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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-17 12:54:37 -0600 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2020-02-21 15:36:24 +0100 |
| commit | aa0ed0d00f1d33d179cb531766176cf6b2a03934 (patch) | |
| tree | 4cd33926296f4fc52175a0122bc0f1ddf793f8bc | |
| parent | b295474360619f71cc6e99c8080ff7d9f66a3c45 (diff) | |
| download | linux-aa0ed0d00f1d33d179cb531766176cf6b2a03934.tar.gz linux-aa0ed0d00f1d33d179cb531766176cf6b2a03934.tar.bz2 linux-aa0ed0d00f1d33d179cb531766176cf6b2a03934.zip | |
pinctrl: uniphier: 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/20200217185437.GA20901@embeddedor
Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
| -rw-r--r-- | drivers/pinctrl/uniphier/pinctrl-uniphier-core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c b/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c index 57babf31e320..ade348b49b31 100644 --- a/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c +++ b/drivers/pinctrl/uniphier/pinctrl-uniphier-core.c @@ -29,7 +29,7 @@ struct uniphier_pinctrl_reg_region { struct list_head node; unsigned int base; unsigned int nregs; - u32 vals[0]; + u32 vals[]; }; struct uniphier_pinctrl_priv { |