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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-03-19 16:44:38 -0500 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2020-03-22 11:52:52 +0000 |
| commit | b2e1cbfd2d4af6f0797ed259de5f48e7dde60014 (patch) | |
| tree | 28dd9b296b190014badabfce7d35d93e4f496fc9 | |
| parent | 6a214a28132f19ace3d835a6d8f6422ec80ad200 (diff) | |
| download | linux-b2e1cbfd2d4af6f0797ed259de5f48e7dde60014.tar.bz2 | |
irqchip/irq-bcm7038-l1: 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>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200319214438.GA21123@embeddedor.com
| -rw-r--r-- | drivers/irqchip/irq-bcm7038-l1.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-bcm7038-l1.c b/drivers/irqchip/irq-bcm7038-l1.c index cbf01afcd2a6..eb9bce93cd05 100644 --- a/drivers/irqchip/irq-bcm7038-l1.c +++ b/drivers/irqchip/irq-bcm7038-l1.c @@ -50,7 +50,7 @@ struct bcm7038_l1_chip { struct bcm7038_l1_cpu { void __iomem *map_base; - u32 mask_cache[0]; + u32 mask_cache[]; }; /* |