linux-kernel - [PATCH RFC 1/4] kunit: Allocate assertion data with GFP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250224-page-alloc-kunit-v1-1-d337bb440889@google.com>
Date: Mon, 24 Feb 2025 14:47:11 +0000
From: Brendan Jackman <jackmanb@...gle.com>
To: Brendan Higgins <brendan.higgins@...ux.dev>, David Gow <davidgow@...gle.com>, 
	Rae Moar <rmoar@...gle.com>, Andrew Morton <akpm@...ux-foundation.org>, 
	David Hildenbrand <david@...hat.com>, Oscar Salvador <osalvador@...e.de>
Cc: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>, Vlastimil Babka <vbabka@...e.cz>, 
	Michal Hocko <mhocko@...nel.org>, linux-kselftest@...r.kernel.org, 
	kunit-dev@...glegroups.com, linux-kernel@...r.kernel.org, linux-mm@...ck.org, 
	Brendan Jackman <jackmanb@...gle.com>, Yosry Ahmed <yosry.ahmed@...ux.dev>
Subject: [PATCH RFC 1/4] kunit: Allocate assertion data with GFP_ATOMIC

At present KUnit doesn't handle assertions happening in atomic contexts.
A later commit will add tests that make assertions with spinlocks held.

In preparation, switch to GFP_ATOMIC.

"Just use GFP_ATOMIC" is not generally a solution to this kind of
problem: since it uses up memory reserves, instead it should be only
used when truly needed.

However, for test code that should not be expected to run in production
systems it seems tolerable, given that it avoids creating more complex
APIs.

Signed-off-by: Brendan Jackman <jackmanb@...gle.com>
---
 lib/kunit/assert.c   | 2 +-
 lib/kunit/resource.c | 2 +-
 lib/kunit/test.c     | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/lib/kunit/assert.c b/lib/kunit/assert.c
index 867aa5c4bccf764757e190948b8e3a2439116786..f08656c5fb247b510c4215445cc307ed1205a96c 100644
--- a/lib/kunit/assert.c
+++ b/lib/kunit/assert.c
@@ -101,7 +101,7 @@ VISIBLE_IF_KUNIT bool is_literal(const char *text, long long value)
 	if (strlen(text) != len)
 		return false;
 
-	buffer = kmalloc(len+1, GFP_KERNEL);
+	buffer = kmalloc(len+1, GFP_ATOMIC);
 	if (!buffer)
 		return false;
 
diff --git a/lib/kunit/resource.c b/lib/kunit/resource.c
index f0209252b179f8b48d47ecc244c468ed80e23bdc..eac511af4f8d7843d58c4e3976c77a9c4def86a7 100644
--- a/lib/kunit/resource.c
+++ b/lib/kunit/resource.c
@@ -98,7 +98,7 @@ int kunit_add_action(struct kunit *test, void (*action)(void *), void *ctx)
 
 	KUNIT_ASSERT_NOT_NULL_MSG(test, action, "Tried to action a NULL function!");
 
-	action_ctx = kzalloc(sizeof(*action_ctx), GFP_KERNEL);
+	action_ctx = kzalloc(sizeof(*action_ctx), GFP_ATOMIC);
 	if (!action_ctx)
 		return -ENOMEM;
 
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index 146d1b48a0965e8aaddb6162928f408bbb542645..08d0ff51bd85845a08b40cd3933dd588bd10bddf 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -279,7 +279,7 @@ static void kunit_fail(struct kunit *test, const struct kunit_loc *loc,
 
 	kunit_set_failure(test);
 
-	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	stream = kunit_alloc_string_stream(test, GFP_ATOMIC);
 	if (IS_ERR(stream)) {
 		WARN(true,
 		     "Could not allocate stream to print failed assertion in %s:%d\n",

-- 
2.48.1.601.g30ceb7b040-goog