Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!att!watmath!maytag!mks.com!mks!eric From: eric@mks.mks.com (Eric Gisin) Newsgroups: comp.unix.i386 Subject: Kernel trap type 0xE Message-ID: Date: 23 Jul 90 16:20:08 GMT Sender: eric@mks.com (Eric Gisin) Distribution: comp Organization: Mortice Kern Systems Inc., Waterloo, Ontario, CANADA Lines: 26 We have been getting a lot of kernel type 0xE traps on our Interactive 2.2 system. Under 2.0 the machine would crash a lot but there were usually no clues as to why. I looked up interrupt 0xE in the Intel manual and it is a page fault. Several people have claimed they are hardware related (memory or bus), but I can't see how this can be the case. You only get this fault when an address mapping results in a page table entry with the page-present bit of zero or when page access is denied. If a hardware problem was causing random page faults, you would expect some of them to occur in user-mode resulting in a process being killed with SIGSEGV, but I haven't seen any of these. Can anyone explain or speculate how a hardware problem could be causing page faults? Two crashes I did debug had a null-pointer dereference in namei(), one called from open() the other for exece(). Two other crashes occured during reboot in wdrintr(). Could these be software-bug generated faults? We also had to upgrade our CPU from the SX211 version to SX219 to get 2.2 boot/install to come up. This required removing the motherboard to get the CPU to seat properly. Not recommend for non-hardware gurus. Does Interactive acknowledge that you may have to upgrade your CPU to install 2.2?