[RFC v7 04/21] um: host: implement os_initcalls and os_exitcalls

[Johannes Berg]

On Tue, 2020-10-06 at 18:44 +0900, Hajime Tazaki wrote:

> Note that this patch should be merged with "um: move arch/um/os-Linux
> dir to tools/um" but for now it is separate to make the review easier.

Not a fan of that, I must say ...

> +extern void (*__start_os_exitcalls)(void);
> +extern void (*__stop_os_exitcalls)(void);
> +
> +void os_exitcalls(void)
> +{
> +	exitcall_t *call;
> +
> +	call = &__stop_os_exitcalls;
> +	while (--call >= &__start_os_exitcalls)
> +		(*call)();

You should check for and skip NULL pointers, there always are alignment
issues with automatic section filling like this, more so with clang than
gcc.

> +}
> +
> +extern int (*__start_os_initcalls)(void);
> +extern int (*__stop_os_initcalls)(void);
> +
> +int os_initcalls(void)
> +{
> +	initcall_t *call;
> +
> +	call = &__stop_os_initcalls;
> +	while (--call >= &__start_os_initcalls)
> +		(*call)();

Same here.

johannes