linux.git/arch/x86/vdso, branch master

x86/asm/entry, x86/vdso: Move the vDSO code to arch/x86/entry/vdso/

2015-06-03T16:51:37+00:00

Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Thomas Gleixner 
Cc: Andy Lutomirski 
Cc: Denys Vlasenko 
Cc: Brian Gerst 
Cc: Peter Zijlstra 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

x86/vdso: Fix 'make bzImage' on older distros

2015-05-11T08:25:02+00:00

Change HOST_EXTRACFLAGS to include arch/x86/include/uapi along
with include/uapi.

This looks more consistent, and this fixes "make bzImage" on my
old distro which doesn't have asm/bitsperlong.h in /usr/include/.

Signed-off-by: Oleg Nesterov 
Signed-off-by: Borislav Petkov 
Acked-by: Andy Lutomirski 
Cc: 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rusty Russell 
Cc: Thomas Gleixner 
Fixes: 6f121e548f83 ("x86, vdso: Reimplement vdso.so preparation in build-time C")
Link: http://lkml.kernel.org/r/1431332153-18566-6-git-send-email-bp@alien8.de
Link: http://lkml.kernel.org/r/20150507165835.GB18652@redhat.com
Signed-off-by: Ingo Molnar

x86: pvclock: Really remove the sched notifier for cross-cpu migrations

2015-04-27T13:49:30+00:00

This reverts commits 0a4e6be9ca17c54817cf814b4b5aa60478c6df27
and 80f7fdb1c7f0f9266421f823964fd1962681f6ce.

The task migration notifier was originally introduced in order to support
the pvclock vsyscall with non-synchronized TSC, but KVM only supports it
with synchronized TSC.  Hence, on KVM the race condition is only needed
due to a bad implementation on the host side, and even then it's so rare
that it's mostly theoretical.

As far as KVM is concerned it's possible to fix the host, avoiding the
additional complexity in the vDSO and the (re)introduction of the task
migration notifier.

Xen, on the other hand, hasn't yet implemented vsyscall support at
all, so we do not care about its plans for non-synchronized TSC.

Reported-by: Peter Zijlstra 
Suggested-by: Marcelo Tosatti 
Signed-off-by: Paolo Bonzini

Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-04-13T20:36:45+00:00

Pull x86 vdso changes from Ingo Molnar:
 "Misc vDSO updates"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/vdso: Remove x32 intermediates during 'make clean'
  x86/vdso: Teach 'make clean' to remove generated vdso-image-*.c files
  x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
  x86/vdso: Fix the x86 vdso2c tool includes

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

2015-04-13T16:47:01+00:00

Pull KVM updates from Paolo Bonzini:
 "First batch of KVM changes for 4.1

  The most interesting bit here is irqfd/ioeventfd support for ARM and
  ARM64.

  Summary:

  ARM/ARM64:
     fixes for live migration, irqfd and ioeventfd support (enabling
     vhost, too), page aging

  s390:
     interrupt handling rework, allowing to inject all local interrupts
     via new ioctl and to get/set the full local irq state for migration
     and introspection.  New ioctls to access memory by virtual address,
     and to get/set the guest storage keys.  SIMD support.

  MIPS:
     FPU and MIPS SIMD Architecture (MSA) support.  Includes some
     patches from Ralf Baechle's MIPS tree.

  x86:
     bugfixes (notably for pvclock, the others are small) and cleanups.
     Another small latency improvement for the TSC deadline timer"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (146 commits)
  KVM: use slowpath for cross page cached accesses
  kvm: mmu: lazy collapse small sptes into large sptes
  KVM: x86: Clear CR2 on VCPU reset
  KVM: x86: DR0-DR3 are not clear on reset
  KVM: x86: BSP in MSR_IA32_APICBASE is writable
  KVM: x86: simplify kvm_apic_map
  KVM: x86: avoid logical_map when it is invalid
  KVM: x86: fix mixed APIC mode broadcast
  KVM: x86: use MDA for interrupt matching
  kvm/ppc/mpic: drop unused IRQ_testbit
  KVM: nVMX: remove unnecessary double caching of MAXPHYADDR
  KVM: nVMX: checks for address bits beyond MAXPHYADDR on VM-entry
  KVM: x86: cache maxphyaddr CPUID leaf in struct kvm_vcpu
  KVM: vmx: pass error code with internal error #2
  x86: vdso: fix pvclock races with task migration
  KVM: remove kvm_read_hva and kvm_read_hva_atomic
  KVM: x86: optimize delivery of TSC deadline timer interrupt
  KVM: x86: extract blocking logic from __vcpu_run
  kvm: x86: fix x86 eflags fixed bit
  KVM: s390: migrate vcpu interrupt state
  ...

x86: vdso: fix pvclock races with task migration

2015-04-08T08:46:55+00:00

If we were migrated right after __getcpu, but before reading the
migration_count, we wouldn't notice that we read TSC of a different
VCPU, nor that KVM's bug made pvti invalid, as only migration_count
on source VCPU is increased.

Change vdso instead of updating migration_count on destination.

Cc: stable@vger.kernel.org
Signed-off-by: Radim Krčmář 
Fixes: 0a4e6be9ca17 ("x86: kvm: Revert "remove sched notifier for cross-cpu migrations"")
Message-Id: <1428000263-11892-1-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini

x86/vdso: Remove x32 intermediates during 'make clean'

2015-03-31T08:45:15+00:00

The existing clean-files rule was missing vdsox32.so and
vdsox32.so.dbg.  We should really rename the intermediates to
allow a single rule to get them all.

Also-reported-by: Magnus Damm 
Signed-off-by: Andy Lutomirski 
Link: http://lkml.kernel.org/r/7fa2ad4a63bc6f52e214125900d54165ef06cc10.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/vdso: Teach 'make clean' to remove generated vdso-image-*.c files

2015-03-31T08:45:15+00:00

After 'make clean' the following files were left in arch/x86/vdso/:

  vdso-image-32-int80.c
  vdso-image-32-syscall.c
  vdso-image-32-sysenter.c

These file are generated during the build process and are present
in .gitignore, so remove them.

Signed-off-by: Andrey Skvortsov 
Signed-off-by: Andy Lutomirski 
Link: http://lkml.kernel.org/r/f85bb7ef6f8c6f6aa4bf422348018c84321454f8.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/vdso32/syscall.S: Do not load __USER32_DS to %ss

2015-03-31T08:45:15+00:00

This vDSO code only gets used by 64-bit kernels, not 32-bit ones.

On 64-bit kernels, the data segment is the same for 32-bit and
64-bit userspace, and the SYSRET instruction loads %ss with its
selector.

So there's no need to repeat it by hand. Segment loads are somewhat
expensive: tens of cycles.

Signed-off-by: Denys Vlasenko 
[ Removed unnecessary comment. ]
Signed-off-by: Andy Lutomirski 
Cc: Alexei Starovoitov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Steven Rostedt 
Cc: Will Drewry 
Link: http://lkml.kernel.org/r/63da6d778f69fd0f1345d9287f6764d58be519fa.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/vdso: Fix the x86 vdso2c tool includes

2015-03-31T08:45:14+00:00

The build-time tool arch/x86/vdso/vdso2c.c includes ,
but cannot find it, unless the build host happens to provide it.

It should be reading the uapi linux/elf.h

This build regression came along with the vdso2c changes between
v3.15 and v3.16.

Signed-off-by: Tommi Kyntola 
Signed-off-by: Andy Lutomirski 
Link: http://lkml.kernel.org/r/1525002.3cJ7BySVpA@musta
Link: http://lkml.kernel.org/r/efe1ec29eda830b1d0030882706f3dac99ce1f73.1427482099.git.luto@kernel.org
Signed-off-by: Ingo Molnar