selftests/bpf: Unprivileged tests for test_loader.c

Extends test_loader.c:test_loader__run_subtests() by allowing to
execute tests in unprivileged mode, similar to test_verifier.c.

Adds the following new attributes controlling test_loader behavior:

  __msg_unpriv
  __success_unpriv
  __failure_unpriv

* If any of these attributes is present the test would be loaded in
  unprivileged mode.
* If only "privileged" attributes are present the test would be loaded
  only in privileged mode.
* If both "privileged" and "unprivileged" attributes are present the
  test would be loaded in both modes.
* If test has to be executed in both modes, __msg(text) is specified
  and __msg_unpriv is not specified the behavior is the same as if
  __msg_unpriv(text) is specified.
* For test filtering purposes the name of the program loaded in
  unprivileged mode is derived from the usual program name by adding
  `@unpriv' suffix.

Also adds attribute '__description'. This attribute specifies text to
be used instead of a program name for display and filtering purposes.

Signed-off-by: Eduard Zingerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>

1 files changed, 25 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 8b4681a96f89..9defc217a5bd 100644
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -5,12 +5,33 @@
 /* This set of attributes controls behavior of the
  * test_loader.c:test_loader__run_subtests().
  *
+ * The test_loader sequentially loads each program in a skeleton.
+ * Programs could be loaded in privileged and unprivileged modes.
+ * - __success, __failure, __msg imply privileged mode;
+ * - __success_unpriv, __failure_unpriv, __msg_unpriv imply
+ *   unprivileged mode.
+ * If combination of privileged and unprivileged attributes is present
+ * both modes are used. If none are present privileged mode is implied.
+ *
+ * See test_loader.c:drop_capabilities() for exact set of capabilities
+ * that differ between privileged and unprivileged modes.
+ *
+ * For test filtering purposes the name of the program loaded in
+ * unprivileged mode is derived from the usual program name by adding
+ * `@unpriv' suffix.
+ *
  * __msg             Message expected to be found in the verifier log.
  *                   Multiple __msg attributes could be specified.
+ * __msg_unpriv      Same as __msg but for unprivileged mode.
  *
  * __success         Expect program load success in privileged mode.
+ * __success_unpriv  Expect program load success in unprivileged mode.
  *
  * __failure         Expect program load failure in privileged mode.
+ * __failure_unpriv  Expect program load failure in unprivileged mode.
+ *
+ * __description     Text to be used instead of a program name for display
+ *                   and filtering purposes.
  *
  * __log_level       Log level to use for the program, numeric value expected.
  *
@@ -27,6 +48,10 @@
 #define __msg(msg)		__attribute__((btf_decl_tag("comment:test_expect_msg=" msg)))
 #define __failure		__attribute__((btf_decl_tag("comment:test_expect_failure")))
 #define __success		__attribute__((btf_decl_tag("comment:test_expect_success")))
+#define __description(desc)	__attribute__((btf_decl_tag("comment:test_description=" desc)))
+#define __msg_unpriv(msg)	__attribute__((btf_decl_tag("comment:test_expect_msg_unpriv=" msg)))
+#define __failure_unpriv	__attribute__((btf_decl_tag("comment:test_expect_failure_unpriv")))
+#define __success_unpriv	__attribute__((btf_decl_tag("comment:test_expect_success_unpriv")))
 #define __log_level(lvl)	__attribute__((btf_decl_tag("comment:test_log_level="#lvl)))
 #define __flag(flag)		__attribute__((btf_decl_tag("comment:test_prog_flags="#flag)))