1. 06 Mar, 2019 1 commit
    • Qian Cai's avatar
      page_poison: play nicely with KASAN · 4117992d
      Qian Cai authored
      KASAN does not play well with the page poisoning (CONFIG_PAGE_POISONING).
      It triggers false positives in the allocation path:
      
        BUG: KASAN: use-after-free in memchr_inv+0x2ea/0x330
        Read of size 8 at addr ffff88881f800000 by task swapper/0
        CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc1+ #54
        Call Trace:
         dump_stack+0xe0/0x19a
         print_address_description.cold.2+0x9/0x28b
         kasan_report.cold.3+0x7a/0xb5
         __asan_report_load8_noabort+0x19/0x20
         memchr_inv+0x2ea/0x330
         kernel_poison_pages+0x103/0x3d5
         get_page_from_freelist+0x15e7/0x4d90
      
      because KASAN has not yet unpoisoned the shadow page for allocation
      before it checks memchr_inv() but only found a stale poison pattern.
      
      Also, false positives in free path,
      
        BUG: KASAN: slab-out-of-bounds in kernel_poison_pages+0x29e/0x3d5
        Write of size 4096 at addr ffff8888112cc000 by task swapper/0/1
        CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1+ #55
        Call Trace:
         dump_stack+0xe0/0x19a
         print_address_description.cold.2+0x9/0x28b
         kasan_report.cold.3+0x7a/0xb5
         check_memory_region+0x22d/0x250
         memset+0x28/0x40
         kernel_poison_pages+0x29e/0x3d5
         __free_pages_ok+0x75f/0x13e0
      
      due to KASAN adds poisoned redzones around slab objects, but the page
      poisoning needs to poison the whole page.
      
      Link: http://lkml.kernel.org/r/20190114233405.67843-1-cai@lca.pwSigned-off-by: default avatarQian Cai <cai@lca.pw>
      Acked-by: default avatarAndrey Ryabinin <aryabinin@virtuozzo.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4117992d
  2. 31 Oct, 2018 1 commit
    • Mike Rapoport's avatar
      memblock: rename free_all_bootmem to memblock_free_all · c6ffc5ca
      Mike Rapoport authored
      The conversion is done using
      
      sed -i 's@free_all_bootmem@memblock_free_all@' \
          $(git grep -l free_all_bootmem)
      
      Link: http://lkml.kernel.org/r/1536927045-23536-26-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: default avatarMike Rapoport <rppt@linux.vnet.ibm.com>
      Acked-by: default avatarMichal Hocko <mhocko@suse.com>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Greentime Hu <green.hu@gmail.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Guan Xuetao <gxt@pku.edu.cn>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Palmer Dabbelt <palmer@sifive.com>
      Cc: Paul Burton <paul.burton@mips.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Serge Semin <fancer.lancer@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      c6ffc5ca
  3. 25 Oct, 2018 1 commit
  4. 06 Apr, 2018 1 commit
  5. 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
  6. 03 May, 2017 1 commit
  7. 03 Jun, 2016 1 commit
  8. 21 May, 2016 1 commit
  9. 15 Mar, 2016 2 commits
    • Laura Abbott's avatar
      mm/page_poisoning.c: allow for zero poisoning · 1414c7f4
      Laura Abbott authored
      By default, page poisoning uses a poison value (0xaa) on free.  If this
      is changed to 0, the page is not only sanitized but zeroing on alloc
      with __GFP_ZERO can be skipped as well.  The tradeoff is that detecting
      corruption from the poisoning is harder to detect.  This feature also
      cannot be used with hibernation since pages are not guaranteed to be
      zeroed after hibernation.
      
      Credit to Grsecurity/PaX team for inspiring this work
      Signed-off-by: default avatarLaura Abbott <labbott@fedoraproject.org>
      Acked-by: default avatarRafael J. Wysocki <rjw@rjwysocki.net>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Mathias Krause <minipli@googlemail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Jianyu Zhan <nasa4836@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1414c7f4
    • Laura Abbott's avatar
      mm/page_poison.c: enable PAGE_POISONING as a separate option · 8823b1db
      Laura Abbott authored
      Page poisoning is currently set up as a feature if architectures don't
      have architecture debug page_alloc to allow unmapping of pages.  It has
      uses apart from that though.  Clearing of the pages on free provides an
      increase in security as it helps to limit the risk of information leaks.
      Allow page poisoning to be enabled as a separate option independent of
      kernel_map pages since the two features do separate work.  Because of
      how hiberanation is implemented, the checks on alloc cannot occur if
      hibernation is enabled.  The runtime alloc checks can also be enabled
      with an option when !HIBERNATION.
      
      Credit to Grsecurity/PaX team for inspiring this work
      Signed-off-by: default avatarLaura Abbott <labbott@fedoraproject.org>
      Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Mathias Krause <minipli@googlemail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Jianyu Zhan <nasa4836@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8823b1db
  10. 13 Dec, 2014 2 commits
    • Joonsoo Kim's avatar
      mm/debug-pagealloc: make debug-pagealloc boottime configurable · 031bc574
      Joonsoo Kim authored
      Now, we have prepared to avoid using debug-pagealloc in boottime.  So
      introduce new kernel-parameter to disable debug-pagealloc in boottime, and
      makes related functions to be disabled in this case.
      
      Only non-intuitive part is change of guard page functions.  Because guard
      page is effective only if debug-pagealloc is enabled, turning off
      according to debug-pagealloc is reasonable thing to do.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Jungsoo Son <jungsoo.son@lge.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      031bc574
    • Joonsoo Kim's avatar
      mm/debug-pagealloc: prepare boottime configurable on/off · e30825f1
      Joonsoo Kim authored
      Until now, debug-pagealloc needs extra flags in struct page, so we need to
      recompile whole source code when we decide to use it.  This is really
      painful, because it takes some time to recompile and sometimes rebuild is
      not possible due to third party module depending on struct page.  So, we
      can't use this good feature in many cases.
      
      Now, we have the page extension feature that allows us to insert extra
      flags to outside of struct page.  This gets rid of third party module
      issue mentioned above.  And, this allows us to determine if we need extra
      memory for this page extension in boottime.  With these property, we can
      avoid using debug-pagealloc in boottime with low computational overhead in
      the kernel built with CONFIG_DEBUG_PAGEALLOC.  This will help our
      development process greatly.
      
      This patch is the preparation step to achive above goal.  debug-pagealloc
      originally uses extra field of struct page, but, after this patch, it will
      use field of struct page_ext.  Because memory for page_ext is allocated
      later than initialization of page allocator in CONFIG_SPARSEMEM, we should
      disable debug-pagealloc feature temporarily until initialization of
      page_ext.  This patch implements this.
      Signed-off-by: default avatarJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Michal Nazarewicz <mina86@mina86.com>
      Cc: Jungsoo Son <jungsoo.son@lge.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e30825f1
  11. 06 Dec, 2011 1 commit
  12. 01 Nov, 2011 3 commits
  13. 01 Apr, 2009 1 commit