Merge branch 'libbpf: error reporting changes for v1.0'

Andrii Nakryiko says:

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

Implement error reporting changes discussed in "Libbpf: the road to v1.0"
([0]) document.

Libbpf gets a new API, libbpf_set_strict_mode() which accepts a set of flags
that turn on a set of libbpf 1.0 changes, that might be potentially breaking.
It's possible to opt-in into all current and future 1.0 features by specifying
LIBBPF_STRICT_ALL flag.

When some of the 1.0 "features" are requested, libbpf APIs might behave
differently. In this patch set a first set of changes are implemented, all
related to the way libbpf returns errors. See individual patches for details.

Patch #1 adds a no-op libbpf_set_strict_mode() functionality to enable
updating selftests.

Patch #2 gets rid of all the bad code patterns that will break in libbpf 1.0
(exact -1 comparison for low-level APIs, direct IS_ERR() macro usage to check
pointer-returning APIs for error, etc). These changes make selftest work in
both legacy and 1.0 libbpf modes. Selftests also opt-in into 100% libbpf 1.0
mode to automatically gain all the subsequent changes, which will come in
follow up patches.

Patch #3 streamlines error reporting for low-level APIs wrapping bpf() syscall.

Patch #4 streamlines errors for all the rest APIs.

Patch #5 ensures that BPF skeletons propagate errors properly as well, as
currently on error some APIs will return NULL with no way of checking exact
error code.

  [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY

v1->v2:
  - move libbpf_set_strict_mode() implementation to patch #1, where it belongs
    (Alexei);
  - add acks, slight rewording of commit messages.
====================

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

1 files changed, 5 insertions, 10 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c b/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c
index 08d19cafd5e8..1fa772079967 100644
--- a/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c
+++ b/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c
@@ -353,8 +353,7 @@ static void fastopen_estab(void)
 		return;
 
 	link = bpf_program__attach_cgroup(skel->progs.estab, cg_fd);
-	if (CHECK(IS_ERR(link), "attach_cgroup(estab)", "err: %ld\n",
-		  PTR_ERR(link)))
+	if (!ASSERT_OK_PTR(link, "attach_cgroup(estab)"))
 		return;
 
 	if (sk_fds_connect(&sk_fds, true)) {
@@ -398,8 +397,7 @@ static void syncookie_estab(void)
 		return;
 
 	link = bpf_program__attach_cgroup(skel->progs.estab, cg_fd);
-	if (CHECK(IS_ERR(link), "attach_cgroup(estab)", "err: %ld\n",
-		  PTR_ERR(link)))
+	if (!ASSERT_OK_PTR(link, "attach_cgroup(estab)"))
 		return;
 
 	if (sk_fds_connect(&sk_fds, false)) {
@@ -431,8 +429,7 @@ static void fin(void)
 		return;
 
 	link = bpf_program__attach_cgroup(skel->progs.estab, cg_fd);
-	if (CHECK(IS_ERR(link), "attach_cgroup(estab)", "err: %ld\n",
-		  PTR_ERR(link)))
+	if (!ASSERT_OK_PTR(link, "attach_cgroup(estab)"))
 		return;
 
 	if (sk_fds_connect(&sk_fds, false)) {
@@ -471,8 +468,7 @@ static void __simple_estab(bool exprm)
 		return;
 
 	link = bpf_program__attach_cgroup(skel->progs.estab, cg_fd);
-	if (CHECK(IS_ERR(link), "attach_cgroup(estab)", "err: %ld\n",
-		  PTR_ERR(link)))
+	if (!ASSERT_OK_PTR(link, "attach_cgroup(estab)"))
 		return;
 
 	if (sk_fds_connect(&sk_fds, false)) {
@@ -509,8 +505,7 @@ static void misc(void)
 		return;
 
 	link = bpf_program__attach_cgroup(misc_skel->progs.misc_estab, cg_fd);
-	if (CHECK(IS_ERR(link), "attach_cgroup(misc_estab)", "err: %ld\n",
-		  PTR_ERR(link)))
+	if (!ASSERT_OK_PTR(link, "attach_cgroup(misc_estab)"))
 		return;
 
 	if (sk_fds_connect(&sk_fds, false)) {