Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   xiaolinkui <xiaolinkui@kylinos.cn>
To:     hch@lst.de, sagi@grimberg.me
Cc:     linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
        xiaolinkui@kylinos.cn
Subject: [PATCH] nvme: target: use struct_size() in kmalloc()
Date:   Fri, 17 May 2019 15:03:35 +0800
Message-Id: <1558076615-8576-1-git-send-email-xiaolinkui@kylinos.cn>
Feedback-ID: bizesmtp:kylinos.cn:qybgforeign:qybgforeign1
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Use struct_size() to keep code sample.
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;
    struct boo entry[];
};

instance = kmalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);

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

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

Signed-off-by: xiaolinkui <xiaolinkui@kylinos.cn>
---
 drivers/nvme/target/admin-cmd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 9f72d51..6f9f830 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -248,8 +248,8 @@ static void nvmet_execute_get_log_page_ana(struct nvmet_req *req)
 	u16 status;
 
 	status = NVME_SC_INTERNAL;
-	desc = kmalloc(sizeof(struct nvme_ana_group_desc) +
-			NVMET_MAX_NAMESPACES * sizeof(__le32), GFP_KERNEL);
+	desc = kmalloc(struct_size(desc, nsids, NVMET_MAX_NAMESPACES),
+			GFP_KERNEL);
 	if (!desc)
 		goto out;
 
-- 
2.7.4