Song!
On Wed, Dec 07 2022 at 11:26, Song Liu wrote:
> On Wed, Dec 7, 2022 at 7:36 AM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>> > I think we can handle all these with a single module_alloc() and a few
>> > module_arch_* functions().
>> struct mod_alloc_type {
>> unsigned int mapto_type;
>> unsigned int flags;
>> unsigned int granularity;
>> unsigned int alignment;
>> unsigned long start[MOD_MAX_ADDR_SPACES];
>> unsigned long end[MOD_MAX_ADDR_SPACES];
>> pgprot_t pgprot;
>> void (*fill)(void *dst, void *src, unsigned int size);
>> void (*invalidate)(void *dst, unsigned int size);
>> };
>
> Yeah, this is a lot better than arch_ functions.
Remember the order of things to worry about: #3 :)
> We probably want two more function pointers here:
>
> int (*protect)(unsigned long addr, int numpages);
> int (*unprotect)(unsigned long addr, int numpages);
>
> These two functions will be NULL for archs that support text_poke;
> while legacy archs use them for set_memory_[ro|x|rw|nx]. Then, I
> think we can get rid of VM_FLUSH_RESET_PERMS.
Depends. You can implement
fill()
memcpy(...);
set_memory_ro();
and
invalidate()
set_memory_rw();
memset();
as global helpers which can be used by the architecture for the init
struct or used as default for certain types.
> I think I am ready to dive into the code and prepare the first RFC/PATCH.
> Please let me know if there is anything we should discuss/clarify before that.
I think we covered most of it by now, so sure a POC is probably due, but
please yell when you find a gap in step #1 - #3 which we did not cover
yet.
Thanks,
tglx
