linux: implement pkey_alloc, pkey_free and pkey_mprotect

Bridge the Linux memory protection key syscalls to FreeBSD's native
MPK support instead of returning ENOSYS. Modern Linux software
probes the

linux: implement pkey_alloc, pkey_free and pkey_mprotect

Bridge the Linux memory protection key syscalls to FreeBSD's native
MPK support instead of returning ENOSYS. Modern Linux software
probes these at startup: Chromium-based browsers (found via
www/linux-brave) use protection keys for V8's heap and JIT
sandboxing, and glibc >= 2.27 exposes the full API.

pkey_alloc() allocates from a per-process bitmap kept in the process
emuldata (key 0 implicitly allocated, matching Linux's
mm_pkey_allocation_map; ENOSPC once keys 1..15 are exhausted or when
PKU is absent, as Linux returns on such hardware) and applies the
requested initial access rights to the calling thread's PKRU, located
in the XSAVE area via xsave_area_offset(). pkey_free() is
bookkeeping only: as on Linux, freeing neither untags pages nor
updates PKRU. pkey_mprotect() performs the protection change and
tags the range through amd64_pkru_update(), factored out of
sysarch(2)'s AMD64_SET_PKRU/AMD64_CLEAR_PKRU implementation so that
both share the same argument checking and map read lock
synchronization with a parallel pmap_vmspace_copy() on fork; tags die
with the mapping, matching Linux VMA semantics. A pkey of -1
degrades to plain mprotect.

The allocation map is inherited on fork and reset on exec. At exec
the Linux sysvecs initialize PKRU to 0x55555554, Linux's init_pkru
default (access disabled for keys 1..15), so memory tagged with a
not yet allocated key is inaccessible to threads that were never
granted rights -- the property V8's thread isolation relies on.
Setting PKRU at exec initializes the user FPU state slightly earlier
than the lazy first-use path; the state would be initialized moments
later in rtld/libc startup regardless. Protection key faults
already deliver SEGV_PKUERR through the existing siginfo
translation.

The common code carries no architecture ifdefs. Machine-dependent
state lives in struct linux_pemuldata_md, embedded in the process
emuldata in the manner of struct mdthread, and common code calls
per-arch lifecycle hooks (linux_pemuldata_init_md/_exec_md) and pkey
back ends after performing the parameter validation Linux applies
regardless of hardware support. On amd64 the implementation lives
in sys/amd64/linux/linux_pkru.c, compiled into linux_common and
serving both the 64-bit and 32-bit Linux ABIs. Elsewhere (arm64,
i386) linux_emul_md.c provides stubs returning what Linux returns on
hardware without protection keys (ENOSPC from pkey_alloc;
pkey_mprotect with a pkey of -1 acts as plain mprotect), so
applications take their normal no-PKU fallback instead of the ENOSYS
path.

PR: 297427
MFC after: 1 month
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D58782

show more ...

linux: Add required symbol to EXPORT_SYMS list

PR: 291270

linux: separate all ifnet(9) related code into linux_ifnet.c

Remove linux_use_real_ifname(). It is no longer used outside of the
file since 3ab3c9c29cf0. There is no functional change.

Reviewed b

linux: separate all ifnet(9) related code into linux_ifnet.c

Remove linux_use_real_ifname(). It is no longer used outside of the
file since 3ab3c9c29cf0. There is no functional change.

Reviewed by: melifaro, dchagin
Differential Revision: https://reviews.freebsd.org/D54076

show more ...

Remove residual blank line at start of Makefile

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

netlink: move NETLINK define to opt_global.h

Move the NETLINK define into opt_global.h so we can rely on it being
set correctly, without having to remember to include opt_netlink.h.
This ensures tha

netlink: move NETLINK define to opt_global.h

Move the NETLINK define into opt_global.h so we can rely on it being
set correctly, without having to remember to include opt_netlink.h.
This ensures that the NETLINK define is correctly set. If not we
may end up with unloadable modules, due to missing symbols (such as
nlmsg_get_group_writer).

PR: 274306
Reviewed by: imp, markj
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D42179

show more ...

sys: Remove $FreeBSD$: one-line sh pattern

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

linux(4): Make linux_emul_path private

There is no need to refer to linux_emul_path from outside anymore.

MFC after: 2 month

linux(4): Fix opt_netlink.h inclusion

Add opt_netlink.h to the linux_common module, on i386, where we don't
uses linux_common module, move opt_netlink.h inclusion under
i386 condition.

MFC after:

linux(4): Fix opt_netlink.h inclusion

Add opt_netlink.h to the linux_common module, on i386, where we don't
uses linux_common module, move opt_netlink.h inclusion under
i386 condition.

MFC after: 2 weeks

show more ...

linux_common: Fixup .PATH.

Since we have arm64, and awaiting ppc64 Linuxulator, do not include x86 specific
path to the module build for non x86 architectures.

MFC after: 1 week

modules: Add missing opt_*.h files for stand-alone compile

Standalone compile that we at least create these opt_*.h files.

Sponsored by: Netflix

linuxolator: add netlink support

Add the glue code to support netlink in Linuxolator.
linux_common(4) now depends on netlink(4).

All netlink protocol constants are consistent with the Linux version

linuxolator: add netlink support

Add the glue code to support netlink in Linuxolator.
linux_common(4) now depends on netlink(4).

All netlink protocol constants are consistent with the Linux version.
However, certain OS-specific constants such as AF_INET6, interface
flags or default routing table id, are different between FreeBSD and
Linux. Thus, it may be needed to rewrite some message parts or even
rewrite the whole message, adding or removing some TLVs. The core
netlink implementation code provides efficient rewriting callbacks
which Linuxolator now uses.

Reviewed by: dchagin
Differential Revision: https://reviews.freebsd.org/D36361
MFC after: 2 months

show more ...

linux(4); Move vdso_selector_x86.c to the linux_common module

MFC after: 2 weeks

linux(4): Deduplicate translate_traps()

As translate_traps() is common for x86 Linuxulators,
move it under x86/linux.

MFC after: 2 weeks

linux: add sysctl to pass untranslated interface names

Reviewed by: kib
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D33792

Fix some modules to export more used symbols

and remove non-present symbols that are now reported by kmod_syms.awk.

Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differ

Fix some modules to export more used symbols

and remove non-present symbols that are now reported by kmod_syms.awk.

Reviewed by: emaste
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D32878

show more ...

linux(4): Deduplicate unimpl/dummy syscall handlers

No functional change.

Reviewed by: emaste, trasz
Differential Revision: https://reviews.freebsd.org/D27099

Make linux_errtbl[] static.

MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D27004

MFHead @348740

Sponsored by: The FreeBSD Foundation

Add warning to the Linuxulator makefiles that building it outside of a
kernel does not make sence.

PR: 222861
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20179

Linuxulator depends on a fundamental kernel settings such as SMP. Many
of them listed in opt_global.h which is not generated while building
modules outside of a kernel and such modules never match re

Linuxulator depends on a fundamental kernel settings such as SMP. Many
of them listed in opt_global.h which is not generated while building
modules outside of a kernel and such modules never match real cofigured
kernel.

So, we should prevent our users from building obviously defective modules.

Therefore, remove the root cause of the building of modules outside of a
kernel - the possibility of building modules with DEBUG or KTR flags.
And remove all of DEBUG printfs as it is incomplete and in threaded
programms not informative, also a half of system call does not have DEBUG
printf. For debuging Linux programms we have dtrace, ktr and ktrace ability.

PR: 222861
Reviewed by: trasz
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20178

show more ...

Our bsd_to_linux_sockaddr() and linux_to_bsd_sockaddr() functions
alter the userspace sockaddr to convert the format between linux and BSD versions.
That's the minimum 3 of copyin/copyout operations

Our bsd_to_linux_sockaddr() and linux_to_bsd_sockaddr() functions
alter the userspace sockaddr to convert the format between linux and BSD versions.
That's the minimum 3 of copyin/copyout operations for one syscall.

Also some syscall uses linux_sa_put() and linux_getsockaddr() when load
sockaddr to userspace or from userspace accordingly.

To avoid this chaos, especially converting sockaddr in the userspace,
rewrite these 4 functions to convert sockaddr only in kernel and leave
only 2 of this functions.

Also in order to reduce duplication between MD parts of the Linuxulator put
struct sockaddr conversion functions that are MI out into linux_common module.

PR: 232920
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20157

show more ...

Move most of the contents of opt_compat.h to opt_global.h.

opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
close

Move most of the contents of opt_compat.h to opt_global.h.

opt_compat.h is mentioned in nearly 180 files. In-progress network
driver compabibility improvements may add over 100 more so this is
closer to "just about everywhere" than "only some files" per the
guidance in sys/conf/options.

Keep COMPAT_LINUX32 in opt_compat.h as it is confined to a subset of
sys/compat/linux/*.c. A fake _COMPAT_LINUX option ensure opt_compat.h
is created on all architectures.

Move COMPAT_LINUXKPI to opt_dontuse.h as it is only used to control the
set of compiled files.

Reviewed by: kib, cem, jhb, jtl
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D14941

show more ...

Share Linux errno table with libsysdecode

Requested by: jhb
Reviewed by: jhb
Sponsored by: Turing Robotic Industries Inc.

Share a single bsd-linux errno table across MD consumers

Three copies of the linuxulator linux_sysvec.c contained identical
BSD to Linux errno translation tables, and future work to support other
ar

Share a single bsd-linux errno table across MD consumers

Three copies of the linuxulator linux_sysvec.c contained identical
BSD to Linux errno translation tables, and future work to support other
architectures will also use the same table. Move the table to a common
file to be used by all. Make it 'const int' to place it in .rodata.

(Some existing Linux architectures use MD errno values, but x86 and Arm
share the generic set.)

This change should introduce no functional change; a followup will add
missing errno values.

MFC after: 3 weeks
Sponsored by: Turing Robotic Industries Inc.
Differential Revision: https://reviews.freebsd.org/D14665

show more ...

sys/modules: normalize .CURDIR-relative paths to SRCTOP

This simplifies make output/logic

Tested with: `cd sys/modules; make ALL_MODULES=` on amd64
MFC after: 1 month
Sponsored by: Dell EMC Isilon