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/

Move kstack_contains() and GET_STACK_USAGE() to MD machine/stack.h

Reviewed by: jhb
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38320

amd64: -m32 support for machine/proc.h

Install the i386 proc.h under /usr/include/i386 on amd64 and include
when targeting i386.

Reviewed by: jhb, imp

Make struct syscall_args machine independent

After a round of cleanups in late 2020, all definitions are
functionally identical.

This removes a rotted __aligned(8) on arm. It was added in
b7112ead3

Make struct syscall_args machine independent

After a round of cleanups in late 2020, all definitions are
functionally identical.

This removes a rotted __aligned(8) on arm. It was added in
b7112ead32bc50ef9744099bdbb1cfbd6e906b2a and was intended to align the
args member so that 64-bit types (off_t, etc) could be safely read on
armeb compiled with clang. With the removal of armev, this is no
longer needed (armv7 requires that 32-bit aligned reads of 64-bit
values be supported and we enable such support on armv6). As further
evidence this is unnecessary, cleanups to struct syscall_args have
resulted in args being 32-bit aligned on 32-bit systems. The sole
effect is to bloat the struct by 4 bytes.

Reviewed by: kib, jhb, imp
Differential Revision: https://reviews.freebsd.org/D33308

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Revert "linux32: add a hack to avoid redefining the type of the savefpu tag"

This reverts commit 0f6829488ef32142b9ea1c0806fb5ecfe0872c02.
Also it changes the type of md_usr_fpu_save struct mdthread

Revert "linux32: add a hack to avoid redefining the type of the savefpu tag"

This reverts commit 0f6829488ef32142b9ea1c0806fb5ecfe0872c02.
Also it changes the type of md_usr_fpu_save struct mdthread member
to void *, which is what uncovered this trouble. Now the save area
is untyped, but since it is hidden behind accessors, it is not too
significant. Since apparently there are consumers affected outside
the tree, this hack is better than one from the reverted revision.

PR: 258678
Reported by: cy
Reviewed by: cy, kevans, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32060

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amd64: eliminate td_md.md_fpu_scratch

For signal send, copyout from the user FPU save area directly.

For sigreturn, we are in sleepable context and can do temporal
allocation of the transient save

amd64: eliminate td_md.md_fpu_scratch

For signal send, copyout from the user FPU save area directly.

For sigreturn, we are in sleepable context and can do temporal
allocation of the transient save area. We cannot copying from userspace
directly to user save area because XSAVE state needs to be validated,
also partial copyins can corrupt it.

Requested by: jhb
Reviewed by: jhb, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31954

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amd64: stop using top of the thread' kernel stack for FPU user save area

Instead do one more allocation at the thread creation time. This frees
a lot of space on the stack.

Also do not use alloca(

amd64: stop using top of the thread' kernel stack for FPU user save area

Instead do one more allocation at the thread creation time. This frees
a lot of space on the stack.

Also do not use alloca() for temporal storage in signal delivery sendsig()
function and signal return syscall sys_sigreturn(). This saves equal
amount of space, again by the cost of one more allocation at the thread
creation time.

A useful experiment now would be to reduce KSTACK_PAGES.

Reviewed by: jhb, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D31954

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Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossi

Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.

This reapplies 3a522ba1bc852c3d4660a4fa32e4a94999d09a47 with a fix for
the static assertion failure on i386.

Approved by: markj (mentor)

Reviewed by: kib, bcr (manpages)

Differential Revision: https://reviews.freebsd.org/D29185

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Revert "Pass the syscall number to capsicum permission-denied signals"

This broke the i386 build.

This reverts commit 3a522ba1bc852c3d4660a4fa32e4a94999d09a47.

Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossi

Pass the syscall number to capsicum permission-denied signals

The syscall number is stored in the same register as the syscall return
on amd64 (and possibly other architectures) and so it is impossible to
recover in the signal handler after the call has returned. This small
tweak delivers it in the `si_value` field of the signal, which is
sufficient to catch capability violations and emulate them with a call
to a more-privileged process in the signal handler.

Approved by: markj (mentor)

Reviewed by: kib, bcr (manpages)

Differential Revision: https://reviews.freebsd.org/D29185

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Get rid of sa->narg. It serves no purpose; use sa->callp->sy_narg instead.

Reviewed by: kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26458

MFH

Sponsored by: Rubicon Communications, LLC (netgate.com)

amd64 pmap: LA57 AKA 5-level paging

Since LA57 was moved to the main SDM document with revision 072, it
seems that we should have a support for it, and silicons are coming.

This patch makes pmap su

amd64 pmap: LA57 AKA 5-level paging

Since LA57 was moved to the main SDM document with revision 072, it
seems that we should have a support for it, and silicons are coming.

This patch makes pmap support both LA48 and LA57 hardware. The
selection of page table level is done at startup, kernel always
receives control from loader with 4-level paging. It is not clear how
UEFI spec would adapt LA57, for instance it could hand out control in
LA57 mode sometimes.

To switch from LA48 to LA57 requires turning off long mode, requesting
LA57 in CR4, then re-entering long mode. This is somewhat delicate
and done in pmap_bootstrap_la57(). AP startup in LA57 mode is much
easier, we only need to toggle a bit in CR4 and load right value in CR3.

I decided to not change kernel map for now. Single PML5 entry is
created that points to the existing kernel_pml4 (KML4Phys) page, and a
pml5 entry to create our recursive mapping for vtopte()/vtopde().
This decision is motivated by the fact that we cannot overcommit for
KVA, so large space there is unusable until machines start providing
wider physical memory addressing. Another reason is that I do not
want to break our fragile autotuning, so the KVA expansion is not
included into this first step. Nice side effect is that minidumps are
compatible.

On the other hand, (very) large address space is definitely
immediately useful for some userspace applications.

For userspace, numbering of pte entries (or page table pages) is
always done for 5-level structures even if we operate in 4-level mode.
The pmap_is_la57() function is added to report the mode of the
specified pmap, this is done not to allow simultaneous 4-/5-levels
(which is not allowed by hw), but to accomodate for EPT which has
separate level control and in principle might not allow 5-leve EPT
despite x86 paging supports it. Anyway, it does not seems critical to
have 5-level EPT support now.

Tested by: pho (LA48 hardware)
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D25273

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amd64: move pcb out of kstack to struct thread.

This saves 320 bytes of the precious stack space.

The only negative aspect of the change I can think of is that the
struct thread increased by 320 by

amd64: move pcb out of kstack to struct thread.

This saves 320 bytes of the precious stack space.

The only negative aspect of the change I can think of is that the
struct thread increased by 320 bytes obviously, and that 320 bytes are
not swapped out anymore. I believe the freed stack space is much more
important than that. Also, current struct thread size is 1392 bytes
on amd64, so UMA will allocate two thread structures per (4KB) slab,
which leaves a space for pcb without increasing zone memory use.

Reviewed by: alc, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D22138

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MFHead @348740

Sponsored by: The FreeBSD Foundation

amd64 pmap: rework delayed invalidation, removing global mutex.

For machines having cmpxcgh16b instruction, i.e. everything but very
early Athlons, provide lockless implementation of delayed
invalid

amd64 pmap: rework delayed invalidation, removing global mutex.

For machines having cmpxcgh16b instruction, i.e. everything but very
early Athlons, provide lockless implementation of delayed
invalidation.

The implementation maintains lock-less single-linked list with the
trick from the T.L. Harris article about volatile mark of the elements
being removed. Double-CAS is used to atomically update both link and
generation. New thread starting DI appends itself to the end of the
queue, setting the generation to the generation of the last element
+1. On DI finish, thread donates its generation to the previous
element. The generation of the fake head of the list is the last
passed DI generation. Basically, the implementation is a queued
spinlock but without spinlock.

Many thanks both to Peter Holm and Mark Johnson for keeping with me
while I produced intermediate versions of the patch.

Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
MFC note: td_md.md_invl_gen should go to the end of struct thread
Differential revision: https://reviews.freebsd.org/D19630

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MFHead@r345275

amd64: Add md process flags and first P_MD_PTI flag.

PTI mode for the process pmap on exec is activated iff P_MD_PTI is set.

On exec, the existing vmspace can be reused only if pti mode of the
pmap

amd64: Add md process flags and first P_MD_PTI flag.

PTI mode for the process pmap on exec is activated iff P_MD_PTI is set.

On exec, the existing vmspace can be reused only if pti mode of the
pmap matches the P_MD_PTI flag of the process. Add MD
cpu_exec_vmspace_reuse() callback for exec_new_vmspace() which can
vetoed reuse of the existing vmspace.

MFC note: md_flags change struct proc KBI.

Reviewed by: jhb, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D19514

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Merge ^/head r339015 through r339669.

amd64: partially depessimize cpu_fetch_syscall_args and cpu_set_syscall_retval

Vast majority of syscalls take 6 or less arguments. Move handling of other
cases to a fallback function. Similarly, spe

amd64: partially depessimize cpu_fetch_syscall_args and cpu_set_syscall_retval

Vast majority of syscalls take 6 or less arguments. Move handling of other
cases to a fallback function. Similarly, special casing for _syscall
and __syscall
magic syscalls is moved away.

Return is almost always 0. The change replaces 3 branches with 1 in the common
case. Also the 'frame' variable convinces clang not to reload it on each access.

Reviewed by: kib
Approved by: re (gjb)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17542

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Merge ^/head r338392 through r338594.

Add amd64 mdthread fields needed for the upcoming EFI RT exception
handling.

This is split into a separate commit from the main change to make it
easier to handle possible revert after upcoming KBI

Add amd64 mdthread fields needed for the upcoming EFI RT exception
handling.

This is split into a separate commit from the main change to make it
easier to handle possible revert after upcoming KBI freeze.

Reviewed by: kevans
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (rgrimes)
Differential revision: https://reviews.freebsd.org/D16972

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Amd64 user_ldt_deref() is not used outside sys_machdep.c. Mark it as
static.

Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Merge ^/head r325999 through r326131.