From the submitter description:
The process is forked transitioning a map entry to COW
Thread A writes to a page on the map entry, faults, updates the pmap to
writable at a new phys addr, and starts TLB invalidations...
Thread B acquires a lock, writes to a location on the new phys addr, and
releases the lock
Thread C acquires the lock, reads from the location on the old phys addr...
Thread A ...continues the TLB invalidations which are completed
Thread C ...reads from the location on the new phys addr, and releases
the lock
In this example Thread B and C [lock, use and unlock] properly and
neither own the lock at the same time. Thread A was writing somewhere
else on the page and so never had/needed the lock. Thread C sees a
location that is only ever read|modified under a lock change beneath
it while it is the lock owner.
To fix this, perform the two-stage update of the copied PTE. First,
the PTE is updated with the address of the new physical page with
copied content, but in read-only mode. The pmap locking and the page
busy state during PTE update and TLB invalidation IPIs ensure that any
writer to the page cannot upgrade the PTE to the writable state until
all CPUs updated their TLB to not cache old mapping. Then, after the
busy state of the page is lifted, the faults for write can proceed and
do not violate the consistency of the reads.
The change is done in vm_fault because most architectures do need IPIs
to invalidate remote TLBs. More, I think that hardware guarantees of
atomicity of the remote TLB invalidation are not enough to prevent the
inconsistent reads of non-atomic reads, like multi-word accesses
protected by a lock. So instead of modifying each pmap invalidation
code, I did it there.
Discovered and analyzed by: Elliott.Rabe@dell.com
Reviewed by: markj
PR: 225584 (appeared to have the same cause)
Tested by: Elliott.Rabe@dell.com, emaste, Mike Tancsa <mike@sentex.net>, truckman
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D14347
If the map entry elookup was performed due to the mapping changes, we
need to ensure that there is still some access permission bit
requested which is compatible with the current vm_map_entry mode. If
not, restart the handler from scratch instead of trying to save the
current progress.
Also adjust fault_type to not include cleared permission bits.
Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D14347
BWN_DEBUG_HWCRYPTO debug flag.
The MAC will attempt decryption (and set BWN_RX_MAC_DEC) even if a key has
not been supplied to the hardware; this is expected behavior, and there's
no need to spam users' console with this debugging printf.
This works similarly to the existing gzip compression support, but
zstd is typically faster and gives better compression ratios.
Support for this functionality must be configured by adding ZSTDIO to
one's kernel configuration file. dumpon(8)'s new -Z option is used to
configure zstd compression for kernel dumps. savecore(8) now recognizes
and saves zstd-compressed kernel dumps with a .zst extension.
Submitted by: cem (original version)
Relnotes: yes
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D13101,
https://reviews.freebsd.org/D13633
The definitions otherwise leak into anything that includes zstd.h,
which is not desirable for native FreeBSD code.
Reviewed by: allanjude, cem, imp
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D14352
This came about when r328489 made ports modules builds no longer use the
in-tree share/mk files, but didn't cleanup MAKEOBJDIR from the
environment.
This fixes "Variable OBJTOP is recursive".
Sponsored by: Dell EMC
A race in g_part_wither() can lead to I/O being performed with a freed GEOM
when the device disappears. Close the race as best as we can for now,
following the code patterns from g_part_ctl_destroy() and g_part_ctl_undo().
This also fixes a leak, as g_wither_geom() does not wither providers, it
only orphans them, so the partition entries would never get destroyed in
g_wither_washer().
Note, this is not a complete fix, it can still race with g_part_start(), the
race has merely been narrowed.
Reviewed by: markj
Sponsored by: Dell EMC Isilon
PR36157: When injecting an implicit function declaration in C89, find
the right DeclContext rather than injecting it wherever we happen to
be.
This avoids creating functions whose DeclContext is a struct or
similar.
This fixes assertion failures when parsing certain not-completely-valid
struct declarations.
Reported by: ae
PR: 225862
MFC after: 3 months
X-MFC-With: r327952
compilation under FreeBSD. The mthca driver was temporarily removed as
part of the Linux 4.9 RoCE/infinband upgrade.
Top commit in Linux source tree:
69973b830859bc6529a7a0468ba0d80ee5117826
Sponsored by: Mellanox Technologies
When the owner of the wire reference releases the last reference, it
might be that the page was already attempted to be freed (but free
cannot be performed at that time due to wire). Check that the page
was removed from the object as the indicator of the free attempt and
finish the free operation if so.
Reported and tested by: Slava Shwartsman
Reviewed by: hselasky
Sponsored by: Mellanox Technologies
MFC after: 1 week
Suppose that we have an object with a mapped superpage, and that all
pages in the superpages are held (by some driver). Additionally,
suppose that the object is terminated, e.g. because the only process
mapping it is exiting. Then the reservation is broken, but the pages
cannot be freed until later, when they are unheld. In this situation,
the reservation code cannot clean psind, since no pages are freed, and
the page is freed and then reused with invalid psind.
Clean psind on vm_reserv_break() to avoid the situation.
Reported and tested by: Slava Shwartsman
Reviewed by: markj
Sponsored by: Mellanox Technologies
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D14335
Do not use C constant suffixes. Bit values are small enough to not
require typing, despite they are used for 64bit MSR writes. The added
cast in hw_ibrs_recalculate() is redundand but I prefer to add it for
clarity.
Reported by: bde
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Summary:
All metadata.c files are very similar, with only trivial changes. Unify them
into a single common file, with minor special-casing where needed.
Reviewed By: imp
Differential Revision: https://reviews.freebsd.org/D13978
significant source of cache line contention from vm_page_alloc(). Use
accessors and vm_page_unwire_noq() so that the mechanism can be easily
changed in the future.
Reviewed by: markj
Discussed with: kib, glebius
Tested by: pho (earlier version)
Sponsored by: Netflix, Dell/EMC Isilon
Differential Revision: https://reviews.freebsd.org/D14273
ip6_calcmtu() only looks at the interface MTU if neither the TCP hostcache
nor the route provides an MTU. Update the routes so they do not provide
stale MTUs.
This fixes UNH IPv6 conformance test cases v6LC_4_1_08 and v6LC_4_1_09,
which use a RA to reduce the link MTU from 1500 to 1280.
Reported and tested by: Farrell Woods <Farrell_Woods@Dell.com>
Reviewed by: dab, melifaro
Discussed with: ae
MFC after: 1 week
Sponsored by: Dell EMC
Differential Revision: https://reviews.freebsd.org/D14257
Previously, the address regions described by disabled admatch entries would
be treated as being mapped to the given core; while incorrect, this was
essentially harmless given that the entries describe unused address space
on the few affected devices.
We now perform parsing of per-core admatch registers and interrupt flags in
siba_erom, correctly skip any disabled admatch entries, and use the
siba_erom API in siba_add_children() to perform enumeration of attached
cores.
read or write of all registered realtime clocks. In the read case, the
values read are simply discarded. For writes, there's no alternative but
to actually write the current system time to the device.
makes them consistent with the way other page-table pages are allocated.
It also provides the rest of the VM system a good clue that these pages
are used.
Reviewed by: alc, kib, markj
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D14269
These are the .lua files from from Pedro Souza's 2014 Summer of Code
project. Rui Paulo, Pedro Arthur and Wojciech A. Koszek also
contributed.
Obtained from: https://wiki.freebsd.org/SummerOfCode2014/LuaLoader
Sponsored by: Google Summer of Code
Improve the SoC lua menu code to bring it in line with forth
menu functionality
Submitted by: Zakary Nafziger
Sponsored by: FreeBSD Foundation
Use loader.setenv and loader.unsetenv instead of loader.perform
Convert from include("/boot/foo.lua") to foo = require("foo");
to bring in line with latest lua module conventions.
Enforce a uniform style for the new .lua files:
o hard tab indenation for 8 spaces
o don't have if foo then bar; else bas; end on one line
MFC After: 1 month
Relnotes: yes
Differential Review: https://reviews.freebsd.org/D14295
liblua glues the lua run time into the boot loader. It implements all
the runtime routines that lua expects. In addition, it has a few
standard 'C' headers that nueter various aspects of the LUA build that
are too specific to lua to be in libsa. Many refinements from the
original code to improve implementation and the number of included lua
libraries. Use int64_t for lua_Number. Have "/boot/lua" be the default
module path. Numerous cleanups from the original GSoC project,
including hacking libsa to allow lua to be built with only one change
outside luaconf.h.
Add the final bit of lua glue to bring in liblua and plug into the
multiple interpreter framework, previously committed.
Add LOADER_LUA option, currently off by default.
Presently, this is an experimental option. One must opt-in to using
this by defining WITH_LOADER_LUA and WITHOUT_FORTH. It's been
lightly tested, so keep a backup copy of your old loader handy.
The menu code, coming in the next commit, hasn't been exhaustively
tested. A LUA boot loader is 60k larger than a FORTH one, which is
80k larger than a no-interpreter one. Subtle changes in size
may tip things past some subtle limit (the binary is ~430k now
when built with LUA). A future version may offer coexistance.
Bump FreeBSD version to 1200058 to mark the milestone.
Pedro Souza's 2014 Summer of Code project. Rui Paulo, Pedro Arthur,
Zakary Nafziger and Wojciech A. Koszek also contributed. Warner Losh
reworked it extensively into its current form.
Obtained from: https://wiki.freebsd.org/SummerOfCode2014/LuaLoader
Sponsored by: Google Summer of Code
Relnotes: Yes
MFC After: 1 month
Differential Review: https://reviews.freebsd.org/D14295
