1. 14 6月, 2018 1 次提交
    • L
      Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables · 050e9baa
      Linus Torvalds 提交于
      The changes to automatically test for working stack protector compiler
      support in the Kconfig files removed the special STACKPROTECTOR_AUTO
      option that picked the strongest stack protector that the compiler
      supported.
      
      That was all a nice cleanup - it makes no sense to have the AUTO case
      now that the Kconfig phase can just determine the compiler support
      directly.
      
      HOWEVER.
      
      It also meant that doing "make oldconfig" would now _disable_ the strong
      stackprotector if you had AUTO enabled, because in a legacy config file,
      the sane stack protector configuration would look like
      
        CONFIG_HAVE_CC_STACKPROTECTOR=y
        # CONFIG_CC_STACKPROTECTOR_NONE is not set
        # CONFIG_CC_STACKPROTECTOR_REGULAR is not set
        # CONFIG_CC_STACKPROTECTOR_STRONG is not set
        CONFIG_CC_STACKPROTECTOR_AUTO=y
      
      and when you ran this through "make oldconfig" with the Kbuild changes,
      it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
      been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
      CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
      used to be disabled (because it was really enabled by AUTO), and would
      disable it in the new config, resulting in:
      
        CONFIG_HAVE_CC_STACKPROTECTOR=y
        CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
        CONFIG_CC_STACKPROTECTOR=y
        # CONFIG_CC_STACKPROTECTOR_STRONG is not set
        CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
      
      That's dangerously subtle - people could suddenly find themselves with
      the weaker stack protector setup without even realizing.
      
      The solution here is to just rename not just the old RECULAR stack
      protector option, but also the strong one.  This does that by just
      removing the CC_ prefix entirely for the user choices, because it really
      is not about the compiler support (the compiler support now instead
      automatially impacts _visibility_ of the options to users).
      
      This results in "make oldconfig" actually asking the user for their
      choice, so that we don't have any silent subtle security model changes.
      The end result would generally look like this:
      
        CONFIG_HAVE_CC_STACKPROTECTOR=y
        CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
        CONFIG_STACKPROTECTOR=y
        CONFIG_STACKPROTECTOR_STRONG=y
        CONFIG_CC_HAS_SANE_STACKPROTECTOR=y
      
      where the "CC_" versions really are about internal compiler
      infrastructure, not the user selections.
      Acked-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      050e9baa
  2. 22 5月, 2018 3 次提交
  3. 08 5月, 2018 1 次提交
  4. 25 4月, 2018 3 次提交
    • E
      signal/xtensa: Use force_sig_fault where appropriate · 91810105
      Eric W. Biederman 提交于
      Filling in struct siginfo before calling force_sig_info a tedious and
      error prone process, where once in a great while the wrong fields
      are filled out, and siginfo has been inconsistently cleared.
      
      Simplify this process by using the helper force_sig_fault.  Which
      takes as a parameters all of the information it needs, ensures
      all of the fiddly bits of filling in struct siginfo are done properly
      and then calls force_sig_info.
      
      In short about a 5 line reduction in code for every time force_sig_info
      is called, which makes the calling function clearer.
      
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: linux-xtensa@linux-xtensa.org
      Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      91810105
    • E
      signal/xtensa: Consistenly use SIGBUS in do_unaligned_user · 7de712cc
      Eric W. Biederman 提交于
      While working on changing this code to use force_sig_fault I
      discovered that do_unaliged_user is sets si_signo to SIGBUS and passes
      SIGSEGV to force_sig_info.  Which is just b0rked.
      
      The code is reporting a SIGBUS error so replace the SIGSEGV with SIGBUS.
      
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: linux-xtensa@linux-xtensa.org
      Cc: stable@vger.kernel.org
      Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
      Fixes: 5a0015d6 ("[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 3")
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      7de712cc
    • E
      signal: Ensure every siginfo we send has all bits initialized · 3eb0f519
      Eric W. Biederman 提交于
      Call clear_siginfo to ensure every stack allocated siginfo is properly
      initialized before being passed to the signal sending functions.
      
      Note: It is not safe to depend on C initializers to initialize struct
      siginfo on the stack because C is allowed to skip holes when
      initializing a structure.
      
      The initialization of struct siginfo in tracehook_report_syscall_exit
      was moved from the helper user_single_step_siginfo into
      tracehook_report_syscall_exit itself, to make it clear that the local
      variable siginfo gets fully initialized.
      
      In a few cases the scope of struct siginfo has been reduced to make it
      clear that siginfo siginfo is not used on other paths in the function
      in which it is declared.
      
      Instances of using memset to initialize siginfo have been replaced
      with calls clear_siginfo for clarity.
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      3eb0f519
  5. 03 4月, 2018 1 次提交
  6. 01 3月, 2018 1 次提交
  7. 17 2月, 2018 1 次提交
  8. 31 1月, 2018 1 次提交
  9. 23 1月, 2018 1 次提交
    • E
      signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed · f71dd7dc
      Eric W. Biederman 提交于
      There are so many places that build struct siginfo by hand that at
      least one of them is bound to get it wrong.  A handful of cases in the
      kernel arguably did just that when using the errno field of siginfo to
      pass no errno values to userspace.  The usage is limited to a single
      si_code so at least does not mess up anything else.
      
      Encapsulate this questionable pattern in a helper function so
      that the userspace ABI is preserved.
      
      Update all of the places that use this pattern to use the new helper
      function.
      Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      f71dd7dc
  10. 18 12月, 2017 1 次提交
  11. 17 12月, 2017 5 次提交
    • M
      xtensa: add support for KASAN · c633544a
      Max Filippov 提交于
      Cover kernel addresses above 0x90000000 by the shadow map. Enable
      HAVE_ARCH_KASAN when MMU is enabled. Provide kasan_early_init that fills
      shadow map with writable copies of kasan_zero_page. Call
      kasan_early_init right after mmu initialization in the setup_arch.
      Provide kasan_init that allocates proper shadow map pages from the
      memblock and puts these pages into the shadow map for addresses from
      VMALLOC area to the end of KSEG. Call kasan_init right after memblock
      initialization. Don't use KASAN for the boot code, MMU and KASAN
      initialization and page fault handler. Make kernel stack size 4 times
      larger when KASAN is enabled to avoid stack overflows.
      GCC 7.3, 8 or newer is required to build the xtensa kernel with KASAN.
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      c633544a
    • M
      xtensa: extract init_kio · c2edb35a
      Max Filippov 提交于
      KIO region placement may be specified in the device tree, that's why
      it's initialized with the rest of MMU after the early_init_devtree. In
      order to support KASAN the MMU must be initialized earlier.
      Separate KIO initialization from the rest of MMU initialization.
      Reinitialize KIO if its location is specified in the device tree.
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      c2edb35a
    • M
      xtensa: clean up exception handling structure · f21a79ca
      Max Filippov 提交于
      Instead of using flat array of longs use normal C structure and generate
      EXC_TABLE_* constants in the asm-offsets.c
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      f21a79ca
    • M
      xtensa: clean up custom-controlled debug output · c130d3be
      Max Filippov 提交于
      Replace #ifdef'fed/commented out debug printk statements with pr_debug.
      Replace printk statements with pr_* equivalents.
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      c130d3be
    • M
      xtensa: enable stack protector · 40d1a07b
      Max Filippov 提交于
      The implementation is adopted from the ARM arch. GCC 7.3, 8 or newer is
      required for building the xtensa kernel with SSP.
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      40d1a07b
  12. 11 12月, 2017 5 次提交
  13. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      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: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  14. 19 10月, 2017 1 次提交
  15. 10 8月, 2017 1 次提交
  16. 02 8月, 2017 1 次提交
  17. 19 6月, 2017 1 次提交
    • H
      mm: larger stack guard gap, between vmas · 1be7107f
      Hugh Dickins 提交于
      Stack guard page is a useful feature to reduce a risk of stack smashing
      into a different mapping. We have been using a single page gap which
      is sufficient to prevent having stack adjacent to a different mapping.
      But this seems to be insufficient in the light of the stack usage in
      userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
      used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
      which is 256kB or stack strings with MAX_ARG_STRLEN.
      
      This will become especially dangerous for suid binaries and the default
      no limit for the stack size limit because those applications can be
      tricked to consume a large portion of the stack and a single glibc call
      could jump over the guard page. These attacks are not theoretical,
      unfortunatelly.
      
      Make those attacks less probable by increasing the stack guard gap
      to 1MB (on systems with 4k pages; but make it depend on the page size
      because systems with larger base pages might cap stack allocations in
      the PAGE_SIZE units) which should cover larger alloca() and VLA stack
      allocations. It is obviously not a full fix because the problem is
      somehow inherent, but it should reduce attack space a lot.
      
      One could argue that the gap size should be configurable from userspace,
      but that can be done later when somebody finds that the new 1MB is wrong
      for some special case applications.  For now, add a kernel command line
      option (stack_guard_gap) to specify the stack gap size (in page units).
      
      Implementation wise, first delete all the old code for stack guard page:
      because although we could get away with accounting one extra page in a
      stack vma, accounting a larger gap can break userspace - case in point,
      a program run with "ulimit -S -v 20000" failed when the 1MB gap was
      counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
      and strict non-overcommit mode.
      
      Instead of keeping gap inside the stack vma, maintain the stack guard
      gap as a gap between vmas: using vm_start_gap() in place of vm_start
      (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
      places which need to respect the gap - mainly arch_get_unmapped_area(),
      and and the vma tree's subtree_gap support for that.
      Original-patch-by: NOleg Nesterov <oleg@redhat.com>
      Original-patch-by: NMichal Hocko <mhocko@suse.com>
      Signed-off-by: NHugh Dickins <hughd@google.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Tested-by: Helge Deller <deller@gmx.de> # parisc
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1be7107f
  18. 14 6月, 2017 1 次提交
  19. 06 6月, 2017 2 次提交
    • M
      xtensa: don't use linux IRQ #0 · e5c86679
      Max Filippov 提交于
      Linux IRQ #0 is reserved for error reporting and may not be used.
      Increase NR_IRQS for one additional slot and increase
      irq_domain_add_legacy parameter first_irq value to 1, so that linux
      IRQ #0 is not associated with hardware IRQ #0 in legacy IRQ domains.
      Introduce macro XTENSA_PIC_LINUX_IRQ for static translation of xtensa
      PIC hardware IRQ # to linux IRQ #. Use this macro in XTFPGA platform
      data definitions.
      
      This fixes inability to use hardware IRQ #0 in configurations that don't
      use device tree and allows for non-identity mapping between linux IRQ #
      and hardware IRQ #.
      
      Cc: stable@vger.kernel.org
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      e5c86679
    • M
      xtensa: reduce double exception literal reservation · 6bf28969
      Max Filippov 提交于
      Double exception vector only needs 20 bytes of space for 5 literals, not
      48. Reduce the reservation for double exception vector literals
      accordingly. This fixes build for configurations with small user
      exception vector size.
      Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
      6bf28969
  20. 09 5月, 2017 1 次提交
  21. 02 5月, 2017 1 次提交
  22. 01 5月, 2017 3 次提交
  23. 29 4月, 2017 1 次提交
  24. 20 4月, 2017 1 次提交
  25. 19 4月, 2017 1 次提交