CloudABI executables already provide support for passing in vDSOs. This
functionality is used by the emulator for OS X to inject system call
handlers. On FreeBSD, we could use it to optimize calls to
gettimeofday(), etc.
Though I don't have any plans to optimize any system calls right now,
let's go ahead and already pass in a vDSO. This will allow us to
simplify the executables, as the traditional "syscall" shims can be
removed entirely. It also means that we gain more flexibility with
regards to adding and removing system calls.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D7438
exception is caught in kernel mode. There are third-party modules
which trigger the issue, and since the problem causes usermode state
corruption at least, panic in production kernels as well.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
302181:
Add a tunable to disable migration of MSI-X interrupts.
The new 'machdep.disable_msix_migration' tunable can be set to 1 to
disable migration of MSI-X interrupts.
Xen versions prior to 4.6.0 do not properly handle updates to MSI-X
table entries after the initial write. In particular, the operation
to unmask a table entry after updating it during migration is not
propagated to the "real" table for passthrough devices causing the
interrupt to remain masked. At least some systems in EC2 are
affected by this bug when using SRIOV. The tunable can be set in
loader.conf as a workaround.
302635:
xen: automatically disable MSI-X interrupt migration
If the hypervisor version is smaller than 4.6.0. Xen commits 74fd00 and
70a3cb are required on the hypervisor side for this to be fixed, and those
are only included in 4.6.0, so stay on the safe side and disable MSI-X
interrupt migration on anything older than 4.6.0.
It should not cause major performance degradation unless a lot of MSI-X
interrupts are allocated.
difference between files.
For pc98, put x86/mp_x86.c into the same place as used by i386 file list.
Fix typo in comment.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
The current implementation uses non-temporal writes. This turns out to
be detrimental to performance if the page is used shortly after, which
is the typical case with page faults.
Switch to rep stos.
Reviewed by: kib
MFC after: 1 week
Any sensible workflow will include a revision control system from which
to restore the old files if required. In normal usage, developers just
have to clean up the mess.
Reviewed by: jhb
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D7353
Fix a copy/paste bug introduced during X86_64 Linuxulator work.
FreeBSD support NX bit on X86_64 processors out of the box, for i386 emulation
use READ_IMPLIES_EXEC flag, introduced in r302515.
While here move common part of mmap() and mprotect() code to the files in compat/linux
to reduce code dupcliation between Linuxulator's.
MFC r302518, r302626:
Add linux_mmap.c to the appropriate conf/files.
Implement Linux personality() system call mainly due to READ_IMPLIES_EXEC flag.
In Linux if this flag is set, PROT_READ implies PROT_EXEC for mmap().
Linux/i386 set this flag automatically if the binary requires executable stack.
READ_IMPLIES_EXEC flag will be used in the next Linux mmap() commit.
Set vm_guest to a new enum value (VM_GUEST_KVM) when kvm is detected and use
vm_guest in conditionals testing for KVM.
Also, fix a conditional checking if we're running in a VM which caught only
the generic VM case, but not more specific VMs (KVM, VMWare, etc.). (Spotted
by: vangyzen).
Differential revision: https://reviews.freebsd.org/D7172
Sponsored by: Dell Inc.
Approved by: kib (mentor), vangyzen (mentor)
Reviewed by: alc
MFC after: 4 weeks
If the hypervisor version is smaller than 4.6.0. Xen commits 74fd00 and
70a3cb are required on the hypervisor side for this to be fixed, and those
are only included in 4.6.0, so stay on the safe side and disable MSI-X
interrupt migration on anything older than 4.6.0.
It should not cause major performance degradation unless a lot of MSI-X
interrupts are allocated.
Sponsored by: Citrix Systems R&D
MFC after: 3 days
Reviewed by: jhb
Differential revision: https://reviews.freebsd.org/D7148
FreeBSD support NX bit on X86_64 processors out of the box, for i386 emulation
use READ_IMPLIES_EXEC flag, introduced in r302515.
While here move common part of mmap() and mprotect() code to the files in compat/linux
to reduce code dupcliation between Linuxulator's.
Reported by: Johannes Jost Meixner, Shawn Webb
MFC after: 1 week
XMFC with: r302515, r302516
In Linux if this flag is set, PROT_READ implies PROT_EXEC for mmap().
Linux/i386 set this flag automatically if the binary requires executable stack.
READ_IMPLIES_EXEC flag will be used in the next Linux mmap() commit.
It turns out that this value is not used within the system call code
under normal conditions, except when using tracing tools like ktrace.
If we forget to set this value, it is set to random garbage. This may
cause ktrace to hang indefinitely, making it impossible to kill.
Reported by: Michael Plass
PR: 210800
MFC before: 11.0-RELEASE
mp_maxid or CPU_FOREACH() as appropriate. This fixes a number of places in
the kernel that assumed CPU IDs are dense in [0, mp_ncpus) and would try,
for example, to run tasks on CPUs that did not exist or to allocate too
few buffers on systems with sparse CPU IDs in which there are holes in the
range and mp_maxid > mp_ncpus. Such circumstances generally occur on
systems with SMT, but on which SMT is disabled. This patch restores system
operation at least on POWER8 systems configured in this way.
There are a number of other places in the kernel with potential problems
in these situations, but where sparse CPU IDs are not currently known
to occur, mostly in the ARM machine-dependent code. These will be fixed
in a follow-up commit after the stable/11 branch.
PR: kern/210106
Reviewed by: jhb
Approved by: re (glebius)
297931
Expose doreti as a global symbol on amd64 and i386.
doreti provides the common code path for returning from interrupt
andlers on x86. Exposing doreti as a global symbol allows kernel
modules to include low-level interrupt handlers instead of requiring
all low-level handlers to be statically compiled into the kernel.
Submitted by: Howard Su <howard0su@gmail.com>
Reviewed by: kib
298022
hyperv: Deprecate HYPERV option by moving Hyper-V IDT vector into vmbus
Submitted by: Jun Su <junsu microsoft com>
Reviewed by: jhb, kib, sephe
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D5910
threads, to make it less confusing and using modern kernel terms.
Rename the functions to reflect current use of the functions, instead
of the historic KSE conventions:
cpu_set_fork_handler -> cpu_fork_kthread_handler (for kthreads)
cpu_set_upcall -> cpu_copy_thread (for forks)
cpu_set_upcall_kse -> cpu_set_upcall (for new threads creation)
Reviewed by: jhb (previous version)
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (hrs)
Differential revision: https://reviews.freebsd.org/D6731
does not cover the dynamically registered ficititious ranges, and
fictitious pages mappings are not promoted. Offer a dummy struct
md_page to fetch constant superpage pv list generation to satisfy
logic. Also, by initializing the pv_dummy pv_list to empty, we can
remove several explicit PG_FICTITIOUS tests.
Reported and tested by: Michael Butler <imb@protected-networks.net>
(previous version)
Reviewed by: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D6728
Approved by: re (hrs)
Do not try to change attributes for DMAP when working on a mapping
which is not covered by the DMAP. This was reported on real system
where a BAR of a device (NTB) was mapped outside the PCI window.
Reported and tested by: mav
Reviewed by: jhb, mav
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D6668
