vm: improve kstack_object pindex calculation to avoid pindex holes

This commit replaces the linear transformation of kernel virtual
addresses to kstack_object pindex values with a non-linear
scheme

vm: improve kstack_object pindex calculation to avoid pindex holes

This commit replaces the linear transformation of kernel virtual
addresses to kstack_object pindex values with a non-linear
scheme that circumvents physical memory fragmentation caused by
kernel stack guard pages. The new mapping scheme is used to
effectively "skip" guard pages and assign pindices for
non-guard pages in a contiguous fashion.

The new allocation scheme requires that all default-sized kstack KVAs
come from a separate, specially aligned region of the KVA space.
For this to work, this commited introduces a dedicated per-domain
kstack KVA arena used to allocate kernel stacks of default size.
The behaviour on 32-bit platforms remains unchanged due to a
significatly smaller KVA space.

Aside from fullfilling the requirements imposed by the new scheme, a
separate kstack KVA arena facilitates superpage promotion in the rest
of kernel and causes most kstacks to have guard pages at both ends.

Reviewed by: alc, kib, markj
Tested by: markj
Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D38852

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vm: Add kva_alloc_aligned

Add a function like kva_alloc that allows us to specify the alignment
of the virtual address space returned.

Reviewed by: alc, kib, markj
Sponsored by: Arm Ltd
Differentia

vm: Add kva_alloc_aligned

Add a function like kva_alloc that allows us to specify the alignment
of the virtual address space returned.

Reviewed by: alc, kib, markj
Sponsored by: Arm Ltd
Differential Revision: https://reviews.freebsd.org/D42788

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sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl s

sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

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sys: Remove $FreeBSD$: one-line .h pattern

Remove /^\s*\*+\s*\$FreeBSD\$.*$\n/

kmem_malloc/free: Use void * instead of vm_offset_t for kernel pointers.

Reviewed by: kib, markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D36549

vm/vm_extern.h, vm/vm_page.h: use sys/kassert.h

instead of fatty sys/systm.h.

Suggested by: jhb
Reviewed by: alc, imp, jhb (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

vm/vm_extern.h, vm/vm_page.h: use sys/kassert.h

instead of fatty sys/systm.h.

Suggested by: jhb
Reviewed by: alc, imp, jhb (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34089

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Make <vm/vm_extern.h> more self-contained.

Add a nested include of <sys/systm.h> for recently added assertions.
Without this, existing code (such as in drm-kmod) needs to be patched
to add the newly

Make <vm/vm_extern.h> more self-contained.

Add a nested include of <sys/systm.h> for recently added assertions.
Without this, existing code (such as in drm-kmod) needs to be patched
to add the newly required header.

While here, rewrite the assertions using KASSERT().

Reviewed by: dougm, alc, imp, kib
Differential Revision: https://reviews.freebsd.org/D34070

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vm_addr_ok: add power2 invariant check

With INVARIANTS defined, have vm_addr_align_ok and vm_addr_bound_ok
panic when passed an alignment/boundary parameter that is not a power
of two.

Reviewed by:

vm_addr_ok: add power2 invariant check

With INVARIANTS defined, have vm_addr_align_ok and vm_addr_bound_ok
panic when passed an alignment/boundary parameter that is not a power
of two.

Reviewed by: alc
Suggested by: kib, se
Differential Revision: https://reviews.freebsd.org/D33725

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vm_extern: use standard address checkers everywhere

Define simple functions for alignment and boundary checks and use them
everywhere instead of having slightly different implementations
scattered a

vm_extern: use standard address checkers everywhere

Define simple functions for alignment and boundary checks and use them
everywhere instead of having slightly different implementations
scattered about. Define them in vm_extern.h and use them where
possible where vm_extern.h is included.

Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D33685

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Add vnode_pager_purge_range(9) KPI

This KPI is created in addition to the existing vnode_pager_setsize(9)
KPI. The KPI is intended for file systems that are able to turn a range
of file into sparse

Add vnode_pager_purge_range(9) KPI

This KPI is created in addition to the existing vnode_pager_setsize(9)
KPI. The KPI is intended for file systems that are able to turn a range
of file into sparse range, also known as hole-punching.

Sponsored by: The FreeBSD Foundation
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D27194

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Remove the VM map zone.

Today, the zone is only used to allocate a trio of kernel maps: the
kernel map itself, and the exec and pipe submaps. Maps for user
processes are dynamically allocated but a

Remove the VM map zone.

Today, the zone is only used to allocate a trio of kernel maps: the
kernel map itself, and the exec and pipe submaps. Maps for user
processes are dynamically allocated but are embedded in the vmspace
structure, which is allocated from its own zone. Make the
aforementioned kernel maps statically allocated and get rid of the zone.

While here, remove a stale comment above vmspace_alloc() and change the
names of locks initialized in vm_map_init() to match vmspace_zinit().

Reported by: alc
Reviewed by: alc, kib
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26052

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Use a single VM object for kernel stacks.

Previously we allocated a separate VM object for each kernel stack.
However, fully constructed kernel stacks are cached by UMA, so there is
no harm in using

Use a single VM object for kernel stacks.

Previously we allocated a separate VM object for each kernel stack.
However, fully constructed kernel stacks are cached by UMA, so there is
no harm in using a single global object for all stacks. This reduces
memory consumption and makes it easier to define a memory allocation
policy for kernel stack pages, with the aim of reducing physical memory
fragmentation.

Add a global kstack_object, and use the stack KVA address to index into
the object like we do with kernel_object.

Reviewed by: kib
Tested by: pho
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D24473

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Improve MD page fault handlers.

Centralize calculation of signal and ucode delivered on unhandled page
fault in new function vm_fault_trap(). MD trap_pfault() now almost
always uses the signal numb

Improve MD page fault handlers.

Centralize calculation of signal and ucode delivered on unhandled page
fault in new function vm_fault_trap(). MD trap_pfault() now almost
always uses the signal numbers and error codes calculated in
consistent MI way.

This introduces the protection fault compatibility sysctls to all
non-x86 architectures which did not have that bug, but apparently they
were already much more wrong in selecting delivered signals on
protection violations.

Change the delivered signal for accesses to mapped area after the
backing object was truncated. According to POSIX description for
mmap(2):
The system shall always zero-fill any partial page at the end of an
object. Further, the system shall never write out any modified
portions of the last page of an object which are beyond its
end. References within the address range starting at pa and
continuing for len bytes to whole pages following the end of an
object shall result in delivery of a SIGBUS signal.

An implementation may generate SIGBUS signals when a reference
would cause an error in the mapped object, such as out-of-space
condition.
Adjust according to the description, keeping the existing
compatibility code for SIGSEGV/SIGBUS on protection failures.

For situations where kernel cannot handle page fault due to resource
limit enforcement, SIGBUS with a new error code BUS_OBJERR is
delivered. Also, provide a new error code SEGV_PKUERR for SIGSEGV on
amd64 due to protection key access violation.

vm_fault_hold() is renamed to vm_fault(). Fixed some nits in
trap_pfault()s like mis-interpreting Mach errors as errnos. Removed
unneeded truncations of the fault addresses reported by hardware.

PR: 211924
Reviewed by: alc
Discussed with: jilles, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21566

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Add malloc_domainset(9) and _domainset variants to other allocator KPIs.

Remove malloc_domain(9) and most other _domain KPIs added in r327900.
The new functions allow the caller to specify a general

Add malloc_domainset(9) and _domainset variants to other allocator KPIs.

Remove malloc_domain(9) and most other _domain KPIs added in r327900.
The new functions allow the caller to specify a general NUMA domain
selection policy, rather than specifically requesting an allocation from
a specific domain. The latter policy tends to interact poorly with
M_WAITOK, resulting in situations where a caller is blocked indefinitely
because the specified domain is depleted. Most existing consumers of
the _domain KPIs are converted to instead use a DOMAINSET_PREF() policy,
in which we fall back to other domains to satisfy the allocation
request.

This change also defines a set of DOMAINSET_FIXED() policies, which
only permit allocations from the specified domain.

Discussed with: gallatin, jeff
Reported and tested by: pho (previous version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17418

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Eliminate the arena parameter to kmem_free(). Implicitly this corrects an
error in the function hypercall_memfree(), where the wrong arena was being
passed to kmem_free().

Introduce a per-page flag

Eliminate the arena parameter to kmem_free(). Implicitly this corrects an
error in the function hypercall_memfree(), where the wrong arena was being
passed to kmem_free().

Introduce a per-page flag, VPO_KMEM_EXEC, to mark physical pages that are
mapped in kmem with execute permissions. Use this flag to determine which
arena the kmem virtual addresses are returned to.

Eliminate UMA_SLAB_KRWX. The introduction of VPO_KMEM_EXEC makes it
redundant.

Update the nearby comment for UMA_SLAB_KERNEL.

Reviewed by: kib, markj
Discussed with: jeff
Approved by: re (marius)
Differential Revision: https://reviews.freebsd.org/D16845

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Eliminate kmem_malloc()'s unused arena parameter. (The arena parameter
became unused in FreeBSD 12.x as a side-effect of the NUMA-related
changes.)

Reviewed by: kib, markj
Discussed with: jeff, re@

Eliminate kmem_malloc()'s unused arena parameter. (The arena parameter
became unused in FreeBSD 12.x as a side-effect of the NUMA-related
changes.)

Reviewed by: kib, markj
Discussed with: jeff, re@
Differential Revision: https://reviews.freebsd.org/D16825

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Eliminate kmem_alloc_contig()'s unused arena parameter.

Reviewed by: hselasky, kib, markj
Discussed with: jeff
Differential Revision: https://reviews.freebsd.org/D16799

Eliminate the unused arena parameter from kmem_alloc_attr().

Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D16793

Eliminate the arena parameter to kmem_malloc_domain(). It is redundant.
The domain and flags parameters suffice. In fact, the related functions
kmem_alloc_{attr,contig}_domain() don't have an arena

Eliminate the arena parameter to kmem_malloc_domain(). It is redundant.
The domain and flags parameters suffice. In fact, the related functions
kmem_alloc_{attr,contig}_domain() don't have an arena parameter.

Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D16713

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Have preload_delete_name() free pages backing preloaded data.

On i386 and amd64, add a vm_phys segment for physical memory used to
store the kernel binary and other preloaded data. This makes it
po

Have preload_delete_name() free pages backing preloaded data.

On i386 and amd64, add a vm_phys segment for physical memory used to
store the kernel binary and other preloaded data. This makes it
possible to free such memory back to the system once it is no longer
needed, e.g., when a preloaded kernel module is unloaded. Previously,
it would have remained unused.

Reviewed by: kib, royger
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D16330

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Make UMA and malloc(9) return non-executable memory in most cases.

Most kernel memory that is allocated after boot does not need to be
executable. There are a few exceptions. For example, kernel m

Make UMA and malloc(9) return non-executable memory in most cases.

Most kernel memory that is allocated after boot does not need to be
executable. There are a few exceptions. For example, kernel modules
do need executable memory, but they don't use UMA or malloc(9). The
BPF JIT compiler also needs executable memory and did use malloc(9)
until r317072.

(Note that a side effect of r316767 was that the "small allocation"
path in UMA on amd64 already returned non-executable memory. This
meant that some calls to malloc(9) or the UMA zone(9) allocator could
return executable memory, while others could return non-executable
memory. This change makes the behavior consistent.)

This change makes malloc(9) return non-executable memory unless the new
M_EXEC flag is specified. After this change, the UMA zone(9) allocator
will always return non-executable memory, and a KASSERT will catch
attempts to use the M_EXEC flag to allocate executable memory using
uma_zalloc() or its variants.

Allocations that do need executable memory have various choices. They
may use the M_EXEC flag to malloc(9), or they may use a different VM
interfact to obtain executable pages.

Now that malloc(9) again allows executable allocations, this change also
reverts most of r317072.

PR: 228927
Reviewed by: alc, kib, markj, jhb (previous version)
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D15691

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Use per-domain locks for vm page queue free. Move paging control from
global to per-domain state. Protect reservations with the free lock
from the domain that they belong to. Refactor to make vm d

Use per-domain locks for vm page queue free. Move paging control from
global to per-domain state. Protect reservations with the free lock
from the domain that they belong to. Refactor to make vm domains more
of a first class object.

Reviewed by: markj, kib, gallatin
Tested by: pho
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14000

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Implement NUMA policy for kmem_*(9). This maintains compatibility with
reservations by giving each memory domain its own KVA space in vmem that
is naturally aligned on superpage boundaries.

Reviewe

Implement NUMA policy for kmem_*(9). This maintains compatibility with
reservations by giving each memory domain its own KVA space in vmem that
is naturally aligned on superpage boundaries.

Reviewed by: alc, markj, kib (some objections)
Sponsored by: Netflix, Dell/EMC Isilon
Tested by; pho
Differential Revision: https://reviews.freebsd.org/D13289

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sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

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Move swapout code into vm/vm_swapout.c.

There is no NO_SWAPPING #ifdef left in the code.

Requested by: alc
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differenti

Move swapout code into vm/vm_swapout.c.

There is no NO_SWAPPING #ifdef left in the code.

Requested by: alc
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks
Differential revision: https://reviews.freebsd.org/D12663

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