From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: Jean Delvare <jdelvare@suse.com>, Guenter Roeck <linux@roeck-us.net>
Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] hwmon: (ibmaem) Replace zero-length array with flexible-array member
Date: Tue, 11 Feb 2020 17:42:37 -0600 [thread overview]
Message-ID: <20200211234237.GA26971@embeddedor> (raw)
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertenly introduced[3] to the codebase from now on.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/hwmon/ibmaem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/hwmon/ibmaem.c b/drivers/hwmon/ibmaem.c
index db63c1295cb2..fb052c2d9c34 100644
--- a/drivers/hwmon/ibmaem.c
+++ b/drivers/hwmon/ibmaem.c
@@ -232,7 +232,7 @@ struct aem_read_sensor_req {
struct aem_read_sensor_resp {
struct aem_iana_id id;
- u8 bytes[0];
+ u8 bytes[];
} __packed;
/* Data structures to talk to the IPMI layer */
--
2.25.0
next reply other threads:[~2020-02-12 0:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-11 23:42 Gustavo A. R. Silva [this message]
2020-02-12 20:45 ` [PATCH] hwmon: (ibmaem) Replace zero-length array with flexible-array member Guenter Roeck
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