commit fbbd7f1a51 upstream.
The switch_to() macro has an optimization to avoid saving and
restoring register contents that aren't needed for kernel threads.
There is however the possibility that a kernel thread execve's a user
space program. In such a case the execve'd process can partially see
the contents of the previous process, which shouldn't be allowed.
To avoid this, simply always save and restore register contents on
context switch.
Fixes: fdb6d070ef ("switch_to: dont restore/save access & fpu regs for kernel threads")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 48070c7305 ]
As of today QEMU does not provide the AIS facility to its guest. This
prevents Linux guests from using PCI devices as the ais facility is
checked during init. As this is just a performance optimization, we can
move the ais check into the code where we need it (calling the SIC
instruction). This is used at initialization and on interrupt. Both
places do not require any serialization, so we can simply skip the
instruction.
Since we will now get all interrupts, we can also avoid the 2nd scan.
As we can have multiple interrupts in parallel we might trigger spurious
irqs more often for the non-AIS case but the core code can handle that.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8d9047f8b9 upstream.
Free data structures required for runtime instrumentation from
arch_release_task_struct(). This allows to simplify the code a bit,
and also makes the semantics a bit easier: arch_release_task_struct()
is never called from the task that is being removed.
In addition this allows to get rid of exit_thread() in a later patch.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit cabab3f9f5 ]
s390 version of commit 334bb77387 ("x86/kbuild: enable modversions
for symbols exported from asm") so we get also rid of all these
warnings:
WARNING: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "memcpy" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "memmove" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "save_fpu_regs" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "sie64a" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "sie_exit" [vmlinux] version generation failed, symbol will not be versioned.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a1c5befc1c upstream.
Dan Horák reported the following crash related to transactional execution:
User process fault: interruption code 0013 ilc:3 in libpthread-2.26.so[3ff93c00000+1b000]
CPU: 2 PID: 1 Comm: /init Not tainted 4.13.4-300.fc27.s390x #1
Hardware name: IBM 2827 H43 400 (z/VM 6.4.0)
task: 00000000fafc8000 task.stack: 00000000fafc4000
User PSW : 0705200180000000 000003ff93c14e70
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:2 PM:0 RI:0 EA:3
User GPRS: 0000000000000077 000003ff00000000 000003ff93144d48 000003ff93144d5e
0000000000000000 0000000000000002 0000000000000000 000003ff00000000
0000000000000000 0000000000000418 0000000000000000 000003ffcc9fe770
000003ff93d28f50 000003ff9310acf0 000003ff92b0319a 000003ffcc9fe6d0
User Code: 000003ff93c14e62: 60e0b030 std %f14,48(%r11)
000003ff93c14e66: 60f0b038 std %f15,56(%r11)
#000003ff93c14e6a: e5600000ff0e tbegin 0,65294
>000003ff93c14e70: a7740006 brc 7,3ff93c14e7c
000003ff93c14e74: a7080000 lhi %r0,0
000003ff93c14e78: a7f40023 brc 15,3ff93c14ebe
000003ff93c14e7c: b2220000 ipm %r0
000003ff93c14e80: 8800001c srl %r0,28
There are several bugs with control register handling with respect to
transactional execution:
- on task switch update_per_regs() is only called if the next task has
an mm (is not a kernel thread). This however is incorrect. This
breaks e.g. for user mode helper handling, where the kernel creates
a kernel thread and then execve's a user space program. Control
register contents related to transactional execution won't be
updated on execve. If the previous task ran with transactional
execution disabled then the new task will also run with
transactional execution disabled, which is incorrect. Therefore call
update_per_regs() unconditionally within switch_to().
- on startup the transactional execution facility is not enabled for
the idle thread. This is not really a bug, but an inconsistency to
other facilities. Therefore enable the facility if it is available.
- on fork the new thread's per_flags field is not cleared. This means
that a child process inherits the PER_FLAG_NO_TE flag. This flag can
be set with a ptrace request to disable transactional execution for
the current process. It should not be inherited by new child
processes in order to be consistent with the handling of all other
PER related debugging options. Therefore clear the per_flags field in
copy_thread_tls().
Reported-and-tested-by: Dan Horák <dan@danny.cz>
Fixes: d35339a42d ("s390: add support for transactional memory")
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 91c575b335 upstream.
Commit 227be799c3 ("s390/mm: uninline pmdp_xxx functions from pgtable.h")
inadvertently changed the behavior of pmdp_invalidate(), so that it now
clears the pmd instead of just marking it as invalid. Fix this by restoring
the original behavior.
A possible impact of the misbehaving pmdp_invalidate() would be the
MADV_DONTNEED races (see commits ced10803 and 58ceeb6b), although we
should not have any negative impact on the related dirty/young flags,
since those flags are not set by the hardware on s390.
Fixes: 227be799c3 ("s390/mm: uninline pmdp_xxx functions from pgtable.h")
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 60f07c8ec5 upstream.
The order in __tlb_flush_mm_lazy is to flush TLB first and then clear
the mm->context.flush_mm bit. This can lead to missed flushes as the
bit can be set anytime, the order needs to be the other way aronud.
But this leads to a different race, __tlb_flush_mm_lazy may be called
on two CPUs concurrently. If mm->context.flush_mm is cleared first then
another CPU can bypass __tlb_flush_mm_lazy although the first CPU has
not done the flush yet. In a virtualized environment the time until the
flush is finally completed can be arbitrarily long.
Add a spinlock to serialize __tlb_flush_mm_lazy and use the function
in finish_arch_post_lock_switch as well.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b3e5dc45fd upstream.
The local TLB flushing code keeps an additional mask in the mm.context,
the cpu_attach_mask. At the time a global flush of an address space is
done the cpu_attach_mask is copied to the mm_cpumask in order to avoid
future global flushes in case the mm is used by a single CPU only after
the flush.
Trouble is that the reset of the mm_cpumask is racy against the detach
of an mm address space by switch_mm. The current order is first the
global TLB flush and then the copy of the cpu_attach_mask to the
mm_cpumask. The order needs to be the other way around.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fa41ba0d08 upstream.
Right now there is a potential hang situation for postcopy migrations,
if the guest is enabling storage keys on the target system during the
postcopy process.
For storage key virtualization, we have to forbid the empty zero page as
the storage key is a property of the physical page frame. As we enable
storage key handling lazily we then drop all mappings for empty zero
pages for lazy refaulting later on.
This does not work with the postcopy migration, which relies on the
empty zero page never triggering a fault again in the future. The reason
is that postcopy migration will simply read a page on the target system
if that page is a known zero page to fault in an empty zero page. At
the same time postcopy remembers that this page was already transferred
- so any future userfault on that page will NOT be retransmitted again
to avoid races.
If now the guest enters the storage key mode while in postcopy, we will
break this assumption of postcopy.
The solution is to disable the empty zero page for KVM guests early on
and not during storage key enablement. With this change, the postcopy
migration process is guaranteed to start after no zero pages are left.
As guest pages are very likely not empty zero pages anyway the memory
overhead is also pretty small.
While at it this also adds proper page table locking to the zero page
removal.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c46fc0424c upstream.
Zorro reported following crash while having enabled
syscall tracing (CONFIG_FTRACE_SYSCALLS):
Unable to handle kernel pointer dereference at virtual ...
Oops: 0011 [#1] SMP DEBUG_PAGEALLOC
SNIP
Call Trace:
([<000000000024d79c>] ftrace_syscall_enter+0xec/0x1d8)
[<00000000001099c6>] do_syscall_trace_enter+0x236/0x2f8
[<0000000000730f1c>] sysc_tracesys+0x1a/0x32
[<000003fffcf946a2>] 0x3fffcf946a2
INFO: lockdep is turned off.
Last Breaking-Event-Address:
[<000000000022dd44>] rb_event_data+0x34/0x40
---[ end trace 8c795f86b1b3f7b9 ]---
The crash happens in syscall_get_arguments function for
syscalls with zero arguments, that will try to access
first argument (args[0]) in event entry, but it's not
allocated.
Bail out of there are no arguments.
Reported-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e991c24d68 ]
We have quite a lot of code that depends on the order of the
__ctl_load inline assemby and subsequent memory accesses, like
e.g. disabling lowcore protection and the writing to lowcore.
Since the __ctl_load macro does not have memory barrier semantics, nor
any other dependencies the compiler is, theoretically, free to shuffle
code around. Or in other words: storing to lowcore could happen before
lowcore protection is disabled.
In order to avoid this class of potential bugs simply add a full
memory barrier to the __ctl_load macro.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a8f60d1fad upstream.
On heavy paging with KSM I see guest data corruption. Turns out that
KSM will add pages to its tree, where the mapping return true for
pte_unused (or might become as such later). KSM will unmap such pages
and reinstantiate with different attributes (e.g. write protected or
special, e.g. in replace_page or write_protect_page)). This uncovered
a bug in our pagetable handling: We must remove the unused flag as
soon as an entry becomes present again.
Signed-of-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d09c5373e8 upstream.
Commit fd2d2b191f ("s390: get_user() should zero on failure")
intended to fix s390's get_user() implementation which did not zero
the target operand if the read from user space faulted. Unfortunately
the patch has no effect: the corresponding inline assembly specifies
that the operand is only written to ("=") and the previous value is
discarded.
Therefore the compiler is free to and actually does omit the zero
initialization.
To fix this simply change the contraint modifier to "+", so the
compiler cannot omit the initialization anymore.
Fixes: c9ca78415a ("s390/uaccess: provide inline variants of get_user/put_user")
Fixes: fd2d2b191f ("s390: get_user() should zero on failure")
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb94a687d9 upstream.
Return a sensible value if TASK_SIZE if called from a kernel thread.
This gets us around an issue with copy_mount_options that does a magic
size calculation "TASK_SIZE - (unsigned long)data" while in a kernel
thread and data pointing to kernel space.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With commit ef6000b4c6 ("Disable the __builtin_return_address()
warning globally after all)" the kernel does not warn at all again if
__builtin_return_address(n) is called with n > 0.
Besides the fact that this was a false warning on s390 anyway, due to
the always present backchain, we can now revert commit 5606330627
("s390/dumpstack: implement and use return_address()") again, to
simplify the code again.
After all I shouldn't have had return_address() implememted at all to
workaround this issue. So get rid of this again.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Before merging all different stack tracers the call traces printed had
an indicator if an entry can be considered reliable or not.
Unreliable entries were put in braces, reliable not. Currently all
lines contain these extra braces.
This patch restores the old behaviour by adding an extra "reliable"
parameter to the callback functions. Only show_trace makes currently
use of it.
Before:
[ 0.804751] Call Trace:
[ 0.804753] ([<000000000017d0e0>] try_to_wake_up+0x318/0x5e0)
[ 0.804756] ([<0000000000161d64>] create_worker+0x174/0x1c0)
After:
[ 0.804751] Call Trace:
[ 0.804753] ([<000000000017d0e0>] try_to_wake_up+0x318/0x5e0)
[ 0.804756] [<0000000000161d64>] create_worker+0x174/0x1c0
Fixes: 758d39ebd3 ("s390/dumpstack: merge all four stack tracers")
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Ignore the pkey systems calls since they don't make any sense on s390.
In addition any user could trigger a warning if issueing the pkey_free
system call, if it would be wired up on a system without pkey support.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull kbuild updates from Michal Marek:
- EXPORT_SYMBOL for asm source by Al Viro.
This does bring a regression, because genksyms no longer generates
checksums for these symbols (CONFIG_MODVERSIONS). Nick Piggin is
working on a patch to fix this.
Plus, we are talking about functions like strcpy(), which rarely
change prototypes.
- Fixes for PPC fallout of the above by Stephen Rothwell and Nick
Piggin
- fixdep speedup by Alexey Dobriyan.
- preparatory work by Nick Piggin to allow architectures to build with
-ffunction-sections, -fdata-sections and --gc-sections
- CONFIG_THIN_ARCHIVES support by Stephen Rothwell
- fix for filenames with colons in the initramfs source by me.
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (22 commits)
initramfs: Escape colons in depfile
ppc: there is no clear_pages to export
powerpc/64: whitelist unresolved modversions CRCs
kbuild: -ffunction-sections fix for archs with conflicting sections
kbuild: add arch specific post-link Makefile
kbuild: allow archs to select link dead code/data elimination
kbuild: allow architectures to use thin archives instead of ld -r
kbuild: Regenerate genksyms lexer
kbuild: genksyms fix for typeof handling
fixdep: faster CONFIG_ search
ia64: move exports to definitions
sparc32: debride memcpy.S a bit
[sparc] unify 32bit and 64bit string.h
sparc: move exports to definitions
ppc: move exports to definitions
arm: move exports to definitions
s390: move exports to definitions
m68k: move exports to definitions
alpha: move exports to actual definitions
x86: move exports to actual definitions
...
Pull KVM updates from Radim Krčmář:
"All architectures:
- move `make kvmconfig` stubs from x86
- use 64 bits for debugfs stats
ARM:
- Important fixes for not using an in-kernel irqchip
- handle SError exceptions and present them to guests if appropriate
- proxying of GICV access at EL2 if guest mappings are unsafe
- GICv3 on AArch32 on ARMv8
- preparations for GICv3 save/restore, including ABI docs
- cleanups and a bit of optimizations
MIPS:
- A couple of fixes in preparation for supporting MIPS EVA host
kernels
- MIPS SMP host & TLB invalidation fixes
PPC:
- Fix the bug which caused guests to falsely report lockups
- other minor fixes
- a small optimization
s390:
- Lazy enablement of runtime instrumentation
- up to 255 CPUs for nested guests
- rework of machine check deliver
- cleanups and fixes
x86:
- IOMMU part of AMD's AVIC for vmexit-less interrupt delivery
- Hyper-V TSC page
- per-vcpu tsc_offset in debugfs
- accelerated INS/OUTS in nVMX
- cleanups and fixes"
* tag 'kvm-4.9-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (140 commits)
KVM: MIPS: Drop dubious EntryHi optimisation
KVM: MIPS: Invalidate TLB by regenerating ASIDs
KVM: MIPS: Split kernel/user ASID regeneration
KVM: MIPS: Drop other CPU ASIDs on guest MMU changes
KVM: arm/arm64: vgic: Don't flush/sync without a working vgic
KVM: arm64: Require in-kernel irqchip for PMU support
KVM: PPC: Book3s PR: Allow access to unprivileged MMCR2 register
KVM: PPC: Book3S PR: Support 64kB page size on POWER8E and POWER8NVL
KVM: PPC: Book3S: Remove duplicate setting of the B field in tlbie
KVM: PPC: BookE: Fix a sanity check
KVM: PPC: Book3S HV: Take out virtual core piggybacking code
KVM: PPC: Book3S: Treat VTB as a per-subcore register, not per-thread
ARM: gic-v3: Work around definition of gic_write_bpr1
KVM: nVMX: Fix the NMI IDT-vectoring handling
KVM: VMX: Enable MSR-BASED TPR shadow even if APICv is inactive
KVM: nVMX: Fix reload apic access page warning
kvmconfig: add virtio-gpu to config fragment
config: move x86 kvm_guest.config to a common location
arm64: KVM: Remove duplicating init code for setting VMID
ARM: KVM: Support vgic-v3
...
Pull s390 updates from Martin Schwidefsky:
"The new features and main improvements in this merge for v4.9
- Support for the UBSAN sanitizer
- Set HAVE_EFFICIENT_UNALIGNED_ACCESS, it improves the code in some
places
- Improvements for the in-kernel fpu code, in particular the overhead
for multiple consecutive in kernel fpu users is recuded
- Add a SIMD implementation for the RAID6 gen and xor operations
- Add RAID6 recovery based on the XC instruction
- The PCI DMA flush logic has been improved to increase the speed of
the map / unmap operations
- The time synchronization code has seen some updates
And bug fixes all over the place"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (48 commits)
s390/con3270: fix insufficient space padding
s390/con3270: fix use of uninitialised data
MAINTAINERS: update DASD maintainer
s390/cio: fix accidental interrupt enabling during resume
s390/dasd: add missing \n to end of dev_err messages
s390/config: Enable config options for Docker
s390/dasd: make query host access interruptible
s390/dasd: fix panic during offline processing
s390/dasd: fix hanging offline processing
s390/pci_dma: improve lazy flush for unmap
s390/pci_dma: split dma_update_trans
s390/pci_dma: improve map_sg
s390/pci_dma: simplify dma address calculation
s390/pci_dma: remove dma address range check
iommu/s390: simplify registration of I/O address translation parameters
s390: migrate exception table users off module.h and onto extable.h
s390: export header for CLP ioctl
s390/vmur: fix irq pointer dereference in int handler
s390/dasd: add missing KOBJ_CHANGE event for unformatted devices
s390: enable UBSAN
...
Lazy unmap (defer tlb flush after unmap until dma address reuse) can
greatly reduce the number of RPCIT instructions in the best case. In
reality we are often far away from the best case scenario because our
implementation suffers from the following problem:
To create dma addresses we maintain an iommu bitmap and a pointer into
that bitmap to mark the start of the next search. That pointer moves from
the start to the end of that bitmap and we issue a global tlb flush
once that pointer wraps around. To prevent address reuse before we issue
the tlb flush we even have to move the next pointer during unmaps - when
clearing a bit > next. This could lead to a situation where we only use
the rear part of that bitmap and issue more tlb flushes than expected.
To fix this we no longer clear bits during unmap but maintain a 2nd
bitmap which we use to mark addresses that can't be reused until we issue
the global tlb flush after wrap around.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull uaccess fixes from Al Viro:
"Fixes for broken uaccess primitives - mostly lack of proper zeroing
in copy_from_user()/get_user()/__get_user(), but for several
architectures there's more (broken clear_user() on frv and
strncpy_from_user() on hexagon)"
* 'uaccess-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits)
avr32: fix copy_from_user()
microblaze: fix __get_user()
microblaze: fix copy_from_user()
m32r: fix __get_user()
blackfin: fix copy_from_user()
sparc32: fix copy_from_user()
sh: fix copy_from_user()
sh64: failing __get_user() should zero
score: fix copy_from_user() and friends
score: fix __get_user/get_user
s390: get_user() should zero on failure
ppc32: fix copy_from_user()
parisc: fix copy_from_user()
openrisc: fix copy_from_user()
nios2: fix __get_user()
nios2: copy_from_user() should zero the tail of destination
mn10300: copy_from_user() should zero on access_ok() failure...
mn10300: failing __get_user() and get_user() should zero
mips: copy_from_user() must zero the destination on access_ok() failure
ARC: uaccess: get_user to zero out dest in cause of fault
...
Paul Mackerras writes:
The highlights are:
* Reduced latency for interrupts from PCI pass-through devices, from
Suresh Warrier and me.
* Halt-polling implementation from Suraj Jitindar Singh.
* 64-bit VCPU statistics, also from Suraj.
* Various other minor fixes and improvements.
If the SCA entries aren't used by the hardware (no SIGPIF), we
can simply not set the entries, stick to the basic sca and allow more
than 64 VCPUs.
To hinder any other facility from using these entries, let's properly
provoke intercepts by not setting the MCN and keeping the entries
unset.
This effectively allows when running KVM under KVM (vSIE) or under z/VM to
provide more than 64 VCPUs to a guest. Let's limit it to 255 for now, to
not run into problems if the CPU numbers are limited somewhere else.
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
vms and vcpus have statistics associated with them which can be viewed
within the debugfs. Currently it is assumed within the vcpu_stat_get() and
vm_stat_get() functions that all of these statistics are represented as
u32s, however the next patch adds some u64 vcpu statistics.
Change all vcpu statistics to u64 and modify vcpu_stat_get() accordingly.
Since vcpu statistics are per vcpu, they will only be updated by a single
vcpu at a time so this shouldn't present a problem on 32-bit machines
which can't atomically increment 64-bit numbers. However vm statistics
could potentially be updated by multiple vcpus from that vm at a time.
To avoid the overhead of atomics make all vm statistics ulong such that
they are 64-bit on 64-bit systems where they can be atomically incremented
and are 32-bit on 32-bit systems which may not be able to atomically
increment 64-bit numbers. Modify vm_stat_get() to expect ulongs.
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
There are three usercopy warnings which are currently being silenced for
gcc 4.6 and newer:
1) "copy_from_user() buffer size is too small" compile warning/error
This is a static warning which happens when object size and copy size
are both const, and copy size > object size. I didn't see any false
positives for this one. So the function warning attribute seems to
be working fine here.
Note this scenario is always a bug and so I think it should be
changed to *always* be an error, regardless of
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS.
2) "copy_from_user() buffer size is not provably correct" compile warning
This is another static warning which happens when I enable
__compiletime_object_size() for new compilers (and
CONFIG_DEBUG_STRICT_USER_COPY_CHECKS). It happens when object size
is const, but copy size is *not*. In this case there's no way to
compare the two at build time, so it gives the warning. (Note the
warning is a byproduct of the fact that gcc has no way of knowing
whether the overflow function will be called, so the call isn't dead
code and the warning attribute is activated.)
So this warning seems to only indicate "this is an unusual pattern,
maybe you should check it out" rather than "this is a bug".
I get 102(!) of these warnings with allyesconfig and the
__compiletime_object_size() gcc check removed. I don't know if there
are any real bugs hiding in there, but from looking at a small
sample, I didn't see any. According to Kees, it does sometimes find
real bugs. But the false positive rate seems high.
3) "Buffer overflow detected" runtime warning
This is a runtime warning where object size is const, and copy size >
object size.
All three warnings (both static and runtime) were completely disabled
for gcc 4.6 with the following commit:
2fb0815c9e ("gcc4: disable __compiletime_object_size for GCC 4.6+")
That commit mistakenly assumed that the false positives were caused by a
gcc bug in __compiletime_object_size(). But in fact,
__compiletime_object_size() seems to be working fine. The false
positives were instead triggered by #2 above. (Though I don't have an
explanation for why the warnings supposedly only started showing up in
gcc 4.6.)
So remove warning #2 to get rid of all the false positives, and re-enable
warnings #1 and #3 by reverting the above commit.
Furthermore, since #1 is a real bug which is detected at compile time,
upgrade it to always be an error.
Having done all that, CONFIG_DEBUG_STRICT_USER_COPY_CHECKS is no longer
needed.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The CPACF code makes some assumptions about the availablity of hardware
support. E.g. if the machine supports KM(AES-256) without chaining it is
assumed that KMC(AES-256) with chaining is available as well. For the
existing CPUs this is true but the architecturally correct way is to
check each CPACF functions on its own. This is what the query function
of each instructions is all about.
Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The CPACF instructions can complete with three different condition codes:
CC=0 for successful completion, CC=1 if the protected key verification
failed, and CC=3 for partial completion.
The inline functions will restart the CPACF instruction for partial
completion, this removes the CC=3 case. The CC=1 case is only relevant
for the protected key functions of the KM, KMC, KMAC and KMCTR
instructions. As the protected key functions are not used by the
current code, there is no need for any kind of return code handling.
Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Use a separate define for the decryption modifier bit instead of
duplicating the function codes for encryption / decrypton.
In addition use an unsigned type for the function code.
Reviewed-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
In case of nested user of the FPU or vector registers in the kernel
the current code uses the mask of the FPU/vector registers of the
previous contexts to decide which registers to save and restore.
E.g. if the previous context used KERNEL_VXR_V0V7 and the next
context wants to use KERNEL_VXR_V24V31 the first 8 vector registers
are stored to the FPU state structure. But this is not necessary
as the next context does not use these registers.
Rework the FPU/vector register save and restore code. The new code
does a few things differently:
1) A lowcore field is used instead of a per-cpu variable.
2) The kernel_fpu_end function now has two parameters just like
kernel_fpu_begin. The register flags are required by both
functions to save / restore the minimal register set.
3) The inline functions kernel_fpu_begin/kernel_fpu_end now do the
update of the register masks. If the user space FPU registers
have already been stored neither save_fpu_regs nor the
__kernel_fpu_begin/__kernel_fpu_end functions have to be called
for the first context. In this case kernel_fpu_begin adds 7
instructions and kernel_fpu_end adds 4 instructions.
3) The inline assemblies in __kernel_fpu_begin / __kernel_fpu_end
to save / restore the vector registers are simplified a bit.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
To make the vx-insn.h more versatile avoid cpp preprocessor macros
and allow to use plain numbers for vector and general purpose register
operands. With that you can emit an .include from a C file into the
assembler text and then use the vx-insn macros in inline assemblies.
For example:
asm (".include \"asm/vx-insn.h\"");
static inline void xor_vec(int x, int y, int z)
{
asm volatile("VX %0,%1,%2"
: : "i" (x), "i" (y), "i" (z));
}
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Pull facility mask patch from the KVM tree.
* tag 's390forkvm' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux
KVM: s390: generate facility mask from readable list
Automatically generate the KVM facility mask out of a readable list.
Manually changing the masks is very error prone, especially if the
special IBM bit numbering has to be considered.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
The 'report_error' interface for PCI devices found on s390 can be
used by a user space program to inject an adapter error notification.
Add a new kernel interface zpci_report_error to allow a PCI device
driver to inject these error notifications without a detour over
user space.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge the __p[m|u]xdp_idte and __p[m|u]dp_idte_local functions into a
single __p[m|u]dp_idte function with an additional parameter.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge the __ptep_ipte and __ptep_ipte_local functions into a single
__ptep_ipte function with an additional parameter. The __pte_ipte_range
function is still extra as the while loops makes it hard to merge.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The __tlb_flush_mm() helper uses a global flush if the mm struct
has a gmap structure attached to it. Replace the global flush with
two individual flushes by means of the IDTE instruction if only a
single gmap is attached the the mm.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The local-clearing control of the IDTE instruction does not have any effect
for the clearing-by-ASCE operation. Only the invalidation-and-clearing
operation respects the local-clearing bit.
Remove __tlb_flush_idte_local and simplify the batched TLB flushing code.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The dma-mapping core and the implementations do not change the DMA
attributes passed by pointer. Thus the pointer can point to const data.
However the attributes do not have to be a bitfield. Instead unsigned
long will do fine:
1. This is just simpler. Both in terms of reading the code and setting
attributes. Instead of initializing local attributes on the stack
and passing pointer to it to dma_set_attr(), just set the bits.
2. It brings safeness and checking for const correctness because the
attributes are passed by value.
Semantic patches for this change (at least most of them):
virtual patch
virtual context
@r@
identifier f, attrs;
@@
f(...,
- struct dma_attrs *attrs
+ unsigned long attrs
, ...)
{
...
}
@@
identifier r.f;
@@
f(...,
- NULL
+ 0
)
and
// Options: --all-includes
virtual patch
virtual context
@r@
identifier f, attrs;
type t;
@@
t f(..., struct dma_attrs *attrs);
@@
identifier r.f;
@@
f(...,
- NULL
+ 0
)
Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
Acked-by: Mark Salter <msalter@redhat.com> [c6x]
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris]
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm]
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp]
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core]
Acked-by: David Vrabel <david.vrabel@citrix.com> [xen]
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb]
Acked-by: Joerg Roedel <jroedel@suse.de> [iommu]
Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390]
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32]
Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc]
Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull KVM updates from Paolo Bonzini:
- ARM: GICv3 ITS emulation and various fixes. Removal of the
old VGIC implementation.
- s390: support for trapping software breakpoints, nested
virtualization (vSIE), the STHYI opcode, initial extensions
for CPU model support.
- MIPS: support for MIPS64 hosts (32-bit guests only) and lots
of cleanups, preliminary to this and the upcoming support for
hardware virtualization extensions.
- x86: support for execute-only mappings in nested EPT; reduced
vmexit latency for TSC deadline timer (by about 30%) on Intel
hosts; support for more than 255 vCPUs.
- PPC: bugfixes.
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits)
KVM: PPC: Introduce KVM_CAP_PPC_HTM
MIPS: Select HAVE_KVM for MIPS64_R{2,6}
MIPS: KVM: Reset CP0_PageMask during host TLB flush
MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX()
MIPS: KVM: Sign extend MFC0/RDHWR results
MIPS: KVM: Fix 64-bit big endian dynamic translation
MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase
MIPS: KVM: Use 64-bit CP0_EBase when appropriate
MIPS: KVM: Set CP0_Status.KX on MIPS64
MIPS: KVM: Make entry code MIPS64 friendly
MIPS: KVM: Use kmap instead of CKSEG0ADDR()
MIPS: KVM: Use virt_to_phys() to get commpage PFN
MIPS: Fix definition of KSEGX() for 64-bit
KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD
kvm: x86: nVMX: maintain internal copy of current VMCS
KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE
KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures
KVM: arm64: vgic-its: Simplify MAPI error handling
KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers
KVM: arm64: vgic-its: Turn device_id validation into generic ID validation
...
AT_VECTOR_SIZE_ARCH should be defined with the maximum number of
NEW_AUX_ENT entries that ARCH_DLINFO can contain, but it wasn't defined
for s390 at all even though ARCH_DLINFO can contain one NEW_AUX_ENT when
VDSO is enabled.
This shouldn't be a problem as AT_VECTOR_SIZE_BASE includes space for
AT_BASE_PLATFORM which s390 doesn't use, but lets define it now and add
the comment above ARCH_DLINFO as found in several other architectures to
remind future modifiers of ARCH_DLINFO to keep AT_VECTOR_SIZE_ARCH up to
date.
Fixes: b020632e40 ("[S390] introduce vdso on s390")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
The hugetlbfs pte<->pmd conversion functions currently assume that the pmd
bit layout is consistent with the pte layout, which is not really true.
The SW read and write bits are encoded as the sequence "wr" in a pte, but
in a pmd it is "rw". The hugetlbfs conversion assumes that the sequence
is identical in both cases, which results in swapped read and write bits
in the pmd. In practice this is not a problem, because those pmd bits are
only relevant for THP pmds and not for hugetlbfs pmds. The hugetlbfs code
works on (fake) ptes, and the converted pte bits are correct.
There is another variation in pte/pmd encoding which affects dirty
prot-none ptes/pmds. In this case, a pmd has both its HW read-only and
invalid bit set, while it is only the invalid bit for a pte. This also has
no effect in practice, but it should better be consistent.
This patch fixes both inconsistencies by changing the SW read/write bit
layout for pmds as well as the PAGE_NONE encoding for ptes. It also makes
the hugetlbfs conversion functions more robust by introducing a
move_set_bit() macro that uses the pte/pmd bit #defines instead of
constant shifts.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge updates from Andrew Morton:
- a few misc bits
- ocfs2
- most(?) of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits)
thp: fix comments of __pmd_trans_huge_lock()
cgroup: remove unnecessary 0 check from css_from_id()
cgroup: fix idr leak for the first cgroup root
mm: memcontrol: fix documentation for compound parameter
mm: memcontrol: remove BUG_ON in uncharge_list
mm: fix build warnings in <linux/compaction.h>
mm, thp: convert from optimistic swapin collapsing to conservative
mm, thp: fix comment inconsistency for swapin readahead functions
thp: update Documentation/{vm/transhuge,filesystems/proc}.txt
shmem: split huge pages beyond i_size under memory pressure
thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE
khugepaged: add support of collapse for tmpfs/shmem pages
shmem: make shmem_inode_info::lock irq-safe
khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()
thp: extract khugepaged from mm/huge_memory.c
shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
shmem: add huge pages support
shmem: get_unmapped_area align huge page
shmem: prepare huge= mount option and sysfs knob
mm, rmap: account shmem thp pages
...
