diff options
author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2020-02-27 22:07:21 +0300 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2020-03-04 13:08:17 +0300 |
commit | 27565c9e22ddd158f918456b2712a06b05b4da5e (patch) | |
tree | 89d936ddd649b79d6ba9e90535b487b13c2c32d7 /drivers | |
parent | 98d54f81e36ba3bf92172791eba5ca5bd813989b (diff) | |
download | linux-27565c9e22ddd158f918456b2712a06b05b4da5e.tar.xz |
powercap: idle_inject: 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]
Lastly, fix the following checkpatch warning:
WARNING: Prefer 'unsigned long' over 'unsigned long int' as the int is unnecessary
+ unsigned long int cpumask[];
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: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/powercap/idle_inject.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/powercap/idle_inject.c b/drivers/powercap/idle_inject.c index cd1270614cc6..e9bbd3c42eef 100644 --- a/drivers/powercap/idle_inject.c +++ b/drivers/powercap/idle_inject.c @@ -67,7 +67,7 @@ struct idle_inject_device { struct hrtimer timer; unsigned int idle_duration_us; unsigned int run_duration_us; - unsigned long int cpumask[0]; + unsigned long cpumask[]; }; static DEFINE_PER_CPU(struct idle_inject_thread, idle_inject_thread); |