From nobody Tue Nov 12 18:49:11 2024 X-Original-To: dev-commits-src-all@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 4XnwS934kXz5cwGv; Tue, 12 Nov 2024 18:49:13 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Received: from omta002.cacentral1.a.cloudfilter.net (omta002.cacentral1.a.cloudfilter.net [3.97.99.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "Client", Issuer "CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4XnwS921tzz3xP3; Tue, 12 Nov 2024 18:49:13 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Authentication-Results: mx1.freebsd.org; none Received: from shw-obgw-4003a.ext.cloudfilter.net ([10.228.9.183]) by cmsmtp with ESMTPS id Av9GtmuX1MArNAvwutucrg; Tue, 12 Nov 2024 18:49:12 +0000 Received: from spqr.komquats.com ([70.66.152.170]) by cmsmtp with ESMTPSA id AvwttAOcNE0IVAvwutjotu; Tue, 12 Nov 2024 18:49:12 +0000 X-Auth-User: cschuber X-Authority-Analysis: v=2.4 cv=cI9DsUeN c=1 sm=1 tr=0 ts=6733a328 a=y8EK/9tc/U6QY+pUhnbtgQ==:117 a=y8EK/9tc/U6QY+pUhnbtgQ==:17 a=kj9zAlcOel0A:10 a=VlfZXiiP6vEA:10 a=YxBL1-UpAAAA:8 a=6I5d2MoRAAAA:8 a=EkcXrb_YAAAA:8 a=VxmjJ2MpAAAA:8 a=qoy45kKaB9dZ2ii3csIA:9 a=CjuIK1q_8ugA:10 a=Ia-lj3WSrqcvXOmTRaiG:22 a=LK5xJRSDVpKd5WXXoEvA:22 a=7gXAzLPJhVmCkEl4_tsf:22 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTP id 2C8EFD0A; Tue, 12 Nov 2024 10:49:11 -0800 (PST) Received: by slippy.cwsent.com (Postfix, from userid 1000) id 28C0EFA; Tue, 12 Nov 2024 10:49:11 -0800 (PST) X-Mailer: exmh version 2.9.0 11/07/2018 with nmh-1.8+dev Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.cschubert.com/ To: jlduran@freebsd.org cc: Cy Schubert , John Baldwin , src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 1fa6daaafd74 - main - ipfilter: Avoid stopping with a lock held In-reply-to: References: <202411120347.4AC3lPOA015167@gitrepo.freebsd.org> <09923ad3-4065-4a31-b35f-74f84e09cff1@FreeBSD.org> <20241112155219.2E15A2DF@slippy.cwsent.com> <20241112160243.B372532F@slippy.cwsent.com> <20241112184111.2CCA53C2@slippy.cwsent.com> Comments: In-reply-to Jose Luis Duran message dated "Tue, 12 Nov 2024 15:45:44 -0300." List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 12 Nov 2024 10:49:11 -0800 Message-Id: <20241112184911.28C0EFA@slippy.cwsent.com> X-CMAE-Envelope: MS4xfDAccdziw4N+OTL9jUgwfLp63Lyd5nCGqcn+wqazqyNuJGoRIQ2JTQMNq/tT2uzwVA3FPZY9WQ+KNe5+XeE5NLgicTJxGkKrLRxAD8Ov0bUd3stAz2SZ XVPylKY+x4EvS2O8evAiNAvtt/rNAI5ZpNRUlMUSLr9ekh2JYkhynn13RIY0QFIFPoE8kEO6Qy+EDUYRLC/vM24ODPRnqGYe558BYoT5r8u8YCwrvzA9FGgP OdF7iFBQdXoOxsk9nWHbYYQP6zIWEZa4jxhjX0EvgEyCwXlGR7RePKOzDsgSBQOwwH9Tx3a3ymihbomdbeJUU+OyN+8Dx+XKfsyLtceCXK4QEy2ECbfSfluk W0TGMJde X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:16509, ipnet:3.96.0.0/15, country:US] X-Rspamd-Queue-Id: 4XnwS921tzz3xP3 X-Spamd-Bar: ---- In message , Jose Luis Duran writes: > On Tue, Nov 12, 2024 at 3:41=E2=80=AFPM Cy Schubert com> wrote: > > > > I'm building a test patch on my sandbox machine. The patches in my git re= > po > > will, > > > > a) remove another #if 0 from 2013, > > b) revert this commit, > > c) fix the "stopping with lock held" bug > > > > Testing on the sandbox is needed before I submit a review. > > > > You can revert this if you want, or I can push my three commits when my > > testing is complete. > > I'll revert the commit, I feel better with this approach, thank you! -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org e^(i*pi)+1=0 > > > > > > > -- > > Cheers, > > Cy Schubert > > FreeBSD UNIX: Web: https://FreeBSD.org > > NTP: Web: https://nwtime.org > > > > e^(i*pi)+1=3D0 > > > > > > In message ail.c > > om> > > , Jose Luis Duran writes: > > > What would be the recommended approach in this case? > > > Revert, and commit with the fixes, or just fix the problematic code. > > > > > > At any rate, I have created https://reviews.freebsd.org/D47530. Feel > > > free to commandeer it, as my testing is limited to what's currently in > > > the "Test Plan". I was not able to recreate the deadlock described > > > here, but it definitely makes sense. > > > > > > On Tue, Nov 12, 2024 at 1:02=3DE2=3D80=3DAFPM Cy Schubert cschubert.=3D > > > com> wrote: > > > > > > > > In message <20241112155219.2E15A2DF@slippy.cwsent.com>, Cy Schubert w= > rite=3D > > > s: > > > > > In message <09923ad3-4065-4a31-b35f-74f84e09cff1@FreeBSD.org>, John= > Bal=3D > > > dwin > > > > > wri > > > > > tes: > > > > > > On 11/11/24 19:47, Jose Luis Duran wrote: > > > > > > > The branch main has been updated by jlduran: > > > > > > > > > > > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=3D3D1fa6daaafd74c1= > a457dc=3D > > > fe26e0a5 > > > > > 94 > > > > > > 3b5441dc9d > > > > > > > > > > > > > > commit 1fa6daaafd74c1a457dcfe26e0a5943b5441dc9d > > > > > > > Author: Jose Luis Duran > > > > > > > AuthorDate: 2024-11-02 17:58:59 +0000 > > > > > > > Commit: Jose Luis Duran > > > > > > > CommitDate: 2024-11-12 03:46:15 +0000 > > > > > > > > > > > > > > ipfilter: Avoid stopping with a lock held > > > > > > > > > > > > > > Avoid calling _callout_stop_safe with a non-sleepable lock= > hel=3D > > > d when > > > > > > > detaching by initializing callout_init_rw() with CALLOUT_S= > HARE=3D > > > DLOCK. > > > > > > > > > > > > > > It avoids the following WITNESS warning when stopping the = > serv=3D > > > ice: > > > > > > > > > > > > > > # service ipfilter stop > > > > > > > calling _callout_stop_safe with the following non-slee= > pabl=3D > > > e lock > > > > > s > > > > > > held: > > > > > > > shared rw ipf filter load/unload mutex (ipf filter loa= > d/un=3D > > > load m > > > > > ut > > > > > > ex) r =3D3D 0 (0xffff0000417c7530) locked @ /usr/src/sys/netpfil/= > ipfilt=3D > > > er/netin > > > > > et > > > > > > /fil.c:7926 > > > > > > > stack backtrace: > > > > > > > #0 0xffff00000052d394 at witness_debugger+0x60 > > > > > > > #1 0xffff00000052e620 at witness_warn+0x404 > > > > > > > #2 0xffff0000004d4ffc at _callout_stop_safe+0x8c > > > > > > > #3 0xffff0000f7236674 at ipfdetach+0x3c > > > > > > > #4 0xffff0000f723fa4c at ipf_ipf_ioctl+0x788 > > > > > > > #5 0xffff0000f72367e0 at ipfioctl+0x144 > > > > > > > #6 0xffff00000034abd8 at devfs_ioctl+0x100 > > > > > > > #7 0xffff0000005c66a0 at vn_ioctl+0xbc > > > > > > > #8 0xffff00000034b2cc at devfs_ioctl_f+0x24 > > > > > > > #9 0xffff0000005331ec at kern_ioctl+0x2e0 > > > > > > > #10 0xffff000000532eb4 at sys_ioctl+0x140 > > > > > > > #11 0xffff000000880480 at do_el0_sync+0x604 > > > > > > > #12 0xffff0000008579ac at handle_el0_sync+0x4c > > > > > > > > > > > > > > PR: 282478 > > > > > > > Suggested by: markj > > > > > > > Reviewed by: cy > > > > > > > Approved by: emaste (mentor) > > > > > > > MFC after: 1 week > > > > > > > --- > > > > > > > sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c | 4 ++-- > > > > > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > > > > > > > > > diff --git a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c b/sy= > s/ne=3D > > > tpfil/ > > > > > ip > > > > > > filter/netinet/ip_fil_freebsd.c > > > > > > > index bcde0d2c7323..b3dea40c3d8c 100644 > > > > > > > --- a/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c > > > > > > > +++ b/sys/netpfil/ipfilter/netinet/ip_fil_freebsd.c > > > > > > > @@ -181,7 +181,7 @@ ipf_timer_func(void *arg) > > > > > > > #if 0 > > > > > > > softc->ipf_slow_ch =3D3D timeout(ipf_timer_fu= > nc, so=3D > > > ftc, hz/ > > > > > 2); > > > > > > > #endif > > > > > > > - callout_init(&softc->ipf_slow_ch, 1); > > > > > > > + callout_init_rw(&softc->ipf_slow_ch, &softc->ipf_glob= > al.i=3D > > > pf_lk, > > > > > > CALLOUT_SHAREDLOCK); > > > > > > > callout_reset(&softc->ipf_slow_ch, > > > > > > > (hz / IPF_HZ_DIVIDE) * IPF_HZ_MULT, > > > > > > > ipf_timer_func, softc); > > > > > > > @@ -221,7 +221,7 @@ ipfattach(ipf_main_softc_t *softc) > > > > > > > softc->ipf_slow_ch =3D3D timeout(ipf_timer_func, soft= > c, > > > > > > > (hz / IPF_HZ_DIVIDE) * I= > PF_H=3D > > > Z_MULT > > > > > ); > > > > > > > #endif > > > > > > > - callout_init(&softc->ipf_slow_ch, 1); > > > > > > > + callout_init_rw(&softc->ipf_slow_ch, &softc->ipf_global.ipf_l= > k, C=3D > > > ALLOUT > > > > > > _SHAREDLOCK); > > > > > > > callout_reset(&softc->ipf_slow_ch, (hz / IPF_HZ_DIVID= > E) *=3D > > > IPF_H > > > > > Z_MULT, > > > > > > > ipf_timer_func, softc); > > > > > > > return (0); > > > > > > > > > > > > But this means the callout is now called with the lock held, and = > I do=3D > > > n't se > > > > > e > > > > > > any changes > > > > > > to ipf_timer_func. Hmm, so you now recurse on the lock? You nee= > d to=3D > > > take > > > > > ou > > > > > > t the locking > > > > > > in ipf_timer_func I think as it is now spurious. You can also ax= > e th=3D > > > e #if > > > > > 0' > > > > > > d code around > > > > > > timeout() while you are at it. > > > > > > > > > > Reviewing all the #if 0's in ipfilter, discovering why they are the= > re, =3D > > > and > > > > > either removing them or implementing what Darren had initially inte= > nded=3D > > > is > > > > > in my queue. The upstream git log isn't helpful for reasons I preac= > h ab=3D > > > out > > > > > proper commit logs. > > > > > > > > > > Given that this one is in ip_fil_freebsd.c (specific to FreeBSD), i= > t ca=3D > > > n be > > > > > removed. Others require more grokking. > > > > > > > > It can go. It was #if 0'd by ea3022cbbd3f5, IIRC in discussion with y= > ou a=3D > > > t > > > > the time (2013). > > > > > > > > ea3022cbbd3f5 converted timeout(9) to callout(9). This code remained = > as a=3D > > > n > > > > artifact of the conversion. It was sent by you to me following the ip= > filt=3D > > > er > > > > upgrade from 4.1.28 to 5.1.2 earlier that year. > > > > > > > > > > > > -- > > > > Cheers, > > > > Cy Schubert > > > > FreeBSD UNIX: Web: https://FreeBSD.org > > > > NTP: Web: https://nwtime.org > > > > > > > > e^(i*pi)+1=3D3D0 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > --=3D20 > > > Jose Luis Duran > > > > > > > --=20 > Jose Luis Duran