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media: rc: iguanair: Replace zero-length array with flexible-array member

PATCH New Gustavo A. R. Silva 1 participant 1 message Feb 11, 2020

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PATCH 1/1 media: rc: iguanair: Replace zero-length array with flexible-array member

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")

---
 drivers/media/rc/iguanair.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/media/rc/iguanair.c +1 -1
index fbacb13b614b..028374b04e47 100644
@@ -85,7 +85,7 @@ struct send_packet {
 	uint8_t channels;
 	uint8_t busy7;
 	uint8_t busy4;
-	uint8_t payload[0];
+	uint8_t payload[];
 };
 
 static void process_ir_data(struct iguanair *ir, unsigned len)
Signature · 1 line
2.25.0