Re: [PATCH bpf-next v2 4/6] selftests/bpf: test struct_ops with epoll

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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@xxxxxxxxx>
---
  .../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.

  }
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.

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.

+	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.

+
+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?

+
+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,
+};





[Index of Archives]     [Linux Samsung SoC]     [Linux Rockchip SoC]     [Linux Actions SoC]     [Linux for Synopsys ARC Processors]     [Linux NFS]     [Linux NILFS]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]


  Powered by Linux