diff mbox series

[121/165] drivers/rapidio/rio-scan.c: use struct_size() helper

Message ID 20200812013640.6i0R9Swhe%akpm@linux-foundation.org (mailing list archive)
State New, archived
Headers show
Series [001/165] percpu: return number of released bytes from pcpu_free_area() | expand

Commit Message

Andrew Morton Aug. 12, 2020, 1:36 a.m. UTC 
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Subject: drivers/rapidio/rio-scan.c: use struct_size() helper

Make use of the struct_size() helper instead of an open-coded version in
order to avoid any potential type mistakes.

Also, while there, use the preferred form for passing a size of a struct. 
The alternative form where struct name is spelled out hurts readability
and introduces an opportunity for a bug when the pointer variable type is
changed but the corresponding sizeof that is passed as argument is not.

This issue was found with the help of Coccinelle and, audited and fixed
manually.

Addresses KSPP ID: https://github.com/KSPP/linux/issues/83

Link: http://lkml.kernel.org/r/20200619170445.GA22641@embeddedor
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/rapidio/rio-scan.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)
diff mbox series

Patch

--- a/drivers/rapidio/rio-scan.c~rapidio-use-struct_size-helper
+++ a/drivers/rapidio/rio-scan.c
@@ -330,7 +330,7 @@  static struct rio_dev *rio_setup_device(
 	size_t size;
 	u32 swpinfo = 0;
 
-	size = sizeof(struct rio_dev);
+	size = sizeof(*rdev);
 	if (rio_mport_read_config_32(port, destid, hopcount,
 				     RIO_PEF_CAR, &result))
 		return NULL;
@@ -338,10 +338,8 @@  static struct rio_dev *rio_setup_device(
 	if (result & (RIO_PEF_SWITCH | RIO_PEF_MULTIPORT)) {
 		rio_mport_read_config_32(port, destid, hopcount,
 					 RIO_SWP_INFO_CAR, &swpinfo);
-		if (result & RIO_PEF_SWITCH) {
-			size += (RIO_GET_TOTAL_PORTS(swpinfo) *
-				sizeof(rswitch->nextdev[0])) + sizeof(*rswitch);
-		}
+		if (result & RIO_PEF_SWITCH)
+			size += struct_size(rswitch, nextdev, RIO_GET_TOTAL_PORTS(swpinfo));
 	}
 
 	rdev = kzalloc(size, GFP_KERNEL);