diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-23 18:01:11 -0500 |
|---|---|---|
| committer | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-04-18 15:44:55 -0500 |
| commit | 7856e9f12f1f59cc6abb25f92b336528d0660ebb (patch) | |
| tree | 5468e10355bb3cdabe1019be17baf6d2ca15433c | |
| parent | 1d9e13e8ef05029c61d52ad9a6f48f14771d14b7 (diff) | |
| download | linux-7856e9f12f1f59cc6abb25f92b336528d0660ebb.tar.bz2 | |
irq.h: 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 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
| -rw-r--r-- | include/linux/irq.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h index 9315fbb87db3..fa8ad93029ad 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -1043,7 +1043,7 @@ struct irq_chip_generic { unsigned long unused; struct irq_domain *domain; struct list_head list; - struct irq_chip_type chip_types[0]; + struct irq_chip_type chip_types[]; }; /** @@ -1079,7 +1079,7 @@ struct irq_domain_chip_generic { unsigned int irq_flags_to_clear; unsigned int irq_flags_to_set; enum irq_gc_flags gc_flags; - struct irq_chip_generic *gc[0]; + struct irq_chip_generic *gc[]; }; /* Generic chip callback functions */ |