diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-14 11:16:57 -0600 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-02-19 17:48:40 +0530 |
| commit | 1ee44529cc79e1ae95dd613e03b0c2434da8d052 (patch) | |
| tree | c7f42acee99a6bd9467044150b0882ddec333f35 | |
| parent | a18cd9bebdca50722534329948adf614239b8c4d (diff) | |
dmaengine: tegra210-adma: 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/20200214171657.GA25663@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
| -rw-r--r-- | drivers/dma/tegra210-adma.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c index 6e1268552f74..c4ce5dfb149b 100644 --- a/drivers/dma/tegra210-adma.c +++ b/drivers/dma/tegra210-adma.c @@ -164,7 +164,7 @@ struct tegra_adma { const struct tegra_adma_chip_data *cdata; /* Last member of the structure */ - struct tegra_adma_chan channels[0]; + struct tegra_adma_chan channels[]; }; static inline void tdma_write(struct tegra_adma *tdma, u32 reg, u32 val) |