This email appears truncated. My original reply was,

Yes, this fixes the screen and pkg regressions.

Thanks for the patch.


-- 
Cheers,
Cy Schubert <cy.schub...@cschubert.com>
FreeBSD UNIX:  <c...@freebsd.org>   Web:  https://FreeBSD.org
NTP:           <c...@nwtime.org>    Web:  https://nwtime.org

                        e^(i*pi)+1=0


In message <20230720180230.18bdf...@slippy.cwsent.com>, Cy Schubert writes:
> In message <zllwk0sm57aoe...@kib.kiev.ua>, Konstantin Belousov writes:
> > On Thu, Jul 20, 2023 at 10:06:24AM -0700, Cy Schubert wrote:
> > > In message <20230720164145.0cf13...@slippy.cwsent.com>, Cy Schubert write
> s:
> > > > In message <20230720163231.b1d4...@slippy.cwsent.com>, Cy Schubert writ
> es
> > :
> > > > > In message <202307201412.36kecdsu084...@gitrepo.freebsd.org>, Konstan
> ti
> > n 
> > > > > Belous
> > > > > ov writes:
> > > > > > The branch main has been updated by kib:
> > > > > >
> > > > > > URL: https://cgit.FreeBSD.org/src/commit/?id=21e45c30c35c9aa732073f
> 72
> > 5924
> > > > ca
> > > > > f5
> > > > > > 81c93460
> > > > > >
> > > > > > commit 21e45c30c35c9aa732073f725924caf581c93460
> > > > > > Author:     Konstantin Belousov <k...@freebsd.org>
> > > > > > AuthorDate: 2023-07-19 11:05:32 +0000
> > > > > > Commit:     Konstantin Belousov <k...@freebsd.org>
> > > > > > 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 currentl
> y 
> > grow
> > > > n
> > > > > >     stack region, currently the changed protection would be used fo
> r 
> > the
> > > > > >     stack grow on next fault.  This is arguably unexpected.
> > > > > >     
> > > > > >     Store the original protection for the entry at mmap(2) time in 
> th
> > e
> > > > > >     offset member of the gap vm_map_entry, and use it for protectio
> n 
> > of t
> > > > he
> > > > > >     grown stack region.
> > > > > >     
> > > > > >     PR:     272585
> > > > > >     Reported by:    John F. Carr <j...@mit.edu>
> > > > > >     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 m
> ax
> > _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(ne
> > w_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 ad
> dr
> > , 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_protectio
> > n,
> > > > > > -               MAP_STACK_GROWS_DOWN);
> > > > > > +               grow_start + grow_amount, prot, prot, MAP_STACK_GRO
> > WS_DOWN)
> > > > > > ;
> > > > > >             if (rv != KERN_SUCCESS) {
> > > > > >                     if (gap_deleted) {
> > > > > >                             rv1 = vm_map_insert(map, NULL, 0, gap_s
> > tart,
> > > > > > 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 follow
> in
> > g 
> > > > > 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 <cy.schub...@cschubert.com>
> > > > > FreeBSD UNIX:  <c...@freebsd.org>   Web:  https://FreeBSD.org
> > > > > NTP:           <c...@nwtime.org>    Web:  https://nwtime.org
> > > > >
> > > > >                       e^(i*pi)+1=0
> > > > >
> > > > >
> > > >
> > > > I'm also seeing artifacts in emails by 
> > > > nmh
> or
> > y 
> > > > and in the email cc'd to me.
> > > >
> > > >
> > > > -- 
> > > > Cheers,
> > > > Cy Schubert <cy.schub...@cschubert.com>
> > > > FreeBSD UNIX:  <c...@freebsd.org>   Web:  https://FreeBSD.org
> > > > NTP:           <c...@nwtime.org>    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
> >
> > Can you check this?
> >
> > diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c
> > index 8c864c943f5d..4c5f1c08954d 100644
> > --- a/sys/vm/vm_map.c
> > +++ b/sys/vm/vm_map.c
> > @@ -4202,7 +4202,8 @@ vm_map_copy_entry(
> >                         src_entry->start);
> >             } else {
> >                     dst_entry->object.vm_object = NULL;
> > -                   dst_entry->offset = 0;
> > +                   if ((dst_entry->eflags &


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