Commit Graph

63 Commits

Author SHA1 Message Date
Vincenzo Frascino c7e5789b24 kselftest: Move test_vdso to the vDSO test suite
Move test_vdso from x86 to the vDSO test suite.

Suggested-by: Andy Lutomirski <luto@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-10-27 17:58:33 -06:00
Linus Torvalds 4da9f33026 Support for FSGSBASE. Almost 5 years after the first RFC to support it,
this has been brought into a shape which is maintainable and actually
 works.
 
 This final version was done by Sasha Levin who took it up after Intel
 dropped the ball. Sasha discovered that the SGX (sic!) offerings out there
 ship rogue kernel modules enabling FSGSBASE behind the kernels back which
 opens an instantanious unpriviledged root hole.
 
 The FSGSBASE instructions provide a considerable speedup of the context
 switch path and enable user space to write GSBASE without kernel
 interaction. This enablement requires careful handling of the exception
 entries which go through the paranoid entry path as they cannot longer rely
 on the assumption that user GSBASE is positive (as enforced via prctl() on
 non FSGSBASE enabled systemn). All other entries (syscalls, interrupts and
 exceptions) can still just utilize SWAPGS unconditionally when the entry
 comes from user space. Converting these entries to use FSGSBASE has no
 benefit as SWAPGS is only marginally slower than WRGSBASE and locating and
 retrieving the kernel GSBASE value is not a free operation either. The real
 benefit of RD/WRGSBASE is the avoidance of the MSR reads and writes.
 
 The changes come with appropriate selftests and have held up in field
 testing against the (sanitized) Graphene-SGX driver.
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Merge tag 'x86-fsgsbase-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fsgsbase from Thomas Gleixner:
 "Support for FSGSBASE. Almost 5 years after the first RFC to support
  it, this has been brought into a shape which is maintainable and
  actually works.

  This final version was done by Sasha Levin who took it up after Intel
  dropped the ball. Sasha discovered that the SGX (sic!) offerings out
  there ship rogue kernel modules enabling FSGSBASE behind the kernels
  back which opens an instantanious unpriviledged root hole.

  The FSGSBASE instructions provide a considerable speedup of the
  context switch path and enable user space to write GSBASE without
  kernel interaction. This enablement requires careful handling of the
  exception entries which go through the paranoid entry path as they
  can no longer rely on the assumption that user GSBASE is positive (as
  enforced via prctl() on non FSGSBASE enabled systemn).

  All other entries (syscalls, interrupts and exceptions) can still just
  utilize SWAPGS unconditionally when the entry comes from user space.
  Converting these entries to use FSGSBASE has no benefit as SWAPGS is
  only marginally slower than WRGSBASE and locating and retrieving the
  kernel GSBASE value is not a free operation either. The real benefit
  of RD/WRGSBASE is the avoidance of the MSR reads and writes.

  The changes come with appropriate selftests and have held up in field
  testing against the (sanitized) Graphene-SGX driver"

* tag 'x86-fsgsbase-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (21 commits)
  x86/fsgsbase: Fix Xen PV support
  x86/ptrace: Fix 32-bit PTRACE_SETREGS vs fsbase and gsbase
  selftests/x86/fsgsbase: Add a missing memory constraint
  selftests/x86/fsgsbase: Fix a comment in the ptrace_write_gsbase test
  selftests/x86: Add a syscall_arg_fault_64 test for negative GSBASE
  selftests/x86/fsgsbase: Test ptracer-induced GS base write with FSGSBASE
  selftests/x86/fsgsbase: Test GS selector on ptracer-induced GS base write
  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
  x86/entry/64: Handle FSGSBASE enabled paranoid entry/exit
  x86/entry/64: Introduce the FIND_PERCPU_BASE macro
  x86/entry/64: Switch CR3 before SWAPGS in paranoid entry
  x86/speculation/swapgs: Check FSGSBASE in enabling SWAPGS mitigation
  x86/process/64: Use FSGSBASE instructions on thread copy and ptrace
  x86/process/64: Use FSBSBASE in switch_to() if available
  x86/process/64: Make save_fsgs_for_kvm() ready for FSGSBASE
  x86/fsgsbase/64: Enable FSGSBASE instructions in helper functions
  x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions
  x86/cpu: Add 'unsafe_fsgsbase' to enable CR4.FSGSBASE
  ...
2020-08-04 21:16:22 -07:00
Andy Lutomirski 40c45904f8 x86/ptrace: Fix 32-bit PTRACE_SETREGS vs fsbase and gsbase
Debuggers expect that doing PTRACE_GETREGS, then poking at a tracee
and maybe letting it run for a while, then doing PTRACE_SETREGS will
put the tracee back where it was.  In the specific case of a 32-bit
tracer and tracee, the PTRACE_GETREGS/SETREGS data structure doesn't
have fs_base or gs_base fields, so FSBASE and GSBASE fields are
never stored anywhere.  Everything used to still work because
nonzero FS or GS would result full reloads of the segment registers
when the tracee resumes, and the bases associated with FS==0 or
GS==0 are irrelevant to 32-bit code.

Adding FSGSBASE support broke this: when FSGSBASE is enabled, FSBASE
and GSBASE are now restored independently of FS and GS for all tasks
when context-switched in.  This means that, if a 32-bit tracer
restores a previous state using PTRACE_SETREGS but the tracee's
pre-restore and post-restore bases don't match, then the tracee is
resumed with the wrong base.

Fix it by explicitly loading the base when a 32-bit tracer pokes FS
or GS on a 64-bit kernel.

Also add a test case.

Fixes: 673903495c ("x86/process/64: Use FSBSBASE in switch_to() if available")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/229cc6a50ecbb701abd50fe4ddaf0eda888898cd.1593192140.git.luto@kernel.org
2020-07-01 15:27:20 +02:00
Andy Lutomirski cced0b24bb selftests/x86: Consolidate and fix get/set_eflags() helpers
There are several copies of get_eflags() and set_eflags() and they all are
buggy.  Consolidate them and fix them.  The fixes are:

Add memory clobbers.  These are probably unnecessary but they make sure
that the compiler doesn't move something past one of these calls when it
shouldn't.

Respect the redzone on x86_64.  There has no failure been observed related
to this, but it's definitely a bug.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/982ce58ae8dea2f1e57093ee894760e35267e751.1593191971.git.luto@kernel.org
2020-07-01 10:00:27 +02:00
Ram Pai 804eb64615 selftests/x86/pkeys: move selftests to arch-neutral directory
Patch series "selftests, powerpc, x86: Memory Protection Keys", v19.

Memory protection keys enables an application to protect its address space
from inadvertent access by its own code.

This feature is now enabled on powerpc and has been available since
4.16-rc1.  The patches move the selftests to arch neutral directory and
enhance their test coverage.

Tested on powerpc64 and x86_64 (Skylake-SP).

This patch (of 24):

Move selftest files from tools/testing/selftests/x86/ to
tools/testing/selftests/vm/.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: "Desnes A. Nunes do Rosario" <desnesn@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Michal Suchanek <msuchanek@suse.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Shuah Khan <shuah@kernel.org>
Link: http://lkml.kernel.org/r/14d25194c3e2e652e0047feec4487e269e76e8c9.1585646528.git.sandipan@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-04 19:06:26 -07:00
Linus Torvalds e0d60a1e68 Merge branch 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 entry updates from Ingo Molnar:
 "This contains x32 and compat syscall improvements, the biggest one of
  which splits x32 syscalls into their own table, which allows new
  syscalls to share the x32 and x86-64 number - which turns the
  512-547 special syscall numbers range into a legacy wart that won't be
  extended going forward"

* 'x86-entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/syscalls: Split the x32 syscalls into their own table
  x86/syscalls: Disallow compat entries for all types of 64-bit syscalls
  x86/syscalls: Use the compat versions of rt_sigsuspend() and rt_sigprocmask()
  x86/syscalls: Make __X32_SYSCALL_BIT be unsigned long
2019-09-16 19:06:29 -07:00
Dave Hansen 48febc03e6 x86/mpx: Remove selftests Makefile entry
MPX is being removed from the kernel due to a lack of support in the
toolchain going forward (gcc).

This is the smallest possible patch to fix some issues that have been
reported around running the MPX selftests.  It it would also have been part
of any removal series, it is offered first.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190705175318.784C233E@viggo.jf.intel.com
2019-07-22 11:54:56 +02:00
Andy Lutomirski 6365b842aa x86/syscalls: Split the x32 syscalls into their own table
For unfortunate historical reasons, the x32 syscalls and the x86_64
syscalls are not all numbered the same.  As an example, ioctl() is nr 16 on
x86_64 but 514 on x32.

This has potentially nasty consequences, since it means that there are two
valid RAX values to do ioctl(2) and two invalid RAX values.  The valid
values are 16 (i.e. ioctl(2) using the x86_64 ABI) and (514 | 0x40000000)
(i.e. ioctl(2) using the x32 ABI).

The invalid values are 514 and (16 | 0x40000000).  514 will enter the
"COMPAT_SYSCALL_DEFINE3(ioctl, ...)" entry point with in_compat_syscall()
and in_x32_syscall() returning false, whereas (16 | 0x40000000) will enter
the native entry point with in_compat_syscall() and in_x32_syscall()
returning true.  Both are bogus, and both will exercise code paths in the
kernel and in any running seccomp filters that really ought to be
unreachable.

Splitting out the x32 syscalls into their own tables, allows both bogus
invocations to return -ENOSYS.  I've checked glibc, musl, and Bionic, and
all of them appear to call syscalls with their correct numbers, so this
change should have no effect on them.

There is an added benefit going forward: new syscalls that need special
handling on x32 can share the same number on x32 and x86_64.  This means
that the special syscall range 512-547 can be treated as a legacy wart
instead of something that may need to be extended in the future.

Also add a selftest to verify the new behavior.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/208024256b764312598f014ebfb0a42472c19354.1562185330.git.luto@kernel.org
2019-07-22 10:31:23 +02:00
Andy Lutomirski 9402eaf4c1 selftests/x86: Test SYSCALL and SYSENTER manually with TF set
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 <vegard.nossum@oracle.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc:  "BaeChang Seok" <chang.seok.bae@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Cc: "Bae, Chang Seok" <chang.seok.bae@intel.com>
Link: https://lkml.kernel.org/r/5f5de10441ab2e3005538b4c33be9b1965d1bb63.1562035429.git.luto@kernel.org
2019-07-02 08:45:20 +02:00
Florian Weimer 0dd3a6945f selftests/x86: Detect -no-pie availability
Some toolchains need -no-pie to build all tests, others do not support
the -no-pie flag at all.  Therefore, add another test for the
availability of the flag.

This amends commit 3346a6a4e5
("selftests: x86: sysret_ss_attrs doesn't build on a PIE build").

Signed-off-by: Florian Weimer <fweimer@redhat.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
2018-05-30 15:21:51 -06:00
Andy Lutomirski 59c2a7226f x86/selftests: Add mov_to_ss test
This exercises a nasty corner case of the x86 ISA.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/67e08b69817171da8026e0eb3af0214b06b4d74f.1525800455.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-05-14 11:14:45 +02:00
Linus Torvalds d4667ca142 Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 PTI and Spectre related fixes and updates from Ingo Molnar:
 "Here's the latest set of Spectre and PTI related fixes and updates:

  Spectre:
   - Add entry code register clearing to reduce the Spectre attack
     surface
   - Update the Spectre microcode blacklist
   - Inline the KVM Spectre helpers to get close to v4.14 performance
     again.
   - Fix indirect_branch_prediction_barrier()
   - Fix/improve Spectre related kernel messages
   - Fix array_index_nospec_mask() asm constraint
   - KVM: fix two MSR handling bugs

  PTI:
   - Fix a paranoid entry PTI CR3 handling bug
   - Fix comments

  objtool:
   - Fix paranoid_entry() frame pointer warning
   - Annotate WARN()-related UD2 as reachable
   - Various fixes
   - Add Add Peter Zijlstra as objtool co-maintainer

  Misc:
   - Various x86 entry code self-test fixes
   - Improve/simplify entry code stack frame generation and handling
     after recent heavy-handed PTI and Spectre changes. (There's two
     more WIP improvements expected here.)
   - Type fix for cache entries

  There's also some low risk non-fix changes I've included in this
  branch to reduce backporting conflicts:

   - rename a confusing x86_cpu field name
   - de-obfuscate the naming of single-TLB flushing primitives"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  x86/entry/64: Fix CR3 restore in paranoid_exit()
  x86/cpu: Change type of x86_cache_size variable to unsigned int
  x86/spectre: Fix an error message
  x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping
  selftests/x86/mpx: Fix incorrect bounds with old _sigfault
  x86/mm: Rename flush_tlb_single() and flush_tlb_one() to __flush_tlb_one_[user|kernel]()
  x86/speculation: Add <asm/msr-index.h> dependency
  nospec: Move array_index_nospec() parameter checking into separate macro
  x86/speculation: Fix up array_index_nospec_mask() asm constraint
  x86/debug: Use UD2 for WARN()
  x86/debug, objtool: Annotate WARN()-related UD2 as reachable
  objtool: Fix segfault in ignore_unreachable_insn()
  selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
  selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
  selftests/x86: Do not rely on "int $0x80" in test_mremap_vdso.c
  selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
  selftests/x86/pkeys: Remove unused functions
  selftests/x86: Clean up and document sscanf() usage
  selftests/x86: Fix vDSO selftest segfault for vsyscall=none
  x86/entry/64: Remove the unused 'icebp' macro
  ...
2018-02-14 17:02:15 -08:00
Dominik Brodowski 9279ddf23c selftests/x86: Disable tests requiring 32-bit support on pure 64-bit systems
The ldt_gdt and ptrace_syscall selftests, even in their 64-bit variant, use
hard-coded 32-bit syscall numbers and call "int $0x80".

This will fail on 64-bit systems with CONFIG_IA32_EMULATION=y disabled.

Therefore, do not build these tests if we cannot build 32-bit binaries
(which should be a good approximation for CONFIG_IA32_EMULATION=y being enabled).

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: shuah@kernel.org
Link: http://lkml.kernel.org/r/20180211111013.16888-6-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-15 01:15:48 +01:00
Dominik Brodowski 4105c69703 selftests/x86: Do not rely on "int $0x80" in single_step_syscall.c
On 64-bit builds, we should not rely on "int $0x80" working (it only does if
CONFIG_IA32_EMULATION=y is enabled). To keep the "Set TF and check int80"
test running on 64-bit installs with CONFIG_IA32_EMULATION=y enabled, build
this test only if we can also build 32-bit binaries (which should be a
good approximation for that).

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: shuah@kernel.org
Link: http://lkml.kernel.org/r/20180211111013.16888-5-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-15 01:15:48 +01:00
Dominik Brodowski 7f95122067 selftests/x86: Fix build bug caused by the 5lvl test which has been moved to the VM directory
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: shuah@kernel.org
Fixes: 235266b8e1 "selftests/vm: move 128TB mmap boundary test to generic directory"
Link: http://lkml.kernel.org/r/20180211111013.16888-2-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-02-13 09:05:32 +01:00
Linus Torvalds 6cb7903e37 linux-kselftest-4.16-rc1
This update to Kselftest consists of fixes, cleanups, and SPDX license
 additions.
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Merge tag 'linux-kselftest-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:
 "This update to Kselftest consists of fixes, cleanups, and SPDX license
  additions"

* tag 'linux-kselftest-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests: vm: update .gitignore with missing generated file
  selftests/x86: Add <test_name>{,_32,_64} targets
  selftests: Fix loss of test output in run_kselftests.sh
  selftest: ftrace: Fix to add 256 kprobe events correctly
  selftest: ftrace: Fix to pick text symbols for kprobes
  selftests: media_tests: Add SPDX license identifier
  selftests: kselftest.h: Add SPDX license identifier
  selftests: kselftest_install.sh: Add SPDX license identifier
  selftests: gen_kselftest_tar.h: Add SPDX license identifier
  selftests: media_tests: Fix Makefile 'clean' target warning
  tools/testing: Fix trailing semicolon
  kselftest: fix OOM in memory compaction test
  selftests: seccomp: fix compile error seccomp_bpf
2018-02-03 13:01:19 -08:00
Dmitry Safonov cc08d1b91d selftests/x86: Add <test_name>{,_32,_64} targets
One can only use `make all` or `make <test_name>_<bitness>`
as make targets.
`make <test_name>` doesn't work as Ingo noticed:
  x86> make test_vsyscall
  gcc -O2 -g -std=gnu99 -pthread -Wall -no-pie test_vsyscall.c -o test_vsyscall
  /tmp/aBaoo3nb.o: In function `init_vdso':
  test_vsyscall.c:68: undefined reference to `dlopen'
  test_vsyscall.c:76: undefined reference to `dlsym'
  test_vsyscall.c:80: undefined reference to `dlsym'
  test_vsyscall.c:84: undefined reference to `dlsym'
  test_vsyscall.c:88: undefined reference to `dlsym'
  test_vsyscall.c:70: undefined reference to `dlopen'
  collect2: error: ld returned 1 exit status
  <builtin>: recipe for target 'test_vsyscall' failed
  make: *** [test_vsyscall] Error 1

Makefile target substitution neither works :-/

Generate .PHONY targets per-test and fix target substitution.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: x86@kernel.org
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2018-01-23 07:46:55 -07:00
Linus Torvalds 40548c6b6c Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 pti updates from Thomas Gleixner:
 "This contains:

   - a PTI bugfix to avoid setting reserved CR3 bits when PCID is
     disabled. This seems to cause issues on a virtual machine at least
     and is incorrect according to the AMD manual.

   - a PTI bugfix which disables the perf BTS facility if PTI is
     enabled. The BTS AUX buffer is not globally visible and causes the
     CPU to fault when the mapping disappears on switching CR3 to user
     space. A full fix which restores BTS on PTI is non trivial and will
     be worked on.

   - PTI bugfixes for EFI and trusted boot which make sure that the user
     space visible page table entries have the NX bit cleared

   - removal of dead code in the PTI pagetable setup functions

   - add PTI documentation

   - add a selftest for vsyscall to verify that the kernel actually
     implements what it advertises.

   - a sysfs interface to expose vulnerability and mitigation
     information so there is a coherent way for users to retrieve the
     status.

   - the initial spectre_v2 mitigations, aka retpoline:

      + The necessary ASM thunk and compiler support

      + The ASM variants of retpoline and the conversion of affected ASM
        code

      + Make LFENCE serializing on AMD so it can be used as speculation
        trap

      + The RSB fill after vmexit

   - initial objtool support for retpoline

  As I said in the status mail this is the most of the set of patches
  which should go into 4.15 except two straight forward patches still on
  hold:

   - the retpoline add on of LFENCE which waits for ACKs

   - the RSB fill after context switch

  Both should be ready to go early next week and with that we'll have
  covered the major holes of spectre_v2 and go back to normality"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
  x86,perf: Disable intel_bts when PTI
  security/Kconfig: Correct the Documentation reference for PTI
  x86/pti: Fix !PCID and sanitize defines
  selftests/x86: Add test_vsyscall
  x86/retpoline: Fill return stack buffer on vmexit
  x86/retpoline/irq32: Convert assembler indirect jumps
  x86/retpoline/checksum32: Convert assembler indirect jumps
  x86/retpoline/xen: Convert Xen hypercall indirect jumps
  x86/retpoline/hyperv: Convert assembler indirect jumps
  x86/retpoline/ftrace: Convert ftrace assembler indirect jumps
  x86/retpoline/entry: Convert entry assembler indirect jumps
  x86/retpoline/crypto: Convert crypto assembler indirect jumps
  x86/spectre: Add boot time option to select Spectre v2 mitigation
  x86/retpoline: Add initial retpoline support
  objtool: Allow alternatives to be ignored
  objtool: Detect jumps to retpoline thunks
  x86/pti: Make unpoison of pgd for trusted boot work for real
  x86/alternatives: Fix optimize_nops() checking
  sysfs/cpu: Fix typos in vulnerability documentation
  x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC
  ...
2018-01-14 09:51:25 -08:00
Andy Lutomirski 352909b49b selftests/x86: Add test_vsyscall
This tests that the vsyscall entries do what they're expected to do.
It also confirms that attempts to read the vsyscall page behave as
expected.

If changes are made to the vsyscall code or its memory map handling,
running this test in all three of vsyscall=none, vsyscall=emulate,
and vsyscall=native are helpful.

(Because it's easy, this also compares the vsyscall results to their
 vDSO equivalents.)

Note to KAISER backporters: please test this under all three
vsyscall modes.  Also, in the emulate and native modes, make sure
that test_vsyscall_64 agrees with the command line or config
option as to which mode you're in.  It's quite easy to mess up
the kernel such that native mode accidentally emulates
or vice versa.

Greg, etc: please backport this to all your Meltdown-patched
kernels.  It'll help make sure the patches didn't regress
vsyscalls.

CSigned-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/2b9c5a174c1d60fd7774461d518aa75598b1d8fd.1515719552.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-13 11:23:03 +01:00
Kirill A. Shutemov 97f404ad3e x86/selftests: Add test for mapping placement for 5-level paging
5-level paging provides a 56-bit virtual address space for user space
application. But the kernel defaults to mappings below the 47-bit address
space boundary, which is the upper bound for 4-level paging, unless an
application explicitely request it by using a mmap(2) address hint above
the 47-bit boundary. The kernel prevents mappings which spawn across the
47-bit boundary unless mmap(2) was invoked with MAP_FIXED.

Add a self-test that covers the corner cases of the interface and validates
the correctness of the implementation.

[ tglx: Massaged changelog once more ]

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: linux-mm@kvack.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20171115143607.81541-2-kirill.shutemov@linux.intel.com
2017-11-16 11:43:12 +01:00
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Shuah Khan 3346a6a4e5 selftests: x86: sysret_ss_attrs doesn't build on a PIE build
sysret_ss_attrs fails to compile leading x86 test run to fail on systems
configured to build using PIE by default. Add -no-pie fix it.

Relocation might still fail if relocated above 4G. For now this change
fixes the build and runs x86 tests.

tools/testing/selftests/x86$ make
gcc -m64 -o .../tools/testing/selftests/x86/single_step_syscall_64 -O2
-g -std=gnu99 -pthread -Wall  single_step_syscall.c -lrt -ldl
gcc -m64 -o .../tools/testing/selftests/x86/sysret_ss_attrs_64 -O2 -g
-std=gnu99 -pthread -Wall  sysret_ss_attrs.c thunks.S -lrt -ldl
/usr/bin/ld: /tmp/ccS6pvIh.o: relocation R_X86_64_32S against `.text'
can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Nonrepresentable section on output
collect2: error: ld returned 1 exit status
Makefile:49: recipe for target
'.../tools/testing/selftests/x86/sysret_ss_attrs_64' failed
make: *** [.../tools/testing/selftests/x86/sysret_ss_attrs_64] Error 1

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-10-05 11:34:14 -06:00
Shuah Khan eebed11a3d selftests: x86: override clean in lib.mk to fix warnings
Add override with EXTRA_CLEAN for lib.mk clean to fix the following
warnings from clean target run.

Makefile:44: warning: overriding recipe for target 'clean'
../lib.mk:55: warning: ignoring old recipe for target 'clean'

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-04-27 08:05:23 -06:00
Linus Torvalds 2d62e0768d Second batch of KVM changes for 4.11 merge window
PPC:
  * correct assumption about ASDR on POWER9
  * fix MMIO emulation on POWER9
 
 x86:
  * add a simple test for ioperm
  * cleanup TSS
    (going through KVM tree as the whole undertaking was caused by VMX's
     use of TSS)
  * fix nVMX interrupt delivery
  * fix some performance counters in the guest
 
 And two cleanup patches.
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Merge tag 'kvm-4.11-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull more KVM updates from Radim Krčmář:
 "Second batch of KVM changes for the 4.11 merge window:

  PPC:
   - correct assumption about ASDR on POWER9
   - fix MMIO emulation on POWER9

  x86:
   - add a simple test for ioperm
   - cleanup TSS (going through KVM tree as the whole undertaking was
     caused by VMX's use of TSS)
   - fix nVMX interrupt delivery
   - fix some performance counters in the guest

  ... and two cleanup patches"

* tag 'kvm-4.11-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: nVMX: Fix pending events injection
  x86/kvm/vmx: remove unused variable in segment_base()
  selftests/x86: Add a basic selftest for ioperm
  x86/asm: Tidy up TSS limit code
  kvm: convert kvm.users_count from atomic_t to refcount_t
  KVM: x86: never specify a sample period for virtualized in_tx_cp counters
  KVM: PPC: Book3S HV: Don't use ASDR for real-mode HPT faults on POWER9
  KVM: PPC: Book3S HV: Fix software walk of guest process page tables
2017-03-04 11:36:19 -08:00
Andy Lutomirski 0eb1d0fa6a selftests/x86: Add a basic selftest for ioperm
This doesn't fully exercise the interaction between KVM and ioperm(),
but it does test basic functionality.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-03-01 17:03:23 +01:00
Linus Torvalds c4f3f22edd linux-kselftest-4.11-rc1
This update consists of:
 
 -- fixes to several existing tests from Stafford Horne
 -- cpufreq tests from Viresh Kumar
 -- Selftest build and install fixes from Bamvor Jian Zhang
    and Michael Ellerman
 -- Fixes to protection-keys tests from Dave Hansen
 -- Warning fixes from Shuah Khan
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Merge tag 'linux-kselftest-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull Kselftest update from Shuah Khan:
 "This update consists of:

   - fixes to several existing tests from Stafford Horne

   - cpufreq tests from Viresh Kumar

   - Selftest build and install fixes from Bamvor Jian Zhang and Michael
     Ellerman

   - Fixes to protection-keys tests from Dave Hansen

   - Warning fixes from Shuah Khan"

* tag 'linux-kselftest-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (28 commits)
  selftests/powerpc: Fix remaining fallout from recent changes
  selftests/powerpc: Fix the clean rule since recent changes
  selftests: Fix the .S and .S -> .o rules
  selftests: Fix the .c linking rule
  selftests: Fix selftests build to just build, not run tests
  selftests, x86, protection_keys: fix wrong offset in siginfo
  selftests, x86, protection_keys: fix uninitialized variable warning
  selftest: cpufreq: Update MAINTAINERS file
  selftest: cpufreq: Add special tests
  selftest: cpufreq: Add support to test cpufreq modules
  selftest: cpufreq: Add suspend/resume/hibernate support
  selftest: cpufreq: Add support for cpufreq tests
  selftests: Add intel_pstate to TARGETS
  selftests/intel_pstate: Update makefile to match new style
  selftests/intel_pstate: Fix warning on loop index overflow
  cpupower: Restore format of frequency-info limit
  selftests/futex: Add headers to makefile dependencies
  selftests/futex: Add stdio used for logging
  selftests: x86 protection_keys remove dead code
  selftests: x86 protection_keys fix unused variable compile warnings
  ...
2017-02-25 15:32:53 -08:00
Linus Torvalds 8b5abde16b Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar:
 "A laundry list of changes: KASAN improvements/fixes for ptdump, a
  self-test fix, PAT cleanup and wbinvd() avoidance, removal of stale
  code and documentation updates"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm/ptdump: Add address marker for KASAN shadow region
  x86/mm/ptdump: Optimize check for W+X mappings for CONFIG_KASAN=y
  x86/mm/pat: Use rb_entry()
  x86/mpx: Re-add MPX to selftests Makefile
  x86/mm: Remove CONFIG_DEBUG_NX_TEST
  x86/mm/cpa: Avoid wbinvd() for PREEMPT
  x86/mm: Improve documentation for low-level device I/O functions
2017-02-20 15:57:19 -08:00
Dave Hansen e64d5fbe56 x86/mpx: Re-add MPX to selftests Makefile
Ingo pointed out that the MPX tests were no longer in the selftests
Makefile.  It appears that I shot myself in the foot on this one
and accidentally removed them when I added the pkeys tests, probably
from bungling a merge conflict.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 5f23f6d082 ("x86/pkeys: Add self-tests")
Link: http://lkml.kernel.org/r/20170201225629.C3070852@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-02 08:09:18 +01:00
bamvor.zhangjian@huawei.com a8ba798bc8 selftests: enable O and KBUILD_OUTPUT
Enable O and KBUILD_OUTPUT for kselftest. User could compile kselftest
to another directory by passing O or KBUILD_OUTPUT. And O is high
priority than KBUILD_OUTPUT.

Signed-off-by: Bamvor Jian Zhang <bamvor.zhangjian@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
2017-01-05 13:42:22 -07:00
Andy Lutomirski 6606021401 selftests/x86: Add a selftest for SYSRET to noncanonical addresses
SYSRET to a noncanonical address will blow up on Intel CPUs.  Linux
needs to prevent this from happening in two major cases, and the
criteria will become more complicated when support for larger virtual
address spaces is added.

A fast-path SYSCALL will fall through to the following instruction
using SYSRET without any particular checking.  To prevent fall-through
to a noncanonical address, Linux prevents the highest canonical page
from being mapped.  This test case checks a variety of possible maximum
addresses to make sure that either we can't map code there or that
SYSCALL fall-through works.

A slow-path system call can return anywhere.  Linux needs to make sure
that, if the return address is non-canonical, it won't use SYSRET.
This test cases causes sigreturn() to return to a variety of addresses
(with RCX == RIP) and makes sure that nothing explodes.

Some of this code comes from Kirill Shutemov.

Kirill reported the following output with 5-level paging enabled:

  [RUN]   sigreturn to 0x800000000000
  [OK]    Got SIGSEGV at RIP=0x800000000000
  [RUN]   sigreturn to 0x1000000000000
  [OK]    Got SIGSEGV at RIP=0x1000000000000
  [RUN]   sigreturn to 0x2000000000000
  [OK]    Got SIGSEGV at RIP=0x2000000000000
  [RUN]   sigreturn to 0x4000000000000
  [OK]    Got SIGSEGV at RIP=0x4000000000000
  [RUN]   sigreturn to 0x8000000000000
  [OK]    Got SIGSEGV at RIP=0x8000000000000
  [RUN]   sigreturn to 0x10000000000000
  [OK]    Got SIGSEGV at RIP=0x10000000000000
  [RUN]   sigreturn to 0x20000000000000
  [OK]    Got SIGSEGV at RIP=0x20000000000000
  [RUN]   sigreturn to 0x40000000000000
  [OK]    Got SIGSEGV at RIP=0x40000000000000
  [RUN]   sigreturn to 0x80000000000000
  [OK]    Got SIGSEGV at RIP=0x80000000000000
  [RUN]   sigreturn to 0x100000000000000
  [OK]    Got SIGSEGV at RIP=0x100000000000000
  [RUN]   sigreturn to 0x200000000000000
  [OK]    Got SIGSEGV at RIP=0x200000000000000
  [RUN]   sigreturn to 0x400000000000000
  [OK]    Got SIGSEGV at RIP=0x400000000000000
  [RUN]   sigreturn to 0x800000000000000
  [OK]    Got SIGSEGV at RIP=0x800000000000000
  [RUN]   sigreturn to 0x1000000000000000
  [OK]    Got SIGSEGV at RIP=0x1000000000000000
  [RUN]   sigreturn to 0x2000000000000000
  [OK]    Got SIGSEGV at RIP=0x2000000000000000
  [RUN]   sigreturn to 0x4000000000000000
  [OK]    Got SIGSEGV at RIP=0x4000000000000000
  [RUN]   sigreturn to 0x8000000000000000
  [OK]    Got SIGSEGV at RIP=0x8000000000000000
  [RUN]   Trying a SYSCALL that falls through to 0x7fffffffe000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x7ffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x800000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0xfffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x1000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x1fffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x2000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x3fffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x4000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x7fffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x8000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0xffffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x10000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x1ffffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x20000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x3ffffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x40000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x7ffffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x80000000000000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0xfffffffffff000
  [OK]    We survived
  [RUN]   Trying a SYSCALL that falls through to 0x100000000000000
  [OK]    mremap to 0xfffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x1fffffffffff000
  [OK]    mremap to 0x1ffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x200000000000000
  [OK]    mremap to 0x1fffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x3fffffffffff000
  [OK]    mremap to 0x3ffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x400000000000000
  [OK]    mremap to 0x3fffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x7fffffffffff000
  [OK]    mremap to 0x7ffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x800000000000000
  [OK]    mremap to 0x7fffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0xffffffffffff000
  [OK]    mremap to 0xfffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x1000000000000000
  [OK]    mremap to 0xffffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x1ffffffffffff000
  [OK]    mremap to 0x1fffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x2000000000000000
  [OK]    mremap to 0x1ffffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x3ffffffffffff000
  [OK]    mremap to 0x3fffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x4000000000000000
  [OK]    mremap to 0x3ffffffffffff000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x7ffffffffffff000
  [OK]    mremap to 0x7fffffffffffe000 failed
  [RUN]   Trying a SYSCALL that falls through to 0x8000000000000000
  [OK]    mremap to 0x7ffffffffffff000 failed

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e70bd9a3f90657ba47b755100a20475d038fa26b.1482808435.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-05 09:20:02 +01:00
Andy Lutomirski 3200ca8069 selftests/x86: Add test_vdso to test getcpu()
I'll eventually add tests for more vDSO functions here.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Megha <megha.dey@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/945cd29901a62a3cc6ea7d6ee5e389ab1ec1ac0c.1479320367.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-17 08:31:22 +01:00
Dave Hansen 5f23f6d082 x86/pkeys: Add self-tests
This code should be a good demonstration of how to use the new
system calls as well as how to use protection keys in general.

This code shows how to:
1. Manipulate the Protection Keys Rights User (PKRU) register
2. Set a protection key on memory
3. Fetch and/or modify PKRU from the signal XSAVE state
4. Read the kernel-provided protection key in the siginfo
5. Set up an execute-only mapping

There are currently 13 tests:

  test_read_of_write_disabled_region
  test_read_of_access_disabled_region
  test_write_of_write_disabled_region
  test_write_of_access_disabled_region
  test_kernel_write_of_access_disabled_region
  test_kernel_write_of_write_disabled_region
  test_kernel_gup_of_access_disabled_region
  test_kernel_gup_write_to_write_disabled_region
  test_executing_on_unreadable_memory
  test_ptrace_of_child
  test_pkey_syscalls_on_non_allocated_pkey
  test_pkey_syscalls_bad_args
  test_pkey_alloc_exhaust

Each of the tests is run with plain memory (via mmap(MAP_ANON)),
transparent huge pages, and hugetlb.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Cc: Dave Hansen <dave@sr71.net>
Cc: mgorman@techsingularity.net
Cc: arnd@arndb.de
Cc: linux-api@vger.kernel.org
Cc: shuahkh@osg.samsung.com
Cc: linux-mm@kvack.org
Cc: luto@kernel.org
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/20160729163024.FC5A0C2D@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-09-09 13:02:28 +02:00
Ingo Molnar 38452af242 Merge branch 'x86/asm' into x86/mm, to resolve conflicts
Conflicts:
	tools/testing/selftests/x86/Makefile

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-15 10:26:04 +02:00
Dmitry Safonov f80fd3a5ff selftests/x86: Add vDSO mremap() test
Should print this on vDSO remapping success (on new kernels):

 [root@localhost ~]# ./test_mremap_vdso_32
	AT_SYSINFO_EHDR is 0xf773f000
 [NOTE]	Moving vDSO: [f773f000, f7740000] -> [a000000, a001000]
 [OK]

Or print that mremap() for vDSOs is unsupported:

 [root@localhost ~]# ./test_mremap_vdso_32
	AT_SYSINFO_EHDR is 0xf773c000
 [NOTE]	Moving vDSO: [0xf773c000, 0xf773d000] -> [0xf7737000, 0xf7738000]
 [FAIL]	mremap() of the vDSO does not work on this kernel!

Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kselftest@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160628113539.13606-3-dsafonov@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-08 14:17:51 +02:00
Dave Hansen e754aedc26 x86/mpx, selftests: Add MPX self test
I've had this code for a while, but never submitted it upstream.  Now
that Skylake hardware is out in the wild, folks can actually run this
for real.  It tests the following:

	1. The MPX hardware is enabled by the kernel and doing what it
	   is supposed to
	2. The MPX management code is present and enabled in the kernel
	3. MPX Signal handling
	4. The MPX bounds table population code (on-demand population)
	5. The MPX bounds table unmapping code (kernel-initiated freeing
	   when unused)

This has also caught bugs in the XSAVE code because MPX state is
saved/restored with XSAVE.

I'm submitting it now because it would have caught the recent issues
with the compat_siginfo code not being properly augmented when new
siginfo state is added.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160608172535.5B40B0EE@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-14 12:19:24 +02:00
Andy Lutomirski 0051202f6a selftests/x86: Test the FSBASE/GSBASE API and context switching
This catches two distinct bugs in the current code.  I'll fix them.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rudolf Marek <r.marek@assembler.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/7e5941148d1e2199f070dadcdf7355959f5f8e85.1460075211.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-13 10:20:41 +02:00
Andy Lutomirski b08983015c selftests/x86: Add an iopl test
This exercises two cases that are known to be buggy on Xen PV right
now.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/61afe904c95c92abb29cd075b51e10e7feb0f774.1458162709.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-17 09:49:26 +01:00
Andy Lutomirski 6c25da5ad5 x86/signal/64: Re-add support for SS in the 64-bit signal context
This is a second attempt to make the improvements from c6f2062935
("x86/signal/64: Fix SS handling for signals delivered to 64-bit
programs"), which was reverted by 51adbfbba5c6 ("x86/signal/64: Add
support for SS in the 64-bit signal context").

This adds two new uc_flags flags.  UC_SIGCONTEXT_SS will be set for
all 64-bit signals (including x32).  It indicates that the saved SS
field is valid and that the kernel supports the new behavior.

The goal is to fix a problems with signal handling in 64-bit tasks:
SS wasn't saved in the 64-bit signal context, making it awkward to
determine what SS was at the time of signal delivery and making it
impossible to return to a non-flat SS (as calling sigreturn clobbers
SS).

This also made it extremely difficult for 64-bit tasks to return to
fully-defined 16-bit contexts, because only the kernel can easily do
espfix64, but sigreturn was unable to set a non-flag SS:ESP.
(DOSEMU has a monstrous hack to partially work around this
limitation.)

If we could go back in time, the correct fix would be to make 64-bit
signals work just like 32-bit signals with respect to SS: save it
in signal context, reset it when delivering a signal, and restore
it in sigreturn.

Unfortunately, doing that (as I tried originally) breaks DOSEMU:
DOSEMU wouldn't reset the signal context's SS when clearing the LDT
and changing the saved CS to 64-bit mode, since it predates the SS
context field existing in the first place.

This patch is a bit more complicated, and it tries to balance a
bunch of goals.  It makes most cases of changing ucontext->ss during
signal handling work as expected.

I do this by special-casing the interesting case.  On sigreturn,
ucontext->ss will be honored by default, unless the ucontext was
created from scratch by an old program and had a 64-bit CS
(unfortunately, CRIU can do this) or was the result of changing a
32-bit signal context to 64-bit without resetting SS (as DOSEMU
does).

For the benefit of new 64-bit software that uses segmentation (new
versions of DOSEMU might), the new behavior can be detected with a
new ucontext flag UC_SIGCONTEXT_SS.

To avoid compilation issues, __pad0 is left as an alias for ss in
ucontext.

The nitty-gritty details are documented in the header file.

This patch also re-enables the sigreturn_64 and ldt_gdt_64 selftests,
as the kernel change allows both of them to pass.

Tested-by: Stas Sergeev <stsp@list.ru>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/749149cbfc3e75cd7fcdad69a854b399d792cc6f.1455664054.git.luto@kernel.org
[ Small readability edit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-17 08:32:11 +01:00
Andy Lutomirski e21d50f386 selftests/x86: Add check_initial_reg_state()
This checks that ELF binaries are started with an appropriately
blank register state.

( There's currently a nasty special case in the entry asm to
  arrange for this. I'm planning on removing the special case,
  and this will help make sure I don't break it. )

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ef54f8d066b30a3eb36bbf26300eebb242185700.1454022279.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 09:46:37 +01:00
Andy Lutomirski c31b34255b selftests/x86: Extend Makefile to allow 64-bit-only tests
Previously the Makefile supported 32-bit-only tests and tests
that were 32-bit and 64-bit.  This adds the support for tests
that are only built as 64-bit binaries.

There aren't any yet, but there might be a few some day.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkhan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/99789bfe65706e6df32cc7e13f656e8c9fa92031.1454022279.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29 09:46:36 +01:00
Andy Lutomirski 65cacec1ba selftests/x86: Test __kernel_sigreturn and __kernel_rt_sigreturn
The vdso-based sigreturn mechanism is fragile and isn't used by
modern glibc so, if we break it, we'll only notice when someone
tests an unusual libc.

Add an explicit selftest.

[ I wrote this while debugging a Bionic breakage -- my first guess
  was that I had somehow messed up sigreturn.  I've caused problems in
  that code before, and it's really easy to fail to notice it because
  there's nothing on a modern distro that needs vdso-based sigreturn. ]

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/32946d714156879cd8e5d8eab044cd07557ed558.1452628504.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-13 10:34:40 +01:00
Andy Lutomirski 0f672809f9 selftests/x86: Disable the ldt_gdt_64 test for now
ldt_gdt.c relies on cross-cpu invalidation of SS to do one of
its tests.  On 32-bit builds, this works fine, but on 64-bit
builds, it only works if the kernel has proper SS sigcontext
handling for 64-bit user programs.

Since the SS fixes are currently reverted, restrict the test
case to 32 bits for now.

In principle, I could change the test to use a different segment
register, but it would be messy: CS can't point to the LDT for
64-bit code, and the other registers don't result in immediate
faults because they aren't reloaded on kernel -> user
transitions.

When we fix sigcontext (in 4.6?), we can revert this.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/231591d9122d282402d8f53175134f8db5b3bc73.1452561752.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-12 11:09:26 +01:00
Linus Torvalds ce4d72fac1 Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu changes from Ingo Molnar:
 "There are two main areas of changes:

   - Rework of the extended FPU state code to robustify the kernel's
     usage of cpuid provided xstate sizes - and related changes (Dave
     Hansen)"

   - math emulation enhancements: new modern FPU instructions support,
     with testcases, plus cleanups (Denys Vlasnko)"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  x86/fpu: Fixup uninitialized feature_name warning
  x86/fpu/math-emu: Add support for FISTTP instructions
  x86/fpu/math-emu, selftests: Add test for FISTTP instructions
  x86/fpu/math-emu: Add support for FCMOVcc insns
  x86/fpu/math-emu: Add support for F[U]COMI[P] insns
  x86/fpu/math-emu: Remove define layer for undocumented opcodes
  x86/fpu/math-emu, selftests: Add tests for FCMOV and FCOMI insns
  x86/fpu/math-emu: Remove !NO_UNDOC_CODE
  x86/fpu: Check CPU-provided sizes against struct declarations
  x86/fpu: Check to ensure increasing-offset xstate offsets
  x86/fpu: Correct and check XSAVE xstate size calculations
  x86/fpu: Add C structures for AVX-512 state components
  x86/fpu: Rework YMM definition
  x86/fpu/mpx: Rework MPX 'xstate' types
  x86/fpu: Add xfeature_enabled() helper instead of test_bit()
  x86/fpu: Remove 'xfeature_nr'
  x86/fpu: Rework XSTATE_* macros to remove magic '2'
  x86/fpu: Rename XFEATURES_NR_MAX
  x86/fpu: Rename XSAVE macros
  x86/fpu: Remove partial LWP support definitions
  ...
2015-11-03 20:50:26 -08:00
Andy Lutomirski 04235c00b6 selftests/x86: Add a test for ptrace syscall restart and arg modification
This tests assumptions about how fast syscall works wrt pt_regs
and, in particular, what happens if IP is decremented by 2
during a syscall.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1c44dbfe59000ba135bbf35ccc5d2433a0b31618.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:34:07 +02:00
Andy Lutomirski 3b56aae34b selftests/x86: Add a test for vDSO unwinding
While the kernel itself doesn't use DWARF unwinding, user code
expects to be able to unwind the vDSO.  The vsyscall
(AT_SYSINFO) entry is manually CFI-annotated, and this tests
that it unwinds correctly.

I tested the test by incorrectly annotating __kernel_vsyscall,
and the test indeed fails if I do that.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/8bf736d1925cdd165c0f980156a4248e55af47a1.1444091584.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-10-07 11:34:06 +02:00
Denys Vlasenko a58e2ecd01 x86/fpu/math-emu, selftests: Add test for FISTTP instructions
$ ./test_FISTTP_32
  [RUN]	Testing fisttp instructions
  [OK]	fisttp

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1442757790-27233-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-20 16:19:01 +02:00
Denys Vlasenko 57ca6897cd x86/fpu/math-emu, selftests: Add tests for FCMOV and FCOMI insns
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1442494933-13798-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-20 10:19:52 +02:00
Denys Vlasenko c25be94f28 x86/asm/entry/32, selftests: Add 'test_syscall_vdso' test
This new test checks that all x86 registers are preserved across
32-bit syscalls. It tests syscalls through VDSO (if available)
and through INT 0x80, normally and under ptrace.

If kernel is a 64-bit one, high registers (r8..r15) are poisoned
before the syscall is called and are checked afterwards.

They must be either preserved, or cleared to zero (but r11 is
special); r12..15 must be preserved for INT 0x80.

EFLAGS is checked for changes too, but change there is not
considered to be a bug (paravirt kernels do not preserve
arithmetic flags).

Run-tested on 64-bit kernel:

	$ ./test_syscall_vdso_32
	[RUN]	Executing 6-argument 32-bit syscall via VDSO
	[OK]	Arguments are preserved across syscall
	[NOTE]	R11 has changed:0000000000200ed7 - assuming clobbered by
	SYSRET insn [OK]	R8..R15 did not leak kernel data
	[RUN]	Executing 6-argument 32-bit syscall via INT 80
	[OK]	Arguments are preserved across syscall
	[OK]	R8..R15 did not leak kernel data
	[RUN]	Running tests under ptrace
	[RUN]	Executing 6-argument 32-bit syscall via VDSO
	[OK]	Arguments are preserved across syscall
	[OK]	R8..R15 did not leak kernel data
	[RUN]	Executing 6-argument 32-bit syscall via INT 80
	[OK]	Arguments are preserved across syscall
	[OK]	R8..R15 did not leak kernel data

On 32-bit paravirt kernel:

	$ ./test_syscall_vdso_32
	[NOTE]	Not a 64-bit kernel, won't test R8..R15 leaks
	[RUN]	Executing 6-argument 32-bit syscall via VDSO
	[WARN]	Flags before=0000000000200ed7 id 0 00 o d i s z 0 a 0 p 1 c
	[WARN]	Flags  after=0000000000200246 id 0 00 i z 0 0 p 1
	[WARN]	Flags change=0000000000000c91 0 00 o d s 0 a 0 0 c
	[OK]	Arguments are preserved across syscall
	[RUN]	Executing 6-argument 32-bit syscall via INT 80
	[OK]	Arguments are preserved across syscall
	[RUN]	Running tests under ptrace
	[RUN]	Executing 6-argument 32-bit syscall via VDSO
	[OK]	Arguments are preserved across syscall
	[RUN]	Executing 6-argument 32-bit syscall via INT 80
	[OK]	Arguments are preserved across syscall

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Drewry <wad@chromium.org>
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1442427809-2027-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-18 09:40:48 +02:00
Andy Lutomirski a9c909ce8c selftests/x86: Add syscall_nt selftest
I've had this sitting around for a while.  Add it to the
selftests tree.  Far Cry running under Wine depends on this
behavior.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ee4d63799a9e5294b70930618b71d04d2770eb2d.1439838962.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-18 09:43:38 +02:00
Andy Lutomirski 33f3df41d0 selftests/x86: Disable sigreturn_64
sigreturn_64 was broken by ed596cde94 ("Revert x86 sigcontext
cleanups").  Turn it off until we have a better fix.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a184e75ff170a0bcd76bf376c41cad2c402fe9f7.1439838962.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-18 09:43:31 +02:00