linux-stable.git/arch/s390, branch v4.2

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2015-08-05T15:50:38+00:00

Pull KVM fixes from Paolo Bonzini:
 "Just two very small & simple patches"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: MTRR: Use default type for non-MTRR-covered gfn before WARN_ON
  KVM: s390: Fix hang VCPU hang/loop regression

KVM: s390: Fix hang VCPU hang/loop regression

2015-07-30T11:11:13+00:00

commit 785dbef407d8 ("KVM: s390: optimize round trip time in request
handling") introduced a regression. This regression was seen with
CPU hotplug in the guest and switching between 1 or 2 CPUs. This will
set/reset the IBS control via synced request.

Whenever we make a synced request, we first set the vcpu->requests
bit and then block the vcpu. The handler, on the other hand, unblocks
itself, processes vcpu->requests (by clearing them) and unblocks itself
once again.

Now, if the requester sleeps between setting of vcpu->requests and
blocking, the handler will clear the vcpu->requests bit and try to
unblock itself (although no bit is set). When the requester wakes up,
it blocks the VCPU and we have a blocked VCPU without requests.

Solution is to always unset the block bit.

Signed-off-by: Christian Borntraeger 
Reviewed-by: David Hildenbrand 
Fixes: 785dbef407d8 ("KVM: s390: optimize round trip time in request handling")

s390/cachinfo: add missing facility check to init_cache_level()

2015-07-28T06:54:42+00:00

Stephen Powell reported the following crash on a z890 machine:

Kernel BUG at 00000000001219d0 [verbose debug info unavailable]
illegal operation: 0001 ilc:3 [#1] SMP
Krnl PSW : 0704e00180000000 00000000001219d0 (init_cache_level+0x38/0xe0)
	   R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 EA:3
Krnl Code: 00000000001219c2: a7840056		brc	8,121a6e
	   00000000001219c6: a7190000		lghi	%r1,0
	  #00000000001219ca: eb101000004c	ecag	%r1,%r0,0(%r1)
	  >00000000001219d0: a7390000		lghi	%r3,0
	   00000000001219d4: e310f0a00024	stg	%r1,160(%r15)
	   00000000001219da: a7080000		lhi	%r0,0
	   00000000001219de: a7b9f000		lghi	%r11,-4096
	   00000000001219e2: c0a0002899d9	larl	%r10,634d94
Call Trace:
 [<0000000000478ee2>] detect_cache_attributes+0x2a/0x2b8
 [<000000000097c9b0>] cacheinfo_sysfs_init+0x60/0xc8
 [<00000000001001c0>] do_one_initcall+0x98/0x1c8
 [<000000000094fdc2>] kernel_init_freeable+0x212/0x2d8
 [<000000000062352e>] kernel_init+0x26/0x118
 [<000000000062fd2e>] kernel_thread_starter+0x6/0xc

The illegal operation was executed because of a missing facility check,
which should have made sure that the ECAG execution would only be executed
on machines which have the general-instructions-extension facility
installed.

Reported-and-tested-by: Stephen Powell 
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

s390/bpf: clear correct BPF accumulator register

2015-07-27T07:08:11+00:00

Currently we assumed the following BPF to eBPF register mapping:

 - BPF_REG_A -> BPF_REG_7
 - BPF_REG_X -> BPF_REG_8

Unfortunately this mapping is wrong. The correct mapping is:

 - BPF_REG_A -> BPF_REG_0
 - BPF_REG_X -> BPF_REG_7

So clear the correct registers and use the BPF_REG_A and BPF_REG_X
macros instead of BPF_REG_0/7.

Fixes: 054623105728 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Michael Holzheu 
Signed-off-by: Martin Schwidefsky

s390: adapt entry.S to the move of thread_struct

2015-07-20T11:22:18+00:00

git commit 0c8c0f03e3a292e031596484275c14cf39c0ab7a
"x86/fpu, sched: Dynamically allocate 'struct fpu'"
moved the thread_struct to the end of the task_struct.

This causes some of the offsets used in entry.S to overflow their
instruction operand field. To fix this  use aghi to create a
dedicated pointer for the thread_struct.

Signed-off-by: Martin Schwidefsky

mm: clean up per architecture MM hook header files

2015-07-17T23:39:53+00:00

Commit 2ae416b142b6 ("mm: new mm hook framework") introduced an empty
header file (mm-arch-hooks.h) for every architecture, even those which
doesn't need to define mm hooks.

As suggested by Geert Uytterhoeven, this could be cleaned through the use
of a generic header file included via each per architecture
asm/include/Kbuild file.

The PowerPC architecture is not impacted here since this architecture has
to defined the arch_remap MM hook.

Signed-off-by: Laurent Dufour 
Suggested-by: Geert Uytterhoeven 
Acked-by: Geert Uytterhoeven 
Acked-by: Vineet Gupta 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

s390/hugetlb: add hugepages_supported define

2015-07-17T23:39:52+00:00

On s390 we only can enable hugepages if the underlying hardware/hypervisor
also does support this.  Common code now would assume this to be
signaled by setting HPAGE_SHIFT to 0.  But on s390, where we only
support one hugepage size, there is a link between HPAGE_SHIFT and
pageblock_order.

So instead of setting HPAGE_SHIFT to 0, we will implement the check for
the hardware capability.

Signed-off-by: Dominik Dingel 
Acked-by: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Christian Borntraeger 
Cc: Michael Holzheu 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "s390/mm: make hugepages_supported a boot time decision"

2015-07-17T23:39:52+00:00

Heiko noticed that the current check for hugepage support on s390 is a
little bit too harsh as systems which do not support will crash.

The reason is that pageblock_order can now get negative when we set
HPAGE_SHIFT to 0.  To avoid all this and to avoid opening another can of
worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best
to simply allow architectures to define their own hugepages_supported().

Revert bea41197ead3 ("s390/mm: make hugepages_supported a boot time
decision") in preparation.

Signed-off-by: Dominik Dingel 
Acked-by: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Christian Borntraeger 
Cc: Michael Holzheu 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

revert "s390/mm: change HPAGE_SHIFT type to int"

2015-07-17T23:39:52+00:00

Heiko noticed that the current check for hugepage support on s390 is a
little bit too harsh as systems which do not support will crash.

The reason is that pageblock_order can now get negative when we set
HPAGE_SHIFT to 0.  To avoid all this and to avoid opening another can of
worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best
to simply allow architectures to define their own hugepages_supported().

This patch (of 4): revert commit cf54e2fce51c ("s390/mm: change
HPAGE_SHIFT type to int") in preparation.

Signed-off-by: Dominik Dingel 
Acked-by: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Christian Borntraeger 
Cc: Michael Holzheu 
Cc: Gerald Schaefer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2015-07-15T20:12:44+00:00

Pull s390 fixes from Martin Schwidefsky:
 "One improvement for the zcrypt driver, the quality attribute for the
  hwrng device has been missing.  Without it the kernel entropy seeding
  will not happen automatically.

  And six bug fixes, the most important one is the fix for the vector
  register corruption due to machine checks"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/nmi: fix vector register corruption
  s390/process: fix sfpc inline assembly
  s390/dasd: fix kernel panic when alias is set offline
  s390/sclp: clear upper register halves in _sclp_print_early
  s390/oprofile: fix compile error
  s390/sclp: fix compile error
  s390/zcrypt: enable s390 hwrng to seed kernel entropy