On Tue, 5 Jan 2016, Taylor R Campbell wrote:
Date: Tue, 5 Jan 2016 09:13:01 +0800 (PHT) From: Paul Goyette <p...@whooppee.com>Note: from the kernel map, 0xffffffff805e3120 is the address of vmspace0, as would be expected from the above initialization code. The map doesn't have anything that corresponds to 0xffffffff805dea80 - the closest items are 0xffffffff805ddd70 kmembase .bss 0xffffffff805deba0 0x70 uvm_loan.o The address you see in kernel_map, 0xffffffff805dea80, is doubtless that of kernel_map_store, defined in uvm/uvm_km.c. Its function appears to be for uvm_km(9) allocations. But it shares a pmap with vmspace0's vm_map, namely the kernel pmap -- that is, it refers to the same assignment of physical pages to virtual addresses. I'm not clear on what purpose vmspace0's vm_map serves. It may be that nothing uses it, in which case maybe kernel_map should just be vmspace0's vm_map and there shouldn't be a separate kernel_map_store. But that's neither here nor there. It's clear that, with the status quo, inif (&uio->uio_vmspace->vm_map != kernel_map && uio->uio_vmspace != curproc->p_vmspace)the first condition will never be true unless someone assigns kernel_map, which I don't expect to ever happen -- kernel_map = &kernel_map_store is not the vm_map of any vmspace. So I think DIAGNOSTIC condition is wrong. I think the right condition is probably uio->uio_vmspace == vmspace_kernel().
Yes, this make a lot of sense. I will fix it in both spec_write() and in spec_read().
While you're here, please change #if DIAGNOSTIC into KASSERT or KASSERTMSG.
Definitely! Thanks for the quick response! +------------------+--------------------------+------------------------+ | Paul Goyette | PGP Key fingerprint: | E-mail addresses: | | (Retired) | FA29 0E3B 35AF E8AE 6651 | paul at whooppee.com | | Kernel Developer | 0786 F758 55DE 53BA 7731 | pgoyette at netbsd.org | +------------------+--------------------------+------------------------+
