linux.git/arch/x86/kernel/process_64.c, branch v4.12

x86/xen: add CONFIG_XEN_PV to Kconfig

2017-05-02T08:50:19+00:00

All code to support Xen PV will get under this new option. For the
beginning, check for it in the common code.

Signed-off-by: Vitaly Kuznetsov 
Reviewed-by: Juergen Gross 
Signed-off-by: Juergen Gross

x86/mm: Make in_compat_syscall() work during exec

2017-03-31T14:53:02+00:00

The x86 mmap() code selects the mmap base for an allocation depending on
the bitness of the syscall. For 64bit sycalls it select mm->mmap_base and
for 32bit mm->mmap_compat_base.

On execve the registers of the task invoking exec() are copied to the child
pt_regs. So child->pt_regs->orig_ax contains the execve syscall number of the
parent.

exec() calls mmap() which in turn uses in_compat_syscall() to check whether
the mapping is for a 32bit or a 64bit task. The decision is made on the
following criteria:

  ia32	  child->thread.status & TS_COMPAT
   x32	  child->pt_regs.orig_ax & __X32_SYSCALL_BIT
  ia64	  !ia32 && !x32 

child->thread.status is corretly set up in set_personality_*(), but the
syscall number in child->pt_regs.orig_ax is left unmodified.

Therefore the parent/child combinations work or fail in the following way:

Parent Child Child->thread_status  child->pt_regs.orig_ax  in_compat()  Works
ia64    ia64   TS_COMPAT == 0	   __X32_SYSCALL_BIT == 0     false       Y
ia64    ia32   TS_COMPAT == 1	   __X32_SYSCALL_BIT == 0     true        Y
ia64     x32   TS_COMPAT == 0	   __X32_SYSCALL_BIT == 0     false       N
ia32    ia64   TS_COMPAT == 0	   __X32_SYSCALL_BIT == 0     false       Y
ia32    ia32   TS_COMPAT == 1	   __X32_SYSCALL_BIT == 0     true        Y
ia32     x32   TS_COMPAT == 0	   __X32_SYSCALL_BIT == 0     false       N
 x32    ia64   TS_COMPAT == 0	   __X32_SYSCALL_BIT == 1     true        N
 x32    ia32   TS_COMPAT == 1	   __X32_SYSCALL_BIT == 1     true        Y
 x32     x32   TS_COMPAT == 0	   __X32_SYSCALL_BIT == 1     true        Y

Make set_personality_*() store the syscall number incl. __X32_SYSCALL_BIT
which corresponds to the newly started ELF executable in the childs
pt_regs, i.e. pretend that the exec was invoked from a task with the same
executable format.

So both thread.status and pt_regs.orig_ax correspond to the new ELF format
and in_compat_syscall() returns the correct result.

[ tglx: Rewrote changelog ]

Fixes: commit 1b028f784e8c ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()")
Reported-by: Adam Borowski 
Suggested-by: H. Peter Anvin 
Suggested-by: Thomas Gleixner 
Signed-off-by: Dmitry Safonov 
Cc: 0x7f454c46@gmail.com
Cc: linux-mm@kvack.org
Cc: Andrei Vagin 
Cc: Andy Lutomirski 
Cc: Cyrill Gorcunov 
Cc: Borislav Petkov 
Cc: "Kirill A. Shutemov" 
Link: http://lkml.kernel.org/r/20170331111137.28170-1-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner

x86/syscalls/32: Wire up arch_prctl on x86-32

2017-03-20T15:10:33+00:00

Hook up arch_prctl to call do_arch_prctl() on x86-32, and in 32 bit compat
mode on x86-64. This allows to have arch_prctls that are not specific to 64
bits.

On UML, simply stub out this syscall.

Signed-off-by: Kyle Huey 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-7-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

x86/arch_prctl: Add do_arch_prctl_common()

2017-03-20T15:10:33+00:00

Add do_arch_prctl_common() to handle arch_prctls that are not specific to 64
bit mode. Call it from the syscall entry point, but not any of the other
callsites in the kernel, which all want one of the existing 64 bit only
arch_prctls.

Signed-off-by: Kyle Huey 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-6-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64()

2017-03-20T15:10:32+00:00

In order to introduce new arch_prctls that are not 64 bit only, rename the
existing 64 bit implementation to do_arch_prctl_64(). Also rename the
second argument of that function from 'addr' to 'arg2', because it will no
longer always be an address.

Signed-off-by: Kyle Huey 
Reviewed-by: Andy Lutomirski 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-5-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

x86/arch_prctl/64: Use SYSCALL_DEFINE2 to define sys_arch_prctl()

2017-03-20T15:10:32+00:00

Use the SYSCALL_DEFINE2 macro instead of manually defining it.

Signed-off-by: Kyle Huey 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-4-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

x86/arch_prctl: Rename 'code' argument to 'option'

2017-03-20T15:10:32+00:00

The x86 specific arch_prctl() arbitrarily changed prctl's 'option' to
'code'. Before adding new options, rename it.

Signed-off-by: Kyle Huey 
Cc: Grzegorz Andrejczuk 
Cc: kvm@vger.kernel.org
Cc: Radim Krčmář 
Cc: Peter Zijlstra 
Cc: Dave Hansen 
Cc: Andi Kleen 
Cc: linux-kselftest@vger.kernel.org
Cc: Nadav Amit 
Cc: Robert O'Callahan 
Cc: Richard Weinberger 
Cc: "Rafael J. Wysocki" 
Cc: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Len Brown 
Cc: Shuah Khan 
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: Jeff Dike 
Cc: Alexander Viro 
Cc: user-mode-linux-user@lists.sourceforge.net
Cc: David Matlack 
Cc: Boris Ostrovsky 
Cc: Dmitry Safonov 
Cc: linux-fsdevel@vger.kernel.org
Cc: Paolo Bonzini 
Link: http://lkml.kernel.org/r/20170320081628.18952-3-khuey@kylehuey.com
Signed-off-by: Thomas Gleixner

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:35+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

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

2016-12-22T17:25:45+00:00

Pull x86 cache allocation interface from Thomas Gleixner:
 "This provides support for Intel's Cache Allocation Technology, a cache
  partitioning mechanism.

  The interface is odd, but the hardware interface of that CAT stuff is
  odd as well.

  We tried hard to come up with an abstraction, but that only allows
  rather simple partitioning, but no way of sharing and dealing with the
  per package nature of this mechanism.

  In the end we decided to expose the allocation bitmaps directly so all
  combinations of the hardware can be utilized.

  There are two ways of associating a cache partition:

   - Task

     A task can be added to a resource group. It uses the cache
     partition associated to the group.

   - CPU

     All tasks which are not member of a resource group use the group to
     which the CPU they are running on is associated with.

     That allows for simple CPU based partitioning schemes.

  The main expected user sare:

   - Virtualization so a VM can only trash only the associated part of
     the cash w/o disturbing others

   - Real-Time systems to seperate RT and general workloads.

   - Latency sensitive enterprise workloads

   - In theory this also can be used to protect against cache side
     channel attacks"

[ Intel RDT is "Resource Director Technology". The interface really is
  rather odd and very specific, which delayed this pull request while I
  was thinking about it. The pull request itself came in early during
  the merge window, I just delayed it until things had calmed down and I
  had more time.

  But people tell me they'll use this, and the good news is that it is
  _so_ specific that it's rather independent of anything else, and no
  user is going to depend on the interface since it's pretty rare. So if
  push comes to shove, we can just remove the interface and nothing will
  break ]

* 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
  x86/intel_rdt: Implement show_options() for resctrlfs
  x86/intel_rdt: Call intel_rdt_sched_in() with preemption disabled
  x86/intel_rdt: Update task closid immediately on CPU in rmdir and unmount
  x86/intel_rdt: Fix setting of closid when adding CPUs to a group
  x86/intel_rdt: Update percpu closid immeditately on CPUs affected by changee
  x86/intel_rdt: Reset per cpu closids on unmount
  x86/intel_rdt: Select KERNFS when enabling INTEL_RDT_A
  x86/intel_rdt: Prevent deadlock against hotplug lock
  x86/intel_rdt: Protect info directory from removal
  x86/intel_rdt: Add info files to Documentation
  x86/intel_rdt: Export the minimum number of set mask bits in sysfs
  x86/intel_rdt: Propagate error in rdt_mount() properly
  x86/intel_rdt: Add a missing #include
  MAINTAINERS: Add maintainer for Intel RDT resource allocation
  x86/intel_rdt: Add scheduler hook
  x86/intel_rdt: Add schemata file
  x86/intel_rdt: Add tasks files
  x86/intel_rdt: Add cpus file
  x86/intel_rdt: Add mkdir to resctrl file system
  x86/intel_rdt: Add "info" files to resctrl file system
  ...