linux-kernel - [PATCH v3 1/2] PM: hibernate: dynamically allocate crc->unc

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 for Android: free password hash cracker in your pocket

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

Message-ID: <1bd58d2398ab79a9ecdfe239d6097051d8606724.1757680816.git.luoxueqin@kylinos.cn>
Date: Mon, 15 Sep 2025 10:21:24 +0800
From: Xueqin Luo <luoxueqin@...inos.cn>
To: rafael@...nel.org,
	pavel@...nel.org,
	lenb@...nel.org,
	linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Cc: Xueqin Luo <luoxueqin@...inos.cn>
Subject: [PATCH v3 1/2] PM: hibernate: dynamically allocate crc->unc_len/unc for configurable threads

Convert crc->unc_len and crc->unc from fixed-size arrays to dynamically
allocated arrays, sized according to the actual number of threads selected
at runtime. This removes the fixed limit imposed by CMP_THREADS.

Signed-off-by: Xueqin Luo <luoxueqin@...inos.cn>
---
 kernel/power/swap.c | 58 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 44 insertions(+), 14 deletions(-)

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 0beff7eeaaba..f8c13f5672ec 100644
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -585,10 +585,48 @@ struct crc_data {
 	wait_queue_head_t go;                     /* start crc update */
 	wait_queue_head_t done;                   /* crc update done */
 	u32 *crc32;                               /* points to handle's crc32 */
-	size_t *unc_len[CMP_THREADS];             /* uncompressed lengths */
-	unsigned char *unc[CMP_THREADS];          /* uncompressed data */
+	size_t **unc_len;			  /* uncompressed lengths */
+	unsigned char **unc;			  /* uncompressed data */
 };
 
+static struct crc_data *alloc_crc_data(int nr_threads)
+{
+	struct crc_data *crc;
+
+	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
+	if (!crc)
+		return NULL;
+
+	crc->unc = kcalloc(nr_threads, sizeof(*crc->unc), GFP_KERNEL);
+	if (!crc->unc)
+		goto err_free_crc;
+
+	crc->unc_len = kcalloc(nr_threads, sizeof(*crc->unc_len), GFP_KERNEL);
+	if (!crc->unc_len)
+		goto err_free_unc;
+
+	return crc;
+
+err_free_unc:
+	kfree(crc->unc);
+err_free_crc:
+	kfree(crc);
+	return NULL;
+}
+
+static void free_crc_data(struct crc_data *crc)
+{
+	if (!crc)
+		return;
+
+	if (crc->thr)
+		kthread_stop(crc->thr);
+
+	kfree(crc->unc_len);
+	kfree(crc->unc);
+	kfree(crc);
+}
+
 /*
  * CRC32 update function that runs in its own thread.
  */
@@ -719,7 +757,7 @@ static int save_compressed_image(struct swap_map_handle *handle,
 		goto out_clean;
 	}
 
-	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
+	crc = alloc_crc_data(nr_threads);
 	if (!crc) {
 		pr_err("Failed to allocate crc\n");
 		ret = -ENOMEM;
@@ -885,11 +923,7 @@ static int save_compressed_image(struct swap_map_handle *handle,
 
 out_clean:
 	hib_finish_batch(&hb);
-	if (crc) {
-		if (crc->thr)
-			kthread_stop(crc->thr);
-		kfree(crc);
-	}
+	free_crc_data(crc);
 	if (data) {
 		for (thr = 0; thr < nr_threads; thr++) {
 			if (data[thr].thr)
@@ -1239,7 +1273,7 @@ static int load_compressed_image(struct swap_map_handle *handle,
 		goto out_clean;
 	}
 
-	crc = kzalloc(sizeof(*crc), GFP_KERNEL);
+	crc = alloc_crc_data(nr_threads);
 	if (!crc) {
 		pr_err("Failed to allocate crc\n");
 		ret = -ENOMEM;
@@ -1506,11 +1540,7 @@ static int load_compressed_image(struct swap_map_handle *handle,
 	hib_finish_batch(&hb);
 	for (i = 0; i < ring_size; i++)
 		free_page((unsigned long)page[i]);
-	if (crc) {
-		if (crc->thr)
-			kthread_stop(crc->thr);
-		kfree(crc);
-	}
+	free_crc_data(crc);
 	if (data) {
 		for (thr = 0; thr < nr_threads; thr++) {
 			if (data[thr].thr)
-- 
2.43.0