From owner-freebsd-current@freebsd.org Sat Oct 20 16:56:15 2018 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id A973FFEC660 for ; Sat, 20 Oct 2018 16:56:15 +0000 (UTC) (envelope-from pho@holm.cc) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 4D3787B42D for ; Sat, 20 Oct 2018 16:56:15 +0000 (UTC) (envelope-from pho@holm.cc) Received: by mailman.ysv.freebsd.org (Postfix) id 0F105FEC65F; Sat, 20 Oct 2018 16:56:15 +0000 (UTC) Delivered-To: current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id F1CACFEC65E for ; Sat, 20 Oct 2018 16:56:14 +0000 (UTC) (envelope-from pho@holm.cc) Received: from relay01.pair.com (relay01.pair.com [209.68.5.15]) (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 A694A7B42C for ; Sat, 20 Oct 2018 16:56:14 +0000 (UTC) (envelope-from pho@holm.cc) Received: from x2.osted.lan (87-58-223-204-dynamic.dk.customer.tdc.net [87.58.223.204]) by relay01.pair.com (Postfix) with ESMTP id 42FDCD00B24 for ; Sat, 20 Oct 2018 12:56:07 -0400 (EDT) Received: from x2.osted.lan (localhost [127.0.0.1]) by x2.osted.lan (8.15.2/8.15.2) with ESMTPS id w9KGu5L3005089 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Sat, 20 Oct 2018 18:56:05 +0200 (CEST) (envelope-from pho@x2.osted.lan) Received: (from pho@localhost) by x2.osted.lan (8.15.2/8.15.2/Submit) id w9KGu5cL005088 for current@freebsd.org; Sat, 20 Oct 2018 18:56:05 +0200 (CEST) (envelope-from pho) Date: Sat, 20 Oct 2018 18:56:05 +0200 From: Peter Holm To: current@freebsd.org Subject: Page fault in midi/sequencer.c Message-ID: <20181020165604.GA4946@x2.osted.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.0 (2018-05-17) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Oct 2018 16:56:15 -0000 I can trigger this on 13.0-CURRENT r339445 with a non-root test program: Calling uiomove() with the following non-sleepable locks held: exclusive sleep mutex seqflq (seqflq) r = 0 (0xfffff80003860c08) locked @ dev/sound/midi/sequencer.c:952 stack backtrace: #0 0xffffffff80bfe263 at witness_debugger+0x73 #1 0xffffffff80bff1b8 at witness_warn+0x448 #2 0xffffffff80bf6a91 at uiomove_faultflag+0x71 #3 0xffffffff809439e6 at mseq_write+0x4c6 #4 0xffffffff80a4f725 at devfs_write_f+0x185 #5 0xffffffff80c02a87 at dofilewrite+0x97 #6 0xffffffff80c0287f at kern_pwritev+0x5f #7 0xffffffff80c0277d at sys_pwrite+0x8d #8 0xffffffff81070af7 at amd64_syscall+0x2a7 #9 0xffffffff8104a4ad at fast_syscall_common+0x101 Kernel page fault with the following non-sleepable locks held: exclusive sleep mutex seqflq (seqflq) r = 0 (0xfffff80003860c08) locked @ dev/sound/midi/sequencer.c:952 stack backtrace: #0 0xffffffff80bfe263 at witness_debugger+0x73 #1 0xffffffff80bff1b8 at witness_warn+0x448 #2 0xffffffff810700d3 at trap_pfault+0x53 #3 0xffffffff8106f70a at trap+0x2ba #4 0xffffffff81049bc5 at calltrap+0x8 #5 0xffffffff80bf6b42 at uiomove_faultflag+0x122 #6 0xffffffff809439e6 at mseq_write+0x4c6 #7 0xffffffff80a4f725 at devfs_write_f+0x185 #8 0xffffffff80c02a87 at dofilewrite+0x97 #9 0xffffffff80c0287f at kern_pwritev+0x5f #10 0xffffffff80c0277d at sys_pwrite+0x8d #11 0xffffffff81070af7 at amd64_syscall+0x2a7 #12 0xffffffff8104a4ad at fast_syscall_common+0x101 Fatal trap 12: page fault while in kernel mode cpuid = 4; apic id = 04 fault virtual address = 0x20ea6b fault code = supervisor read data, page not present instruction pointer = 0x20:0xffffffff8106d32d stack pointer = 0x28:0xfffffe00a844a660 frame pointer = 0x28:0xfffffe00a844a660 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, long 1, def32 0, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 2356 (xxx) [ thread pid 2356 tid 100278 ] Stopped at copyin_nosmap_erms+0xdd: movl (%rsi),%edx db> -- Peter