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bpf, tests: Add module parameter test_suite to test_bpf module
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After commit 9298e63 ("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 <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Tested-by: Johan Almbladh <[email protected]>
Acked-by: Johan Almbladh <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
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@borkmann
Tiezhu Yang authored and borkmann committed Oct 28, 2021
1 parent 252c765 commit b066abb
Showing 1 changed file with 135 additions and 77 deletions.
212 changes: 135 additions & 77 deletions lib/test_bpf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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];
Expand Down Expand Up @@ -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)) {
Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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)
Expand Down

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