bpf, tests: Add module parameter test_suite to test_bpf module

After commit 9298e63eafea ("bpf/tests: Add exhaustive tests of ALU
operand magnitudes"), when modprobe test_bpf.ko with JIT on mips64,
there exists segment fault due to the following reason:

  [...]
  ALU64_MOV_X: all register value magnitudes jited:1
  Break instruction in kernel code[#1]
  [...]

It seems that the related JIT implementations of some test cases
in test_bpf() have problems. At this moment, I do not care about
the segment fault while I just want to verify the test cases of
tail calls.

Based on the above background and motivation, add the following
module parameter test_suite to the test_bpf.ko:

  test_suite=<string>: only the specified test suite will be run, the
  string can be "test_bpf", "test_tail_calls" or "test_skb_segment".

If test_suite is not specified, but test_id, test_name or test_range
is specified, set 'test_bpf' as the default test suite. This is useful
to only test the corresponding test suite when specifying the valid
test_suite string.

Any invalid test suite will result in -EINVAL being returned and no
tests being run. If the test_suite is not specified or specified as
empty string, it does not change the current logic, all of the test
cases will be run.

Here are some test results:

 # dmesg -c
 # modprobe test_bpf
 # dmesg | grep Summary
 test_bpf: Summary: 1009 PASSED, 0 FAILED, [0/997 JIT'ed]
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_bpf
 # dmesg | tail -1
 test_bpf: Summary: 1009 PASSED, 0 FAILED, [0/997 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_tail_calls
 # dmesg
 test_bpf: #0 Tail call leaf jited:0 21 PASS
 [...]
 test_bpf: #7 Tail call error path, index out of range jited:0 32 PASS
 test_bpf: test_tail_calls: Summary: 8 PASSED, 0 FAILED, [0/8 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_skb_segment
 # dmesg
 test_bpf: #0 gso_with_rx_frags PASS
 test_bpf: #1 gso_linear_no_head_frag PASS
 test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_id=1
 # dmesg
 test_bpf: test_bpf: set 'test_bpf' as the default test_suite.
 test_bpf: #1 TXA jited:0 54 51 50 PASS
 test_bpf: Summary: 1 PASSED, 0 FAILED, [0/1 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_bpf test_name=TXA
 # dmesg
 test_bpf: #1 TXA jited:0 54 50 51 PASS
 test_bpf: Summary: 1 PASSED, 0 FAILED, [0/1 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_tail_calls test_range=6,7
 # dmesg
 test_bpf: #6 Tail call error path, NULL target jited:0 41 PASS
 test_bpf: #7 Tail call error path, index out of range jited:0 32 PASS
 test_bpf: test_tail_calls: Summary: 2 PASSED, 0 FAILED, [0/2 JIT'ed]

 # rmmod test_bpf
 # dmesg -c
 # modprobe test_bpf test_suite=test_skb_segment test_id=1
 # dmesg
 test_bpf: #1 gso_linear_no_head_frag PASS
 test_bpf: test_skb_segment: Summary: 1 PASSED, 0 FAILED

By the way, the above segment fault has been fixed in the latest bpf-next
tree which contains the mips64 JIT rework.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Link: https://lore.kernel.org/bpf/1635384321-28128-1-git-send-email-yangtiezhu@loongson.cn

diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index e5b10fdefab54a80493c6f5a46d236472482e58f..adae39567264f27f431dae1d8863fd53c7255512 100644 (file)
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -14316,72 +14316,9 @@ module_param_string(test_name, test_name, sizeof(test_name), 0);
 static int test_id = -1;
 module_param(test_id, int, 0);
 
-static int test_range[2] = { 0, ARRAY_SIZE(tests) - 1 };
+static int test_range[2] = { 0, INT_MAX };
 module_param_array(test_range, int, NULL, 0);
 
-static __init int find_test_index(const char *test_name)
-{
-       int i;
-
-       for (i = 0; i < ARRAY_SIZE(tests); i++) {
-               if (!strcmp(tests[i].descr, test_name))
-                       return i;
-       }
-       return -1;
-}
-
-static __init int prepare_bpf_tests(void)
-{
-       if (test_id >= 0) {
-               /*
-                * if a test_id was specified, use test_range to
-                * cover only that test.
-                */
-               if (test_id >= ARRAY_SIZE(tests)) {
-                       pr_err("test_bpf: invalid test_id specified.\n");
-                       return -EINVAL;
-               }
-
-               test_range[0] = test_id;
-               test_range[1] = test_id;
-       } else if (*test_name) {
-               /*
-                * if a test_name was specified, find it and setup
-                * test_range to cover only that test.
-                */
-               int idx = find_test_index(test_name);
-
-               if (idx < 0) {
-                       pr_err("test_bpf: no test named '%s' found.\n",
-                              test_name);
-                       return -EINVAL;
-               }
-               test_range[0] = idx;
-               test_range[1] = idx;
-       } else {
-               /*
-                * check that the supplied test_range is valid.
-                */
-               if (test_range[0] >= ARRAY_SIZE(tests) ||
-                   test_range[1] >= ARRAY_SIZE(tests) ||
-                   test_range[0] < 0 || test_range[1] < 0) {
-                       pr_err("test_bpf: test_range is out of bound.\n");
-                       return -EINVAL;
-               }
-
-               if (test_range[1] < test_range[0]) {
-                       pr_err("test_bpf: test_range is ending before it starts.\n");
-                       return -EINVAL;
-               }
-       }
-
-       return 0;
-}
-
-static __init void destroy_bpf_tests(void)
-{
-}
-
 static bool exclude_test(int test_id)
 {
        return test_id < test_range[0] || test_id > test_range[1];
@@ -14553,6 +14490,10 @@ static __init int test_skb_segment(void)
        for (i = 0; i < ARRAY_SIZE(skb_segment_tests); i++) {
                const struct skb_segment_test *test = &skb_segment_tests[i];
 
+               cond_resched();
+               if (exclude_test(i))
+                       continue;
+
                pr_info("#%d %s ", i, test->descr);
 
                if (test_skb_segment_single(test)) {
@@ -14934,6 +14875,8 @@ static __init int test_tail_calls(struct bpf_array *progs)
                int ret;
 
                cond_resched();
+               if (exclude_test(i))
+                       continue;
 
                pr_info("#%d %s ", i, test->descr);
                if (!fp) {
@@ -14966,29 +14909,144 @@ static __init int test_tail_calls(struct bpf_array *progs)
        return err_cnt ? -EINVAL : 0;
 }
 
+static char test_suite[32];
+module_param_string(test_suite, test_suite, sizeof(test_suite), 0);
+
+static __init int find_test_index(const char *test_name)
+{
+       int i;
+
+       if (!strcmp(test_suite, "test_bpf")) {
+               for (i = 0; i < ARRAY_SIZE(tests); i++) {
+                       if (!strcmp(tests[i].descr, test_name))
+                               return i;
+               }
+       }
+
+       if (!strcmp(test_suite, "test_tail_calls")) {
+               for (i = 0; i < ARRAY_SIZE(tail_call_tests); i++) {
+                       if (!strcmp(tail_call_tests[i].descr, test_name))
+                               return i;
+               }
+       }
+
+       if (!strcmp(test_suite, "test_skb_segment")) {
+               for (i = 0; i < ARRAY_SIZE(skb_segment_tests); i++) {
+                       if (!strcmp(skb_segment_tests[i].descr, test_name))
+                               return i;
+               }
+       }
+
+       return -1;
+}
+
+static __init int prepare_test_range(void)
+{
+       int valid_range;
+
+       if (!strcmp(test_suite, "test_bpf"))
+               valid_range = ARRAY_SIZE(tests);
+       else if (!strcmp(test_suite, "test_tail_calls"))
+               valid_range = ARRAY_SIZE(tail_call_tests);
+       else if (!strcmp(test_suite, "test_skb_segment"))
+               valid_range = ARRAY_SIZE(skb_segment_tests);
+       else
+               return 0;
+
+       if (test_id >= 0) {
+               /*
+                * if a test_id was specified, use test_range to
+                * cover only that test.
+                */
+               if (test_id >= valid_range) {
+                       pr_err("test_bpf: invalid test_id specified for '%s' suite.\n",
+                              test_suite);
+                       return -EINVAL;
+               }
+
+               test_range[0] = test_id;
+               test_range[1] = test_id;
+       } else if (*test_name) {
+               /*
+                * if a test_name was specified, find it and setup
+                * test_range to cover only that test.
+                */
+               int idx = find_test_index(test_name);
+
+               if (idx < 0) {
+                       pr_err("test_bpf: no test named '%s' found for '%s' suite.\n",
+                              test_name, test_suite);
+                       return -EINVAL;
+               }
+               test_range[0] = idx;
+               test_range[1] = idx;
+       } else if (test_range[0] != 0 || test_range[1] != INT_MAX) {
+               /*
+                * check that the supplied test_range is valid.
+                */
+               if (test_range[0] < 0 || test_range[1] >= valid_range) {
+                       pr_err("test_bpf: test_range is out of bound for '%s' suite.\n",
+                              test_suite);
+                       return -EINVAL;
+               }
+
+               if (test_range[1] < test_range[0]) {
+                       pr_err("test_bpf: test_range is ending before it starts.\n");
+                       return -EINVAL;
+               }
+       }
+
+       return 0;
+}
+
 static int __init test_bpf_init(void)
 {
        struct bpf_array *progs = NULL;
        int ret;
 
-       ret = prepare_bpf_tests();
+       if (strlen(test_suite) &&
+           strcmp(test_suite, "test_bpf") &&
+           strcmp(test_suite, "test_tail_calls") &&
+           strcmp(test_suite, "test_skb_segment")) {
+               pr_err("test_bpf: invalid test_suite '%s' specified.\n", test_suite);
+               return -EINVAL;
+       }
+
+       /*
+        * if test_suite is not specified, but test_id, test_name or test_range
+        * is specified, set 'test_bpf' as the default test suite.
+        */
+       if (!strlen(test_suite) &&
+           (test_id != -1 || strlen(test_name) ||
+           (test_range[0] != 0 || test_range[1] != INT_MAX))) {
+               pr_info("test_bpf: set 'test_bpf' as the default test_suite.\n");
+               strscpy(test_suite, "test_bpf", sizeof(test_suite));
+       }
+
+       ret = prepare_test_range();
        if (ret < 0)
                return ret;
 
-       ret = test_bpf();
-       destroy_bpf_tests();
-       if (ret)
-               return ret;
+       if (!strlen(test_suite) || !strcmp(test_suite, "test_bpf")) {
+               ret = test_bpf();
+               if (ret)
+                       return ret;
+       }
 
-       ret = prepare_tail_call_tests(&progs);
-       if (ret)
-               return ret;
-       ret = test_tail_calls(progs);
-       destroy_tail_call_tests(progs);
-       if (ret)
-               return ret;
+       if (!strlen(test_suite) || !strcmp(test_suite, "test_tail_calls")) {
+               ret = prepare_tail_call_tests(&progs);
+               if (ret)
+                       return ret;
+               ret = test_tail_calls(progs);
+               destroy_tail_call_tests(progs);
+               if (ret)
+                       return ret;
+       }
 
-       return test_skb_segment();
+       if (!strlen(test_suite) || !strcmp(test_suite, "test_skb_segment"))
+               return test_skb_segment();
+
+       return 0;
 }
 
 static void __exit test_bpf_exit(void)