Extends test_loader.c:test_loader__run_subtests() by allowing to
execute BPF_PROG_TEST_RUN bpf command for selected programs.
This is similar to functionality provided by test_verifier.
Adds the following new attributes controlling test_loader behavior:
__retval(...)
__retval_unpriv(...)
* If any of these attributes is present, the annotated program would
be executed using libbpf's bpf_prog_test_run_opts() function.
* If __retval is present, the test run would be done for program
loaded in privileged mode.
* If __retval_unpriv is present, the test run would be done for
program loaded in unprivileged mode.
* To mimic test_verifier behavior, the actual run is initiated in
privileged mode.
* The value returned by a test run is compared against retval
parameter.
The retval attribute takes one of the following parameters:
- a decimal number
- a hexadecimal number (must start from '0x')
- any of a three special literals (provided for compatibility with
test_verifier):
- INT_MIN
- POINTER_VALUE
- TEST_DATA_LEN
An example of the attribute usage:
SEC("socket")
__description("return 42")
__success __success_unpriv __retval(42)
__naked void the_42_test(void)
{
asm volatile (" \
r0 = 42; \
exit; \
" ::: __clobber_all);
}
Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
---
tools/testing/selftests/bpf/progs/bpf_misc.h | 15 ++
tools/testing/selftests/bpf/test_loader.c | 149 +++++++++++++++++--
2 files changed, 150 insertions(+), 14 deletions(-)
diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h
index 9defc217a5bd..6e3b4903c541 100644
--- a/tools/testing/selftests/bpf/progs/bpf_misc.h
+++ b/tools/testing/selftests/bpf/progs/bpf_misc.h
@@ -30,6 +30,15 @@
* __failure Expect program load failure in privileged mode.
* __failure_unpriv Expect program load failure in unprivileged mode.
*
+ * __retval Execute the program using BPF_PROG_TEST_RUN command,
+ * expect return value to match passed parameter:
+ * - a decimal number
+ * - a hexadecimal number, when starts from 0x
+ * - literal INT_MIN
+ * - literal POINTER_VALUE (see definition below)
+ * - literal TEST_DATA_LEN (see definition below)
+ * __retval_unpriv Same, but load program in unprivileged mode.
+ *
* __description Text to be used instead of a program name for display
* and filtering purposes.
*
@@ -54,6 +63,8 @@
#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)))
+#define __retval(val) __attribute__((btf_decl_tag("comment:test_retval="#val)))
+#define __retval_unpriv(val) __attribute__((btf_decl_tag("comment:test_retval_unpriv="#val)))
/* Convenience macro for use with 'asm volatile' blocks */
#define __naked __attribute__((naked))
@@ -65,6 +76,10 @@
#define __imm_ptr(name) [name]"p"(&name)
#define __imm_insn(name, expr) [name]"i"(*(long *)&(expr))
+/* Magic constants used with __retval() */
+#define POINTER_VALUE 0xcafe4all
+#define TEST_DATA_LEN 64
+
#if defined(__TARGET_ARCH_x86)
#define SYSCALL_WRAPPER 1
#define SYS_PREFIX "__x64_"
diff --git a/tools/testing/selftests/bpf/test_loader.c b/tools/testing/selftests/bpf/test_loader.c
index 41cddb303885..47e9e076bc8f 100644
--- a/tools/testing/selftests/bpf/test_loader.c
+++ b/tools/testing/selftests/bpf/test_loader.c
@@ -23,6 +23,12 @@
#define TEST_TAG_LOG_LEVEL_PFX "comment:test_log_level="
#define TEST_TAG_PROG_FLAGS_PFX "comment:test_prog_flags="
#define TEST_TAG_DESCRIPTION_PFX "comment:test_description="
+#define TEST_TAG_RETVAL_PFX "comment:test_retval="
+#define TEST_TAG_RETVAL_PFX_UNPRIV "comment:test_retval_unpriv="
+
+/* Warning: duplicated in bpf_misc.h */
+#define POINTER_VALUE 0xcafe4all
+#define TEST_DATA_LEN 64
#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
#define EFFICIENT_UNALIGNED_ACCESS 1
@@ -42,6 +48,8 @@ struct test_subspec {
bool expect_failure;
const char **expect_msgs;
size_t expect_msg_cnt;
+ int retval;
+ bool execute;
};
struct test_spec {
@@ -96,6 +104,46 @@ static int push_msg(const char *msg, struct test_subspec *subspec)
return 0;
}
+static int parse_int(const char *str, int *val, const char *name)
+{
+ char *end;
+ long tmp;
+
+ errno = 0;
+ if (str_has_pfx(str, "0x"))
+ tmp = strtol(str + 2, &end, 16);
+ else
+ tmp = strtol(str, &end, 10);
+ if (errno || end[0] != '\0') {
+ PRINT_FAIL("failed to parse %s from '%s'\n", name, str);
+ return -EINVAL;
+ }
+ *val = tmp;
+ return 0;
+}
+
+static int parse_retval(const char *str, int *val, const char *name)
+{
+ struct {
+ char *name;
+ int val;
+ } named_values[] = {
+ { "INT_MIN" , INT_MIN },
+ { "POINTER_VALUE", POINTER_VALUE },
+ { "TEST_DATA_LEN", TEST_DATA_LEN },
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(named_values); ++i) {
+ if (strcmp(str, named_values[i].name) != 0)
+ continue;
+ *val = named_values[i].val;
+ return 0;
+ }
+
+ return parse_int(str, val, name);
+}
+
/* Uses btf_decl_tag attributes to describe the expected test
* behavior, see bpf_misc.h for detailed description of each attribute
* and attribute combinations.
@@ -107,6 +155,7 @@ static int parse_test_spec(struct test_loader *tester,
{
const char *description = NULL;
bool has_unpriv_result = false;
+ bool has_unpriv_retval = false;
int func_id, i, err = 0;
struct btf *btf;
@@ -129,7 +178,7 @@ static int parse_test_spec(struct test_loader *tester,
for (i = 1; i < btf__type_cnt(btf); i++) {
const char *s, *val, *msg;
const struct btf_type *t;
- char *e;
+ int tmp;
t = btf__type_by_id(btf, i);
if (!btf_is_decl_tag(t))
@@ -167,15 +216,26 @@ static int parse_test_spec(struct test_loader *tester,
if (err)
goto cleanup;
spec->mode_mask |= UNPRIV;
+ } else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX)) {
+ val = s + sizeof(TEST_TAG_RETVAL_PFX) - 1;
+ err = parse_retval(val, &spec->priv.retval, "__retval");
+ if (err)
+ goto cleanup;
+ spec->priv.execute = true;
+ spec->mode_mask |= PRIV;
+ } else if (str_has_pfx(s, TEST_TAG_RETVAL_PFX_UNPRIV)) {
+ val = s + sizeof(TEST_TAG_RETVAL_PFX_UNPRIV) - 1;
+ err = parse_retval(val, &spec->unpriv.retval, "__retval_unpriv");
+ if (err)
+ goto cleanup;
+ spec->mode_mask |= UNPRIV;
+ spec->unpriv.execute = true;
+ has_unpriv_retval = true;
} else if (str_has_pfx(s, TEST_TAG_LOG_LEVEL_PFX)) {
val = s + sizeof(TEST_TAG_LOG_LEVEL_PFX) - 1;
- errno = 0;
- spec->log_level = strtol(val, &e, 0);
- if (errno || e[0] != '\0') {
- PRINT_FAIL("failed to parse test log level from '%s'\n", s);
- err = -EINVAL;
+ err = parse_int(val, &spec->log_level, "test log level");
+ if (err)
goto cleanup;
- }
} else if (str_has_pfx(s, TEST_TAG_PROG_FLAGS_PFX)) {
val = s + sizeof(TEST_TAG_PROG_FLAGS_PFX) - 1;
if (strcmp(val, "BPF_F_STRICT_ALIGNMENT") == 0) {
@@ -191,14 +251,10 @@ static int parse_test_spec(struct test_loader *tester,
} else if (strcmp(val, "BPF_F_XDP_HAS_FRAGS") == 0) {
spec->prog_flags |= BPF_F_XDP_HAS_FRAGS;
} else /* assume numeric value */ {
- errno = 0;
- spec->prog_flags |= strtol(val, &e, 0);
- if (errno || e[0] != '\0') {
- PRINT_FAIL("failed to parse test prog flags from '%s'\n",
- val);
- err = -EINVAL;
+ err = parse_int(val, &tmp, "test prog flags");
+ if (err)
goto cleanup;
- }
+ spec->prog_flags |= tmp;
}
}
}
@@ -239,6 +295,11 @@ static int parse_test_spec(struct test_loader *tester,
if (!has_unpriv_result)
spec->unpriv.expect_failure = spec->priv.expect_failure;
+ if (!has_unpriv_retval) {
+ spec->unpriv.retval = spec->priv.retval;
+ spec->unpriv.execute = spec->priv.execute;
+ }
+
if (!spec->unpriv.expect_msgs) {
size_t sz = spec->priv.expect_msg_cnt * sizeof(void *);
@@ -402,6 +463,51 @@ static bool is_unpriv_capable_map(struct bpf_map *map)
}
}
+static int do_prog_test_run(int fd_prog, int *retval)
+{
+ __u8 tmp_out[TEST_DATA_LEN << 2] = {};
+ __u8 tmp_in[TEST_DATA_LEN] = {};
+ int err, saved_errno;
+ LIBBPF_OPTS(bpf_test_run_opts, topts,
+ .data_in = tmp_in,
+ .data_size_in = sizeof(tmp_in),
+ .data_out = tmp_out,
+ .data_size_out = sizeof(tmp_out),
+ .repeat = 1,
+ );
+
+ err = bpf_prog_test_run_opts(fd_prog, &topts);
+ saved_errno = errno;
+
+ if (err) {
+ PRINT_FAIL("FAIL: Unexpected bpf_prog_test_run error: %d (%s) ",
+ saved_errno, strerror(saved_errno));
+ return err;
+ }
+
+ ASSERT_OK(0, "bpf_prog_test_run");
+ *retval = topts.retval;
+
+ return 0;
+}
+
+static bool should_do_test_run(struct test_spec *spec, struct test_subspec *subspec)
+{
+ if (!subspec->execute)
+ return false;
+
+ if (subspec->expect_failure)
+ return false;
+
+ if ((spec->prog_flags & BPF_F_ANY_ALIGNMENT) && !EFFICIENT_UNALIGNED_ACCESS) {
+ if (env.verbosity != VERBOSE_NONE)
+ printf("alignment prevents execution\n");
+ return false;
+ }
+
+ return true;
+}
+
/* this function is forced noinline and has short generic name to look better
* in test_progs output (in case of a failure)
*/
@@ -418,6 +524,7 @@ void run_subtest(struct test_loader *tester,
struct bpf_program *tprog;
struct bpf_object *tobj;
struct bpf_map *map;
+ int retval;
int err;
if (!test__start_subtest(subspec->name))
@@ -476,6 +583,20 @@ void run_subtest(struct test_loader *tester,
emit_verifier_log(tester->log_buf, false /*force*/);
validate_case(tester, subspec, tobj, tprog, err);
+ if (should_do_test_run(spec, subspec)) {
+ /* For some reason test_verifier executes programs
+ * with all capabilities restored. Do the same here.
+ */
+ if (!restore_capabilities(&caps))
+ goto tobj_cleanup;
+
+ do_prog_test_run(bpf_program__fd(tprog), &retval);
+ if (retval != subspec->retval && subspec->retval != POINTER_VALUE) {
+ PRINT_FAIL("Unexpected retval: %d != %d\n", retval, subspec->retval);
+ goto tobj_cleanup;
+ }
+ }
+
tobj_cleanup:
bpf_object__close(tobj);
subtest_cleanup:
--
2.40.0
