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author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-14 20:14:35 +0300 |
---|---|---|
committer | Vinod Koul <vkoul@kernel.org> | 2020-02-19 15:18:40 +0300 |
commit | bfb59d4a330e584838861d4ed2a4fb046ea0afb1 (patch) | |
tree | 59cf5c54c85cacc814a9399bb32b0fa5db37d010 /drivers/dma/sa11x0-dma.c | |
parent | 8faa77332fe01a681ef3097581a37b82adc1c14b (diff) | |
download | linux-bfb59d4a330e584838861d4ed2a4fb046ea0afb1.tar.xz |
dmaengine: sa11x0: 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/20200214171435.GA22930@embeddedor
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma/sa11x0-dma.c')
-rw-r--r-- | drivers/dma/sa11x0-dma.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/dma/sa11x0-dma.c b/drivers/dma/sa11x0-dma.c index afb68055ed1b..0fa7f14a65a1 100644 --- a/drivers/dma/sa11x0-dma.c +++ b/drivers/dma/sa11x0-dma.c @@ -78,7 +78,7 @@ struct sa11x0_dma_desc { bool cyclic; unsigned sglen; - struct sa11x0_dma_sg sg[0]; + struct sa11x0_dma_sg sg[]; }; struct sa11x0_dma_phy; |