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ath10k: use struct_size() in kzalloc()

PATCH In review Gustavo A. R. Silva 3 participants 4 messages Aug 24, 2018 – Aug 28, 2018

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#0 lore raw

PATCH 1/1 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.

---
 drivers/net/wireless/ath/ath10k/ce.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)
drivers/net/wireless/ath/ath10k/ce.c +8 -16
index 18c709c..d0381aa 100644
@@ -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);
 
Signature · 1 line
2.7.4
Reviewed-by on v1 1/1
#1 lore raw
Quoted 11 lines · Gustavo A. R. Silva

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);

Quoted 8 lines

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.

-Kees

Quoted 63 lines
---
 drivers/net/wireless/ath/ath10k/ce.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)
drivers/net/wireless/ath/ath10k/ce.c +8 -17
index 18c709c..d0381aa 100644
@@ -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);
 
--

2.7.4

Signature · 2 lines
Kees Cook
Pixel Security
#2 lore raw
In reply to Gustavo A. R. Silva
Quoted 14 lines · Gustavo A. R. Silva

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:

Quoted 7 lines

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

This issue was detected with the help of Coccinelle.

Patch applied to ath-next branch of ath.git, thanks.

06ae8dc00433 ath10k: use struct_size() in kzalloc()

Signature · 3 lines
https://patchwork.kernel.org/patch/10574741/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
#3 lore raw
In reply to Gustavo A. R. Silva
Quoted 14 lines · Gustavo A. R. Silva

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:

Quoted 7 lines

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

This issue was detected with the help of Coccinelle.

Patch applied to ath-next branch of ath.git, thanks.

06ae8dc00433 ath10k: use struct_size() in kzalloc()

Signature · 3 lines
https://patchwork.kernel.org/patch/10574741/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches