kernel_optimize_test/drivers/powercap
Gustavo A. R. Silva 27565c9e22 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 7649773293 ("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>
2020-03-04 11:08:17 +01:00
..
idle_inject.c powercap: idle_inject: Replace zero-length array with flexible-array member 2020-03-04 11:08:17 +01:00
intel_rapl_common.c Merge back power capping changes for v5.6. 2020-01-13 10:32:19 +01:00
intel_rapl_msr.c intel_rapl: Fix module autoloading issue 2019-07-11 15:08:58 +02:00
Kconfig intel_rapl: abstract RAPL common code 2019-07-11 15:08:58 +02:00
Makefile intel_rapl: abstract RAPL common code 2019-07-11 15:08:58 +02:00
powercap_sys.c powercap: Invoke powercap_init() and rapl_init() earlier 2019-07-22 11:23:00 +02:00