Remove dead code from vm_map_unlink_entry made dead by r351476, and also
a no-longer-used enumerant.

Reviewed by: alc
Approved by: markj (mentor, implicit)
Tested by: pho (as part of a larger change

Remove dead code from vm_map_unlink_entry made dead by r351476, and also
a no-longer-used enumerant.

Reviewed by: alc
Approved by: markj (mentor, implicit)
Tested by: pho (as part of a larger change)
Differential Revision: https://reviews.freebsd.org/D21668

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Merge ^/head r351732 through r352104.

madvise(MADV_FREE): Quick fix to time rewind.

Don't free pages in a shadowing object. While this degrades MADV_FREE
to a no-op (and we could, instead, choose to fall back to
MADV_DONTNEED, at the c

madvise(MADV_FREE): Quick fix to time rewind.

Don't free pages in a shadowing object. While this degrades MADV_FREE
to a no-op (and we could, instead, choose to fall back to
MADV_DONTNEED, at the cost of changing pmap_madvise), this is
presently considered a temporary fix. We may prefer to risk a little
fragmentation of the map by creating a zero/OBJT_DEFAULT entry over
top of the existing object and, simultaneously, revert to the existing
marking any pages in the former shadowing object in the advised region
as reclaimable. At least one consumer of MADV_FREE (snmalloc) may use
mmap() to construct zeroed pages "eventually" here anyway, so the
fragmentation may be coming anyway.

Submitted by: Nathaniel Filardo <nwf20@cl.cam.ac.uk>
PR: 240061
Reviewed by: markj
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21517

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vm pager: writemapping accounting for OBJT_SWAP

Currently writemapping accounting is only done for vnode_pager which does
some accounting on the underlying vnode.

Extend this to allow accounting to

vm pager: writemapping accounting for OBJT_SWAP

Currently writemapping accounting is only done for vnode_pager which does
some accounting on the underlying vnode.

Extend this to allow accounting to be possible for any of the pager types.
New pageops are added to update/release writecount that need to be
implemented for any pager wishing to do said accounting, and we implement
these methods now for both vnode_pager (unchanged) and swap_pager.

The primary motivation for this is to allow other systems with OBJT_SWAP
objects to check if their objects have any write mappings and reject
operations with EBUSY if so. posixshm will be the first to do so in order to
reject adding write seals to the shmfd if any writable mappings exist.

Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21456

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Add procctl(PROC_STACKGAP_CTL)

It allows a process to request that stack gap was not applied to its
stacks, retroactively. Also it is possible to control the gaps in the
process after exec.

PR: 23

Add procctl(PROC_STACKGAP_CTL)

It allows a process to request that stack gap was not applied to its
stacks, retroactively. Also it is possible to control the gaps in the
process after exec.

PR: 239894
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D21352

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Merge ^/head r351317 through r351731.

vm_map_simplify_entry considers merging an entry with its two
neighbors, and is used in a way so that if entries a and b cannot be
merged, we consider them twice, first not-merging a with its success

vm_map_simplify_entry considers merging an entry with its two
neighbors, and is used in a way so that if entries a and b cannot be
merged, we consider them twice, first not-merging a with its successor
b, and then not-merging b with its predecessor a. This change replaces
vm_map_simplify_entry with vm_map_try_merge_entries, which compares
two adjacent entries only, and uses it to avoid duplicated
merge-checks.

Tested by: pho
Reviewed by: alc
Approved by: markj (implicit)
Differential Revision: https://reviews.freebsd.org/D20814

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Make stack grow use the same gap as stack create.

Store stack_guard_page * PAGE_SIZE into the gap->next_read field at
the time of the stack creation. This makes the used guard size
consistent betwe

Make stack grow use the same gap as stack create.

Store stack_guard_page * PAGE_SIZE into the gap->next_read field at
the time of the stack creation. This makes the used guard size
consistent between stack creation and stack grow time.

Suggested by: alc
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21384

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Change locking requirements for VOP_UNSET_TEXT().

Require the vnode to be locked for the VOP_UNSET_TEXT() call. This
will be used by the following bug fix for a tmpfs issue.

Tested by: sbruno, pho

Change locking requirements for VOP_UNSET_TEXT().

Require the vnode to be locked for the VOP_UNSET_TEXT() call. This
will be used by the following bug fix for a tmpfs issue.

Tested by: sbruno, pho (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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Fix stack grow for init.

During early stages of kern_exec(), including strings copyout,
p_textvp for init is NULL. This prevented stack grow from working for
init execution.

Without stack gap enab

Fix stack grow for init.

During early stages of kern_exec(), including strings copyout,
p_textvp for init is NULL. This prevented stack grow from working for
init execution.

Without stack gap enabled, initial stack segment size is enough for
strings passed by kernel to init. With the gap enabled, the used
address might fall out of the initial segment, which kills init.

Exclude initproc from the check for contexts which should not cause
stack grow in the target map.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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MFHead @r350386

Sponsored by: The FreeBSD Foundation

Define vm_map_entry_in_transition to handle an in-transition map
entry, combining code currently in vm_map_unwire and
vm_map_wire_locked into a single function, called by each of them for
entries in

Define vm_map_entry_in_transition to handle an in-transition map
entry, combining code currently in vm_map_unwire and
vm_map_wire_locked into a single function, called by each of them for
entries in transition.

Discussed with: kib, markj
Reviewed by: alc
Approved by: kib, markj (mentors, implicit)
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D20833

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Move an assignment, drop a label, and change gotos to break statements
in vm_map_unwire. The code generated on amd86 is unchanged.

Approved by: markj (mentor)
Differential Revision: https://reviews.

Move an assignment, drop a label, and change gotos to break statements
in vm_map_unwire. The code generated on amd86 is unchanged.

Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D20850

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Replace a 'goto' with an 'else' in vm_map_wire_locked.

Reviewed by: alc
Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D20855

Change boolean_t variables in vm_map_unwire and vm_map_wire_locked to
bool. Drop result variable. Add holes_ok bool to replace repeated
masking of flags parameter.

Approved by: markj (mentor)
Differ

Change boolean_t variables in vm_map_unwire and vm_map_wire_locked to
bool. Drop result variable. Add holes_ok bool to replace repeated
masking of flags parameter.

Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D20846

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Drop a temp variable from vm_map_insert, with no effect on the
resulting amd64 machine code.

Reviewed by: alc
Approved by: kib, markj (mentors, implicit)
Differential Revision: https://reviews.freeb

Drop a temp variable from vm_map_insert, with no effect on the
resulting amd64 machine code.

Reviewed by: alc
Approved by: kib, markj (mentors, implicit)
Differential Revision: https://reviews.freebsd.org/D20849

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Eliminate a goto and a label in vm_map_wire_locked by inserting an 'else'.

Reviewed by: alc
Approved by: kib, markj (mentors, implicit)
Differential Revision: https://reviews.freebsd.org/D20845

Remove a call to vm_map_simplify_entry from _vm_map_clip_start.
Recent changes to vm_map_protect have made it unnecessary.

Reviewed by: alc
Approved by: kib (mentor)
Tested by: pho
Differential Revi

Remove a call to vm_map_simplify_entry from _vm_map_clip_start.
Recent changes to vm_map_protect have made it unnecessary.

Reviewed by: alc
Approved by: kib (mentor)
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D20633

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If vm_map_protect fails with KERN_RESOURCE_SHORTAGE, be sure to
simplify modified entries before returning.

Reviewed by: alc, markj (earlier version), kib (earlier version)
Approved by: kib, markj (

If vm_map_protect fails with KERN_RESOURCE_SHORTAGE, be sure to
simplify modified entries before returning.

Reviewed by: alc, markj (earlier version), kib (earlier version)
Approved by: kib, markj (mentors, implicit)
Differential Revision: https://reviews.freebsd.org/D20753

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MFHead @349476

Sponsored by: The FreeBSD Foundation

Revert r349393, which leads to an assertion failure on bootup, in vm_map_stack_locked.

Reported by: ler@lerctr.org
Approved by: kib, markj (mentors, implicit)

Eliminate some uses of the prev and next fields of vm_map_entry_t.

Since the only caller to vm_map_splay is vm_map_lookup_entry, move the
implementation of vm_map_splay into vm_map_lookup_helper, ca

Eliminate some uses of the prev and next fields of vm_map_entry_t.

Since the only caller to vm_map_splay is vm_map_lookup_entry, move the
implementation of vm_map_splay into vm_map_lookup_helper, called by
vm_map_lookup_entry.

vm_map_lookup_entry returns the greatest entry less than or equal to a
given address, but in many cases the caller wants the least entry
greater than or equal to the address and uses the next pointer to get
to it. Provide an alternative interface to lookup,
vm_map_lookup_entry_ge, to provide the latter behavior, and let
callers use one or the other rather than having them use the next
pointer after a lookup miss to get what they really want.

In vm_map_growstack, the caller wants an entry that includes a given
address, and either the preceding or next entry depending on the value
of eflags in the first entry. Incorporate that behavior into
vm_map_lookup_helper, the function that implements all of these
lookups.

Eliminate some temporary variables used with vm_map_lookup_entry, but
inessential.

Reviewed by: markj (earlier version)
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D20664

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vm_map_protect may return an INVALID_ARGUMENT or PROTECTION_FAILURE
error response after clipping the first map entry in the region to be
reserved. This creates a pair of matching entries that should

vm_map_protect may return an INVALID_ARGUMENT or PROTECTION_FAILURE
error response after clipping the first map entry in the region to be
reserved. This creates a pair of matching entries that should have
been "simplified" back into one, or never created. This change defers
the clipping of that entry until those two vm_map_protect failure
cases have been ruled out.

Reviewed by: alc
Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D20711

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MFHead @349234

Sponsored by: The FreeBSD Foundation

Critical comments were lost in r349203. This patch seeks to restore
the lost information in new comments.

Reported by: alc
Reviewed by: alc
Approved by: kib (mentor)
Differential Revision: https://r

Critical comments were lost in r349203. This patch seeks to restore
the lost information in new comments.

Reported by: alc
Reviewed by: alc
Approved by: kib (mentor)
Differential Revision: https://reviews.freebsd.org/D20632

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