Re: [PATCH][RFC] disable built-in modules V2

[Magnus Damm <magnus.damm@gmail.com>]

On Apr 6, 2005 12:32 PM, Malcolm Rowe <malcolm-linux@farside.org.uk> wrote:
> Magnus Damm writes:
> > Here comes version 2 of the disable built-in patch.
> 
> > +void __init disable_initcall(void *fn)
> > +{
> > +     initcall_t *call;
> > +
> > +     for (call = __initcall_start; call < __initcall_end; call++) {
> > +
> > +             if (*call == fn)
> > +                     *call = NULL;
> > +     }
> > +}
> 
> Regardless of anything else, won't this break booting with initcall_debug on
> PPC64/IA64 machines? (see the definition of print_fn_descriptor_symbol() in
> kallsyms.h)

Correct, thanks for pointing that out. The code below is probably better:

 static void __init do_initcalls(void)
 {
        initcall_t *call;
@@ -547,6 +558,9 @@ static void __init do_initcalls(void)
        for (call = __initcall_start; call < __initcall_end; call++) {
                char *msg;

+               if (!*call)
+                       continue;
+
                if (initcall_debug) {
                        printk(KERN_DEBUG "Calling initcall 0x%p", *call);
                        print_fn_descriptor_symbol(": %s()", (unsigned
long) *call);

And I guess the idea of replacing the initcall pointer with NULL will
work both with and without function descriptors, right? So we should
be safe on IA64 and PPC64.

Regards,

/ magnus