From nobody Thu Jul 20 17:06:24 2023 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 4R6Jxc2Jsqz4dQL7; Thu, 20 Jul 2023 17:06:28 +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 4R6Jxb25K6z4dyS; Thu, 20 Jul 2023 17:06:27 +0000 (UTC) (envelope-from cy.schubert@cschubert.com) Authentication-Results: mx1.freebsd.org; dkim=none; spf=none (mx1.freebsd.org: domain of cy.schubert@cschubert.com has no SPF policy when checking 3.97.99.33) smtp.mailfrom=cy.schubert@cschubert.com; dmarc=none Received: from shw-obgw-4002a.ext.cloudfilter.net ([10.228.9.250]) by cmsmtp with ESMTP id MPsKqYs7c6NwhMX6gqRf19; Thu, 20 Jul 2023 17:06:26 +0000 Received: from spqr.komquats.com ([70.66.152.170]) by cmsmtp with ESMTPA id MX6fqGyBCyAOeMX6gq85aq; Thu, 20 Jul 2023 17:06:26 +0000 X-Authority-Analysis: v=2.4 cv=e5oV9Il/ c=1 sm=1 tr=0 ts=64b96992 a=y8EK/9tc/U6QY+pUhnbtgQ==:117 a=y8EK/9tc/U6QY+pUhnbtgQ==:17 a=kj9zAlcOel0A:10 a=ws7JD89P4LkA:10 a=VxmjJ2MpAAAA:8 a=6I5d2MoRAAAA:8 a=YxBL1-UpAAAA:8 a=EkcXrb_YAAAA:8 a=8ToWh4kbUNh_1jlTTwUA:9 a=CjuIK1q_8ugA:10 a=8k-k-Cn0ORkA:10 a=QHqjWXHE9tEA:10 a=UJ0tAi3fqDAA:10 a=7gXAzLPJhVmCkEl4_tsf:22 a=IjZwj45LgO3ly-622nXo:22 a=Ia-lj3WSrqcvXOmTRaiG:22 a=LK5xJRSDVpKd5WXXoEvA:22 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTP id C809E2CB; Thu, 20 Jul 2023 10:06:24 -0700 (PDT) Received: by slippy.cwsent.com (Postfix, from userid 1000) id B8F28DB; Thu, 20 Jul 2023 10:06:24 -0700 (PDT) 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: Konstantin Belousov , src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: Re: git: 21e45c30c35c - main - mmap(MAP_STACK): on stack grow, use original protection In-reply-to: <20230720164145.0CF1311F@slippy.cwsent.com> References: <202307201412.36KECDSU084918@gitrepo.freebsd.org> <20230720163231.B1D4277@slippy.cwsent.com> <20230720164145.0CF1311F@slippy.cwsent.com> Comments: In-reply-to Cy Schubert message dated "Thu, 20 Jul 2023 09:41:44 -0700." 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: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 20 Jul 2023 10:06:24 -0700 Message-Id: <20230720170624.B8F28DB@slippy.cwsent.com> X-CMAE-Envelope: MS4xfBzyki60zrg9DC8yLCVPdAvqggsm/4Nna7+sDZeZEXFgr+lba53MsAsOTFRuGEIN40ibsaR65CRjTU5eV3Kpk4VKPdmlxdnsXzgeNUV4c7N5iW0A9CQg Prr5JN5WKAFvE4X41IUolennSubfvfnOBBw6RCTqTbPq2gj72Sbnv0X3H4wZiN7w+Pdp5V14OkIZatKEpGdFsmvmUWDULITLDLNMkyQr/3M/AJe9gFkVTu58 iFW4sGJMncL1E3fQfs3vWE2kJr3sfIao9J4TcRd8iQhwTl1uTNWVRBd+A/OyCqr3UNSlRC2pp/IjPnCwITyEOjLFVzHTt4WFJ59TRGD8g4I= X-Spamd-Result: default: False [-1.67 / 15.00]; AUTH_NA(1.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.97)[-0.967]; MV_CASE(0.50)[]; RCVD_IN_DNSWL_LOW(-0.10)[3.97.99.33:from]; MIME_GOOD(-0.10)[text/plain]; MLMMJ_DEST(0.00)[dev-commits-src-main@freebsd.org,dev-commits-src-all@freebsd.org]; ASN(0.00)[asn:16509, ipnet:3.96.0.0/15, country:US]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; R_SPF_NA(0.00)[no SPF record]; TO_DN_SOME(0.00)[]; ARC_NA(0.00)[]; REPLYTO_EQ_FROM(0.00)[]; RCVD_COUNT_FIVE(0.00)[5]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCVD_TLS_LAST(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; DMARC_NA(0.00)[cschubert.com]; HAS_REPLYTO(0.00)[Cy.Schubert@cschubert.com] X-Rspamd-Queue-Id: 4R6Jxb25K6z4dyS X-Spamd-Bar: - In message <20230720164145.0CF1311F@slippy.cwsent.com>, Cy Schubert writes: > In message <20230720163231.B1D4277@slippy.cwsent.com>, Cy Schubert writes: > > In message <202307201412.36KECDSU084918@gitrepo.freebsd.org>, Konstantin > > Belous > > ov writes: > > > The branch main has been updated by kib: > > > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=21e45c30c35c9aa732073f725924 > ca > > f5 > > > 81c93460 > > > > > > commit 21e45c30c35c9aa732073f725924caf581c93460 > > > Author: Konstantin Belousov > > > AuthorDate: 2023-07-19 11:05:32 +0000 > > > Commit: Konstantin Belousov > > > CommitDate: 2023-07-20 14:11:42 +0000 > > > > > > mmap(MAP_STACK): on stack grow, use original protection > > > > > > If mprotect(2) changed protection in the bottom of the currently grow > n > > > stack region, currently the changed protection would be used for the > > > stack grow on next fault. This is arguably unexpected. > > > > > > Store the original protection for the entry at mmap(2) time in the > > > offset member of the gap vm_map_entry, and use it for protection of t > he > > > grown stack region. > > > > > > PR: 272585 > > > Reported by: John F. Carr > > > Reviewed by: alc, markj > > > Sponsored by: The FreeBSD Foundation > > > MFC after: 1 week > > > Differential revision: https://reviews.freebsd.org/D41089 > > > --- > > > sys/vm/vm_map.c | 24 ++++++++++++++++-------- > > > sys/vm/vm_map.h | 4 ++++ > > > 2 files changed, 20 insertions(+), 8 deletions(-) > > > > > > diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c > > > index a02107b5e64d..997a49111a59 100644 > > > --- a/sys/vm/vm_map.c > > > +++ b/sys/vm/vm_map.c > > > @@ -4493,7 +4493,7 @@ static int > > > vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssi > ze > > , > > > vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow) > > > { > > > - vm_map_entry_t new_entry, prev_entry; > > > + vm_map_entry_t gap_entry, new_entry, prev_entry; > > > vm_offset_t bot, gap_bot, gap_top, top; > > > vm_size_t init_ssize, sgp; > > > int orient, rv; > > > @@ -4575,11 +4575,14 @@ vm_map_stack_locked(vm_map_t map, vm_offset_t add > rb > > os > > > , vm_size_t max_ssize, > > > * read-ahead logic is never used for it. Re-use > > > * next_read of the gap entry to store > > > * stack_guard_page for vm_map_growstack(). > > > + * Similarly, since a gap cannot have a backing object, > > > + * store the original stack protections in the > > > + * object offset. > > > */ > > > - if (orient == MAP_STACK_GROWS_DOWN) > > > - vm_map_entry_pred(new_entry)->next_read = sgp; > > > - else > > > - vm_map_entry_succ(new_entry)->next_read = sgp; > > > + gap_entry = orient == MAP_STACK_GROWS_DOWN ? > > > + vm_map_entry_pred(new_entry) : vm_map_entry_succ(new_entry) > > > ; > > > + gap_entry->next_read = sgp; > > > + gap_entry->offset = prot; > > > } else { > > > (void)vm_map_delete(map, bot, top); > > > } > > > @@ -4599,6 +4602,7 @@ vm_map_growstack(vm_map_t map, vm_offset_t addr, vm > _m > > ap > > > _entry_t gap_entry) > > > struct ucred *cred; > > > vm_offset_t gap_end, gap_start, grow_start; > > > vm_size_t grow_amount, guard, max_grow; > > > + vm_prot_t prot; > > > rlim_t lmemlim, stacklim, vmemlim; > > > int rv, rv1 __diagused; > > > bool gap_deleted, grow_down, is_procstack; > > > @@ -4739,6 +4743,12 @@ retry: > > > } > > > > > > if (grow_down) { > > > + /* > > > + * The gap_entry "offset" field is overloaded. See > > > + * vm_map_stack_locked(). > > > + */ > > > + prot = gap_entry->offset; > > > + > > > grow_start = gap_entry->end - grow_amount; > > > if (gap_entry->start + grow_amount == gap_entry->end) { > > > gap_start = gap_entry->start; > > > @@ -4751,9 +4761,7 @@ retry: > > > gap_deleted = false; > > > } > > > rv = vm_map_insert(map, NULL, 0, grow_start, > > > - grow_start + grow_amount, > > > - stack_entry->protection, stack_entry->max_protection, > > > - MAP_STACK_GROWS_DOWN); > > > + grow_start + grow_amount, prot, prot, MAP_STACK_GROWS_DOWN) > > > ; > > > if (rv != KERN_SUCCESS) { > > > if (gap_deleted) { > > > rv1 = vm_map_insert(map, NULL, 0, gap_start, > > > diff --git a/sys/vm/vm_map.h b/sys/vm/vm_map.h > > > index fd8b606e8ddc..c4ed36ce57ba 100644 > > > --- a/sys/vm/vm_map.h > > > +++ b/sys/vm/vm_map.h > > > @@ -97,6 +97,10 @@ union vm_map_object { > > > * a VM object (or sharing map) and offset into that object, > > > * and user-exported inheritance and protection information. > > > * Also included is control information for virtual copy operation > s. > > > + * > > > + * For stack gap map entries (MAP_ENTRY_GUARD | MAP_ENTRY_GROWS_DO > WN > > > + * or UP), the next_read member is reused as the stack_guard_page > > > + * storage, and offset is the stack protection. > > > */ > > > struct vm_map_entry { > > > struct vm_map_entry *left; /* left child or previous entry */ > > > > > > > This commit has caused screen (sysutils/screen) to display the following > > error when opening a new screen window (ctrl-A c): > > > > pid 28473 comm screen-4.9.0 has trashed its stack, killing > > > > > > -- > > Cheers, > > Cy Schubert > > FreeBSD UNIX: Web: https://FreeBSD.org > > NTP: Web: https://nwtime.org > > > > e^(i*pi)+1=0 > > > > > > I'm also seeing artifacts in emails by nmh (mail/nmh) in my sent directory > and in the email cc'd to me. > > > -- > Cheers, > Cy Schubert > FreeBSD UNIX: Web: https://FreeBSD.org > NTP: Web: https://nwtime.org > > e^(i*pi)+1=0 > > Sometimes this occurs at screen start. Then it hangs. slippy$ screen pid 7275 comm screen-4.9.0 has trashed its stack, killing -- Cheers, Cy Schubert FreeBSD UNIX: Web: https://FreeBSD.org NTP: Web: https://nwtime.org e^(i*pi)+1=0