From owner-freebsd-net@freebsd.org Wed Oct 9 14:20:46 2019 Return-Path: Delivered-To: freebsd-net@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 04B8514D3A0 for ; Wed, 9 Oct 2019 14:20:46 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [88.99.82.50]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 46pGbK0z6vz4TyZ; Wed, 9 Oct 2019 14:20:44 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2016.home.selasky.org (unknown [62.141.129.235]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 64C192603D0; Wed, 9 Oct 2019 16:20:41 +0200 (CEST) Subject: Re: panic: sleeping in an epoch section To: Mark Johnston Cc: Yuri Pankov , freebsd-net References: <86cc5d82-50d0-93eb-5900-54e8b0032a08@yuripv.net> <050ba95e-d0d5-dd1a-db6f-9a5c07142efe@selasky.org> <20191009135616.GC66126@raichu> From: Hans Petter Selasky Message-ID: Date: Wed, 9 Oct 2019 16:18:34 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20191009135616.GC66126@raichu> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 46pGbK0z6vz4TyZ X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of hps@selasky.org designates 88.99.82.50 as permitted sender) smtp.mailfrom=hps@selasky.org X-Spamd-Result: default: False [-5.48 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+a:mail.turbocat.net]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[selasky.org]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_ALL(0.00)[]; IP_SCORE(-3.18)[ip: (-9.36), ipnet: 88.99.0.0/16(-4.75), asn: 24940(-1.80), country: DE(-0.01)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:24940, ipnet:88.99.0.0/16, country:DE]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 09 Oct 2019 14:20:46 -0000 On 2019-10-09 15:56, Mark Johnston wrote: > On Wed, Oct 09, 2019 at 10:40:04AM +0200, Hans Petter Selasky wrote: >> On 2019-10-09 06:36, Yuri Pankov wrote: >>> Tried updating from r353072 to r353334 and getting the following panic >>> reproducibly on boot (starting dhclient?): >>> >>> panic: sleeping in an epoch section >>> cpuid = 5 >>> time = 1570591558 >>> KDB: stack backtrace: >>> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame >>> 0xfffffe00af780140 >>> vpanic() at vpanic+0x19d/frame 0xfffffe00af780190 >>> panic() at panic+0x43/frame 0xfffffe00af7801f0 >>> _sleep() at _sleep+0x463/frame 0xfffffe00af780290 >>> pause_sbt() at pause_sbt+0x10f/frame 0xfffffe00af7802d0 >>> e1000_write_phy_reg_mdic() at e1000_write_phy_reg_mdic+0xee/frame >>> 0xfffffe00af780310 >>> e1000_enable_phy_wakeup_reg_access_bm() at >>> e1000_enable_phy_wakeup_reg_access_bm+0x2b/frame 0xfffffe00af780330 >>> e1000_update_mc_addr_list_pch2lan() at >>> e1000_update_mc_addr_list_pch2lan+0x3a/frame 0xfffffe00af780370 >>> em_if_multi_set() at em_if_multi_set+0x1d4/frame 0xfffffe00af7803c0 >>> iflib_if_ioctl() at iflib_if_ioctl+0x100/frame 0xfffffe00af780430 >>> if_addmulti() at if_addmulti+0x2af/frame 0xfffffe00af7804d0 >>> in_joingroup_locked() at in_joingroup_locked+0x235/frame 0xfffffe00af780570 >>> in_joingroup() at in_joingroup+0x5c/frame 0xfffffe00af7805d0 >>> in_control() at in_control+0xadf/frame 0xfffffe00af780680 >>> ifioctl() at ifioctl+0x40f/frame 0xfffffe00af780750 >>> kern_ioctl() at kern_ioctl+0x295/frame 0xfffffe00af7807b0 >>> sys_ioctl() at sys_ioctl+0x15d/frame 0xfffffe00af780880 >>> amd64_syscall() at amd64_syscall+0x2b9/frame 0xfffffe00af7809b0 >>> fast_syscall_common() at fast_syscall_common+0x101/frame 0xfffffe00af7809b0 >>> --- syscall (54, FreeBSD ELF64, sys_ioctl), rip = 0x80048051a, rsp = >>> 0x7fffffffe3e8, rbp = 0x7fffffffe430 --- >> >> The SIOCADDMULTI if_ioctl() is not allowed to sleep, because it can be >> called from the fast-path, so this is a bug in e1000 driver. Does the >> attached patch workaround the issue? > > What fast path are you referring to? The locking protocol used by the > multicast code was changed specifically to allow for sleeps in driver > ioctl handlers. I recall a long time ago seeing that input packet processing may end up calling if_ioctl's . Things may have changed since then though. --HPS