On Tue, Oct 02, 2012 at 01:43:04AM +0100, Jon Masters wrote: > On 07/06/2012 05:05 PM, Catalin Marinas wrote: > > > +/* > > + * PAGE_OFFSET - the virtual address of the start of the kernel image. > > + * VA_BITS - the maximum number of bits for virtual addresses. > > + * TASK_SIZE - the maximum size of a user space task. > > + * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area. > > + * The module space lives between the addresses given by TASK_SIZE > > + * and PAGE_OFFSET - it must be within 128MB of the kernel text. > > + */ > > +#define PAGE_OFFSET UL(0xffffffc000000000) > > +#define MODULES_END (PAGE_OFFSET) > > +#define MODULES_VADDR (MODULES_END - SZ_64M) > > +#define VA_BITS (39) > > +#define TASK_SIZE_64 (UL(1) << VA_BITS) > > Pedantic nit pick. Shouldn't that "it must be within 128MB of the kernel > text" be "within 128MB of the *end* of the kernel text"? The point being > that on AArch64 unconditional branches are encoded as imm26+1 (27 bits) > and so you're going with -64MB to ensure that you're within the range.
I read it to be within 128MB of any part of the kernel text but I can change it to "end of" if that's clearer. -- Catalin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
