] Notify user space when a struct_ops object is detached/unregistered Kui-Feng Lee
2024-05-07 5:55 ` [PATCH bpf-next v2 1/6] bpf: pass bpf_struct_ops_link to callbacks in bpf_struct_ops Kui-Feng Lee
2024-05-07 5:55 ` [PATCH bpf-next v2 2/6] bpf: enable detaching links of struct_ops objects Kui-Feng Lee
2024-05-08 23:22 ` Martin KaFai Lau
2024-05-09 0:14 ` Kui-Feng Lee
2024-05-09 0:36 ` Martin KaFai Lau
2024-05-09 16:59 ` Kui-Feng Lee
2024-05-09 0:46 ` Kui-Feng Lee
2024-05-07 5:55 ` [PATCH bpf-next v2 3/6] bpf: support epoll from bpf struct_ops links Kui-Feng Lee
2024-05-07 5:55 ` [PATCH bpf-next v2 4/6] selftests/bpf: test struct_ops with epoll Kui-Feng Lee
2024-05-08 23:34 ` Martin KaFai Lau
2024-05-09 0:22 ` Kui-Feng Lee [this message]
2024-05-07 5:55 ` [PATCH bpf-next v2 5/6] selftests/bpf: detach a struct_ops link from the subsystem managing it Kui-Feng Lee
2024-05-08 23:50 ` Martin KaFai Lau
2024-05-09 5:50 ` Kui-Feng Lee
2024-05-07 5:56 ` [PATCH bpf-next v2 6/6] selftests/bpf: make sure bpf_testmod handling racing link destroying well Kui-Feng Lee
2024-05-09 0:04 ` Martin KaFai Lau
2024-05-09 17:02 ` Kui-Feng Lee
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