On Tue, Jan 31, 2023 at 10:58:56AM +0000, Christophe Leroy wrote:
>
>
> Le 31/01/2023 à 10:09, Peter Zijlstra a écrit :
>
> >> @@ -573,23 +574,33 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr);
> >> bool is_module_percpu_address(unsigned long addr);
> >> bool is_module_text_address(unsigned long addr);
> >>
> >> +static inline bool within_module_mem_type(unsigned long addr,
> >> + const struct module *mod,
> >> + enum mod_mem_type type)
> >> +{
> >> + unsigned long base, size;
> >> +
> >> + base = (unsigned long)mod->mem[type].base;
> >> + size = mod->mem[type].size;
> >> +
> >> + return base <= addr && addr < base + size;
> >
> > Possible (as inspired by all the above is_{init,core}() etc..
> >
> > return addr - base < size;
> >
>
> In kernel/module/main.c we have a function called within(). Maybe that
> function could be lifted in module.h and used.
More sharing more good. But I don't think we can lift a 'within'
function to the global namespace, that's just asking for pain.
> > static inline bool within_module_mem_types(unsigned long addr,
> > const struct module *mod,
> > enum mod_mem_type first,
> > enum mod_mem_type last)
> > {
> > for (enum mod_mem_type type = first; type <= last; type++) {
> > if (within_module_mem_type(addr, mod, type))
> > return true;
> > }
> > return false;
> > }
>
> Well, ok but what garanties it will always be contiguous types ?
> And you can't anymore see at first look what types it is.
>
> I prefer it to be explicit with within_module_mem_type(TYPE1) ||
> within_module_mem_type(TYPE2) || within_module_mem_type(TYPE3). By the
> way we could make the function name shorter, even within() may be a
> better name as it is used only inside module code.
>
> Something like
>
> return within(addr, mod, MOD_TEXT) || within(addr, mod, MOD_DATA) ||
> within(addr, mod, MOD_RODATA) || within(addr, mod,
> MOD_RO_AFTER_INIT);
Urgh, how about?
for_each_mod_mem_type(type) {
if (!mod_mem_type_is_init(type) && within(addr, mod, type))
return true;
}
return false;
Then you have have a bunch of mod_mem_type_id_foo() filter functions
that are non-contiguous without having to endlessly repeat stuff
manually.
