ath10k: use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
	int stuff;
        void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/ath/ath10k/ce.c b/drivers/net/wireless/ath/ath10k/ce.c
index 18c709c..d0381aa 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/ce.c
+++ b/drivers/net/wireless/ath/ath10k/ce.c
@@ -1416,10 +1416,8 @@ ath10k_ce_alloc_src_ring(struct ath10k *ar, unsigned int ce_id,
 
        nentries = roundup_pow_of_two(nentries);
 
-       src_ring = kzalloc(sizeof(*src_ring) +
-                          (nentries *
-                           sizeof(*src_ring->per_transfer_context)),
-                          GFP_KERNEL);
+       src_ring = kzalloc(struct_size(src_ring, per_transfer_context,
+                                      nentries), GFP_KERNEL);
        if (src_ring == NULL)
                return ERR_PTR(-ENOMEM);
 
@@ -1476,10 +1474,8 @@ ath10k_ce_alloc_src_ring_64(struct ath10k *ar, unsigned int ce_id,
 
        nentries = roundup_pow_of_two(nentries);
 
-       src_ring = kzalloc(sizeof(*src_ring) +
-                          (nentries *
-                           sizeof(*src_ring->per_transfer_context)),
-                          GFP_KERNEL);
+       src_ring = kzalloc(struct_size(src_ring, per_transfer_context,
+                                      nentries), GFP_KERNEL);
        if (!src_ring)
                return ERR_PTR(-ENOMEM);
 
@@ -1534,10 +1530,8 @@ ath10k_ce_alloc_dest_ring(struct ath10k *ar, unsigned int ce_id,
 
        nentries = roundup_pow_of_two(attr->dest_nentries);
 
-       dest_ring = kzalloc(sizeof(*dest_ring) +
-                           (nentries *
-                            sizeof(*dest_ring->per_transfer_context)),
-                           GFP_KERNEL);
+       dest_ring = kzalloc(struct_size(dest_ring, per_transfer_context,
+                                       nentries), GFP_KERNEL);
        if (dest_ring == NULL)
                return ERR_PTR(-ENOMEM);
 
@@ -1580,10 +1574,8 @@ ath10k_ce_alloc_dest_ring_64(struct ath10k *ar, unsigned int ce_id,
 
        nentries = roundup_pow_of_two(attr->dest_nentries);
 
-       dest_ring = kzalloc(sizeof(*dest_ring) +
-                           (nentries *
-                            sizeof(*dest_ring->per_transfer_context)),
-                           GFP_KERNEL);
+       dest_ring = kzalloc(struct_size(dest_ring, per_transfer_context,
+                                       nentries), GFP_KERNEL);
        if (!dest_ring)
                return ERR_PTR(-ENOMEM);