Re: Questions regarding 'struct modstat'

[Paul Goyette <paul%vps1.whooppee.com@localhost>]

> > 1. Despite the comment, aren't the u_int fields of different sizes in
> >    32- vs 64-bit builds?  The comment seems to be somewhat misleading.
>
> u_int is 32 bits in both ILP32 and LP64, so it is fine. It would have
> been better to use uint32_t instead.
>
> > 2. Is there any assurance that the module's load address (in ms_addr)
> >    can fit in a uint64_t?
>
> Yes, for all platforms (currently). If it was uintptr_t be it would have
> been different size in ILP32/LP64.
>
> > 3. If I wanted to add another address field (ms_modaddr for the address
> >    of the module's 'struct module'), would it be better to
> >
> > 	a) insert a new uint64_t in the middle of this structure,
> > 	   after the current ms_addr field,
> >
> > 	b) insert a new uint64_t in the middle of this structure,
> > 	   immediately before the ms_reserved[] array,
> >
> > 	c) append a new uint64_t at the end of this structure, or
> >
> > 	d) replace some number of the ms_reserved[] array with a
> > 	   new uint64_t structure (and how many to replace?)
>
> You need to replace 2 u_ints (each u_int has 4 bytes and you need
> 8 bytes for a uint64_t).

Thanks for the quick responses.

Since the real reason I was contemplating this was to get access to
the mod_flags member of struct module, I decided it was more correct
to directly expose that value, rather than providing a kernel address
of the structure (and then having to use gdb/crash to examine it).




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