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This commit fixes a duplicate-"the" typo in README.
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/20180926182920.27644-3-paulmck@linux.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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release/acquire
More than one kernel developer has expressed the opinion that the LKMM
should enforce ordering of writes by locking. In other words, given
the following code:
WRITE_ONCE(x, 1);
spin_unlock(&s):
spin_lock(&s);
WRITE_ONCE(y, 1);
the stores to x and y should be propagated in order to all other CPUs,
even though those other CPUs might not access the lock s. In terms of
the memory model, this means expanding the cumul-fence relation.
Locks should also provide read-read (and read-write) ordering in a
similar way. Given:
READ_ONCE(x);
spin_unlock(&s);
spin_lock(&s);
READ_ONCE(y); // or WRITE_ONCE(y, 1);
the load of x should be executed before the load of (or store to) y.
The LKMM already provides this ordering, but it provides it even in
the case where the two accesses are separated by a release/acquire
pair of fences rather than unlock/lock. This would prevent
architectures from using weakly ordered implementations of release and
acquire, which seems like an unnecessary restriction. The patch
therefore removes the ordering requirement from the LKMM for that
case.
There are several arguments both for and against this change. Let us
refer to these enhanced ordering properties by saying that the LKMM
would require locks to be RCtso (a bit of a misnomer, but analogous to
RCpc and RCsc) and it would require ordinary acquire/release only to
be RCpc. (Note: In the following, the phrase "all supported
architectures" is meant not to include RISC-V. Although RISC-V is
indeed supported by the kernel, the implementation is still somewhat
in a state of flux and therefore statements about it would be
premature.)
Pros:
The kernel already provides RCtso ordering for locks on all
supported architectures, even though this is not stated
explicitly anywhere. Therefore the LKMM should formalize it.
In theory, guaranteeing RCtso ordering would reduce the need
for additional barrier-like constructs meant to increase the
ordering strength of locks.
Will Deacon and Peter Zijlstra are strongly in favor of
formalizing the RCtso requirement. Linus Torvalds and Will
would like to go even further, requiring locks to have RCsc
behavior (ordering preceding writes against later reads), but
they recognize that this would incur a noticeable performance
degradation on the POWER architecture. Linus also points out
that people have made the mistake, in the past, of assuming
that locking has stronger ordering properties than is
currently guaranteed, and this change would reduce the
likelihood of such mistakes.
Not requiring ordinary acquire/release to be any stronger than
RCpc may prove advantageous for future architectures, allowing
them to implement smp_load_acquire() and smp_store_release()
with more efficient machine instructions than would be
possible if the operations had to be RCtso. Will and Linus
approve this rationale, hypothetical though it is at the
moment (it may end up affecting the RISC-V implementation).
The same argument may or may not apply to RMW-acquire/release;
see also the second Con entry below.
Linus feels that locks should be easy for people to use
without worrying about memory consistency issues, since they
are so pervasive in the kernel, whereas acquire/release is
much more of an "experts only" tool. Requiring locks to be
RCtso is a step in this direction.
Cons:
Andrea Parri and Luc Maranget think that locks should have the
same ordering properties as ordinary acquire/release (indeed,
Luc points out that the names "acquire" and "release" derive
from the usage of locks). Andrea points out that having
different ordering properties for different forms of acquires
and releases is not only unnecessary, it would also be
confusing and unmaintainable.
Locks are constructed from lower-level primitives, typically
RMW-acquire (for locking) and ordinary release (for unlock).
It is illogical to require stronger ordering properties from
the high-level operations than from the low-level operations
they comprise. Thus, this change would make
while (cmpxchg_acquire(&s, 0, 1) != 0)
cpu_relax();
an incorrect implementation of spin_lock(&s) as far as the
LKMM is concerned. In theory this weakness can be ameliorated
by changing the LKMM even further, requiring
RMW-acquire/release also to be RCtso (which it already is on
all supported architectures).
As far as I know, nobody has singled out any examples of code
in the kernel that actually relies on locks being RCtso.
(People mumble about RCU and the scheduler, but nobody has
pointed to any actual code. If there are any real cases,
their number is likely quite small.) If RCtso ordering is not
needed, why require it?
A handful of locking constructs (qspinlocks, qrwlocks, and
mcs_spinlocks) are built on top of smp_cond_load_acquire()
instead of an RMW-acquire instruction. It currently provides
only the ordinary acquire semantics, not the stronger ordering
this patch would require of locks. In theory this could be
ameliorated by requiring smp_cond_load_acquire() in
combination with ordinary release also to be RCtso (which is
currently true on all supported architectures).
On future weakly ordered architectures, people may be able to
implement locks in a non-RCtso fashion with significant
performance improvement. Meeting the RCtso requirement would
necessarily add run-time overhead.
Overall, the technical aspects of these arguments seem relatively
minor, and it appears mostly to boil down to a matter of opinion.
Since the opinions of senior kernel maintainers such as Linus,
Peter, and Will carry more weight than those of Luc and Andrea, this
patch changes the model in accordance with the maintainers' wishes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Link: http://lkml.kernel.org/r/20180926182920.27644-2-paulmck@linux.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This commit documents the scheme used to generate the names for the
litmus tests.
[ paulmck: Apply feedback from Andrea Parri and Will Deacon. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: akiyks@gmail.com
Cc: boqun.feng@gmail.com
Cc: dhowells@redhat.com
Cc: j.alglave@ucl.ac.uk
Cc: linux-arch@vger.kernel.org
Cc: luc.maranget@inria.fr
Cc: npiggin@gmail.com
Cc: parri.andrea@gmail.com
Cc: stern@rowland.harvard.edu
Link: http://lkml.kernel.org/r/20180926182920.27644-1-paulmck@linux.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Both spin locks and write locks currently do:
f0 0f b1 17 lock cmpxchg %edx,(%rdi)
85 c0 test %eax,%eax
75 05 jne [slowpath]
This 'test' insn is superfluous; the cmpxchg insn sets the Z flag
appropriately. Peter pointed out that using atomic_try_cmpxchg_acquire()
will let the compiler know this is true. Comparing before/after
disassemblies show the only effect is to remove this insn.
Take this opportunity to make the spin & write lock code resemble each
other more closely and have similar likely() hints.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Link: http://lkml.kernel.org/r/20180820162639.GC25153@bombadil.infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Anybody trying to assert the cpu_hotplug_lock is held (lockdep_assert_cpus_held())
from AP callbacks will fail, because the lock is held by the BP.
Stick in an explicit annotation in cpuhp_thread_fun() to make this work.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-tip-commits@vger.kernel.org
Fixes: cb538267ea1e ("jump_label/lockdep: Assert we hold the hotplug lock for _cpuslocked() operations")
Link: http://lkml.kernel.org/r/20180911095127.GT24082@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merging v4.14.68 into v4.14-rt I tripped over a conflict in the
rtmutex.c code. There I found that we had:
#ifdef CONFIG_DEBUG_LOCK_ALLOC
[..]
#endif
#ifndef CONFIG_DEBUG_LOCK_ALLOC
[..]
#endif
Really this should be:
#ifdef CONFIG_DEBUG_LOCK_ALLOC
[..]
#else
[..]
#endif
This cleans up that logic.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Rosin <peda@axentia.se>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180910214638.55926030@vmware.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Currently, when a reader acquires a lock, it only sets the
RWSEM_READER_OWNED bit in the owner field. The other bits are simply
not used. When debugging hanging cases involving rwsems and readers,
the owner value does not provide much useful information at all.
This patch modifies the current behavior to always store the task_struct
pointer of the last rwsem-acquiring reader in a reader-owned rwsem. This
may be useful in debugging rwsem hanging cases especially if only one
reader is involved. However, the task in the owner field may not the
real owner or one of the real owners at all when the owner value is
examined, for example, in a crash dump. So it is just an additional
hint about the past history.
If CONFIG_DEBUG_RWSEMS=y is enabled, the owner field will be checked at
unlock time too to make sure the task pointer value is valid. That does
have a slight performance cost and so is only enabled as part of that
debug option.
From the performance point of view, it is expected that the changes
shouldn't have any noticeable performance impact. A rwsem microbenchmark
(with 48 worker threads and 1:1 reader/writer ratio) was ran on a
2-socket 24-core 48-thread Haswell system. The locking rates on a
4.19-rc1 based kernel were as follows:
1) Unpatched kernel: 543.3 kops/s
2) Patched kernel: 549.2 kops/s
3) Patched kernel (CONFIG_DEBUG_RWSEMS on): 546.6 kops/s
There was actually a slight increase in performance (1.1%) in this
particular case. Maybe it was caused by the elimination of a branch or
just a testing noise. Turning on the CONFIG_DEBUG_RWSEMS option also
had less than the expected impact on performance.
The least significant 2 bits of the owner value are now used to designate
the rwsem is readers owned and the owners are anonymous.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/1536265114-10842-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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It was discovered that a constant stream of readers with occassional
writers pounding on a rwsem may cause many of the readers to enter the
slowpath unnecessarily thus increasing latency and lowering performance.
In the current code, a reader entering the slowpath critical section
will unconditionally set the WAITING_BIAS, if not set yet, and clear
its active count even if no one is in the wait queue and no writer
is present. This causes some incoming readers to observe the presence
of waiters in the wait queue and hence have to go into the slowpath
themselves.
With sufficient numbers of readers and a relatively short lock hold time,
the WAITING_BIAS may be repeatedly turned on and off and a substantial
portion of the readers will go into the slowpath sustaining a rather
long queue in the wait queue spinlock and repeated WAITING_BIAS on/off
cycle until the logjam is broken opportunistically.
To avoid this situation from happening, an additional check is added to
detect the special case that the reader in the critical section is the
only one in the wait queue and no writer is present. When that happens,
it can just exit the slowpath and return immediately as its active count
has already been set in the lock. Other incoming readers won't observe
the presence of waiters and so will not be forced into the slowpath.
The issue was found in a customer site where they had an application
that pounded on the pread64 syscalls heavily on an XFS filesystem. The
application was run in a recent 4-socket boxes with a lot of CPUs. They
saw significant spinlock contention in the rwsem_down_read_failed() call.
With this patch applied, the system CPU usage went down from 85% to 57%,
and the spinlock contention in the pread64 syscalls was gone.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1532459425-19204-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Weirdly we seem to have forgotten this...
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There's no 'allocatote' - use the next best thing: 'allocate' :-)
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180907103521.31344-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The following commit:
08295b3b5bee ("Implement an algorithm choice for Wound-Wait mutexes")
introduced a reference in the documentation to a function that was
removed in an earlier commit.
It also forgot to remove a call to debug_mutex_add_waiter() which is now
unconditionally called by __mutex_add_waiter().
Fix those bugs.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dri-devel@lists.freedesktop.org
Fixes: 08295b3b5bee ("Implement an algorithm choice for Wound-Wait mutexes")
Link: http://lkml.kernel.org/r/20180903140708.2401-1-thellstrom@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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... instead of open-coding it, in static_key_mod().
No functional changes.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180909114252.17575-1-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for x86:
- Prevent multiplication result truncation on 32bit. Introduced with
the early timestamp reworrk.
- Ensure microcode revision storage to be consistent under all
circumstances
- Prevent write tearing of PTEs
- Prevent confusion of user and kernel reegisters when dumping fatal
signals verbosely
- Make an error return value in a failure path of the vector
allocation negative. Returning EINVAL might the caller assume
success and causes further wreckage.
- A trivial kernel doc warning fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Use WRITE_ONCE() when setting PTEs
x86/apic/vector: Make error return value negative
x86/process: Don't mix user/kernel regs in 64bit __show_regs()
x86/tsc: Prevent result truncation on 32bit
x86: Fix kernel-doc atomic.h warnings
x86/microcode: Update the new microcode revision unconditionally
x86/microcode: Make sure boot_cpu_data.microcode is up-to-date
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timekeeping fixes from Thomas Gleixner:
"Two fixes for timekeeping:
- Revert to the previous kthread based update, which is unfortunately
required due to lock ordering issues. The removal caused boot
failures on old Core2 machines. Add a proper comment why the thread
needs to stay to prevent accidental removal in the future.
- Fix a silly typo in a function declaration"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource: Revert "Remove kthread"
timekeeping: Fix declaration of read_persistent_wall_and_boot_offset()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irqchip fix from Thomas Gleixner:
"A single fix to prevent allocating excessive memory in the GIC/ITS
driver.
While the subject of the patch might suggest otherwise this is a real
fix as some SoCs exceed the memory allocation limits and fail to boot"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/gic-v3-its: Cap lpi_id_bits to reduce memory footprint
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull cpu hotplug fixes from Thomas Gleixner:
"Two fixes for the hotplug state machine code:
- Move the misplaces smb() in the hotplug thread function to the
proper place, otherwise a half update control struct could be
observed
- Prevent state corruption on error rollback, which causes the state
to advance by one and as a consequence skip it in the bringup
sequence"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Prevent state corruption on error rollback
cpu/hotplug: Adjust misplaced smb() in cpuhp_thread_fun()
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random driver fix from Ted Ts'o:
"Fix things so the choice of whether or not to trust RDRAND to
initialize the CRNG is configurable via the boot option
random.trust_cpu={on,off}"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: make CPU trust a boot parameter
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:
- make setlocalversion more robust about -dirty check
- loosen the pkg-config requirement for Kconfig
- change missing depmod to a warning from an error
- warn modules_install when System.map is missing
* tag 'kbuild-fixes-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: modules_install: warn when missing System.map file
kbuild: make missing $DEPMOD a Warning instead of an Error
kconfig: do not require pkg-config on make {menu,n}config
kconfig: remove a spurious self-assignment
scripts/setlocalversion: git: Make -dirty check more robust
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If there is no System.map file for "make modules_install",
scripts/depmod.sh will silently exit with success, having done
nothing. Since this is an unexpected situation, change it to
report a Warning for the missing file. The behavior is not
changed except for the Warning message.
The (previous) silent success and new Warning can be reproduced
by:
$ make mrproper; make defconfig
$ make modules; make modules_install
and since System.map is produced by "make vmlinux", the steps
above omit producing the System.map file.
Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
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Pull KVM fixes from Radim Krčmář:
"ARM:
- Fix a VFP corruption in 32-bit guest
- Add missing cache invalidation for CoW pages
- Two small cleanups
s390:
- Fallout from the hugetlbfs support: pfmf interpretion and locking
- VSIE: fix keywrapping for nested guests
PPC:
- Fix a bug where pages might not get marked dirty, causing guest
memory corruption on migration
- Fix a bug causing reads from guest memory to use the wrong guest
real address for very large HPT guests (>256G of memory), leading
to failures in instruction emulation.
x86:
- Fix out of bound access from malicious pv ipi hypercalls
(introduced in rc1)
- Fix delivery of pending interrupts when entering a nested guest,
preventing arbitrarily late injection
- Sanitize kvm_stat output after destroying a guest
- Fix infinite loop when emulating a nested guest page fault and
improve the surrounding emulation code
- Two minor cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (28 commits)
KVM: LAPIC: Fix pv ipis out-of-bounds access
KVM: nVMX: Fix loss of pending IRQ/NMI before entering L2
arm64: KVM: Remove pgd_lock
KVM: Remove obsolete kvm_unmap_hva notifier backend
arm64: KVM: Only force FPEXC32_EL2.EN if trapping FPSIMD
KVM: arm/arm64: Clean dcache to PoC when changing PTE due to CoW
KVM: s390: Properly lock mm context allow_gmap_hpage_1m setting
KVM: s390: vsie: copy wrapping keys to right place
KVM: s390: Fix pfmf and conditional skey emulation
tools/kvm_stat: re-animate display of dead guests
tools/kvm_stat: indicate dead guests as such
tools/kvm_stat: handle guest removals more gracefully
tools/kvm_stat: don't reset stats when setting PID filter for debugfs
tools/kvm_stat: fix updates for dead guests
tools/kvm_stat: fix handling of invalid paths in debugfs provider
tools/kvm_stat: fix python3 issues
KVM: x86: Unexport x86_emulate_instruction()
KVM: x86: Rename emulate_instruction() to kvm_emulate_instruction()
KVM: x86: Do not re-{try,execute} after failed emulation in L2
KVM: x86: Default to not allowing emulation retry in kvm_mmu_page_fault
...
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"A few more fixes who have trickled in:
- MMC bus width fixup for some Allwinner platforms
- Fix for NULL deref in ti-aemif when no platform data is passed in
- Fix div by 0 in SCMI code
- Add a missing module alias in a new RPi driver"
* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
memory: ti-aemif: fix a potential NULL-pointer dereference
firmware: arm_scmi: fix divide by zero when sustained_perf_level is zero
hwmon: rpi: add module alias to raspberrypi-hwmon
arm64: allwinner: dts: h6: fix Pine H64 MMC bus width
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https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into fixes
Allwinner fixes for 4.19
Just one fix for H6 mmc on the Pine H64: the mmc bus width was missing
from the device tree. This was added in 4.19-rc1.
* tag 'sunxi-fixes-for-4.19' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux:
arm64: allwinner: dts: h6: fix Pine H64 MMC bus width
Signed-off-by: Olof Johansson <olof@lixom.net>
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When page-table entries are set, the compiler might optimize their
assignment by using multiple instructions to set the PTE. This might
turn into a security hazard if the user somehow manages to use the
interim PTE. L1TF does not make our lives easier, making even an interim
non-present PTE a security hazard.
Using WRITE_ONCE() to set PTEs and friends should prevent this potential
security hazard.
I skimmed the differences in the binary with and without this patch. The
differences are (obviously) greater when CONFIG_PARAVIRT=n as more
code optimizations are possible. For better and worse, the impact on the
binary with this patch is pretty small. Skimming the code did not cause
anything to jump out as a security hazard, but it seems that at least
move_soft_dirty_pte() caused set_pte_at() to use multiple writes.
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180902181451.80520-1-namit@vmware.com
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activate_managed() returns EINVAL instead of -EINVAL in case of
error. While this is unlikely to happen, the positive return value would
cause further malfunction at the call site.
Fixes: 2db1f959d9dc ("x86/vector: Handle managed interrupts proper")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fixes from Wolfram Sang:
- bugfixes for uniphier, i801, and xiic drivers
- ID removal (never produced) for imx
- one MAINTAINER addition
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: xiic: Record xilinx i2c with Zynq fragment
i2c: xiic: Make the start and the byte count write atomic
i2c: i801: fix DNV's SMBCTRL register offset
i2c: imx-lpi2c: Remove mx8dv compatible entry
dt-bindings: imx-lpi2c: Remove mx8dv compatible entry
i2c: uniphier-f: issue STOP only for last message or I2C_M_STOP
i2c: uniphier: issue STOP only for last message or I2C_M_STOP
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git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Pull ARC updates from Vineet Gupta:
- Fix for atomic_fetch_#op [Will Deacon]
- Enable per device IOC [Eugeniy Paltsev]
- Remove redundant gcc version checks [Masahiro Yamada]
- Miscll platform config/DT updates [Alexey Brodkin]
* tag 'arc-4.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: don't check for HIGHMEM pages in arch_dma_alloc
ARC: IOC: panic if both IOC and ZONE_HIGHMEM enabled
ARC: dma [IOC] Enable per device io coherency
ARC: dma [IOC]: mark DMA devices connected as dma-coherent
ARC: atomics: unbork atomic_fetch_##op()
arc: remove redundant GCC version checks
ARC: sort Kconfig
ARC: cleanup show_faulting_vma()
ARC: [plat-axs*]: Enable SWAP
ARC: [plat-axs*/plat-hsdk]: Allow U-Boot to pass MAC-address to the kernel
ARC: configs: cleanup
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Fix the cell specification mechanism to allow cells to be pre-created
without having to specify at least one address (the addresses will be
upcalled for).
This allows the cell information preload service to avoid the need to issue
loads of DNS lookups during boot to get the addresses for each cell (500+
lookups for the 'standard' cell list[*]). The lookups can be done later as
each cell is accessed through the filesystem.
Also remove the print statement that prints a line every time a new cell is
added.
[*] There are 144 cells in the list. Each cell is first looked up for an
SRV record, and if that fails, for an AFSDB record. These get a list
of server names, each of which then has to be looked up to get the
addresses for that server. E.g.:
dig srv _afs3-vlserver._udp.grand.central.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull MD fixes from Shaohua Li:
- Fix a locking issue for md-cluster (Guoqing)
- Fix a sync crash for raid10 (Ni)
- Fix a reshape bug with raid5 cache enabled (me)
* tag 'md/4.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
md-cluster: release RESYNC lock after the last resync message
RAID10 BUG_ON in raise_barrier when force is true and conf->barrier is 0
md/raid5-cache: disable reshape completely
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Pull ceph fixes from Ilya Dryomov:
"Two rbd patches to complete support for images within namespaces that
went into -rc1 and a use-after-free fix.
The rbd changes have been sitting in a branch for quite a while but
couldn't be included into the -rc1 pull request because of a pending
wire protocol backwards compatibility fixup that only got committed
early this week"
* tag 'ceph-for-4.19-rc3' of https://github.com/ceph/ceph-client:
rbd: support cloning across namespaces
rbd: factor out get_parent_info()
ceph: avoid a use-after-free in ceph_destroy_options()
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git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull fsnotify fix from Jan Kara:
"A small fsnotify fix from Amir"
* tag 'for_v4.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
fsnotify: fix ignore mask logic in fsnotify()
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fix from Will Deacon:
"Just one small fix here, preventing a VM_WARN_ON when a !present
PMD/PUD is "freed" as part of a huge ioremap() operation.
The correct behaviour is to skip the free silently in this case, which
is a little weird (the function is a bit of a misnomer), but it
follows the x86 implementation"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: fix erroneous warnings in page freeing functions
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI fixes from Rafael Wysocki:
"These fix a regression from the 4.18 cycle in the ACPI driver for
Intel SoCs (LPSS) and prevent dmi_check_system() from being called on
non-x86 systems in the ACPI core.
Specifics:
- Fix a power management regression in the ACPI driver for Intel SoCs
(LPSS) introduced by a system-wide suspend/resume fix during the
4.18 cycle (Zhang Rui).
- Prevent dmi_check_system() from being called on non-x86 systems in
the ACPI core (Jean Delvare)"
* tag 'acpi-4.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / LPSS: Force LPSS quirks on boot
ACPI / bus: Only call dmi_check_system() on X86
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git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Just a few small fixes:
- a fix for the recursive work cancellation in a specific HD-audio
operation mode
- a fix for potentially uninitialized memory access via rawmidi
- the register bit access fixes for ASoC HD-audio"
* tag 'sound-4.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda: Fix several mismatch for register mask and value
ALSA: rawmidi: Initialize allocated buffers
ALSA: hda - Fix cancel_work_sync() stall from jackpoll work
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Dan Carpenter reported that the untrusted data returns from kvm_register_read()
results in the following static checker warning:
arch/x86/kvm/lapic.c:576 kvm_pv_send_ipi()
error: buffer underflow 'map->phys_map' 's32min-s32max'
KVM guest can easily trigger this by executing the following assembly sequence
in Ring0:
mov $10, %rax
mov $0xFFFFFFFF, %rbx
mov $0xFFFFFFFF, %rdx
mov $0, %rsi
vmcall
As this will cause KVM to execute the following code-path:
vmx_handle_exit() -> handle_vmcall() -> kvm_emulate_hypercall() -> kvm_pv_send_ipi()
which will reach out-of-bounds access.
This patch fixes it by adding a check to kvm_pv_send_ipi() against map->max_apic_id,
ignoring destinations that are not present and delivering the rest. We also check
whether or not map->phys_map[min + i] is NULL since the max_apic_id is set to the
max apic id, some phys_map maybe NULL when apic id is sparse, especially kvm
unconditionally set max_apic_id to 255 to reserve enough space for any xAPIC ID.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
[Add second "if (min > map->max_apic_id)" to complete the fix. -Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
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Consider the case L1 had a IRQ/NMI event until it executed
VMLAUNCH/VMRESUME which wasn't delivered because it was disallowed
(e.g. interrupts disabled). When L1 executes VMLAUNCH/VMRESUME,
L0 needs to evaluate if this pending event should cause an exit from
L2 to L1 or delivered directly to L2 (e.g. In case L1 don't intercept
EXTERNAL_INTERRUPT).
Usually this would be handled by L0 requesting a IRQ/NMI window
by setting VMCS accordingly. However, this setting was done on
VMCS01 and now VMCS02 is active instead. Thus, when L1 executes
VMLAUNCH/VMRESUME we force L0 to perform pending event evaluation by
requesting a KVM_REQ_EVENT.
Note that above scenario exists when L1 KVM is about to enter L2 but
requests an "immediate-exit". As in this case, L1 will
disable-interrupts and then send a self-IPI before entering L2.
Reviewed-by: Nikita Leshchenko <nikita.leshchenko@oracle.com>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm
Fixes for KVM/ARM for Linux v4.19 v2:
- Fix a VFP corruption in 32-bit guest
- Add missing cache invalidation for CoW pages
- Two small cleanups
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux
KVM: s390: Fixes for 4.19
- Fallout from the hugetlbfs support: pfmf interpretion and locking
- VSIE: fix keywrapping for nested guests
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The lock has never been used and the page tables are protected by
mmu_lock in struct kvm.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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kvm_unmap_hva is long gone, and we only have kvm_unmap_hva_range to
deal with. Drop the now obsolete code.
Fixes: fb1522e099f0 ("KVM: update to new mmu_notifier semantic v2")
Cc: James Hogan <jhogan@kernel.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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If trapping FPSIMD in the context of an AArch32 guest, it is critical
to set FPEXC32_EL2.EN to 1 so that the trapping is taken to EL2 and
not EL1.
Conversely, it is just as critical *not* to set FPEXC32_EL2.EN to 1
if we're not going to trap FPSIMD, as we then corrupt the existing
VFP state.
Moving the call to __activate_traps_fpsimd32 to the point where we
know for sure that we are going to trap ensures that we don't set that
bit spuriously.
Fixes: e6b673b741ea ("KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing")
Cc: stable@vger.kernel.org # v4.18
Cc: Dave Martin <dave.martin@arm.com>
Reported-by: Alexander Graf <agraf@suse.de>
Tested-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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When triggering a CoW, we unmap the RO page via an MMU notifier
(invalidate_range_start), and then populate the new PTE using another
one (change_pte). In the meantime, we'll have copied the old page
into the new one.
The problem is that the data for the new page is sitting in the
cache, and should the guest have an uncached mapping to that page
(or its MMU off), following accesses will bypass the cache.
In a way, this is similar to what happens on a translation fault:
We need to clean the page to the PoC before mapping it. So let's just
do that.
This fixes a KVM unit test regression observed on a HiSilicon platform,
and subsequently reproduced on Seattle.
Fixes: a9c0e12ebee5 ("KVM: arm/arm64: Only clean the dcache on translation fault")
Cc: stable@vger.kernel.org # v4.16+
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
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Include xilinx soft i2c controller to Zynq fragment to make clear who is
responsible for it.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Merge ACPI core fix to avoid calling dmi_check_system() on non-x86.
* acpi-bus:
ACPI / bus: Only call dmi_check_system() on X86
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Pull drm fixes from Dave Airlie:
"Seems to have been overly quiet this week so I expect next week will
be more stuff, just one pull from Rodrigo with i915 fixes in it.
Quoting Rodrigo:
'The critical fix here on display side is the DP MST regression one.
But this pull also include fixes for DP SST, small VDSC register
fix and GVT's bucked with "BXT fixes, two guest warning fixes,
dmabuf format mod fix and one for recent multiple VM timeout
failure'."
* tag 'drm-fixes-2018-09-07' of git://anongit.freedesktop.org/drm/drm:
drm/i915/dp_mst: Fix enabling pipe clock for all streams
drm/i915/dsc: Fix PPS register definition macros for 2nd VDSC engine
drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"
drm/i915/gvt: Give new born vGPU higher scheduling chance
drm/i915/gvt: Fix drm_format_mod value for vGPU plane
drm/i915/gvt: move intel_runtime_pm_get out of spin_lock in stop_schedule
drm/i915/gvt: Handle GEN9_WM_CHICKEN3 with F_CMD_ACCESS.
drm/i915/gvt: Make correct handling to vreg BXT_PHY_CTL_FAMILY
drm/i915/gvt: emulate gen9 dbuf ctl register access
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git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu
Pull m68knommu fix from Greg Ungerer:
"A single change to fix booting on ColdFire platforms that have RAM
starting at a non-0 address"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu:
m68k: fix early memory reservation for ColdFire MMU systems
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git://anongit.freedesktop.org/drm/drm-intel into drm-fixes
The critical fix here on display side is the DP MST regression one.
But this pull also include fixes for DP SST, small VDSC register fix
and GVT's bucked with "BXT fixes, two guest warning fixes, dmabuf
format mod fix and one for recent multiple VM timeout failure."
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180905183000.GA2151@intel.com
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git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS fix from Paul Burton:
"A single fix for v4.19-rc3, resolving a problem with our VDSO data
page for systems with dcache aliasing. Those systems could previously
observe stale data, causing clock_gettime() & gettimeofday() to return
incorrect values"
* tag 'mips_fixes_4.19_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: VDSO: Match data page cache colouring when D$ aliases
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Pull cifs fixes from Steve French:
"Four small SMB3 fixes, three for stable, and one minor debug
clarification"
* tag '4.19-rc2-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: connect to servername instead of IP for IPC$ share
smb3: check for and properly advertise directory lease support
smb3: minor debugging clarifications in rfc1001 len processing
SMB3: Backup intent flag missing for directory opens with backupuid mounts
fs/cifs: don't translate SFM_SLASH (U+F026) to backslash
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