This is a 32-bit structure embedded in each vm_page, consisting mostly
of page queue state. The use of a structure makes it easy to store a
snapshot of a page's queue state in a stack variable and use cmpset
loops to update that state without requiring the page lock.
This change merely adds the structure and updates references to atomic
state fields. No functional change intended.
Reviewed by: alc, jeff, kib
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D22650
Partially revert r354741 and r354754 and go back to allocating a
fixed-size chunk of stack space for the auxiliary vector. Keep
sv_copyout_auxargs but change it to accept the address at the end of
the environment vector as an input stack address and no longer
allocate room on the stack. It is now called at the end of
copyout_strings after the argv and environment vectors have been
copied out.
This should fix a regression in r354754 that broke the stack alignment
for newer Linux amd64 binaries (and probably broke Linux arm64 as
well).
Reviewed by: kib
Tested on: amd64 (native, linux64 (only linux-base-c7), and i386)
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22695
Use the power of variable to avoid spelling out source and generated
files too many times. The previous Makefiles were hard to read, hard to
edit, and badly formatted.
Reviewed by: kevans, emaste
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22714
o Remove All Rights Reserved from my notices
o imp@FreeBSD.org everywhere
o regularize punctiation, eliminate date ranges
o Make sure that it's clear that I don't claim All Rights reserved by listing
All Rights Reserved on same line as other copyright holders (but not
me). Other such holders are also listed last where it's clear.
- Use ustringp for the location of the argv and environment strings
and allow destp to travel further down the stack for the stackgap
and auxv regions.
- Update the Linux copyout_strings variants to move destp down the
stack as was done for the native ABIs in r263349.
- Stop allocating a space for a stack gap in the Linux ABIs. This
used to hold translated system call arguments, but hasn't been used
since r159992.
Reviewed by: kib
Tested on: md64 (amd64, i386, linux64), i386 (i386, linux)
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22501
flua is bootstrapped as part of the build for those on older
versions/revisions that don't yet have flua installed. Once upgraded past
r354833, "make sysent" will again naturally work as expected.
Reviewed by: brooks
Differential Revision: https://reviews.freebsd.org/D21894
The purpose of this option is to make it easier to track down memory
corruption bugs by reducing the number of malloc(9) types that might
have recently been associated with a given chunk of memory. However, it
increases fragmentation and is disabled in release kernels.
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Change the FreeBSD ELF ABIs to use this new hook to copyout ELF auxv
instead of doing it in the sv_fixup hook. In particular, this new
hook allows the stack space to be allocated at the same time the auxv
values are copied out to userland. This allows us to avoid wasting
space for unused auxv entries as well as not having to recalculate
where the auxv vector is by walking back up over the argv and
environment vectors.
Reviewed by: brooks, emaste
Tested on: amd64 (amd64 and i386 binaries), i386, mips, mips64
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D22355
This driver allows to usage of the paravirt SCSI controller
in VMware products like ESXi. The pvscsi driver provides a
substantial performance improvement in block devices versus
the emulated mpt and mps SCSI/SAS controllers.
Error handling in this driver has not been extensively tested
yet.
Submitted by: vbhakta@vmware.com
Relnotes: yes
Sponsored by: VMware, Panzura
Differential Revision: D18613
Pointer arguments should be of the form "<type> *..." and not "<type>* ...".
No functional change.
Reviewed by: kevans
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D22373
Save the address of the trap frame in %ebp on kernel entry. This
automatically provides it in struct i386_frame.f_frame to unwinder.
While there, more accurately handle the terminating frames,
Reviewed by: avg, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D22321
This change removes TRAP_INTERRUPT and TRAP_TIMERINT frame types.
Their names are a bit confusing: trap + interrupt, what is that?
The TRAP_TIMERINT name is too specific -- can it only be used for timer
"trap-interrupts"? What is so special about them?
My understanding of the code is that INTERRUPT, TRAP_INTERRUPT and
TRAP_TIMERINT differ only in how an offset from callee's frame pointer to a
trap frame on the stack is calculated. And that depends on a number of
arguments that a special handler passes to a callee (a function with a
normal C calling convention).
So, this change makes that logic explicit and collapses all interrupt frame
types into the INTERRUPT type.
Reviewed by: markj
Discussed with: kib, jhb
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D22303
a tmpfs to be mounted there, and because they like to verify it's
actually a mountpoint, a symlink won't do.
Reviewed by: dchagin (earlier version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20333
Move futex_mtx to linux_common.ko for amd64 and aarch64 along
with respective list/mutex init/destroy.
PR: 240989
Reported by: Alex S <iwtcex@gmail.com>
NetGDB(4) is a component of a system using a panic-time network stack to
remotely debug crashed FreeBSD kernels over the network, instead of
traditional serial interfaces.
There are three pieces in the complete NetGDB system.
First, a dedicated proxy server must be running to accept connections from
both NetGDB and gdb(1), and pass bidirectional traffic between the two
protocols.
Second, the NetGDB client is activated much like ordinary 'gdb' and
similarly to 'netdump' in ddb(4) after a panic. Like other debugnet(4)
clients (netdump(4)), the network interface on the route to the proxy server
must be online and support debugnet(4).
Finally, the remote (k)gdb(1) uses 'target remote <proxy>:<port>' (like any
other TCP remote) to connect to the proxy server.
The NetGDB v1 protocol speaks the literal GDB remote serial protocol, and
uses a 1:1 relationship between GDB packets and sequences of debugnet
packets (fragmented by MTU). There is no encryption utilized to keep
debugging sessions private, so this is only appropriate for local
segments or trusted networks.
Submitted by: John Reimer <john.reimer AT emc.com> (earlier version)
Discussed some with: emaste, markj
Relnotes: sure
Differential Revision: https://reviews.freebsd.org/D21568
Debugnet is a simplistic and specialized panic- or debug-time reliable
datagram transport. It can drive a single connection at a time and is
currently unidirectional (debug/panic machine transmit to remote server
only).
It is mostly a verbatim code lift from netdump(4). Netdump(4) remains
the only consumer (until the rest of this patch series lands).
The INET-specific logic has been extracted somewhat more thoroughly than
previously in netdump(4), into debugnet_inet.c. UDP-layer logic and up, as
much as possible as is protocol-independent, remains in debugnet.c. The
separation is not perfect and future improvement is welcome. Supporting
INET6 is a long-term goal.
Much of the diff is "gratuitous" renaming from 'netdump_' or 'nd_' to
'debugnet_' or 'dn_' -- sorry. I thought keeping the netdump name on the
generic module would be more confusing than the refactoring.
The only functional change here is the mbuf allocation / tracking. Instead
of initiating solely on netdump-configured interface(s) at dumpon(8)
configuration time, we watch for any debugnet-enabled NIC for link
activation and query it for mbuf parameters at that time. If they exceed
the existing high-water mark allocation, we re-allocate and track the new
high-water mark. Otherwise, we leave the pre-panic mbuf allocation alone.
In a future patch in this series, this will allow initiating netdump from
panic ddb(4) without pre-panic configuration.
No other functional change intended.
Reviewed by: markj (earlier version)
Some discussion with: emaste, jhb
Objection from: marius
Differential Revision: https://reviews.freebsd.org/D21421
After r352110 the page lock no longer protects a page's identity, so
there is no purpose in locking the page in pmap_mincore(). Instead,
if vm.mincore_mapped is set to the non-default value of 0, re-lookup
the page after acquiring its object lock, which holds the page's
identity stable.
The change removes the last callers of vm_page_pa_tryrelock(), so
remove it.
Reviewed by: kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21823
callers hold it.
This simplifies pmap code and removes a dependency on the object lock.
Reviewed by: kib, markj
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D21596
busy acquires while held.
This allows code that would need to acquire and release a very large number
of page busy locks to use the old mechanism where busy is only checked and
not held. This comes at the cost of false positives but never false
negatives which the single consumer, vm_fault_soft_fast(), handles.
Reviewed by: kib
Tested by: pho
Sponsored by: Netflix, Intel
Differential Revision: https://reviews.freebsd.org/D21592
At the moment i386 does not provide 64-bit atomic operations in
userland. Exposing some atomic_*_64 defines can cause unnecessary
confusion.
Discussed with: kib
MFC after: 2 weeks
Four drivers (hpt27xx, hptmv, hptnr, hptrr, hpt27xx) include precompiled
binary objects; have users load them as modules if they are needed.
Additional work (i.e., integrating devmatch) required before MFC.
Reviewed by: markj
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21865
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
Convert all remaining references to that field to "ref_count" and update
comments accordingly. No functional change intended.
Reviewed by: alc, kib
Sponsored by: Intel, Netflix
Differential Revision: https://reviews.freebsd.org/D21768
by defining pg_nx as zero for non-PAE and correspondingly simplifying
some expressions.
Suggested and reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D21757
- Remove a dead variable from the amd64 pmap_extract_and_hold().
- Fix grammar in the vm_page_wire man page.
Reported by: alc
Reviewed by: alc, kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21639
Just return EINVAL if flags != 0. The Linux man page documents one
case of EINVAL as "The filesystem does not support one of the flags in
flags."
After r351723 userland binaries will try using new system calls.
Reported by: mjg
Reviewed by: mjg, trasz
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D21590
There are several mechanisms by which a vm_page reference is held,
preventing the page from being freed back to the page allocator. In
particular, holding the page's object lock is sufficient to prevent the
page from being freed; holding the busy lock or a wiring is sufficent as
well. These references are protected by the page lock, which must
therefore be acquired for many per-page operations. This results in
false sharing since the page locks are external to the vm_page
structures themselves and each lock protects multiple structures.
Transition to using an atomically updated per-page reference counter.
The object's reference is counted using a flag bit in the counter. A
second flag bit is used to atomically block new references via
pmap_extract_and_hold() while removing managed mappings of a page.
Thus, the reference count of a page is guaranteed not to increase if the
page is unbusied, unmapped, and the object's write lock is held. As
a consequence of this, the page lock no longer protects a page's
identity; operations which move pages between objects are now
synchronized solely by the objects' locks.
The vm_page_wire() and vm_page_unwire() KPIs are changed. The former
requires that either the object lock or the busy lock is held. The
latter no longer has a return value and may free the page if it releases
the last reference to that page. vm_page_unwire_noq() behaves the same
as before; the caller is responsible for checking its return value and
freeing or enqueuing the page as appropriate. vm_page_wire_mapped() is
introduced for use in pmap_extract_and_hold(). It fails if the page is
concurrently being unmapped, typically triggering a fallback to the
fault handler. vm_page_wire() no longer requires the page lock and
vm_page_unwire() now internally acquires the page lock when releasing
the last wiring of a page (since the page lock still protects a page's
queue state). In particular, synchronization details are no longer
leaked into the caller.
The change excises the page lock from several frequently executed code
paths. In particular, vm_object_terminate() no longer bounces between
page locks as it releases an object's pages, and direct I/O and
sendfile(SF_NOCACHE) completions no longer require the page lock. In
these latter cases we now get linear scalability in the common scenario
where different threads are operating on different files.
__FreeBSD_version is bumped. The DRM ports have been updated to
accomodate the KPI changes.
Reviewed by: jeff (earlier version)
Tested by: gallatin (earlier version), pho
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D20486
Many extern struct pcpu <something>__pcpu declarations were
copied/pasted in sources. The issue is that the definition is MD, but
it cannot be provided by machine/pcpu.h due to actual struct pcpu
defined in sys/pcpu.h later than the inclusion of machine/pcpu.h.
This forced the copying when other code needed direct access to
__pcpu. There is no way around it, due to machine/pcpu.h supplying
part of struct pcpu fields.
To work around the problem, add a new machine/pcpu_aux.h header, which
should fill any needed MD definitions after struct pcpu definition is
completed. This allows to remove copies of __pcpu spread around the
source. Also on x86 it makes it possible to remove work arounds like
OFFSETOF_CURTHREAD or clang specific warnings supressions.
Reported and tested by: lwhsu, bcran
Reviewed by: imp, markj (previous version)
Discussed with: jhb
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D21418
doing so adds more flexibility with less redundant code.
Reviewed by: jhb, markj, kib
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D21250
- Check for an invalid device (vendor is invalid) before reading the
header type register when examining function 0 of a possible device.
- When iterating over functions of a device, reject any device whose
16-bit vendor is invalid rather than requiring the full 32-bit
vendor+device to be all 1's. In practice the latter check is
probably fine, but checking the vendor is what the PCI spec
recommends.
Reviewed by: imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D21147
Previously, AcpiOsMemory was using pmap_mapbios which would always map
the requested address Write-Back (WB). For several AMD Ryzen laptops,
the BIOS uses AcpiOsMemory to directly access the PCI MCFG region in
order to access PCI config registers. This has the side effect of
remapping the MCFG region in the direct map as WB instead of UC
hanging the laptops during boot.
On the one laptop I examined in detail, the _PIC global method used to
switch from 8259A PICs to I/O APICs uses a pair of PCI config space
registers at offset 0x84 in the device at 0:0:0 to as a pair of
address/data registers to access an indirect register in the chipset
and clear a single bit to switch modes.
To fix, alter the semantics of pmap_mapbios() such that it does not
modify the attributes of any existing mappings and instead uses the
existing attributes. If a new mapping is created, this new mapping
uses WB (the default memory attribute).
Special thanks to the gentleman whose name I don't have who brought
two affected laptops to the hacker lounge at BSDCan. Direct access to
the affected systems permitted finding the root cause within an hour
or so.
PR: 231760, 236899
Reviewed by: kib, alc
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D20327
mapping and then destroy one of the 4 KB page mappings so that there is a
potential trigger for repromotion. Currently, we destroy the first 4 KB
page mapping that falls within the (current) superpage mapping or the
virtual address range [sva, eva). However, I have found empirically that
destroying the last 4 KB mapping produces slightly better results,
specifically, more promotions and fewer failed promotion attempts.
Accordingly, this revision changes pmap_advise() to destroy the last 4 KB
page mapping. It also replaces some nearby uses of boolean_t with bool.
Reviewed by: kib, markj
Differential Revision: https://reviews.freebsd.org/D21115
It is assembled using "${CC} -x assembler-with-cpp", which by convention
(bsd.suffixes.mk) uses the .asm extension.
This is a portion of the review referenced below (D18344). That review
also renamed linux_support.s to .S, but that is a functional change
(using the compiler's integrated assembler instead of as) and will be
revisited separately.
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D18344
