diff mbox series

kunit: bail out of test filtering logic quicker if OOM

Message ID 20220406232240.1825048-1-dlatypov@google.com (mailing list archive)
State Accepted
Commit a02353f491622e49c7ddedc6a6dc4f1d6ed2150a
Delegated to: Brendan Higgins
Headers show
Series kunit: bail out of test filtering logic quicker if OOM | expand

Commit Message

Daniel Latypov April 6, 2022, 11:22 p.m. UTC
When filtering what tests to run (suites and/or cases) via
kunit.filter_glob (e.g. kunit.py run <glob>), we allocate copies of
suites.

These allocations can fail, and we largely don't handle that.
Note: realistically, this probably doesn't matter much.
We're not allocating much memory and this happens early in boot, so if
we can't do that, then there's likely far bigger problems.

This patch makes us immediately bail out from the top-level function
(kunit_filter_suites) with -ENOMEM if any of the underlying kmalloc()
calls return NULL.

Implementation note: we used to return NULL pointers from some functions
to indicate either that all suites/tests were filtered out or there was
an error allocating the new array.

We'll log a short error in this case and not run any tests or print a
TAP header. From a kunit.py user's perspective, they'll get a message
about missing/invalid TAP output and have to dig into the test.log to
see it. Since hitting this error seems so unlikely, it's probably fine
to not invent a way to plumb this error message more visibly.

See also: https://lore.kernel.org/linux-kselftest/20220329103919.2376818-1-lv.ruyi@zte.com.cn/

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>
---
 lib/kunit/executor.c      | 27 ++++++++++++++++++++++-----
 lib/kunit/executor_test.c |  4 +++-
 2 files changed, 25 insertions(+), 6 deletions(-)


base-commit: b04d1a8dc7e7ff7ca91a20bef053bcc04265d83a

Comments

Brendan Higgins May 11, 2022, 9:12 p.m. UTC | #1
On Wed, Apr 6, 2022 at 7:22 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> When filtering what tests to run (suites and/or cases) via
> kunit.filter_glob (e.g. kunit.py run <glob>), we allocate copies of
> suites.
>
> These allocations can fail, and we largely don't handle that.
> Note: realistically, this probably doesn't matter much.
> We're not allocating much memory and this happens early in boot, so if
> we can't do that, then there's likely far bigger problems.
>
> This patch makes us immediately bail out from the top-level function
> (kunit_filter_suites) with -ENOMEM if any of the underlying kmalloc()
> calls return NULL.
>
> Implementation note: we used to return NULL pointers from some functions
> to indicate either that all suites/tests were filtered out or there was
> an error allocating the new array.
>
> We'll log a short error in this case and not run any tests or print a
> TAP header. From a kunit.py user's perspective, they'll get a message
> about missing/invalid TAP output and have to dig into the test.log to
> see it. Since hitting this error seems so unlikely, it's probably fine
> to not invent a way to plumb this error message more visibly.
>
> See also: https://lore.kernel.org/linux-kselftest/20220329103919.2376818-1-lv.ruyi@zte.com.cn/
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>

Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Daniel Latypov May 11, 2022, 9:15 p.m. UTC | #2
On Wed, Apr 6, 2022 at 4:22 PM Daniel Latypov <dlatypov@google.com> wrote:
>
> When filtering what tests to run (suites and/or cases) via
> kunit.filter_glob (e.g. kunit.py run <glob>), we allocate copies of
> suites.
>
> These allocations can fail, and we largely don't handle that.
> Note: realistically, this probably doesn't matter much.
> We're not allocating much memory and this happens early in boot, so if
> we can't do that, then there's likely far bigger problems.
>
> This patch makes us immediately bail out from the top-level function
> (kunit_filter_suites) with -ENOMEM if any of the underlying kmalloc()
> calls return NULL.
>
> Implementation note: we used to return NULL pointers from some functions
> to indicate either that all suites/tests were filtered out or there was
> an error allocating the new array.
>
> We'll log a short error in this case and not run any tests or print a
> TAP header. From a kunit.py user's perspective, they'll get a message
> about missing/invalid TAP output and have to dig into the test.log to
> see it. Since hitting this error seems so unlikely, it's probably fine
> to not invent a way to plumb this error message more visibly.
>
> See also: https://lore.kernel.org/linux-kselftest/20220329103919.2376818-1-lv.ruyi@zte.com.cn/
>
> Signed-off-by: Daniel Latypov <dlatypov@google.com>
> Reported-by: Zeal Robot <zealci@zte.com.cn>
> Signed-off-by: Lv Ruyi <lv.ruyi@zte.com.cn>

Oh, I just realized the typo here.
This was meant to be a second "Reported-by:"

Let me sound out a v2 to fix that.
diff mbox series

Patch

diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index 22640c9ee819..2f73a6a35a7e 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -71,9 +71,13 @@  kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
 
 	/* Use memcpy to workaround copy->name being const. */
 	copy = kmalloc(sizeof(*copy), GFP_KERNEL);
+	if (!copy)
+		return ERR_PTR(-ENOMEM);
 	memcpy(copy, suite, sizeof(*copy));
 
 	filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
+	if (!filtered)
+		return ERR_PTR(-ENOMEM);
 
 	n = 0;
 	kunit_suite_for_each_test_case(suite, test_case) {
@@ -106,14 +110,16 @@  kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
 
 	filtered = kmalloc_array(n + 1, sizeof(*filtered), GFP_KERNEL);
 	if (!filtered)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	n = 0;
 	for (i = 0; subsuite[i] != NULL; ++i) {
 		if (!glob_match(filter->suite_glob, subsuite[i]->name))
 			continue;
 		filtered_suite = kunit_filter_tests(subsuite[i], filter->test_glob);
-		if (filtered_suite)
+		if (IS_ERR(filtered_suite))
+			return ERR_CAST(filtered_suite);
+		else if (filtered_suite)
 			filtered[n++] = filtered_suite;
 	}
 	filtered[n] = NULL;
@@ -146,7 +152,8 @@  static void kunit_free_suite_set(struct suite_set suite_set)
 }
 
 static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
-					    const char *filter_glob)
+					    const char *filter_glob,
+					    int *err)
 {
 	int i;
 	struct kunit_suite * const **copy, * const *filtered_subsuite;
@@ -166,6 +173,10 @@  static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 
 	for (i = 0; i < max; ++i) {
 		filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], &filter);
+		if (IS_ERR(filtered_subsuite)) {
+			*err = PTR_ERR(filtered_subsuite);
+			return filtered;
+		}
 		if (filtered_subsuite)
 			*copy++ = filtered_subsuite;
 	}
@@ -236,9 +247,15 @@  int kunit_run_all_tests(void)
 		.start = __kunit_suites_start,
 		.end = __kunit_suites_end,
 	};
+	int err;
 
-	if (filter_glob_param)
-		suite_set = kunit_filter_suites(&suite_set, filter_glob_param);
+	if (filter_glob_param) {
+		suite_set = kunit_filter_suites(&suite_set, filter_glob_param, &err);
+		if (err) {
+			pr_err("kunit executor: error filtering suites: %d\n", err);
+			return err;
+		}
+	}
 
 	if (!action_param)
 		kunit_exec_run_tests(&suite_set);
diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
index 4ed57fd94e42..eac6ff480273 100644
--- a/lib/kunit/executor_test.c
+++ b/lib/kunit/executor_test.c
@@ -137,14 +137,16 @@  static void filter_suites_test(struct kunit *test)
 		.end = suites + 2,
 	};
 	struct suite_set filtered = {.start = NULL, .end = NULL};
+	int err = 0;
 
 	/* Emulate two files, each having one suite */
 	subsuites[0][0] = alloc_fake_suite(test, "suite0", dummy_test_cases);
 	subsuites[1][0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
 
 	/* Filter out suite1 */
-	filtered = kunit_filter_suites(&suite_set, "suite0");
+	filtered = kunit_filter_suites(&suite_set, "suite0", &err);
 	kfree_subsuites_at_end(test, &filtered); /* let us use ASSERTs without leaking */
+	KUNIT_EXPECT_EQ(test, err, 0);
 	KUNIT_ASSERT_EQ(test, filtered.end - filtered.start, (ptrdiff_t)1);
 
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start);