On Mon, 2007-10-15 at 10:54 +1000, David Gibson wrote: > On Fri, Oct 12, 2007 at 06:56:24AM -0500, Josh Boyer wrote: > > On Fri, 2007-10-12 at 13:30 +1000, David Gibson wrote: > > > On Thu, Oct 11, 2007 at 01:42:30PM -0500, Kumar Gala wrote: > > > > Move to using PAGE_OFFSET instead of TASK_SIZE or KERNELBASE value on > > > > 6xx/40x/44x/fsl-booke to determine if the faulting address is a kernel > > > > or > > > > user space address. This mimics how the macro is_kernel_addr() > > > > works. > > > > > > Actually it's ambiguous whether TASK_SIZE or PAGE_OFFSET is correct in > > > most of these cases (KERNELBASE is certainly wrong, though). > > > > > > TASK_SIZE is the top of the userspace mapped area, PAGE_OFFSET is the > > > bottom of the linear mapping. So, strictly speaking there are 3 paths > > > for the miss handlers: < TASK_SIZE => user mapping, >= PAGE_OFFSET => > > > kernel mapping, between the two => immediate fault. > > > > > > We get away with a two way comparison on 32-bit because, a) they have > > > the same value and b) none of the pagetables, user or kernel, should > > > have any entries in the in between region so we'll end up in > > > do_page_fault in the end, anyway. > > > > Kumar's other patch removes the gap. He changed the default > > CONFIG_TASK_SIZE to 0xc0000000. > > That's (a) and only removes the gap in the default configuration..
I believe the idea was that as defconfigs get updated for 2.6.24, they would pick up the new default. josh _______________________________________________ Linuxppc-dev mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-dev
