[PATCH] lib: test_objagg: split test_hints_case() into two functions

[PATCH] lib: test_objagg: split test_hints_case() into two functions

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

With sanitizers enabled, this function uses a lot of stack, causing
a harmless warning:

lib/test_objagg.c: In function 'test_hints_case.constprop':
lib/test_objagg.c:994:1: error: the frame size of 1440 bytes is larger than 1408 bytes [-Werror=frame-larger-than=]

Most of this is from the two 'struct world' structures. Since most of
the work in this function is duplicated for the two, split it up into
separate functions that each use one of them.

The combined stack usage is still the same here, but there is no warning
any more, and the code is still safe because of the known call chain.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 lib/test_objagg.c | 77 +++++++++++++++++++++++++++--------------------
 1 file changed, 45 insertions(+), 32 deletions(-)

diff --git a/lib/test_objagg.c b/lib/test_objagg.c
index d34df4306b87..a67b8ef5c5be 100644
--- a/lib/test_objagg.c
+++ b/lib/test_objagg.c
@@ -906,50 +906,22 @@ static int check_expect_hints_stats(struct objagg_hints *objagg_hints,
 	return err;
 }
 
-static int test_hints_case(const struct hints_case *hints_case)
+static int test_hints_case2(const struct hints_case *hints_case,
+			    struct objagg_hints *hints, struct objagg *objagg)
 {
 	struct objagg_obj *objagg_obj;
-	struct objagg_hints *hints;
 	struct world world2 = {};
-	struct world world = {};
 	struct objagg *objagg2;
-	struct objagg *objagg;
 	const char *errmsg;
 	int i;
 	int err;
 
-	objagg = objagg_create(&delta_ops, NULL, &world);
-	if (IS_ERR(objagg))
-		return PTR_ERR(objagg);
-
-	for (i = 0; i < hints_case->key_ids_count; i++) {
-		objagg_obj = world_obj_get(&world, objagg,
-					   hints_case->key_ids[i]);
-		if (IS_ERR(objagg_obj)) {
-			err = PTR_ERR(objagg_obj);
-			goto err_world_obj_get;
-		}
-	}
-
-	pr_debug_stats(objagg);
-	err = check_expect_stats(objagg, &hints_case->expect_stats, &errmsg);
-	if (err) {
-		pr_err("Stats: %s\n", errmsg);
-		goto err_check_expect_stats;
-	}
-
-	hints = objagg_hints_get(objagg, OBJAGG_OPT_ALGO_SIMPLE_GREEDY);
-	if (IS_ERR(hints)) {
-		err = PTR_ERR(hints);
-		goto err_hints_get;
-	}
-
 	pr_debug_hints_stats(hints);
 	err = check_expect_hints_stats(hints, &hints_case->expect_stats_hints,
 				       &errmsg);
 	if (err) {
 		pr_err("Hints stats: %s\n", errmsg);
-		goto err_check_expect_hints_stats;
+		return err;
 	}
 
 	objagg2 = objagg_create(&delta_ops, hints, &world2);
@@ -981,7 +953,48 @@ static int test_hints_case(const struct hints_case *hints_case)
 		world_obj_put(&world2, objagg, hints_case->key_ids[i]);
 	i = hints_case->key_ids_count;
 	objagg_destroy(objagg2);
-err_check_expect_hints_stats:
+
+	return err;
+}
+
+static int test_hints_case(const struct hints_case *hints_case)
+{
+	struct objagg_obj *objagg_obj;
+	struct objagg_hints *hints;
+	struct world world = {};
+	struct objagg *objagg;
+	const char *errmsg;
+	int i;
+	int err;
+
+	objagg = objagg_create(&delta_ops, NULL, &world);
+	if (IS_ERR(objagg))
+		return PTR_ERR(objagg);
+
+	for (i = 0; i < hints_case->key_ids_count; i++) {
+		objagg_obj = world_obj_get(&world, objagg,
+					   hints_case->key_ids[i]);
+		if (IS_ERR(objagg_obj)) {
+			err = PTR_ERR(objagg_obj);
+			goto err_world_obj_get;
+		}
+	}
+
+	pr_debug_stats(objagg);
+	err = check_expect_stats(objagg, &hints_case->expect_stats, &errmsg);
+	if (err) {
+		pr_err("Stats: %s\n", errmsg);
+		goto err_check_expect_stats;
+	}
+
+	hints = objagg_hints_get(objagg, OBJAGG_OPT_ALGO_SIMPLE_GREEDY);
+	if (IS_ERR(hints)) {
+		err = PTR_ERR(hints);
+		goto err_hints_get;
+	}
+
+	err = test_hints_case2(hints_case, hints, objagg);
+
 	objagg_hints_put(hints);
 err_hints_get:
 err_check_expect_stats:
-- 
2.39.5

Re: [PATCH] lib: test_objagg: split test_hints_case() into two functions

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 20 Jun 2025 13:19:04 +0200 you wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> With sanitizers enabled, this function uses a lot of stack, causing
> a harmless warning:
> 
> lib/test_objagg.c: In function 'test_hints_case.constprop':
> lib/test_objagg.c:994:1: error: the frame size of 1440 bytes is larger than 1408 bytes [-Werror=frame-larger-than=]
> 
> [...]

Here is the summary with links:
  - lib: test_objagg: split test_hints_case() into two functions
    https://git.kernel.org/netdev/net-next/c/7df6c0245595

You are awesome, thank you!
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