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sthyi should only generate a specification exception if the function
code is zero and the response buffer is not on a 4k boundary.
The current code would also test for unknown function codes if the
response buffer, that is currently only defined for function code 0,
is not on a 4k boundary and incorrectly inject a specification
exception instead of returning with condition code 3 and return code 4
(unsupported function code).
Fix this by moving the boundary check.
Fixes: 95ca2cb57985 ("KVM: s390: Add sthyi emulation")
Cc: <stable@vger.kernel.org> # 4.8+
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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The sthyi inline assembly misses register r3 within the clobber
list. The sthyi instruction will always write a return code to
register "R2+1", which in this case would be r3. Due to that we may
have register corruption and see host crashes or data corruption
depending on how gcc decided to allocate and use registers during
compile time.
Fixes: 95ca2cb57985 ("KVM: s390: Add sthyi emulation")
Cc: <stable@vger.kernel.org> # 4.8+
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Removal of spin_unlock_wait()
- SRCU updates
- Torture-test updates
- Documentation updates
- Miscellaneous fixes
- CPU-hotplug fixes
- Miscellaneous non-RCU fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There is no agreed-upon definition of spin_unlock_wait()'s semantics,
and it appears that all callers could do just as well with a lock/unlock
pair. This commit therefore removes the underlying arch-specific
arch_spin_unlock_wait() for all architectures providing them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrea Parri <parri.andrea@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
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Add support for the iommu_device_register interface to make
the s390 hardware iommus visible to the iommu core and in
sysfs.
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Nadav reported parallel MADV_DONTNEED on same range has a stale TLB
problem and Mel fixed it[1] and found same problem on MADV_FREE[2].
Quote from Mel Gorman:
"The race in question is CPU 0 running madv_free and updating some PTEs
while CPU 1 is also running madv_free and looking at the same PTEs.
CPU 1 may have writable TLB entries for a page but fail the pte_dirty
check (because CPU 0 has updated it already) and potentially fail to
flush.
Hence, when madv_free on CPU 1 returns, there are still potentially
writable TLB entries and the underlying PTE is still present so that a
subsequent write does not necessarily propagate the dirty bit to the
underlying PTE any more. Reclaim at some unknown time at the future
may then see that the PTE is still clean and discard the page even
though a write has happened in the meantime. I think this is possible
but I could have missed some protection in madv_free that prevents it
happening."
This patch aims for solving both problems all at once and is ready for
other problem with KSM, MADV_FREE and soft-dirty story[3].
TLB batch API(tlb_[gather|finish]_mmu] uses [inc|dec]_tlb_flush_pending
and mmu_tlb_flush_pending so that when tlb_finish_mmu is called, we can
catch there are parallel threads going on. In that case, forcefully,
flush TLB to prevent for user to access memory via stale TLB entry
although it fail to gather page table entry.
I confirmed this patch works with [4] test program Nadav gave so this
patch supersedes "mm: Always flush VMA ranges affected by zap_page_range
v2" in current mmotm.
NOTE:
This patch modifies arch-specific TLB gathering interface(x86, ia64,
s390, sh, um). It seems most of architecture are straightforward but
s390 need to be careful because tlb_flush_mmu works only if
mm->context.flush_mm is set to non-zero which happens only a pte entry
really is cleared by ptep_get_and_clear and friends. However, this
problem never changes the pte entries but need to flush to prevent
memory access from stale tlb.
[1] http://lkml.kernel.org/r/20170725101230.5v7gvnjmcnkzzql3@techsingularity.net
[2] http://lkml.kernel.org/r/20170725100722.2dxnmgypmwnrfawp@suse.de
[3] http://lkml.kernel.org/r/BD3A0EBE-ECF4-41D4-87FA-C755EA9AB6BD@gmail.com
[4] https://patchwork.kernel.org/patch/9861621/
[minchan@kernel.org: decrease tlb flush pending count in tlb_finish_mmu]
Link: http://lkml.kernel.org/r/20170808080821.GA31730@bbox
Link: http://lkml.kernel.org/r/20170802000818.4760-7-namit@vmware.com
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Reported-by: Nadav Amit <namit@vmware.com>
Reported-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This patch is a preparatory patch for solving race problems caused by
TLB batch. For that, we will increase/decrease TLB flush pending count
of mm_struct whenever tlb_[gather|finish]_mmu is called.
Before making it simple, this patch separates architecture specific part
and rename it to arch_tlb_[gather|finish]_mmu and generic part just
calls it.
It shouldn't change any behavior.
Link: http://lkml.kernel.org/r/20170802000818.4760-5-namit@vmware.com
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This work implements jiting of BPF_J{LT,LE,SLT,SLE} instructions
with BPF_X/BPF_K variants for the s390x eBPF JIT.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The UDP offload conflict is dealt with by simply taking what is
in net-next where we have removed all of the UFO handling code
entirely.
The TCP conflict was a case of local variables in a function
being removed from both net and net-next.
In netvsc we had an assignment right next to where a missing
set of u64 stats sync object inits were added.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Some hypervisors allow to toggle uid checking at runtime. Log
changes to uid checking in s390dbf.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Split the vmcp header file and move the device driver internal
structure to the C file, and move the ioctl definitions to the uapi
directory.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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If memory is fragmented it is unlikely that large order memory
allocations succeed. This has been an issue with the vmcp device
driver since a long time, since it requires large physical contiguous
memory ares for large responses.
To hopefully resolve this issue make use of the contiguous memory
allocator (cma). This patch adds a vmcp specific vmcp cma area with a
default size of 4MB. The size can be changed either via the
VMCP_CMA_SIZE config option at compile time or with the "vmcp_cma"
kernel parameter (e.g. "vmcp_cma=16m").
For any vmcp response buffers larger than 16k memory from the cma area
will be allocated. If such an allocation fails, there is a fallback to
the buddy allocator.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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According to the CP Programming Services manual Diagnose Code 8
"Virtual Console Function" can be used in all addressing modes. Also
the input and output buffers do not have a limitation which specifies
they need to be below the 2GB line.
This is true at least since z/VM 5.4.
Therefore remove the sam31/64 instructions and allow for simple
GFP_KERNEL allocations. This makes it easier to allocate a 1MB page
if the user requested such a large return buffer.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Memory blocks that contain areas for the contiguous memory allocator
(cma) should not be allowed to go offline. Otherwise this would render
cma completely useless.
This might make sense on other architectures where memory might be
taken offline due to hardware errors, but not on architectures which
support memory hotplug for load balancing.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Add all the missing little helper functions like virt_to_pfn(),
phys_to_page(), etc. While we had a couple of these helper functions
like e.g. page_to_phys() the other functions were missing, which is
quite annoying if one is looking for exactly such a function.
Therefore finally add all those little helper functions.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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This implements kvm_arch_vcpu_in_kernel() for s390. DIAG is a privileged
operation, so it cannot be called from problem state (user mode).
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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If a vcpu exits due to request a user mode spinlock, then
the spinlock-holder may be preempted in user mode or kernel mode.
(Note that not all architectures trap spin loops in user mode,
only AMD x86 and ARM/ARM64 currently do).
But if a vcpu exits in kernel mode, then the holder must be
preempted in kernel mode, so we should choose a vcpu in kernel mode
as a more likely candidate for the lock holder.
This introduces kvm_arch_vcpu_in_kernel() to decide whether the
vcpu is in kernel-mode when it's preempted. kvm_vcpu_on_spin's
new argument says the same of the spinning VCPU.
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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While testing some other work that required JIT modifications, I
run into test_bpf causing a hang when JIT enabled on s390. The
problematic test case was the one from ddc665a4bb4b (bpf, arm64:
fix jit branch offset related to ldimm64), and turns out that we
do have a similar issue on s390 as well. In bpf_jit_prog() we
update next instruction address after returning from bpf_jit_insn()
with an insn_count. bpf_jit_insn() returns either -1 in case of
error (e.g. unsupported insn), 1 or 2. The latter is only the
case for ldimm64 due to spanning 2 insns, however, next address
is only set to i + 1 not taking actual insn_count into account,
thus fix is to use insn_count instead of 1. bpf_jit_enable in
mode 2 provides also disasm on s390:
Before fix:
000003ff800349b6: a7f40003 brc 15,3ff800349bc ; target
000003ff800349ba: 0000 unknown
000003ff800349bc: e3b0f0700024 stg %r11,112(%r15)
000003ff800349c2: e3e0f0880024 stg %r14,136(%r15)
000003ff800349c8: 0db0 basr %r11,%r0
000003ff800349ca: c0ef00000000 llilf %r14,0
000003ff800349d0: e320b0360004 lg %r2,54(%r11)
000003ff800349d6: e330b03e0004 lg %r3,62(%r11)
000003ff800349dc: ec23ffeda065 clgrj %r2,%r3,10,3ff800349b6 ; jmp
000003ff800349e2: e3e0b0460004 lg %r14,70(%r11)
000003ff800349e8: e3e0b04e0004 lg %r14,78(%r11)
000003ff800349ee: b904002e lgr %r2,%r14
000003ff800349f2: e3b0f0700004 lg %r11,112(%r15)
000003ff800349f8: e3e0f0880004 lg %r14,136(%r15)
000003ff800349fe: 07fe bcr 15,%r14
After fix:
000003ff80ef3db4: a7f40003 brc 15,3ff80ef3dba
000003ff80ef3db8: 0000 unknown
000003ff80ef3dba: e3b0f0700024 stg %r11,112(%r15)
000003ff80ef3dc0: e3e0f0880024 stg %r14,136(%r15)
000003ff80ef3dc6: 0db0 basr %r11,%r0
000003ff80ef3dc8: c0ef00000000 llilf %r14,0
000003ff80ef3dce: e320b0360004 lg %r2,54(%r11)
000003ff80ef3dd4: e330b03e0004 lg %r3,62(%r11)
000003ff80ef3dda: ec230006a065 clgrj %r2,%r3,10,3ff80ef3de6 ; jmp
000003ff80ef3de0: e3e0b0460004 lg %r14,70(%r11)
000003ff80ef3de6: e3e0b04e0004 lg %r14,78(%r11) ; target
000003ff80ef3dec: b904002e lgr %r2,%r14
000003ff80ef3df0: e3b0f0700004 lg %r11,112(%r15)
000003ff80ef3df6: e3e0f0880004 lg %r14,136(%r15)
000003ff80ef3dfc: 07fe bcr 15,%r14
test_bpf.ko suite runs fine after the fix.
Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The send call ignores unknown flags. Legacy applications may already
unwittingly pass MSG_ZEROCOPY. Continue to ignore this flag unless a
socket opts in to zerocopy.
Introduce socket option SO_ZEROCOPY to enable MSG_ZEROCOPY processing.
Processes can also query this socket option to detect kernel support
for the feature. Older kernels will return ENOPROTOOPT.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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And another header file for which we can use the generic variant,
even though it doesn't look obvious at first glance.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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clang doesn't like s390 specific inline assembler constraints. These
are present in our arch specific uapi/asm/swab.h which again is
required by some ebpf test cases.
For current compiler versions the generic swab.h already makes use of
gcc's builtin functions. Therefore we can simply remove our own header
file and use the generic one.
This will generate worse code if used with compilers before gcc 4.8,
which has no __builtin_bswap16(); or before gcc v4.4, which has no
__builtin_bswap[32|64](). For these cases a C implementation fallback
would be used which generates more code, but is still correct (170KB
extra code for gcc 4.3 with performance_defconfig).
However given that we need (and want) to get rid of the inline
assemblies anyway in order to be able to use clang, the above is just
a minor drawback if old gcc compilers are used.
With current compilers there is close to zero difference, except for
three btrfs bit functions which generate more out-of-line code. The
generated code looks still correct and also uses the s390 specific
byteswap instructions.
Reported-and-tested-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Multiple architectures define this as an empty function, and I'm adding
another one as part of the RISC-V port. Add a __weak version of
pcibios_fixup_bus() and delete the now-obselete ones in a handful of
ports.
The only functional change should be that microblaze used to export
pcibios_fixup_bus(). None of the other architectures exports this, so I
just dropped it.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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Both header files only include the corresponding uapi header file and
therefore can be removed.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The name of bit 36 of the machine check interruption code is "guarded
storage registers validity". Add the missing "validity" part in order
to be consistent with all other comments, which include this piece of
information.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Pull KVM fixes from Paolo Bonzini:
"s390:
- SRCU fix
PPC:
- host crash fixes
x86:
- bugfixes, including making nested posted interrupts really work
Generic:
- tweaks to kvm_stat and to uevents"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: LAPIC: Fix reentrancy issues with preempt notifiers
tools/kvm_stat: add '-f help' to get the available event list
tools/kvm_stat: use variables instead of hard paths in help output
KVM: nVMX: Fix loss of L2's NMI blocking state
KVM: nVMX: Fix posted intr delivery when vcpu is in guest mode
x86: irq: Define a global vector for nested posted interrupts
KVM: x86: do mask out upper bits of PAE CR3
KVM: make pid available for uevents without debugfs
KVM: s390: take srcu lock when getting/setting storage keys
KVM: VMX: remove unused field
KVM: PPC: Book3S HV: Fix host crash on changing HPT size
KVM: PPC: Book3S HV: Enable TM before accessing TM registers
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git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD
KVM: s390: fixup missing srcu lock
We need to hold the srcu lock when accessing memory slots
during migration
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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The z14 machine introduces new mode of the next-instruction-access-intent
NIAI instruction. With NIAI-8 it is possible to pin a cache-line on a
CPU for a small amount of time, NIAI-7 releases the cache-line again.
Finally NIAI-4 can be used to prevent the CPU to speculatively access
memory beyond the compare-and-swap instruction to get the lock.
Use these instruction in the spinlock code.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Add detection for machine type 0x3906 and set the ELF platform name
to z14. Add the miscellaneous-instruction-extension 2 facility to
the list of facilities for z14.
And allow to generate code that only runs on a z14 machine.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The TOD epoch extension adds 8 epoch bits to the TOD clock to provide
a continuous clock after 2042/09/17. The store-clock-extended (STCKE)
instruction will store the epoch index in the first byte of the
16 bytes stored by the instruction. The read_boot_clock64 and the
read_presistent_clock64 functions need to take the additional bits
into account to give the correct result after 2042/09/17.
The clock-comparator register will stay 64 bit wide. The comparison
of the clock-comparator with the TOD clock is limited to bytes
1 to 8 of the extended TOD format. To deal with the overflow problem
due to an epoch change the clock-comparator sign control in CR0 can
be used to switch the comparison of the 64-bit TOD clock with the
clock-comparator to a signed comparison.
The decision between the signed vs. unsigned clock-comparator
comparisons is done at boot time. Only if the TOD clock is in the
second half of a 142 year epoch the signed comparison is used.
This solves the epoch overflow issue as long as the machine is
booted at least once in an epoch.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Add various defines like e.g. _REGION1_SHIFT to reflect the hardware
mmu. We have quite a bit code that does not make use of the Linux
memory management primitives but directly modifies page, segment and
region values.
Most of this is open-coded like e.g. "1UL << 53". In order to clean
this up introduce a couple of new defines. The existing Linux memory
management defines are changed, so the mapping to the hardware
implementation is reflected.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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We have C code also outside of #ifndef __ASSEMBLY__. So these
guards seem to be quite pointless and can be removed.
Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Add the TLB flushing changes via a tip branch to ease merging with
the KVM tree.
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git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky:
"Three bug fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/mm: set change and reference bit on lazy key enablement
s390: chp: handle CRW_ERC_INIT for channel-path status change
s390/perf: fix problem state detection
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The following warning was triggered by missing srcu locks around
the storage key handling functions.
=============================
WARNING: suspicious RCU usage
4.12.0+ #56 Not tainted
-----------------------------
./include/linux/kvm_host.h:572 suspicious rcu_dereference_check() usage!
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by live_migration/4936:
#0: (&mm->mmap_sem){++++++}, at: [<0000000000141be0>]
kvm_arch_vm_ioctl+0x6b8/0x22d0
CPU: 8 PID: 4936 Comm: live_migration Not tainted 4.12.0+ #56
Hardware name: IBM 2964 NC9 704 (LPAR)
Call Trace:
([<000000000011378a>] show_stack+0xea/0xf0)
[<000000000055cc4c>] dump_stack+0x94/0xd8
[<000000000012ee70>] gfn_to_memslot+0x1a0/0x1b8
[<0000000000130b76>] gfn_to_hva+0x2e/0x48
[<0000000000141c3c>] kvm_arch_vm_ioctl+0x714/0x22d0
[<000000000013306c>] kvm_vm_ioctl+0x11c/0x7b8
[<000000000037e2c0>] do_vfs_ioctl+0xa8/0x6c8
[<000000000037e984>] SyS_ioctl+0xa4/0xb8
[<00000000008b20a4>] system_call+0xc4/0x27c
1 lock held by live_migration/4936:
#0: (&mm->mmap_sem){++++++}, at: [<0000000000141be0>]
kvm_arch_vm_ioctl+0x6b8/0x22d0
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Pierre Morel<pmorel@linux.vnet.ibm.com>
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Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The ESSA instruction has a new option that allows to tag pages that
are not used as a page table. Without the tag the hypervisor has to
assume that any guest page could be used in a page table inside the
guest. This forces the hypervisor to flush all guest TLB entries
whenever a host page table entry is invalidated. With the tag
the host can skip the TLB flush if the page is tagged as normal page.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYS
While this looks plausible on the surface, in practice this situation has
not worked well.
- Injected positive signals are not copied to user space properly
unless they have these magic high bits set.
- Injected positive signals are not reported properly by signalfd
unless they have these magic high bits set.
- These kernel internal values leaked to userspace via ptrace_peek_siginfo
- It was possible to inject these kernel internal values and cause the
the kernel to misbehave.
- Kernel developers got confused and expected these kernel internal values
in userspace in kernel self tests.
- Kernel developers got confused and set si_code to __SI_FAULT which
is SI_USER in userspace which causes userspace to think an ordinary user
sent the signal and that it was not kernel generated.
- The values make it impossible to reorganize the code to transform
siginfo_copy_to_user into a plain copy_to_user. As si_code must
be massaged before being passed to userspace.
So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.
To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used. Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.
A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like. The good news is only problem
architectures pay the cost.
Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values. Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.
Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first. The high bits are no
longer used to hold a magic union member.
Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.
The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.
The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.
Ref: 2.4.0-test1
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core fixes from Ingo Molnar:
"A fix to WARN_ON_ONCE() done by modules, plus a MAINTAINERS update"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
debug: Fix WARN_ON_ONCE() for modules
MAINTAINERS: Update the PTRACE entry
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Mike Galbraith reported a situation where a WARN_ON_ONCE() call in DRM
code turned into an oops. As it turns out, WARN_ON_ONCE() seems to be
completely broken when called from a module.
The bug was introduced with the following commit:
19d436268dde ("debug: Add _ONCE() logic to report_bug()")
That commit changed WARN_ON_ONCE() to move its 'once' logic into the bug
trap handler. It requires a writable bug table so that the BUGFLAG_DONE
bit can be written to the flags to indicate the first warning has
occurred.
The bug table was made writable for vmlinux, which relies on
vmlinux.lds.S and vmlinux.lds.h for laying out the sections. However,
it wasn't made writable for modules, which rely on the ELF section
header flags.
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-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>
Fixes: 19d436268dde ("debug: Add _ONCE() logic to report_bug()")
Link: http://lkml.kernel.org/r/a53b04235a65478dd9afc51f5b329fdc65c84364.1500095401.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull uacess-unaligned removal from Al Viro:
"That stuff had just one user, and an exotic one, at that - binfmt_flat
on arm and m68k"
* 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
kill {__,}{get,put}_user_unaligned()
binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail
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When we enable storage keys for a guest lazily, we reset the ACC and F
values. That is correct assuming that these are 0 on a clear reset and
the guest obviously has not used any key setting instruction.
We also zero out the change and reference bit. This is not correct as
the architecture prefers over-indication instead of under-indication
for the keyless->keyed transition.
This patch fixes the behaviour and always sets guest change and guest
reference for all guest storage keys on the keyless -> keyed switch.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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The P sample bit indicates problem state and not PER.
Fixes: commit a752598254 ("s390: rename struct psw_bits members")
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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As Eric said,
"what we need to do is move the variable vmcoreinfo_note out of the
kernel's .bss section. And modify the code to regenerate and keep this
information in something like the control page.
Definitely something like this needs a page all to itself, and ideally
far away from any other kernel data structures. I clearly was not
watching closely the data someone decided to keep this silly thing in
the kernel's .bss section."
This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.
Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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