linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Kalle Valo <kvalo@codeaurora.org>,
	"David S. Miller" <davem@davemloft.net>
Cc: ath10k@lists.infradead.org, linux-wireless@vger.kernel.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Kees Cook <keescook@chromium.org>,
	"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] ath10k: use struct_size() in kzalloc()
Date: Thu, 23 Aug 2018 20:12:47 -0500	[thread overview]
Message-ID: <20180824011247.GA25648@embeddedor.com> (raw)

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>
---
 drivers/net/wireless/ath/ath10k/ce.c | 24 ++++++++----------------
 1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/ce.c b/drivers/net/wireless/ath/ath10k/ce.c
index 18c709c..d0381aa 100644
--- 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);
 
-- 
2.7.4


             reply	other threads:[~2018-08-24  1:13 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-24  1:12 Gustavo A. R. Silva [this message]
2018-08-24  2:59 ` [PATCH] ath10k: use struct_size() in kzalloc() Kees Cook
2018-08-28 13:43 ` Kalle Valo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180824011247.GA25648@embeddedor.com \
    --to=gustavo@embeddedor.com \
    --cc=ath10k@lists.infradead.org \
    --cc=davem@davemloft.net \
    --cc=keescook@chromium.org \
    --cc=kvalo@codeaurora.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).