From owner-freebsd-bugs Thu Apr 15 11:37:37 1999 Delivered-To: freebsd-bugs@freebsd.org Received: from srware.com (stevew.vip.best.com [205.149.166.163]) by hub.freebsd.org (Postfix) with ESMTP id 916F814BD5 for ; Thu, 15 Apr 1999 11:37:27 -0700 (PDT) (envelope-from stevew@srware.com) Received: (from stevew@localhost) by srware.com (8.8.8/8.8.8) id LAA00305 for freebsd-bugs@freebsd.org; Thu, 15 Apr 1999 11:32:17 -0700 (PDT) (envelope-from stevew) Date: Thu, 15 Apr 1999 11:32:17 -0700 (PDT) From: "Stephen R. Whiteley" Message-Id: <199904151832.LAA00305@srware.com> To: freebsd-bugs@freebsd.org Subject: possible kernel VM bug Sender: owner-freebsd-bugs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Attention kernel VM system gurus, I want to report a possible (probable) kernel bug. I am working on a fairly large application (16.7Mb with -g). When I use gdb, I get a kernel panic. This will just about always happen when I re-run the program, presumably as it tries to re-read the symbols, but is not limited to that case. I have had only one non-gdb panic in months. The problem started about the time I cvsupped 2.2.8 (from 2.2.6), however there is uncertainty since the application has changed, and grown, considerably since then. I can say, however, that there was no such problem when I used FBSD 2.1.6 or before (going back to 1.1.15). I use FBSD almost exclusively for software development. There have been no hardware changes in the 2.2.6-2.2.8 era. The machine is a P-Pro 200MHz with 32M, Adaptec scsi, 80Mb swap. It seems to work corectly other than the present problem. I resently set up the kernel core dump feature, which yielded the backtrace below. This is the consistent pattern. I have no experience with the kernel or kernel debugging, but I will attempt to track this down when I have time, since the process would be educational. I would appreaciate any suggestions, and I won't complain if someone spoils my fun by providing a fix. Steve Whiteley Whiteley Research Inc. stevew@srware.com (kgdb) symbol-file kernel.debug Reading symbols from kernel.debug...done. (kgdb) exec-file /var/crash/kernel.0 (kgdb) core-file /var/crash/vmcore.0 IdlePTD 219000 current pcb at 1fd6a8 panic: rlist_free: free start overlaps already freed area #0 boot (howto=256) at ../../kern/kern_shutdown.c:266 266 dumppcb.pcb_cr3 = rcr3(); (kgdb) bt #0 boot (howto=256) at ../../kern/kern_shutdown.c:266 #1 0xf0112992 in panic ( fmt=0xf011943f "rlist_free: free start overlaps already freed area") at ../../kern/kern_shutdown.c:400 #2 0xf0119562 in rlist_free (rlh=0xf020a160, start=0, end=7) at ../../kern/subr_rlist.c:162 #3 0xf01ad657 in swap_pager_freeswapspace (object=0xf06fb680, from=0, to=7) at ../../vm/swap_pager.c:410 #4 0xf01adcff in swap_pager_copy (srcobject=0xf06fb680, srcoffset=0, dstobject=0xf06f1f80, dstoffset=0, offset=0) at ../../vm/swap_pager.c:693 #5 0xf01b5d47 in vm_object_collapse (object=0xf06f1f80) at ../../vm/vm_object.c:1022 #6 0xf01b0115 in vm_fault (map=0xf069a000, vaddr=827392, fault_type=3 '\003', fault_flags=8) at ../../vm/vm_fault.c:712 #7 0xf01c5f72 in trap_pfault (frame=0xefbfffbc, usermode=1) at ../../i386/i386/trap.c:662 #8 0xf01c5b07 in trap (frame={tf_es = -272695257, tf_ds = -272695257, tf_edi = 835720, tf_esi = 911936, tf_ebp = -272640260, tf_isp = -272629788, tf_ebx = 871, tf_edx = 0, tf_ecx = 165649, tf_eax = 920704, tf_trapno = 12, tf_err = 7, tf_eip = 165823, tf_cs = 31, tf_eflags = 66050, tf_esp = -272640476, tf_ss = 39}) at ../../i386/i386/trap.c:248 #9 0x287bf in ?? () #10 0x32319 in ?? () #11 0x534cd in ?? () #12 0x2bdd5 in ?? () #13 0x563f0 in ?? () #14 0x565bb in ?? () #15 0x358dd in ?? () #16 0x1095 in ?? () To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message