Verify whether a user space program is informed through epoll with EPOLLHUP
when a struct_ops object is detached or unregistered using the function
bpf_struct_ops_kvalue_unreg() or BPF_LINK_DETACH.
Signed-off-by: Kui-Feng Lee <thinker.li@xxxxxxxxx>
---
.../selftests/bpf/bpf_testmod/bpf_testmod.c | 18 ++-
.../selftests/bpf/bpf_testmod/bpf_testmod.h | 1 +
.../bpf/prog_tests/test_struct_ops_module.c | 104 ++++++++++++++++++
.../selftests/bpf/progs/struct_ops_module.c | 7 ++
4 files changed, 126 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
index 39ad96a18123..e526ccfad8bf 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c
@@ -539,16 +539,20 @@ static int bpf_testmod_ops_init_member(const struct btf_type *t,
const struct btf_member *member,
void *kdata, const void *udata)
{
+ struct bpf_testmod_ops *ops = kdata;
+
if (member->offset == offsetof(struct bpf_testmod_ops, data) * 8) {
/* For data fields, this function has to copy it and return
* 1 to indicate that the data has been handled by the
* struct_ops type, or the verifier will reject the map if
* the value of the data field is not zero.
*/
- ((struct bpf_testmod_ops *)kdata)->data = ((struct bpf_testmod_ops *)udata)->data;
- return 1;
- }
- return 0;
+ ops->data = ((struct bpf_testmod_ops *)udata)->data;
+ } else if (member->offset == offsetof(struct bpf_testmod_ops, do_unreg) * 8) {
+ ops->do_unreg = ((struct bpf_testmod_ops *)udata)->do_unreg;
+ } else
+ return 0;
+ return 1;
}
static const struct btf_kfunc_id_set bpf_testmod_kfunc_set = {
@@ -572,6 +576,12 @@ static int bpf_dummy_reg(void *kdata)
if (ops->test_2)
ops->test_2(4, ops->data);
+ if (ops->do_unreg) {
+ rcu_read_lock();
+ bpf_struct_ops_kvalue_unreg(kdata);
+ rcu_read_unlock();
+ }
+
return 0;
}
diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
index 23fa1872ee67..ee8d4a2cd187 100644
--- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
+++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.h
@@ -43,6 +43,7 @@ struct bpf_testmod_ops {
int b;
} unsupported;
int data;
+ bool do_unreg;
/* The following pointers are used to test the maps having multiple
* pages of trampolines.
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 7cf2b9ddd3e1..b4d3b29114ca 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
@@ -3,6 +3,8 @@
#include <test_progs.h>
#include <time.h>
+#include <sys/epoll.h>
+
#include "struct_ops_module.skel.h"
static void check_map_info(struct bpf_map_info *info)
@@ -160,6 +162,104 @@ static void test_struct_ops_incompatible(void)
struct_ops_module__destroy(skel);
}
+static void test_detach_link(void)
+{
+ struct epoll_event ev, events[2];
+ struct struct_ops_module *skel;
+ struct bpf_link *link = NULL;
+ int fd, epollfd = -1, nfds;
+ int err;
+
+ skel = struct_ops_module__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "open_and_load"))
+ return;
+
+ link = bpf_map__attach_struct_ops(skel->maps.testmod_1);
+ 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;
+
+ 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);
+ bpf_link__destroy(link);
+ struct_ops_module__destroy(skel);
+}
+
+/* Test bpf_struct_ops_kvalue_unreg() */
+static void test_do_unreg(void)
+{
+ struct epoll_event ev, events[2];
+ struct struct_ops_module *skel;
+ struct bpf_link *link = NULL;
+ int fd, epollfd = -1, nfds;
+ int err;
+
+ skel = struct_ops_module__open_and_load();
+ if (!ASSERT_OK_PTR(skel, "open_and_load"))
+ return;
+
+ /* bpf_testmod will unregister this map immediately through the
+ * function bpf_struct_ops_kvalue_unreg() since "do_unreg" is true.
+ */
+ link = bpf_map__attach_struct_ops(skel->maps.testmod_do_unreg);
+ 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;
+
+ 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);
+ bpf_link__destroy(link);
+ struct_ops_module__destroy(skel);
+}
+
void serial_test_struct_ops_module(void)
{
if (test__start_subtest("test_struct_ops_load"))
@@ -168,5 +268,9 @@ 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();
+ if (test__start_subtest("test_do_unreg"))
+ test_do_unreg();
}
diff --git a/tools/testing/selftests/bpf/progs/struct_ops_module.c b/tools/testing/selftests/bpf/progs/struct_ops_module.c
index 63b065dae002..7a697a7dd0ac 100644
--- a/tools/testing/selftests/bpf/progs/struct_ops_module.c
+++ b/tools/testing/selftests/bpf/progs/struct_ops_module.c
@@ -81,3 +81,10 @@ struct bpf_testmod_ops___incompatible testmod_incompatible = {
.test_2 = (void *)test_2,
.data = 3,
};
+
+SEC(".struct_ops.link")
+struct bpf_testmod_ops testmod_do_unreg = {
+ .test_1 = (void *)test_1,
+ .test_2 = (void *)test_2,
+ .do_unreg = true,
+};
--
2.34.1
