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PM: hibernate: Use flexible array for CRC uncompressed buffers

PATCH New Rosen Penev 1 participant 1 message May 10

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Rosen Penev

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PATCH 1/1 PM: hibernate: Use flexible array for CRC uncompressed buffers

The CRC uncompressed buffer pointer array has the same lifetime as struct crc_data, but it is currently allocated separately. That adds another allocation failure path and a matching cleanup branch without providing any extra flexibility.

Store the pointer array as a flexible array member and allocate it together with the crc_data using kzalloc_flex(). The array remains zero-initialized, while the allocation and error handling become simpler.

Assisted-by Codex:GPT-5.5
Signed-off-by Rosen Penev <[email protected]>
---
 kernel/power/swap.c | 13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)
kernel/power/swap.c +3 -10
index cc4764149e8f..c626e9dc3c1c 100644
@@ -570,29 +570,23 @@ struct crc_data {
 	wait_queue_head_t done;                   /* crc update done */
 	u32 *crc32;                               /* points to handle's crc32 */
 	size_t **unc_len;			  /* uncompressed lengths */
-	unsigned char **unc;			  /* uncompressed data */
+	unsigned char *unc[];			  /* uncompressed data */
 };
 
 static struct crc_data *alloc_crc_data(int nr_threads)
 {
 	struct crc_data *crc;
 
-	crc = kzalloc_obj(*crc);
+	crc = kzalloc_flex(*crc, unc, nr_threads);
 	if (!crc)
 		return NULL;
 
-	crc->unc = kcalloc(nr_threads, sizeof(*crc->unc), GFP_KERNEL);
-	if (!crc->unc)
-		goto err_free_crc;
-
 	crc->unc_len = kzalloc_objs(*crc->unc_len, nr_threads);
 	if (!crc->unc_len)
-		goto err_free_unc;
+		goto err_free_crc;
 
 	return crc;
 
-err_free_unc:
-	kfree(crc->unc);
 err_free_crc:
 	kfree(crc);
 	return NULL;

@@ -607,7 +601,6 @@ static void free_crc_data(struct crc_data *crc)
 		kthread_stop(crc->thr);
 
 	kfree(crc->unc_len);
-	kfree(crc->unc);
 	kfree(crc);
 }
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