Fix module building failed after Linux 6.4

[25077667]

There is the output from Linux 6.5.4 without this patch:

➜ fibdrv git:(master) make

Git hooks are installed successfully.

cc -o client client.c
make -C /lib/modules/6.5.4-arch2-1/build M=/home/scc/git/fibdrv modules
make[1]: Entering directory '/usr/lib/modules/6.5.4-arch2-1/build'
CC [M] /home/scc/git/fibdrv/fibdrv.o
/home/scc/git/fibdrv/fibdrv.c: In function ‘fib_sequence’:
/home/scc/git/fibdrv/fibdrv.c:30:5: warning: ISO C90 forbids variable length array ‘f’ [-Wvla]
30 | long long f[k + 2];
| ^~~~
In file included from ./include/linux/linkage.h:7,
from ./arch/x86/include/asm/cache.h:5,
from ./include/linux/cache.h:6,
from ./arch/x86/include/asm/current.h:9,
from ./include/linux/mutex.h:14,
from ./include/linux/kernfs.h:11,
from ./include/linux/sysfs.h:16,
from ./include/linux/kobject.h:20,
from ./include/linux/cdev.h:5,
from /home/scc/git/fibdrv/fibdrv.c:1:
/home/scc/git/fibdrv/fibdrv.c: In function ‘init_fib_dev’:
./include/linux/export.h:29:22: error: passing argument 1 of ‘class_create’ from incompatible pointer type [-Werror=incompatible-pointer-types]
29 | #define THIS_MODULE (&__this_module)
| ~^~~~~~~~~~~~~~~
| |
| struct module *
/home/scc/git/fibdrv/fibdrv.c:122:30: note: in expansion of macro ‘THIS_MODULE’
122 | fib_class = class_create(THIS_MODULE, DEV_FIBONACCI_NAME);
| ^~~~~~~~~~~
In file included from ./include/linux/device.h:31,
from ./include/linux/cdev.h:8:
./include/linux/device/class.h:230:54: note: expected ‘const char *’ but argument is of type ‘struct module *’
230 | struct class * __must_check class_create(const char *name);
| ~~~~~~~~~~~~^~~~
/home/scc/git/fibdrv/fibdrv.c:122:17: error: too many arguments to function ‘class_create’
122 | fib_class = class_create(THIS_MODULE, DEV_FIBONACCI_NAME);
| ^~~~~~~~~~~~
./include/linux/device/class.h:230:29: note: declared here
230 | struct class * __must_check class_create(const char *name);
| ^~~~~~~~~~~~
cc1: some warnings being treated as errors
make[3]: *** [scripts/Makefile.build:243: /home/scc/git/fibdrv/fibdrv.o] Error 1
make[2]: *** [/usr/lib/modules/6.5.4-arch2-1/build/Makefile:2034: /home/scc/git/fibdrv] Error 2
make[1]: *** [Makefile:234: __sub-make] Error 2
make[1]: Leaving directory '/usr/lib/modules/6.5.4-arch2-1/build'
make: *** [Makefile:13: all] Error 2

[25077667]

I found this issue had been nounce at Bug#1039572: sl-modem-dkms: module fails to build for Linux 6.4

[jserv]

Thank @25077667 for contributing!