From nobody Sat Sep 25 16:25:17 2021 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 984EB17CEC16 for ; Sat, 25 Sep 2021 16:25:21 +0000 (UTC) (envelope-from avg@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4HGvQ93ynqz4m2T; Sat, 25 Sep 2021 16:25:21 +0000 (UTC) (envelope-from avg@freebsd.org) Received: from [192.168.0.88] (unknown [195.64.148.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: avg/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 13A59C3B3; Sat, 25 Sep 2021 16:25:20 +0000 (UTC) (envelope-from avg@freebsd.org) From: Andriy Gapon To: Kristof Provost Cc: net@freebsd.org References: <980E0B5C-41CF-466E-AD45-7B93532199F4@freebsd.org> Subject: Re: page fault in pfioctl Message-ID: Date: Sat, 25 Sep 2021 19:25:17 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.14.0 List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org MIME-Version: 1.0 In-Reply-To: <980E0B5C-41CF-466E-AD45-7B93532199F4@freebsd.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-ThisMailContainsUnwantedMimeParts: N On 13/06/2021 11:19, Kristof Provost wrote: > On 13 Jun 2021, at 09:41, Andriy Gapon wrote: >>Based on >> the panic message (page fault with non-sleepable locks held), it seems that >> the problem is with holding the lock across the copyout. Usually that >> won't panic, but if the destination happens to be paged out... And only >> with INVARIANTS, I guess... > > Oh right. Thanks. I’ve gotten bitten by that one before, but had clearly > garbage collected the memory. > > I’ll fix this one and check for others on Monday. > > I’ll also see of we can persuade copyout to always panic on this bug, not > just when the destination memory is actually paged out. That way we’ll catch > this in the regression tests in the future. I upgraded to the latest stable/13 and hit a fresh panic of the same type. This time it's in pf_getstatus() and it's a copyout while 'pf rulesets' lock is held. <118>Enabling pf Kernel page fault with the following non-sleepable locks held: shared rm pf rulesets (pf rulesets) r = 0 (0xffffffff85764020) locked @ /usr/devel/git/trant/sys/netpfil/pf/pf_ioctl.c:4945 stack backtrace: #0 0xffffffff808cb43d at witness_debugger+0x6d #1 0xffffffff808cc2ab at witness_warn+0x21b #2 0xffffffff80b567f1 at trap_pfault+0x71 #3 0xffffffff80b55df8 at trap+0x288 #4 0xffffffff80b56b59 at trap_check+0x29 #5 0xffffffff80b32298 at calltrap+0x8 #6 0xffffffff8574cae8 at pf_getstatus+0x548 #7 0xffffffff85747430 at pfioctl+0x2590 #8 0xffffffff8073854f at devfs_ioctl+0xcf #9 0xffffffff80bd8c26 at VOP_IOCTL_APV+0x96 #10 0xffffffff8094c424 at VOP_IOCTL+0x34 #11 0xffffffff80947600 at vn_ioctl+0xc0 #12 0xffffffff80738a3e at devfs_ioctl_f+0x1e #13 0xffffffff808cf8fb at fo_ioctl+0xb #14 0xffffffff808cf897 at kern_ioctl+0x1d7 #15 0xffffffff808cf60d at sys_ioctl+0x12d #16 0xffffffff80b57353 at syscallenter+0x163 #17 0xffffffff80b57025 at amd64_syscall+0x15 -- Andriy Gapon