From owner-freebsd-bugs@FreeBSD.ORG Thu Sep 11 15:38:10 2014 Return-Path: Delivered-To: freebsd-bugs@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 982A791C for ; Thu, 11 Sep 2014 15:38:10 +0000 (UTC) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6696DCFA for ; Thu, 11 Sep 2014 15:38:10 +0000 (UTC) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.14.9/8.14.9) with ESMTP id s8BFcA64082776 for ; Thu, 11 Sep 2014 15:38:10 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 193565] New: panic in vm_reserv_alloc_contig Date: Thu, 11 Sep 2014 15:38:10 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 10.0-RELEASE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: eric@vangyzen.net X-Bugzilla-Status: Needs Triage X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version rep_platform op_sys bug_status bug_severity priority component assigned_to reporter Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Sep 2014 15:38:10 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=193565 Bug ID: 193565 Summary: panic in vm_reserv_alloc_contig Product: Base System Version: 10.0-RELEASE Hardware: Any OS: Any Status: Needs Triage Severity: Affects Some People Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: eric@vangyzen.net With code that exercises contigmalloc, I can reliably induce a panic (page fault or GPF) in vm_reserv_alloc_contig. The immediate cause is a bad pointer around line 431 (without INVARIANTS), or failing the (rv->object == NULL) assertion. After a little digging, I see that vm_reserv_alloc_contig calls vm_phys_alloc_contig with an allocpages value that is not a multiple of VM_LEVEL_0_NPAGES. This seems bad. Before the call to vm_phys_alloc_contig, I see the following values (via printf): allocpages=646 minpages=646 maxpages=1024 pindex=2013184 VM_RESERV_INDEX(object, pindex)=0 npages=646 object=0xffffffff80bd3fe8 allocpages is set to minpages by the (msucc != NULL) case. I'm not very familiar with the current VM system, and I unfortunately don't have a lot of time to study it, so I'll need some help from here. It's trivial to reproduce, and the system is set up for remote kgdb, so I can answer questions or try diagnostic code pretty quickly. This is 10.0-RELEASE-p7 with no interesting changes in sys/vm. -- You are receiving this mail because: You are the assignee for the bug.