From owner-freebsd-bugs@freebsd.org Mon Nov 21 20:07:36 2016 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C2655C4D24F for ; Mon, 21 Nov 2016 20:07:36 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 8DB3588 for ; Mon, 21 Nov 2016 20:07:36 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id uALK7aJN060050 for ; Mon, 21 Nov 2016 20:07:36 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 214718] x86bios panics at boot if it cannot obtain memory Date: Mon, 21 Nov 2016 20:07:36 +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: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: emaste@freebsd.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-bugs@FreeBSD.org 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: quoted-printable 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: 2.1.23 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Nov 2016 20:07:36 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D214718 Bug ID: 214718 Summary: x86bios panics at boot if it cannot obtain memory Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: emaste@freebsd.org Due to an LLD issue (http://llvm.org/pr30891) my kernel was linked at 0x100= 0, not 0x200000, meaning that no < 640K memory was available when the system started up. In this case x86bios panics on boot, because it does an M_WAITOK allocation when it is not permissible: ACPI APIC Table: panic: vm_wait in early boot cpuid =3D 0 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xffffffff81e0c= a40 vpanic() at vpanic+0x182/frame 0xffffffff81e0cac0 panic() at panic+0x43/frame 0xffffffff81e0cb20 vm_wait() at vm_wait+0xd6/frame 0xffffffff81e0cb40 kmem_alloc_contig() at kmem_alloc_contig+0x1bd/frame 0xffffffff81e0cc00 contigmalloc() at contigmalloc+0x33/frame 0xffffffff81e0cc40 x86bios_modevent() at x86bios_modevent+0x244/frame 0xffffffff81e0cc60 module_register_init() at module_register_init+0xb0/frame 0xffffffff81e0cc90 mi_startup() at mi_startip+0x118/frame 0xffffffff81e0ccb0 btext() at btext+0x2c KDB: enter: panic [ thread pid 0 tid 0 ] Stopped at kdb_enter+0x3b: movq $0,kdb_why I was quite surprised to find that if I disable x86bios the system boots and runs successfully in this (linked at 0x1000) configuration. --=20 You are receiving this mail because: You are the assignee for the bug.=