The explanation from https://reviews.freebsd.org/D39637 by stevek:
The "use_xsave" variable is a global and that is only supposed to be
initialized early before scheduling gets started. However, with the way
the ifuncs for "fpusave" and "fpurestore" are implemented, the value
could be changed at runtime when scheduling is active if "use_xsave"
was set to 0 by the tunable. This leaves a window of opportunity where
"use_xsave" gets re-initialized to 1 and a context switch could occur
with a thread that was not set up to be able to use xsave functionality.
This can lead to an "privileged instruction fault".
The fix is to protect "use_xsave" from being initialized more than once.
Reported and reviewed by: stevek
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D39660
When vm_map_remove() is called from vm_swapout_map_deactivate_pages()
due to swapout, PKRU attributes for the removed range must be kept
intact. Provide a variant of pmap_remove(), pmap_map_delete(), to
allow pmap to distinguish between real removes of the UVA mappings
and any other internal removes, e.g. swapout.
For non-amd64, pmap_map_delete() is stubbed by define to pmap_remove().
Reported by: andrew
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D39556
Move the xenisrc structure which needs to be shared between the core Xen
interrupt code and architecture-dependent code into a separate header. A
similar situation exists for the NR_EVENT_CHANNELS constant.
Turn xi_intsrc into a type definition named xi_arch to reflect the new
purpose of being an architectural variable for the interrupt source.
This was originally implemented by Julien Grall, but has been heavily
modified. The core side was renamed "intr-internal.h" and is #include'd
by "arch-intr.h" instead of the other way around. This allows the
architecture to add function definitions which use struct xenisrc.
The original version only moved xi_intsrc into xen_arch_isrc_t. Moving
xi_vector was done by the submitter.
The submitter had also moved xi_activehi and xi_edgetrigger into
xen_arch_isrc_t. Those disappeared with the removal of PVHv1 support.
Copyright note. The current xenisrc structure was introduced at
76acc41fb7 by Justin T. Gibbs. Traces remain, but the strength of
Copyright claims from before 2013 seem pretty weak.
Reviewed by: royger
Submitted by: Elliott Mitchell <ehem+freebsd@m5p.com>, 2021-03-17 19:09:01
Original implementation: Julien Grall <julien@xen.org>, 2015-10-20 09:14:56
Differential Revision: https://reviews.freebsd.org/D30648
[royger]
- Adjust some line lengths
- Fix comment about NR_EVENT_CHANNELS after movement.
- Use #include instead of symlinks.
xen_intr_handle_upcall() has two interfaces. It needs to be called by
the x86 assembly code invoked by the APIC. Second, it needs to be called
as a driver_filter_t for the XenPCI code and for architectures besides
x86.
Unfortunately the driver_filter_t interface was implemented as a wrapper
around the x86-APIC interface. Now create a simple wrapper for the
x86-APIC code, which calls an architecture-independent
xen_intr_handle_upcall().
When called via intr_event_handle(), driver_filter_t functions expect
preemption to be disabled. This removes the need for
critical_enter()/critical_exit() when called this way.
The lapic_eoi() call is only needed on x86 in some cases when invoked
directly as an APIC vector handler.
Additionally driver_filter_t functions have no need to handle interrupt
counters. The intrcnt_add() calling function was reworked to match the
current situation. intrcnt_add() is now only called via one path.
The increment/decrement of curthread->td_intr_nesting_level had
previously been left out. Appears this was mostly harmless, but this
was noticed during implementation and has been added.
CONFIG_X86 is a leftover from use with Linux. While the barrier isn't
needed for FreeBSD on x86, it will be needed for FreeBSD on other
architectures.
Copyright note. xen_intr_intrcnt_add() was introduced at 76acc41fb7
by Justin T. Gibbs. xen_intrcnt_init() was introduced at fd036deac1
by John Baldwin.
sys/x86/xen/xen_arch_intr.c was originally created by Julien Grall in
2015 for the purpose of holding the x86 interrupt interface. Later it
was found xen_intr_handle_upcall() was better earlier, and the x86
interrupt interface better later. As such the filename and header list
belong to Julien Grall, but what those were created for is later.
Reviewed by: royger
Differential Revision: https://reviews.freebsd.org/D30006
This overlaps the purpose of __XEN_INTERFACE_VERSION__. Remove Xen 3.0.2
compatibility. __XEN_INTERFACE_VERSION__ has compatibility to Xen 3.2.8
enabled. As Xen 3.3 was released almost 15 years ago, it seems unlikely
anyone hasn't updated.
Reviewed by: royger
Add MODULE_PNP_INFO() to the driver to make it autoload if not linked
statically into the kernel. Remove the device from amd64/i386 GENERIC.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D35074
NETLINK is going to replace rtsock and a number of other ioctl/sysctl interfaces.
In-base utilies such as route(8), netstat(8) and soon ifconfig(8)
are being converted to use netlink sockets as a transport between
kernel and userland.
In the current configuration, it still possible have the kernel
without NETLINK (`nooptions NETLINK`) and use the aforementioned
utilies by buidling the world with `WITHOUT_NETLINK` src.conf knob.
However, this approach does not cover the cases when person unintentionally
builds a custom kernel without netlink and tries to use the standard userland.
This change adds `option NETLINK` to the default options for each
architecture, fixing the custom kernel issue.
For arm, this change uses `std.armv6` and `std.armv7` (netlink already in)
instead of DEFAULTS.
Reviewed By: imp
Differential Revision: https://reviews.freebsd.org/D39339
Now that the atomic macros are always genuinely atomic on x86, they can
be used for synchronization with Xen. A single core VM isn't too
unusual, but actual single core hardware is uncommon.
Replace an open-coding of evtchn_clear_port() with the inline.
Substantially inspired by work done by Julien Grall <julien@xen.org>,
2014-01-13 17:40:58.
Reviewed by: royger
MFC after: 1 week
This makes the detection of VMs common between platforms that
have SMBios.
Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D38800
Most options in kernel config files use "options<space><tab>OPTION".
This allows the option to be commented out without shifting columns.
A few options had two tabs, and some had spaces. Make them consistent.
there is nothing i386-specific about them and equivalent configs already
build for amd64.
Reviewed by: imp
Differential Revision: https://reviews.freebsd.org/D38700
To avoid confusing people, rename linux_timer.h to linux_time.h,
as linux_timer.c is the implementation of timer syscalls only,
while linux_time.c contains implementation of all stuff declared
in linux_time.h.
MFC after: 2 weeks
This obsolete system call is not supported by glibc. In ancient libc
versions (before glibc 2.0), uselib() was used to load the shared
libraries with names found in an array of names in the binary.
On Linux, since 3.15, this system call is available only when
the kernel is configured with the CONFIG_USELIB option.
It doesn't look like anyone needs this syscall for others Linuxulators,
so move it to the corresponding MD Linuxulator.
MFC after: 2 weeks
Since Linux emulation layer build options was removed there is no reason
to keep opt_compat.h.
Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D38548
MFC after: 2 weeks
Use native routines to fixup initial process stack. On Arm64 linux_elf_fixup() is
noop, as it do the stack fixup (room for argc) in the linux_copyout_strings().
MFC after: 1 week
This is a followup of 692e19cf51 (add netlink to GENERIC@amd64).
Netlink is a communication protocol defined in RFC 3549. It is async,
TLV-based protocol, providing 1-1 and 1-many communications between kernel
and userland. Netlink is currently used in Linux kernel to modify, read and
subscribe for nearly all networking states. Interface state, addresses, routes,
firewall, rules, fibs, etc, are controlled via Netlink.
Netlink support was added in D36002. It has got a number of improvements and
first customers since then:
* net/bird2 got netlink support, enabling route multipath in FreeBSD
* netlink-based devd notifications are being worked on ( D37574 ).
* linux(4) fully supports and depends on Netlink
Enabling Netlink in GENERIC targets two goals.
The first one is to provide stability for the third-party userland applications,
so they can rely on the fact that netlink always exists since 14.0 and potentially 13.2.
Loadable module makes life of the app delepers harder. For example, `net/bird2` can be
either build with netlink or rtsock support, but not both.
The second goal is to enable gradual conversion of the base userland tools
to use netlink(4) interfaces. Converting tools like netstat (D36529), route,
ifconfig one-by-one simplifies testing and addressing the feedback.
Othewise, switching all base to use netlink at once may be too big of a leap.
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D37783
Sync serial (e.g. T1/T1/G.703) interfaces are obsolete, this driver
includes obfuscated source, and has reported potential security issues.
Differential Revision: https://reviews.freebsd.org/D33467
The option is not even recognized and with that patched it does not
compile. Even if it did work, it would be prohibitively expensive to
use.
Interested parties can use pmcstat or dtrace instead.
Until bnxt is fixed on i386, remove it from its lint. Create a new
section of the config file for things that work everywhere, except i386.
Sponsored by: Netflix
Some architectures will pretty-print a system call trap in the
backtrace. Rather than printing the symbol, use the syscallname()
function to pull the string from the sv_syscallnames array corresponding
to the process. This simplifies the function somewhat.
Mostly, this will result in dropping the "sys" prefix, e.g. "sys_exit"
will now be printed simply as "exit".
Make two minor tweaks to the function signature: use a u_int for the
syscall number since this is a more correct type (see the 'code' member
of struct syscall_args), and make the thread pointer the first argument.
The latter is more natural and conventional.
Suggested by: jrtc27
Reviewed by: jrtc27, markj, jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37200
This allows the syscallname() function to give a usable result for Linux
ABIs.
Reported by: jrtc27
Reviewed by: jrtc27, markj, jhb
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D37199
Use it and several other vm_page_*_valid() functions in more places.
Suggested and reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D37024
Add a <sys/_pv_entry.h> intended for use in <machine/pmap.h> to
define struct pv_entry, pv_chunk, and related macros and inline
functions.
Note that powerpc does not yet use this as while the mmu_radix pmap
in powerpc uses the new scheme (albeit with fewer PV entries in a
chunk than normal due to an used pv_pmap field in struct pv_entry),
the Book-E pmaps for powerpc use the older style PV entries without
chunks (and thus require the pv_pmap field).
Suggested by: kib
Reviewed by: kib
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D36685
Only i386 and amd64 print the decoded syscall name in the backtrace.
This de-duplication facilitates further changes and adoption by other
platforms.
Reviewed by: jrtc27, markj, jhb
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D36565
This matches the return type of pmap_mapdev/bios.
Reviewed by: kib, markj
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D36548
We don't need the 56 bytes at the end of bootinfo, and never had. Don't
copy them from old boot loaders, and don't provide them with new boot
loaders.
Add comments about what versions of FreeBSD 'old' means in various
contexts. Add note that old disk loader (from 1.x/2.x) is doomed to
failure because it doesn't provide metadata that we now require to boot,
and has been since approximately FreeBSD 7.x. Retain all this
information to explain why we have 4 arguments that are always 0, even
though it's ancient history.
This saves 56 bytes in the boot loader.
Sponsored by: Netflix
Reviewed by: phk, rgrimes, kib
Differential Revision: https://reviews.freebsd.org/D36550
Mark the obsolete fields in bootinfo with _was_. Note that the fields
from bi_memdesc_version to the end of the structure never were used in a
release. They were added in April 2010 for i386 EFI booting. The boot
loader set these fields though 2019, but no kernel ever looked at them
and we never supported i386 EFI booting, and likely never will in this
form. They can likely be deleted entirely in the future, but locore.S
needs to change to do that (it also needs to change to drop support for
really old booting scenarios as well, which will eliminate bi_endcommon
too).
All the other fields haven't been used since the 4.x -> 5.x cutover of
the wdc driver to ata.
The bi_bios_dev field is used in the handoff between bootXX and the
loader. The loader uses it to determine what disk it was loaded off of
to detmerine the default root filesystem. It's not used by the i386
kernel anymore to determine anything.
Sponsored by: Netflix
Reviewed by: tsoome
Differential Revision: https://reviews.freebsd.org/D36544