Commit 274ac283 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by David S. Miller

net: marvell: 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
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

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 76497732 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c5d6cf90
...@@ -2426,7 +2426,7 @@ struct skge_hw { ...@@ -2426,7 +2426,7 @@ struct skge_hw {
spinlock_t phy_lock; spinlock_t phy_lock;
struct tasklet_struct phy_task; struct tasklet_struct phy_task;
char irq_name[0]; /* skge@pci:000:04:00.0 */ char irq_name[]; /* skge@pci:000:04:00.0 */
}; };
enum pause_control { enum pause_control {
......
...@@ -2309,7 +2309,7 @@ struct sky2_hw { ...@@ -2309,7 +2309,7 @@ struct sky2_hw {
struct work_struct restart_work; struct work_struct restart_work;
wait_queue_head_t msi_wait; wait_queue_head_t msi_wait;
char irq_name[0]; char irq_name[];
}; };
static inline int sky2_is_copper(const struct sky2_hw *hw) static inline int sky2_is_copper(const struct sky2_hw *hw)
......
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