1. 25 Dec, 2017 2 commits
  2. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      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: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  3. 26 Jul, 2017 3 commits
    • Josh Poimboeuf's avatar
      x86/kconfig: Consolidate unwinders into multiple choice selection · 81d38719
      Josh Poimboeuf authored
      There are three mutually exclusive unwinders.  Make that more obvious by
      combining them into a multiple-choice selection:
      
        CONFIG_FRAME_POINTER_UNWINDER
        CONFIG_ORC_UNWINDER
        CONFIG_GUESS_UNWINDER (if CONFIG_EXPERT=y)
      
      Frame pointers are still the default (for now).
      
      The old CONFIG_FRAME_POINTER option is still used in some
      arch-independent places, so keep it around, but make it
      invisible to the user on x86 - it's now selected by
      CONFIG_FRAME_POINTER_UNWINDER=y.
      Suggested-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: 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: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/20170725135424.zukjmgpz3plf5pmt@trebleSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      81d38719
    • Josh Poimboeuf's avatar
      x86/kconfig: Make it easier to switch to the new ORC unwinder · a34a766f
      Josh Poimboeuf authored
      A couple of Kconfig changes which make it much easier to switch to the
      new CONFIG_ORC_UNWINDER:
      
      1) Remove x86 dependencies on CONFIG_FRAME_POINTER for lockdep,
         latencytop, and fault injection.  x86 has a 'guess' unwinder which
         just scans the stack for kernel text addresses.  It's not 100%
         accurate but in many cases it's good enough.  This allows those users
         who don't want the text overhead of the frame pointer or ORC
         unwinders to still use these features.  More importantly, this also
         makes it much more straightforward to disable frame pointers.
      
      2) Make CONFIG_ORC_UNWINDER depend on !CONFIG_FRAME_POINTER.  While it
         would be possible to have both enabled, it doesn't really make sense
         to do so.  So enforce a sane configuration to prevent the user from
         making a dumb mistake.
      
      With these changes, when you disable CONFIG_FRAME_POINTER, "make
      oldconfig" will ask if you want to enable CONFIG_ORC_UNWINDER.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: 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: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/9985fb91ce5005fe33ea5cc2a20f14bd33c61d03.1500938583.git.jpoimboe@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a34a766f
    • Josh Poimboeuf's avatar
      x86/unwind: Add the ORC unwinder · ee9f8fce
      Josh Poimboeuf authored
      Add the new ORC unwinder which is enabled by CONFIG_ORC_UNWINDER=y.
      It plugs into the existing x86 unwinder framework.
      
      It relies on objtool to generate the needed .orc_unwind and
      .orc_unwind_ip sections.
      
      For more details on why ORC is used instead of DWARF, see
      Documentation/x86/orc-unwinder.txt - but the short version is
      that it's a simplified, fundamentally more robust debugninfo
      data structure, which also allows up to two orders of magnitude
      faster lookups than the DWARF unwinder - which matters to
      profiling workloads like perf.
      
      Thanks to Andy Lutomirski for the performance improvement ideas:
      splitting the ORC unwind table into two parallel arrays and creating a
      fast lookup table to search a subset of the unwind table.
      Signed-off-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
      Cc: 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: Jiri Slaby <jslaby@suse.cz>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: live-patching@vger.kernel.org
      Link: http://lkml.kernel.org/r/0a6cbfb40f8da99b7a45a1a8302dc6aef16ec812.1500938583.git.jpoimboe@redhat.com
      [ Extended the changelog. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      ee9f8fce
  4. 20 Jul, 2017 1 commit
  5. 18 Jul, 2017 1 commit
  6. 21 Mar, 2017 1 commit
    • Lu Baolu's avatar
      usb/early: Add driver for xhci debug capability · aeb9dd1d
      Lu Baolu authored
      XHCI debug capability (DbC) is an optional but standalone
      functionality provided by an xHCI host controller. Software
      learns this capability by walking through the extended
      capability list of the host. XHCI specification describes
      DbC in section 7.6.
      
      This patch introduces the code to probe and initialize the
      debug capability hardware during early boot. With hardware
      initialized, the debug target (system on which this code is
      running) will present a debug device through the debug port
      (normally the first USB3 port). The debug device is fully
      compliant with the USB framework and provides the equivalent
      of a very high performance (USB3) full-duplex serial link
      between the debug host and target. The DbC functionality is
      independent of the xHCI host. There isn't any precondition
      from the xHCI host side for the DbC to work.
      
      One use for this feature is kernel debugging, for example
      when your machine crashes very early before the regular
      console code is initialized. Other uses include simpler,
      lockless logging instead of a full-blown printk console
      driver and klogd.
      Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
      Acked-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: linux-usb@vger.kernel.org
      Link: http://lkml.kernel.org/r/1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com
      [ Small fix to the Kconfig help text. ]
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      aeb9dd1d
  7. 28 Feb, 2017 1 commit
  8. 07 Feb, 2017 1 commit
  9. 31 Jan, 2017 1 commit
    • Kees Cook's avatar
      x86/mm: Remove CONFIG_DEBUG_NX_TEST · 3ad38ceb
      Kees Cook authored
      CONFIG_DEBUG_NX_TEST has been broken since CONFIG_DEBUG_SET_MODULE_RONX=y
      was added in v2.6.37 via:
      
        84e1c6bb ("x86: Add RO/NX protection for loadable kernel modules")
      
      since the exception table was then made read-only.
      
      Additionally, the manually constructed extables were never fixed when
      relative extables were introduced in v3.5 via:
      
        70627654 ("x86, extable: Switch to relative exception table entries")
      
      However, relative extables won't work for test_nx.c, since test instruction
      memory areas may be more than INT_MAX away from an executable fixup
      (e.g. stack and heap too far away from executable memory with the fixup).
      
      Since clearly no one has been using this code for a while now, and similar
      tests exist in LKDTM, this should just be removed entirely.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arjan van de Ven <arjan@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: Jinbum Park <jinb.park7@gmail.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.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/20170131003711.GA74048@beastSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      3ad38ceb
  10. 22 Feb, 2016 1 commit
    • Kees Cook's avatar
      x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option · 9ccaf77c
      Kees Cook authored
      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: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Brown <david.brown@linaro.org>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Emese Revfy <re.emese@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mathias Krause <minipli@googlemail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: PaX Team <pageexec@freemail.hu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: kernel-hardening@lists.openwall.com
      Cc: linux-arch <linux-arch@vger.kernel.org>
      Link: http://lkml.kernel.org/r/1455748879-21872-4-git-send-email-keescook@chromium.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      9ccaf77c
  11. 30 Jan, 2016 1 commit
    • Borislav Petkov's avatar
      x86/cpufeature: Replace the old static_cpu_has() with safe variant · bc696ca0
      Borislav Petkov authored
      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: default avatarBorislav 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: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1453842730-28463-6-git-send-email-bp@alien8.deSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      bc696ca0
  12. 09 Jan, 2016 1 commit
  13. 23 Nov, 2015 1 commit
    • Kees Cook's avatar
      x86/mm: Turn CONFIG_X86_PTDUMP into a module · 8609d1b5
      Kees Cook authored
      Being able to examine page tables is handy, so make this a
      module that can be loaded as needed.
      Signed-off-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andrey Ryabinin <ryabinin.a.a@gmail.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: 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: Stephen Smalley <sds@tycho.nsa.gov>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Toshi Kani <toshi.kani@hpe.com>
      Cc: Vladimir Murzin <vladimir.murzin@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Link: http://lkml.kernel.org/r/20151120010755.GA9060@www.outflux.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      8609d1b5
  14. 06 Nov, 2015 1 commit
  15. 06 Oct, 2015 1 commit
    • Stephen Smalley's avatar
      x86/mm: Warn on W^X mappings · e1a58320
      Stephen Smalley authored
      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:
         [<ffffffff81380a5f>] dump_stack+0x44/0x55
         [<ffffffff8109d3f2>] warn_slowpath_common+0x82/0xc0
         [<ffffffff8109d48c>] warn_slowpath_fmt+0x5c/0x80
         [<ffffffff8106cfc9>] ? note_page+0x5c9/0x7b0
         [<ffffffff8106d010>] note_page+0x610/0x7b0
         [<ffffffff8106d409>] ptdump_walk_pgd_level_core+0x259/0x3c0
         [<ffffffff8106d5a7>] ptdump_walk_pgd_level_checkwx+0x17/0x20
         [<ffffffff81063905>] mark_rodata_ro+0xf5/0x100
         [<ffffffff817415a0>] ? rest_init+0x80/0x80
         [<ffffffff817415bd>] kernel_init+0x1d/0xe0
         [<ffffffff8174cd1f>] ret_from_fork+0x3f/0x70
         [<ffffffff817415a0>] ? rest_init+0x80/0x80
        ---[ end trace a1f23a1e42a2ac76 ]---
        x86/mm: Checked W+X mappings: FAILED, 171 W+X pages found.
      Signed-off-by: default avatarStephen Smalley <sds@tycho.nsa.gov>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Arjan van de Ven <arjan@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: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      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: default avatarIngo Molnar <mingo@kernel.org>
      e1a58320
  16. 17 Jul, 2015 1 commit
    • Andy Lutomirski's avatar
      x86/entry/64, x86/nmi/64: Add CONFIG_DEBUG_ENTRY NMI testing code · a97439aa
      Andy Lutomirski authored
      It turns out to be rather tedious to test the NMI nesting code.
      Make it easier: add a new CONFIG_DEBUG_ENTRY option that causes
      the NMI handler to pre-emptively unmask NMIs.
      
      With this option set, errors in the repeat_nmi logic or failures
      to detect that we're in a nested NMI will result in quick panics
      under perf (especially if multiple counters are running at high
      frequency) instead of requiring an unusual workload that
      generates page faults or breakpoints inside NMIs.
      
      I called it CONFIG_DEBUG_ENTRY instead of CONFIG_DEBUG_NMI_ENTRY
      because I want to add new non-NMI checks elsewhere in the entry
      code in the future, and I'd rather not add too many new config
      options or add this option and then immediately rename it.
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Reviewed-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a97439aa
  17. 19 May, 2015 1 commit
    • Ingo Molnar's avatar
      x86/fpu: Add CONFIG_X86_DEBUG_FPU=y FPU debugging code · e97131a8
      Ingo Molnar authored
      There are various internal FPU state debugging checks that never
      trigger in practice, but which are useful for FPU code development.
      
      Separate these out into CONFIG_X86_DEBUG_FPU=y, and also add a
      couple of new ones.
      
      The size difference is about 0.5K of code on defconfig:
      
         text        data     bss          filename
         15028906    2578816  1638400      vmlinux
         15029430    2578816  1638400      vmlinux
      
      ( Keep this enabled by default until the new FPU code is debugged. )
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.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: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      e97131a8
  18. 07 May, 2015 1 commit
  19. 07 Mar, 2015 1 commit
  20. 18 Feb, 2015 1 commit
    • Bryan O'Donoghue's avatar
      x86/intel/quark: Add Isolated Memory Regions for Quark X1000 · 28a375df
      Bryan O'Donoghue authored
      Intel's Quark X1000 SoC contains a set of registers called
      Isolated Memory Regions. IMRs are accessed over the IOSF mailbox
      interface. IMRs are areas carved out of memory that define
      read/write access rights to the various system agents within the
      Quark system. For a given agent in the system it is possible to
      specify if that agent may read or write an area of memory
      defined by an IMR with a granularity of 1 KiB.
      
      Quark_SecureBootPRM_330234_001.pdf section 4.5 details the
      concept of IMRs quark-x1000-datasheet.pdf section 12.7.4 details
      the implementation of IMRs in silicon.
      
      eSRAM flush, CPU Snoop write-only, CPU SMM Mode, CPU non-SMM
      mode, RMU and PCIe Virtual Channels (VC0 and VC1) can have
      individual read/write access masks applied to them for a given
      memory region in Quark X1000. This enables IMRs to treat each
      memory transaction type listed above on an individual basis and
      to filter appropriately based on the IMR access mask for the
      memory region. Quark supports eight IMRs.
      
      Since all of the DMA capable SoC components in the X1000 are
      mapped to VC0 it is possible to define sections of memory as
      invalid for DMA write operations originating from Ethernet, USB,
      SD and any other DMA capable south-cluster component on VC0.
      Similarly it is possible to mark kernel memory as non-SMM mode
      read/write only or to mark BIOS runtime memory as SMM mode
      accessible only depending on the particular memory footprint on
      a given system.
      
      On an IMR violation Quark SoC X1000 systems are configured to
      reset the system, so ensuring that the IMR memory map is
      consistent with the EFI provided memory map is critical to
      ensure no IMR violations reset the system.
      
      The API for accessing IMRs is based on MTRR code but doesn't
      provide a /proc or /sys interface to manipulate IMRs. Defining
      the size and extent of IMRs is exclusively the domain of
      in-kernel code.
      
      Quark firmware sets up a series of locked IMRs around pieces of
      memory that firmware owns such as ACPI runtime data. During boot
      a series of unlocked IMRs are placed around items in memory to
      guarantee no DMA modification of those items can take place.
      Grub also places an unlocked IMR around the kernel boot params
      data structure and compressed kernel image. It is necessary for
      the kernel to tear down all unlocked IMRs in order to ensure
      that the kernel's view of memory passed via the EFI memory map
      is consistent with the IMR memory map. Without tearing down all
      unlocked IMRs on boot transitory IMRs such as those used to
      protect the compressed kernel image will cause IMR violations and system reboots.
      
      The IMR init code tears down all unlocked IMRs and sets a
      protective IMR around the kernel .text and .rodata as one
      contiguous block. This sanitizes the IMR memory map with respect
      to the EFI memory map and protects the read-only portions of the
      kernel from unwarranted DMA access.
      Tested-by: default avatarOng, Boon Leong <boon.leong.ong@intel.com>
      Signed-off-by: default avatarBryan O'Donoghue <pure.logic@nexus-software.ie>
      Reviewed-by: default avatarAndy Shevchenko <andy.schevchenko@gmail.com>
      Reviewed-by: default avatarDarren Hart <dvhart@linux.intel.com>
      Reviewed-by: default avatarOng, Boon Leong <boon.leong.ong@intel.com>
      Cc: andy.shevchenko@gmail.com
      Cc: dvhart@infradead.org
      Link: http://lkml.kernel.org/r/1422635379-12476-2-git-send-email-pure.logic@nexus-software.ieSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      28a375df
  21. 04 Mar, 2014 1 commit
  22. 05 Feb, 2014 1 commit
  23. 28 Oct, 2013 1 commit
  24. 04 Jul, 2013 1 commit
  25. 21 Jun, 2013 1 commit
    • Borislav Petkov's avatar
      x86: Sanity-check static_cpu_has usage · 5700f743
      Borislav Petkov authored
      static_cpu_has may be used only after alternatives have run. Before that
      it always returns false if constant folding with __builtin_constant_p()
      doesn't happen. And you don't want that.
      
      This patch is the result of me debugging an issue where I overzealously
      put static_cpu_has in code which executed before alternatives have run
      and had to spend some time with scratching head and cursing at the
      monitor.
      
      So add a jump to a warning which screams loudly when we use this
      function too early. The alternatives patch that check away in
      conjunction with patching the rest of the kernel image.
      
      [ hpa: factored this into its own configuration option.  If we want to
        have an overarching option, it should be an option which selects
        other options, not as a group option in the source code. ]
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Link: http://lkml.kernel.org/r/1370772454-6106-4-git-send-email-bp@alien8.deSigned-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
      5700f743
  26. 13 May, 2013 1 commit
  27. 01 May, 2013 1 commit
    • Stephen Boyd's avatar
      Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS · 446f24d1
      Stephen Boyd authored
      The help text for this config is duplicated across the x86, parisc, and
      s390 Kconfig.debug files.  Arnd Bergman noted that the help text was
      slightly misleading and should be fixed to state that enabling this
      option isn't a problem when using pre 4.4 gcc.
      
      To simplify the rewording, consolidate the text into lib/Kconfig.debug
      and modify it there to be more explicit about when you should say N to
      this config.
      
      Also, make the text a bit more generic by stating that this option
      enables compile time checks so we can cover architectures which emit
      warnings vs.  ones which emit errors.  The details of how an
      architecture decided to implement the checks isn't as important as the
      concept of compile time checking of copy_from_user() calls.
      
      While we're doing this, remove all the copy_from_user_overflow() code
      that's duplicated many times and place it into lib/ so that any
      architecture supporting this option can get the function for free.
      Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Acked-by: default avatarH. Peter Anvin <hpa@zytor.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Acked-by: default avatarHelge Deller <deller@gmx.de>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Stephen Rothwell <sfr@canb.auug.org.au>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      446f24d1
  28. 10 Apr, 2013 1 commit
  29. 28 Jun, 2012 1 commit
  30. 07 Dec, 2011 1 commit
  31. 05 Dec, 2011 3 commits
    • Alan Cox's avatar
      x86/config: Revamp configuration for MID devices · 1ea7c673
      Alan Cox authored
      This follows on from the patch applied in 3.2rc1 which creates
      an INTEL_MID configuration. We can now add the entry for
      Medfield specific code. After this is merged the final patch
      will be submitted which moves the rest of the device Kconfig
      dependancies to MRST/MEDFIELD/INTEL_MID as appropriate.
      Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      1ea7c673
    • Don Zickus's avatar
      x86, NMI: Add NMI IPI selftest · 99e8b9ca
      Don Zickus authored
      The previous patch modified the stop cpus path to use NMI
      instead of IRQ as the way to communicate to the other cpus to
      shutdown.  There were some concerns that various machines may
      have problems with using an NMI IPI.
      
      This patch creates a selftest to check if NMI is working at
      boot. The idea is to help catch any issues before the machine
      panics and we learn the hard way.
      
      Loosely based on the locking-selftest.c file, this separate file
      runs a couple of simple tests and reports the results.  The
      output looks like:
      
      ...
      Brought up 4 CPUs
      ----------------
      | NMI testsuite:
      --------------------
        remote IPI:  ok  |
         local IPI:  ok  |
      --------------------
      Good, all   2 testcases passed! |
      ---------------------------------
      Total of 4 processors activated (21330.61 BogoMIPS).
      ...
      Signed-off-by: default avatarDon Zickus <dzickus@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Robert Richter <robert.richter@amd.com>
      Cc: seiji.aguchi@hds.com
      Cc: vgoyal@redhat.com
      Cc: mjg@redhat.com
      Cc: tony.luck@intel.com
      Cc: gong.chen@intel.com
      Cc: satoru.moriya@hds.com
      Cc: avi@redhat.com
      Cc: Andi Kleen <andi@firstfloor.org>
      Link: http://lkml.kernel.org/r/1318533267-18880-3-git-send-email-dzickus@redhat.comSigned-off-by: default avatarIngo Molnar <mingo@elte.hu>
      99e8b9ca
    • Mitsuo Hayasaka's avatar
      x86: Check stack overflow in detail · 37fe6a42
      Mitsuo Hayasaka authored
      Currently, only kernel stack is checked for the overflow, which
      is not sufficient for systems that need a high reliability. To
      enhance it, it is required to check the IRQ and exception
      stacks, as well.
      
      This patch checks all the stack types and will cause messages of
      stacks in detail when free stack space drops below a certain
      limit except user stack.
      Signed-off-by: default avatarMitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
      Cc: yrl.pp-manager.tt@hitachi.com
      Cc: Randy Dunlap <rdunlap@xenotime.net>
      Link: http://lkml.kernel.org/r/20111129060829.11076.51733.stgit@ltc219.sdl.hitachi.co.jpSigned-off-by: default avatarIngo Molnar <mingo@elte.hu>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      37fe6a42
  32. 27 Sep, 2011 1 commit
    • Paul Bolle's avatar
      doc: fix broken references · 395cf969
      Paul Bolle authored
      There are numerous broken references to Documentation files (in other
      Documentation files, in comments, etc.). These broken references are
      caused by typo's in the references, and by renames or removals of the
      Documentation files. Some broken references are simply odd.
      
      Fix these broken references, sometimes by dropping the irrelevant text
      they were part of.
      Signed-off-by: default avatarPaul Bolle <pebolle@tiscali.nl>
      Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      395cf969
  33. 25 May, 2011 2 commits
  34. 21 Jan, 2011 1 commit
    • David Rientjes's avatar
      kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT · 6a108a14
      David Rientjes authored
      The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
      is used to configure any non-standard kernel with a much larger scope than
      only small devices.
      
      This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
      references to the option throughout the kernel.  A new CONFIG_EMBEDDED
      option is added that automatically selects CONFIG_EXPERT when enabled and
      can be used in the future to isolate options that should only be
      considered for embedded systems (RISC architectures, SLOB, etc).
      
      Calling the option "EXPERT" more accurately represents its intention: only
      expert users who understand the impact of the configuration changes they
      are making should enable it.
      Reviewed-by: default avatarIngo Molnar <mingo@elte.hu>
      Acked-by: default avatarDavid Woodhouse <david.woodhouse@intel.com>
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Greg KH <gregkh@suse.de>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Robin Holt <holt@sgi.com>
      Cc: <linux-arch@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6a108a14