Can I use `strlen()`, `strcpy()`, `strrev()`, `strcmp()` or `strcat()` when creating a kernel in C?

Anyways, I found this snippet of code from osdev.org, which I am going to build off of, to have the strlen() function, although I cant find a way to create the other functions that I listed in the title if this question.

size_t strlen(const char* str) 
{
    size_t len = 0;
    while (str[len])
        len++;
    return len;
}

Will this library work #include <linux/string.h> ? <string.h> library cannot be used in kernel. https://elixir.bootlin.com/linux/latest/source/include/linux/string.h#L48

look at the link, there is a strcmp function and others that you need. I'm new so I'm not 100% sure. If I'm wrong please correct me.

I've found out after experimenting, that you can actually use some libraries, like stdint.h and stdbool.h even when making a kernel in C. Although this can be done, I have implemented my own versions of the functions that I asked about above...