linux-stable.git/arch/x86/Kconfig.debug, branch linux-4.9.y

x86, perf: Fix the dependency of the x86 insn decoder selftest

2020-01-29T09:24:31+00:00

[ Upstream commit 7720804a2ae46c90265a32c81c45fb6f8d2f4e8b ]

Since x86 instruction decoder is not only for kprobes,
it should be tested when the insn.c is compiled.
(e.g. perf is enabled but kprobes is disabled)

Signed-off-by: Masami Hiramatsu 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Fixes: cbe5c34c8c1f ("x86: Compile insn.c and inat.c only for KPROBES")
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

x86/platform: Add PCI dependency for PUNIT_ATOM_DEBUG

2018-02-25T10:05:53+00:00

commit d689c64d189e43d782fec5649fb0afe303c5b3f9 upstream.

The IOSF_MBI option requires PCI support, without it we get a harmless
Kconfig warning when it gets selected by PUNIT_ATOM_DEBUG:

  warning: (X86_INTEL_LPSS && SND_SST_IPC_ACPI && MMC_SDHCI_ACPI && PUNIT_ATOM_DEBUG) selects IOSF_MBI which has unmet direct dependencies (PCI)

This adds another dependency to avoid the warning.

Signed-off-by: Arnd Bergmann 
Cc: Andy Lutomirski 
Cc: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20170719125310.2487451-8-arnd@arndb.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

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
  ...

x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option

2016-02-22T07:51:38+00:00

This removes the CONFIG_DEBUG_RODATA option and makes it always enabled.

This simplifies the code and also makes it clearer that read-only mapped
memory is just as fundamental a security feature in kernel-space as it is
in user-space.

Suggested-by: Ingo Molnar 
Signed-off-by: Kees Cook 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: David Brown 
Cc: Denys Vlasenko 
Cc: Emese Revfy 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Mathias Krause 
Cc: Michael Ellerman 
Cc: PaX Team 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch 
Link: http://lkml.kernel.org/r/1455748879-21872-4-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar

x86/cpufeature: Replace the old static_cpu_has() with safe variant

2016-01-30T10:22:18+00:00

So the old one didn't work properly before alternatives had run.
And it was supposed to provide an optimized JMP because the
assumption was that the offset it is jumping to is within a
signed byte and thus a two-byte JMP.

So I did an x86_64 allyesconfig build and dumped all possible
sites where static_cpu_has() was used. The optimization amounted
to all in all 12(!) places where static_cpu_has() had generated
a 2-byte JMP. Which has saved us a whopping 36 bytes!

This clearly is not worth the trouble so we can remove it. The
only place where the optimization might count - in __switch_to()
- we will handle differently. But that's not subject of this
patch.

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1453842730-28463-6-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

Merge tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2016-01-14T03:15:14+00:00

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has appeared in -next and independently received a
  build success notification from the kbuild robot.  The 'for-4.5/block-
  dax' topic branch was rebased over the weekend to drop the "block
  device end-of-life" rework that Al would like to see re-implemented
  with a notifier, and to address bug reports against the badblocks
  integration.

  There is pending feedback against "libnvdimm: Add a poison list and
  export badblocks" received last week.  Linda identified some localized
  fixups that we will handle incrementally.

  Summary:

   - Media error handling: The 'badblocks' implementation that
     originated in md-raid is up-levelled to a generic capability of a
     block device.  This initial implementation is limited to being
     consulted in the pmem block-i/o path.  Later, 'badblocks' will be
     consulted when creating dax mappings.

   - Raw block device dax: For virtualization and other cases that want
     large contiguous mappings of persistent memory, add the capability
     to dax-mmap a block device directly.

   - Increased /dev/mem restrictions: Add an option to treat all
     io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access
     while a driver is actively using an address range.  This behavior
     is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be
     overridden by the existing "iomem=relaxed" kernel command line
     option.

   - Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
     block device shutdown crash fix, and other small libnvdimm fixes"

* tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits)
  block: kill disk_{check|set|clear|alloc}_badblocks
  libnvdimm, pmem: nvdimm_read_bytes() badblocks support
  pmem, dax: disable dax in the presence of bad blocks
  pmem: fail io-requests to known bad blocks
  libnvdimm: convert to statically allocated badblocks
  libnvdimm: don't fail init for full badblocks list
  block, badblocks: introduce devm_init_badblocks
  block: clarify badblocks lifetime
  badblocks: rename badblocks_free to badblocks_exit
  libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h
  libnvdimm: Add a poison list and export badblocks
  nfit_test: Enable DSMs for all test NFITs
  md: convert to use the generic badblocks code
  block: Add badblock management for gendisks
  badblocks: Add core badblock management code
  block: fix del_gendisk() vs blkdev_ioctl crash
  block: enable dax for raw block devices
  block: introduce bdev_file_inode()
  restrict /dev/mem to idle io memory ranges
  arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug
  ...

arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug

2016-01-09T14:30:49+00:00

Let all the archs that implement devmem_is_allowed() opt-in to a common
definition of CONFIG_STRICT_DEVM in lib/Kconfig.debug.

Cc: Kees Cook 
Cc: Russell King 
Cc: Will Deacon 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Thomas Gleixner 
Cc: "H. Peter Anvin" 
Cc: Andrew Morton 
Cc: Greg Kroah-Hartman 
Cc: "David S. Miller" 
Acked-by: Catalin Marinas 
Acked-by: Heiko Carstens 
[heiko: drop 'default y' for s390]
Acked-by: Ingo Molnar 
Suggested-by: Arnd Bergmann 
Signed-off-by: Dan Williams

x86/mm: Turn CONFIG_X86_PTDUMP into a module

2015-11-23T09:50:13+00:00

Being able to examine page tables is handy, so make this a
module that can be loaded as needed.

Signed-off-by: Kees Cook 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Boris Ostrovsky 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Stephen Smalley 
Cc: Thomas Gleixner 
Cc: Toshi Kani 
Cc: Vladimir Murzin 
Cc: Will Deacon 
Link: http://lkml.kernel.org/r/20151120010755.GA9060@www.outflux.net
Signed-off-by: Ingo Molnar

x86: don't make DEBUG_WX default to 'y' even with DEBUG_RODATA

2015-11-06T17:12:41+00:00

It turns out that we still have issues with the EFI memory map that ends
up polluting our kernel page tables with writable executable pages.

That will get sorted out, but in the meantime let's not make the scary
complaint about them be on by default.  The code is useful for
developers, but not ready for end user testing yet.

Acked-by: Borislav Petkov 
Acked-by: Ingo Molnar 
Signed-off-by: Linus Torvalds

x86/mm: Warn on W^X mappings

2015-10-06T09:11:48+00:00

Warn on any residual W+X mappings after setting NX
if DEBUG_WX is enabled.  Introduce a separate
X86_PTDUMP_CORE config that enables the code for
dumping the page tables without enabling the debugfs
interface, so that DEBUG_WX can be enabled without
exposing the debugfs interface.  Switch EFI_PGT_DUMP
to using X86_PTDUMP_CORE so that it also does not require
enabling the debugfs interface.

On success it prints this to the kernel log:

  x86/mm: Checked W+X mappings: passed, no W+X pages found.

On failure it prints a warning and a count of the failed pages:

  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 1 at arch/x86/mm/dump_pagetables.c:226 note_page+0x610/0x7b0()
  x86/mm: Found insecure W+X mapping at address ffffffff81755000/__stop___ex_table+0xfa8/0xabfa8
  [...]
  Call Trace:
   [] dump_stack+0x44/0x55
   [] warn_slowpath_common+0x82/0xc0
   [] warn_slowpath_fmt+0x5c/0x80
   [] ? note_page+0x5c9/0x7b0
   [] note_page+0x610/0x7b0
   [] ptdump_walk_pgd_level_core+0x259/0x3c0
   [] ptdump_walk_pgd_level_checkwx+0x17/0x20
   [] mark_rodata_ro+0xf5/0x100
   [] ? rest_init+0x80/0x80
   [] kernel_init+0x1d/0xe0
   [] ret_from_fork+0x3f/0x70
   [] ? rest_init+0x80/0x80
  ---[ end trace a1f23a1e42a2ac76 ]---
  x86/mm: Checked W+X mappings: FAILED, 171 W+X pages found.

Signed-off-by: Stephen Smalley 
Acked-by: Kees Cook 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1444064120-11450-1-git-send-email-sds@tycho.nsa.gov
[ Improved the Kconfig help text and made the new option default-y
  if CONFIG_DEBUG_RODATA=y, because it already found buggy mappings,
  so we really want people to have this on by default. ]
Signed-off-by: Ingo Molnar