I'm only following this superficially, but keep in mind that a vm-area MUST NEVER cross a hole. --david On 2/21/06, Chen, Kenneth W <kenneth.w.chen@xxxxxxxxx> wrote: > David Gibson wrote on Tuesday, February 21, 2006 4:14 PM > > First bug (confirmed many months ago by Chris Wedgwood) - you can get > > weird effects if you attempt to mmap() something into one of the > > address space gaps. The ia64 outer wrapper for mmap2() tries to > > prevent it, but doesn't do a good enough job, it's still possible > > indirectly with shmat() and maybe mremap(). Basic trouble is that > > most of the checks applied by the generic code assume that everything > > between 0 and TASK_SIZE is valid. > > Ha ha ha. > > On ia64, the low level tlb fault handler (vhpt_miss and nested_dtlb_miss) > checks that all unused address bits (between REGION_NUMBER and PGDIR_SHIFT) > should be all zero. If they are not zero, it will fall into page fault > handler and in there, ia64 should just send SEGV instead of happily hand > over a page. Buggy buggy.... > > - Ken > > - > : send the line "unsubscribe linux-ia64" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Mosberger Consulting LLC, http://www.mosberger-consulting.com/ - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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