diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-12 18:35:35 -0600 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-02-13 20:15:57 +0530 |
| commit | 6a8785082c83f0a223bc970d99edcd742435dab2 (patch) | |
| tree | be50d028efc1bc77c1b8aaa7762c36b41480b758 /drivers | |
| parent | 57a8cc725622185576dcd3df718e91fcda1ef5dd (diff) | |
dmaengine: uniphier-mdmac: 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>
Link: https://lore.kernel.org/r/20200213003535.GA3269@embeddedor.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/uniphier-mdmac.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/uniphier-mdmac.c b/drivers/dma/uniphier-mdmac.c index 21b8f1131d55..618839df0748 100644 --- a/drivers/dma/uniphier-mdmac.c +++ b/drivers/dma/uniphier-mdmac.c @@ -68,7 +68,7 @@ struct uniphier_mdmac_device { struct dma_device ddev; struct clk *clk; void __iomem *reg_base; - struct uniphier_mdmac_chan channels[0]; + struct uniphier_mdmac_chan channels[]; }; static struct uniphier_mdmac_chan * |