Merge branch 'bpf: Tracing and lsm programs re-attach'

Jiri Olsa says:

====================

hi,
while adding test for pinning the module while there's
trampoline attach to it, I noticed that we don't allow
link detach and following re-attach for trampolines.
Adding that for tracing and lsm programs.

You need to have patch [1] from bpf tree for test module
attach test to pass.

v5 changes:
  - fixed missing hlist_del_init change
  - fixed several ASSERT calls
  - added extra patch for missing ';'
  - added ASSERT macros to lsm test
  - added acks

thanks,
jirka

[1] https://lore.kernel.org/bpf/20210326105900.151466-1-jolsa@kernel.org/
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 41 insertions, 20 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/test_lsm.c b/tools/testing/selftests/bpf/prog_tests/test_lsm.c
index 2755e4f81499..244c01125126 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_lsm.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_lsm.c
@@ -51,43 +51,64 @@ int exec_cmd(int *monitored_pid)
 	return -EINVAL;
 }
 
-void test_test_lsm(void)
+static int test_lsm(struct lsm *skel)
 {
-	struct lsm *skel = NULL;
-	int err, duration = 0;
+	struct bpf_link *link;
 	int buf = 1234;
-
-	skel = lsm__open_and_load();
-	if (CHECK(!skel, "skel_load", "lsm skeleton failed\n"))
-		goto close_prog;
+	int err;
 
 	err = lsm__attach(skel);
-	if (CHECK(err, "attach", "lsm attach failed: %d\n", err))
-		goto close_prog;
+	if (!ASSERT_OK(err, "attach"))
+		return err;
+
+	/* Check that already linked program can't be attached again. */
+	link = bpf_program__attach(skel->progs.test_int_hook);
+	if (!ASSERT_ERR_PTR(link, "attach_link"))
+		return -1;
 
 	err = exec_cmd(&skel->bss->monitored_pid);
-	if (CHECK(err < 0, "exec_cmd", "err %d errno %d\n", err, errno))
-		goto close_prog;
+	if (!ASSERT_OK(err, "exec_cmd"))
+		return err;
 
-	CHECK(skel->bss->bprm_count != 1, "bprm_count", "bprm_count = %d\n",
-	      skel->bss->bprm_count);
+	ASSERT_EQ(skel->bss->bprm_count, 1, "bprm_count");
 
 	skel->bss->monitored_pid = getpid();
 
 	err = stack_mprotect();
-	if (CHECK(errno != EPERM, "stack_mprotect", "want err=EPERM, got %d\n",
-		  errno))
-		goto close_prog;
+	if (!ASSERT_EQ(errno, EPERM, "stack_mprotect"))
+		return err;
 
-	CHECK(skel->bss->mprotect_count != 1, "mprotect_count",
-	      "mprotect_count = %d\n", skel->bss->mprotect_count);
+	ASSERT_EQ(skel->bss->mprotect_count, 1, "mprotect_count");
 
 	syscall(__NR_setdomainname, &buf, -2L);
 	syscall(__NR_setdomainname, 0, -3L);
 	syscall(__NR_setdomainname, ~0L, -4L);
 
-	CHECK(skel->bss->copy_test != 3, "copy_test",
-	      "copy_test = %d\n", skel->bss->copy_test);
+	ASSERT_EQ(skel->bss->copy_test, 3, "copy_test");
+
+	lsm__detach(skel);
+
+	skel->bss->copy_test = 0;
+	skel->bss->bprm_count = 0;
+	skel->bss->mprotect_count = 0;
+	return 0;
+}
+
+void test_test_lsm(void)
+{
+	struct lsm *skel = NULL;
+	int err;
+
+	skel = lsm__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "lsm_skel_load"))
+		goto close_prog;
+
+	err = test_lsm(skel);
+	if (!ASSERT_OK(err, "test_lsm_first_attach"))
+		goto close_prog;
+
+	err = test_lsm(skel);
+	ASSERT_OK(err, "test_lsm_second_attach");
 
 close_prog:
 	lsm__destroy(skel);