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 <rosenp@gmail.com>
Link: https://patch.msgid.link/20260510213948.41750-1-rosenp@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/kernel/power/swap.c b/kernel/power/swap.c
index 2e64869bb5a093d7a1d2decfe7be9e7f20092d47..b28233b8d00ed5917a3b7835355852b29ca2b8df 100644 (file)
--- a/kernel/power/swap.c
+++ b/kernel/power/swap.c
@@ -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);
 }