linux-stable.git/tools/testing/selftests/x86, branch v5.3

selftests/x86: fix spelling mistake "FAILT" -> "FAIL"

2019-07-23T16:45:15+00:00

There is an spelling mistake in an a test error message. Fix it.

Acked-by: Andy Lutomirski 
Signed-off-by: Colin Ian King 
Signed-off-by: Shuah Khan

Revert "x86/ptrace: Prevent ptrace from clearing the FS/GS selector" and fix the test

2019-07-15T15:12:31+00:00

This reverts commit 48f5e52e916b55fb73754833efbacc7f8081a159.

The ptrace ABI change was a prerequisite to the proposed design for
FSGSBASE.  Since FSGSBASE support has been reverted, and since I'm not
convinced that the ABI was ever adequately tested, revert the ABI change as
well.

This also modifies the test case so that it tests the preexisting behavior.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Link: https://lkml.kernel.org/r/fca39c478ea7fb15bc76fe8a36bd180810a067f6.1563200250.git.luto@kernel.org

Merge tag 'docs-5.3' of git://git.lwn.net/linux

2019-07-09T19:34:26+00:00

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...

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

2019-07-08T18:59:59+00:00

Pull x86 CPU feature updates from Thomas Gleixner:
 "Updates for x86 CPU features:

   - Support for UMWAIT/UMONITOR, which allows to use MWAIT and MONITOR
     instructions in user space to save power e.g. in HPC workloads
     which spin wait on synchronization points.

     The maximum time a MWAIT can halt in userspace is controlled by the
     kernel and can be adjusted by the sysadmin.

   - Speed up the MTRR handling code on CPUs which support cache
     self-snooping correctly.

     On those CPUs the wbinvd() invocations can be omitted which speeds
     up the MTRR setup by a factor of 50.

   - Support for the new x86 vendor Zhaoxin who develops processors
     based on the VIA Centaur technology.

   - Prevent 'cat /proc/cpuinfo' from affecting isolated NOHZ_FULL CPUs
     by sending IPIs to retrieve the CPU frequency and use the cached
     values instead.

   - The addition and late revert of the FSGSBASE support. The revert
     was required as it turned out that the code still has hard to
     diagnose issues. Yet another engineering trainwreck...

   - Small fixes, cleanups, improvements and the usual new Intel CPU
     family/model addons"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  x86/fsgsbase: Revert FSGSBASE support
  selftests/x86/fsgsbase: Fix some test case bugs
  x86/entry/64: Fix and clean up paranoid_exit
  x86/entry/64: Don't compile ignore_sysret if 32-bit emulation is enabled
  selftests/x86: Test SYSCALL and SYSENTER manually with TF set
  x86/mtrr: Skip cache flushes on CPUs with cache self-snooping
  x86/cpu/intel: Clear cache self-snoop capability in CPUs with known errata
  Documentation/ABI: Document umwait control sysfs interfaces
  x86/umwait: Add sysfs interface to control umwait maximum time
  x86/umwait: Add sysfs interface to control umwait C0.2 state
  x86/umwait: Initialize umwait control values
  x86/cpufeatures: Enumerate user wait instructions
  x86/cpu: Disable frequency requests via aperfmperf IPI for nohz_full CPUs
  x86/acpi/cstate: Add Zhaoxin processors support for cache flush policy in C3
  ACPI, x86: Add Zhaoxin processors support for NONSTOP TSC
  x86/cpu: Create Zhaoxin processors architecture support file
  x86/cpu: Split Tremont based Atoms from the rest
  Documentation/x86/64: Add documentation for GS/FS addressing mode
  x86/elf: Enumerate kernel FSGSBASE capability in AT_HWCAP2
  x86/cpu: Enable FSGSBASE on 64bit by default and add a chicken bit
  ...

selftests/x86/fsgsbase: Fix some test case bugs

2019-07-03T14:24:56+00:00

This refactors do_unexpected_base() to clean up some code.  It also
fixes the following bugs in test_ptrace_write_gsbase():

 - Incorrect printf() format string caused crashes.

 - Hardcoded 0x7 for the gs selector was not reliably correct.

It also documents the fact that the test is expected to fail on old
kernels.

Fixes: a87730cc3acc ("selftests/x86/fsgsbase: Test ptracer-induced GSBASE write with FSGSBASE")
Fixes: 1b6858d5a2eb ("selftests/x86/fsgsbase: Test ptracer-induced GSBASE write")
Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Cc:  "BaeChang Seok" 
Cc: Borislav Petkov 
Cc: Peter Zijlstra 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: H. Peter Anvin 
Cc: "BaeChang Seok" 
Link: https://lkml.kernel.org/r/bab29c84f2475e2c30ddb00f1b877fcd7f4f96a8.1562125333.git.luto@kernel.org

selftests/x86: Test SYSCALL and SYSENTER manually with TF set

2019-07-02T06:45:20+00:00

Make sure that both variants of the nasty TF-in-compat-syscall are
exercised regardless of what vendor's CPU is running the tests.

Also change the intentional signal after SYSCALL to use ud2, which
is a lot more comprehensible.

This crashes the kernel due to an FSGSBASE bug right now.

This test *also* detects a bug in KVM when run on an Intel host.  KVM
people, feel free to use it to help debug.  There's a bunch of code in this
test to warn instead of going into an infinite looping when the bug gets
triggered.

Reported-by: Vegard Nossum 
Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Cc:  "BaeChang Seok" 
Cc: Borislav Petkov 
Cc: Peter Zijlstra 
Cc: Paolo Bonzini 
Cc: kvm@vger.kernel.org
Cc: "Bae, Chang Seok" 
Link: https://lkml.kernel.org/r/5f5de10441ab2e3005538b4c33be9b1965d1bb63.1562035429.git.luto@kernel.org

selftests/x86: Add a test for process_vm_readv() on the vsyscall page

2019-06-27T22:04:40+00:00

get_gate_page() is a piece of somewhat alarming code to make
get_user_pages() work on the vsyscall page.  Test it via
process_vm_readv().

Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Kees Cook 
Cc: Florian Weimer 
Cc: Jann Horn 
Cc: Borislav Petkov 
Cc: Kernel Hardening 
Cc: Peter Zijlstra 
Link: https://lkml.kernel.org/r/0fe34229a9330e8f9de9765967939cc4f1cf26b1.1561610354.git.luto@kernel.org

selftests/x86/vsyscall: Verify that vsyscall=none blocks execution

2019-06-27T22:04:39+00:00

If vsyscall=none accidentally still allowed vsyscalls, the test wouldn't
fail.  Fix it.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Kees Cook 
Cc: Florian Weimer 
Cc: Jann Horn 
Cc: Borislav Petkov 
Cc: Kernel Hardening 
Cc: Peter Zijlstra 
Link: https://lkml.kernel.org/r/b413397c804265f8865f3e70b14b09485ea7c314.1561610354.git.luto@kernel.org

x86/vsyscall: Document odd SIGSEGV error code for vsyscalls

2019-06-27T22:04:39+00:00

Even if vsyscall=none, user page faults on the vsyscall page are reported
as though the PROT bit in the error code was set.  Add a comment explaining
why this is probably okay and display the value in the test case.

While at it, explain why the behavior is correct with respect to PKRU.

Modify also the selftest to print the odd error code so that there is a
way to demonstrate the odd behaviour.

If anyone really cares about more accurate emulation, the behaviour could
be changed. But that needs a real good justification.

Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Kees Cook 
Cc: Florian Weimer 
Cc: Jann Horn 
Cc: Borislav Petkov 
Cc: Kernel Hardening 
Cc: Peter Zijlstra 
Link: https://lkml.kernel.org/r/75c91855fd850649ace162eec5495a1354221aaa.1561610354.git.luto@kernel.org

selftests/x86/fsgsbase: Test ptracer-induced GSBASE write with FSGSBASE

2019-06-22T09:38:56+00:00

This validates that GS and GSBASE are independently preserved in
ptracer commands.

Suggested-by: Andy Lutomirski 
Signed-off-by: Chang S. Bae 
Signed-off-by: Thomas Gleixner 
Cc: Andi Kleen 
Cc: Ravi Shankar 
Cc: H. Peter Anvin 
Link: https://lkml.kernel.org/r/1557309753-24073-16-git-send-email-chang.seok.bae@intel.com