diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-12 17:59:11 -0600 |
|---|---|---|
| committer | Lee Jones <lee.jones@linaro.org> | 2020-03-30 07:34:57 +0100 |
| commit | 7235d9e48fda6902018e04669eda6f5d1878599f (patch) | |
| tree | 4751fde5c4061d1fba816f0b35a5db88c2b8063f | |
| parent | a0c8498c076d0338860df7e45e5e6f48158a02d8 (diff) | |
mfd: pm8xxx: 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: Lee Jones <lee.jones@linaro.org>
| -rw-r--r-- | drivers/mfd/qcom-pm8xxx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/mfd/qcom-pm8xxx.c b/drivers/mfd/qcom-pm8xxx.c index 29133326c6fd..acd172ddcbd6 100644 --- a/drivers/mfd/qcom-pm8xxx.c +++ b/drivers/mfd/qcom-pm8xxx.c @@ -76,7 +76,7 @@ struct pm_irq_chip { unsigned int num_masters; const struct pm_irq_data *pm_irq_data; /* MUST BE AT THE END OF THIS STRUCT */ - u8 config[0]; + u8 config[]; }; static int pm8xxx_read_block_irq(struct pm_irq_chip *chip, unsigned int bp, |