Messages in this thread | | | Date | Thu, 14 Sep 2006 03:12:14 -0400 | From | "Albert Cahalan" <> | Subject | Re: Assignment of GDT entries |
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On 9/14/06, Zachary Amsden <zach@vmware.com> wrote: > Albert Cahalan wrote:
> > So basically it's not allowed to just grab the 3rd slot? > > You can, but you should be prepared for it to fail as well.
Without knowing details of the kernel's GDT, how?
> > What if I want to find out what is already in use? > > Am I supposed to iterate over all 8191 possible > > GDT entries? How do I even tell how many slots > > are available without using them all up? > > There are only 32 possible GDT entries in 32-bit i386 Linux, and only > three of them are usable for userspace. You can't find out which slots > are in use, but you can cause one to be allocated and returned to you. > This seems like a perfectly reasonable API to me, why do you think it is > so ugly?
Eh, "returned to you" doesn't work for me. I need to figure out what other code (not written by me) uses.
I may need to "borrow" a slot if all three slots are in use. Without using evil knowledge of the GDT, how am I to do that? I don't know what slots might have been allocated by other libraries. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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