linux.git/arch/x86/kernel/cpu/Makefile, branch v4.11

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
  ...

x86/intel_rdt: Add schemata file

2016-10-31T01:10:16+00:00

Last of the per resource group files. Also mode 0644. This one shows
the resources available to the group. Syntax depends on whether the
"cdp" mount option was given. With code/data prioritization disabled
it is simply a list of masks for each cache domain. Initial value
allows access to all of the L3 cache on all domains. E.g. on a 2 socket
Broadwell:
        L3:0=fffff;1=fffff
With CDP enabled, separate masks for data and instructions are provided:
        L3DATA:0=fffff;1=fffff
        L3CODE:0=fffff;1=fffff

Signed-off-by: Tony Luck 
Signed-off-by: Fenghua Yu 
Cc: "Ravi V Shankar" 
Cc: "Shaohua Li" 
Cc: "Sai Prakhya" 
Cc: "Peter Zijlstra" 
Cc: "Stephane Eranian" 
Cc: "Dave Hansen" 
Cc: "David Carrillo-Cisneros" 
Cc: "Nilay Vaish" 
Cc: "Vikas Shivappa" 
Cc: "Ingo Molnar" 
Cc: "Borislav Petkov" 
Cc: "H. Peter Anvin" 
Link: http://lkml.kernel.org/r/1477692289-37412-9-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner

x86/intel_rdt: Add basic resctrl filesystem support

2016-10-31T01:10:14+00:00

Use kernfs as basis for our user interface filesystem. This patch
supports mount/umount, and one mount parameter "cdp" to enable code/data
prioritization (though all we do at this point is ensure that the system
can support CDP).  The file system is not populated yet in this patch.

[ tglx: Fixed up a few nits and added cdp handling in case of error ]

Signed-off-by: Fenghua Yu 
Cc: "Ravi V Shankar" 
Cc: "Tony Luck" 
Cc: "Shaohua Li" 
Cc: "Sai Prakhya" 
Cc: "Peter Zijlstra" 
Cc: "Stephane Eranian" 
Cc: "Dave Hansen" 
Cc: "David Carrillo-Cisneros" 
Cc: "Nilay Vaish" 
Cc: "Vikas Shivappa" 
Cc: "Ingo Molnar" 
Cc: "Borislav Petkov" 
Cc: "H. Peter Anvin" 
Link: http://lkml.kernel.org/r/1477692289-37412-4-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner

x86/intel_rdt: Add CONFIG, Makefile, and basic initialization

2016-10-26T21:12:38+00:00

Introduce CONFIG_INTEL_RDT_A (default: no, dependent on CPU_SUP_INTEL) to
control inclusion of Resource Director Technology in the build.

Simple init() routine just checks which features are present. If they are
pr_info() one line summary for each feature for now.

Signed-off-by: Fenghua Yu 
Cc: "Ravi V Shankar" 
Cc: "Tony Luck" 
Cc: "David Carrillo-Cisneros" 
Cc: "Sai Prakhya" 
Cc: "Peter Zijlstra" 
Cc: "Stephane Eranian" 
Cc: "Dave Hansen" 
Cc: "Shaohua Li" 
Cc: "Nilay Vaish" 
Cc: "Vikas Shivappa" 
Cc: "Ingo Molnar" 
Cc: "Borislav Petkov" 
Cc: "H. Peter Anvin" 
Link: http://lkml.kernel.org/r/1477142405-32078-7-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner

x86/cpu: Merge bugs.c and bugs_64.c

2016-10-25T09:48:50+00:00

Should be easier when following boot paths. It probably is a left over
from the x86 unification eons ago.

No functionality change.

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20161024173844.23038-3-bp@alien8.de
Signed-off-by: Ingo Molnar

kernel: add kcov code coverage

2016-03-22T22:36:02+00:00

kcov provides code coverage collection for coverage-guided fuzzing
(randomized testing).  Coverage-guided fuzzing is a testing technique
that uses coverage feedback to determine new interesting inputs to a
system.  A notable user-space example is AFL
(http://lcamtuf.coredump.cx/afl/).  However, this technique is not
widely used for kernel testing due to missing compiler and kernel
support.

kcov does not aim to collect as much coverage as possible.  It aims to
collect more or less stable coverage that is function of syscall inputs.
To achieve this goal it does not collect coverage in soft/hard
interrupts and instrumentation of some inherently non-deterministic or
non-interesting parts of kernel is disbled (e.g.  scheduler, locking).

Currently there is a single coverage collection mode (tracing), but the
API anticipates additional collection modes.  Initially I also
implemented a second mode which exposes coverage in a fixed-size hash
table of counters (what Quentin used in his original patch).  I've
dropped the second mode for simplicity.

This patch adds the necessary support on kernel side.  The complimentary
compiler support was added in gcc revision 231296.

We've used this support to build syzkaller system call fuzzer, which has
found 90 kernel bugs in just 2 months:

  https://github.com/google/syzkaller/wiki/Found-Bugs

We've also found 30+ bugs in our internal systems with syzkaller.
Another (yet unexplored) direction where kcov coverage would greatly
help is more traditional "blob mutation".  For example, mounting a
random blob as a filesystem, or receiving a random blob over wire.

Why not gcov.  Typical fuzzing loop looks as follows: (1) reset
coverage, (2) execute a bit of code, (3) collect coverage, repeat.  A
typical coverage can be just a dozen of basic blocks (e.g.  an invalid
input).  In such context gcov becomes prohibitively expensive as
reset/collect coverage steps depend on total number of basic
blocks/edges in program (in case of kernel it is about 2M).  Cost of
kcov depends only on number of executed basic blocks/edges.  On top of
that, kernel requires per-thread coverage because there are always
background threads and unrelated processes that also produce coverage.
With inlined gcov instrumentation per-thread coverage is not possible.

kcov exposes kernel PCs and control flow to user-space which is
insecure.  But debugfs should not be mapped as user accessible.

Based on a patch by Quentin Casasnovas.

[akpm@linux-foundation.org: make task_struct.kcov_mode have type `enum kcov_mode']
[akpm@linux-foundation.org: unbreak allmodconfig]
[akpm@linux-foundation.org: follow x86 Makefile layout standards]
Signed-off-by: Dmitry Vyukov 
Reviewed-by: Kees Cook 
Cc: syzkaller 
Cc: Vegard Nossum 
Cc: Catalin Marinas 
Cc: Tavis Ormandy 
Cc: Will Deacon 
Cc: Quentin Casasnovas 
Cc: Kostya Serebryany 
Cc: Eric Dumazet 
Cc: Alexander Potapenko 
Cc: Kees Cook 
Cc: Bjorn Helgaas 
Cc: Sasha Levin 
Cc: David Drysdale 
Cc: Ard Biesheuvel 
Cc: Andrey Ryabinin 
Cc: Kirill A. Shutemov 
Cc: Jiri Slaby 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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

2016-03-15T16:32:27+00:00

Pull x86 asm updates from Ingo Molnar:
 "This is another big update. Main changes are:

   - lots of x86 system call (and other traps/exceptions) entry code
     enhancements.  In particular the complex parts of the 64-bit entry
     code have been migrated to C code as well, and a number of dusty
     corners have been refreshed.  (Andy Lutomirski)

   - vDSO special mapping robustification and general cleanups (Andy
     Lutomirski)

   - cpufeature refactoring, cleanups and speedups (Borislav Petkov)

   - lots of other changes ..."

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  x86/cpufeature: Enable new AVX-512 features
  x86/entry/traps: Show unhandled signal for i386 in do_trap()
  x86/entry: Call enter_from_user_mode() with IRQs off
  x86/entry/32: Change INT80 to be an interrupt gate
  x86/entry: Improve system call entry comments
  x86/entry: Remove TIF_SINGLESTEP entry work
  x86/entry/32: Add and check a stack canary for the SYSENTER stack
  x86/entry/32: Simplify and fix up the SYSENTER stack #DB/NMI fixup
  x86/entry: Only allocate space for tss_struct::SYSENTER_stack if needed
  x86/entry: Vastly simplify SYSENTER TF (single-step) handling
  x86/entry/traps: Clear DR6 early in do_debug() and improve the comment
  x86/entry/traps: Clear TIF_BLOCKSTEP on all debug exceptions
  x86/entry/32: Restore FLAGS on SYSEXIT
  x86/entry/32: Filter NT and speed up AC filtering in SYSENTER
  x86/entry/compat: In SYSENTER, sink AC clearing below the existing FLAGS test
  selftests/x86: In syscall_nt, test NT|TF as well
  x86/asm-offsets: Remove PARAVIRT_enabled
  x86/entry/32: Introduce and use X86_BUG_ESPFIX instead of paravirt_enabled
  uprobes: __create_xol_area() must nullify xol_mapping.fault
  x86/cpufeature: Create a new synthetic cpu capability for machine check recovery
  ...

perf/x86: Move perf_event_msr.c .............. => x86/events/msr.c

2016-02-17T09:11:36+00:00

Signed-off-by: Borislav Petkov 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Link: http://lkml.kernel.org/r/1455098123-11740-17-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

perf/x86: Move perf_event_p6.c ............... => x86/events/intel/p6.c

2016-02-17T09:11:36+00:00

Signed-off-by: Borislav Petkov 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Link: http://lkml.kernel.org/r/1455098123-11740-16-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

perf/x86: Move perf_event_p4.c ............... => x86/events/intel/p4.c

2016-02-17T09:11:35+00:00

Signed-off-by: Borislav Petkov 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Link: http://lkml.kernel.org/r/1455098123-11740-15-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar