1. 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
  2. 24 Dec, 2016 1 commit
  3. 18 Jul, 2016 1 commit
    • Arnd Bergmann's avatar
      Kbuild: arch: look for generated headers in obtree · 58ab5e0c
      Arnd Bergmann authored
      There are very few files that need add an -I$(obj) gcc for the preprocessor
      or the assembler. For C files, we add always these for both the objtree and
      srctree, but for the other ones we require the Makefile to add them, and
      Kbuild then adds it for both trees.
      
      As a preparation for changing the meaning of the -I$(obj) directive to
      only refer to the srctree, this changes the two instances in arch/x86 to use
      an explictit $(objtree) prefix where needed, otherwise we won't find the
      headers any more, as reported by the kbuild 0day builder.
      
      arch/x86/realmode/rm/realmode.lds.S:75:20: fatal error: pasyms.h: No such file or directory
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarMichal Marek <mmarek@suse.com>
      58ab5e0c
  4. 26 May, 2015 1 commit
  5. 08 Mar, 2013 1 commit
  6. 28 Mar, 2012 1 commit
  7. 30 Mar, 2010 1 commit
    • Tejun Heo's avatar
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo authored
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Guess-its-ok-by: default avatarChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  8. 12 Dec, 2009 1 commit
  9. 15 Nov, 2009 1 commit
  10. 22 Sep, 2009 1 commit
  11. 25 Jul, 2008 1 commit
    • Thomas Petazzoni's avatar
      inflate: refactor inflate malloc code · 2d6ffcca
      Thomas Petazzoni authored
      Inflate requires some dynamic memory allocation very early in the boot
      process and this is provided with a set of four functions:
      malloc/free/gzip_mark/gzip_release.
      
      The old inflate code used a mark/release strategy rather than implement
      free.  This new version instead keeps a count on the number of outstanding
      allocations and when it hits zero, it resets the malloc arena.
      
      This allows removing all the mark and release implementations and unifying
      all the malloc/free implementations.
      
      The architecture-dependent code must define two addresses:
       - free_mem_ptr, the address of the beginning of the area in which
         allocations should be made
       - free_mem_end_ptr, the address of the end of the area in which
         allocations should be made. If set to 0, then no check is made on
         the number of allocations, it just grows as much as needed
      
      The architecture-dependent code can also provide an arch_decomp_wdog()
      function call.  This function will be called several times during the
      decompression process, and allow to notify the watchdog that the system is
      still running.  If an architecture provides such a call, then it must
      define ARCH_HAS_DECOMP_WDOG so that the generic inflate code calls
      arch_decomp_wdog().
      
      Work initially done by Matt Mackall, updated to a recent version of the
      kernel and improved by me.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
      Cc: Matt Mackall <mpm@selenic.com>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Mikael Starvik <mikael.starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Acked-by: default avatarPaul Mundt <lethal@linux-sh.org>
      Acked-by: default avatarYoshinori 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>
      2d6ffcca
  12. 31 Jul, 2007 4 commits
    • Meelis Roos's avatar
      add a missing LIB_Y to arch/alpha/boot Makefile · 135db3eb
      Meelis Roos authored
      Add $(LIBS_Y) to get lib/lib.a so srm_printk is present.
      Signed-off-by: default avatarMeelis Roos <mroos@linux.ee>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Jay Estabrook <jay.estabrook@hp.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      135db3eb
    • Meelis Roos's avatar
      alpha: fix boot/main.c warning · 9965a5d5
      Meelis Roos authored
      In current 2.6.23-rc1+git, make bootimage gives the following warning while
      compiling arch/alpha/boot/main.c.  The patch below fixes the warning by
      casting callback argument explicitly to void*.  The original value comes from
      START_ADDR macro and is clearly numeric so only cast it for the callback.
      
        CC      arch/alpha/boot/main.o
      arch/alpha/boot/main.c: In function 'load':
      arch/alpha/boot/main.c:135: warning: passing argument 3 of 'callback_read' makes pointer from integer without a cast
      Signed-off-by: default avatarMeelis Roos <mroos@linux.ee>
      Cc: Jay Estabrook <jay.estabrook@hp.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Richard Henderson <rth@twiddle.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9965a5d5
    • Meelis Roos's avatar
      alpha: fix objstrip.c compilation warnings · 1b2becff
      Meelis Roos authored
      In current 2.6.23-rc1+git, make bootimage gives the following warnings while
      compiling objstrip.c.  The patch below fixes these warnings by casting strncmp
      argument to char * - it does not seem feasible to change its type in struct
      elfhdr.
      
        HOSTCC  arch/alpha/boot/tools/objstrip
      arch/alpha/boot/tools/objstrip.c: In function 'main':
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of 'strlen' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of 'strlen' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of '__builtin_strcmp' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of 'strlen' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of '__builtin_strcmp' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of '__builtin_strcmp' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of '__builtin_strcmp' differ in signedness
      arch/alpha/boot/tools/objstrip.c:147: warning: pointer targets in passing argument 1 of 'strncmp' differ in signedness
      Signed-off-by: default avatarMeelis Roos <mroos@linux.ee>
      Cc: Jay Estabrook <jay.estabrook@hp.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Richard Henderson <rth@twiddle.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1b2becff
    • Meelis Roos's avatar
      alpha: fix mkbb compilation warnings · aeb3f462
      Meelis Roos authored
      In current 2.6.23-rc1+git, make bootimage gives the following warnings while
      compiling mkbb.c.  The patch below fixes these warnings by using the proper
      include for exit() and using appropriate printf format.
      
        HOSTCC  arch/alpha/boot/tools/mkbb
      arch/alpha/boot/tools/mkbb.c: In function 'main':
      arch/alpha/boot/tools/mkbb.c:95: warning: implicit declaration of function 'exit'
      arch/alpha/boot/tools/mkbb.c:95: warning: incompatible implicit declaration of built-in function 'exit'
      arch/alpha/boot/tools/mkbb.c:102: warning: incompatible implicit declaration of built-in function 'exit'
      arch/alpha/boot/tools/mkbb.c:110: warning: incompatible implicit declaration of built-in function 'exit'
      arch/alpha/boot/tools/mkbb.c:117: warning: format '%d' expects type 'int', but argument 3 has type 'long unsigned int'
      arch/alpha/boot/tools/mkbb.c:118: warning: incompatible implicit declaration of built-in function 'exit'
      arch/alpha/boot/tools/mkbb.c:125: warning: format '%d' expects type 'int', but argument 3 has type 'long unsigned int'
      arch/alpha/boot/tools/mkbb.c:126: warning: incompatible implicit declaration of built-in function 'exit'
      arch/alpha/boot/tools/mkbb.c:143: warning: incompatible implicit declaration of built-in function 'exit'
      arch/alpha/boot/tools/mkbb.c:148: warning: incompatible implicit declaration of built-in function 'exit'
      Signed-off-by: default avatarMeelis Roos <mroos@linux.ee>
      Cc: Jay Estabrook <jay.estabrook@hp.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Richard Henderson <rth@twiddle.net>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      aeb3f462
  13. 01 Jun, 2007 1 commit
    • Yoann Padioleau's avatar
      parse errors in ifdefs · f8343685
      Yoann Padioleau authored
      Fix various bits of obviously-busted code which we're not happening to
      compile, due to ifdefs.
      
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jeff Garzik <jeff@garzik.org>
      Cc: Jan Kara <jack@ucw.cz>
      Cc: James Bottomley <James.Bottomley@steeleye.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f8343685
  14. 07 May, 2007 1 commit
  15. 02 May, 2007 1 commit
    • Jeremy Fitzhardinge's avatar
      [PATCH] x86: deflate stack usage in lib/inflate.c · 35c74226
      Jeremy Fitzhardinge authored
      inflate_fixed and huft_build together use around 2.7k of stack.  When
      using 4k stacks, I saw stack overflows from interrupts arriving while
      unpacking the root initrd:
      
      do_IRQ: stack overflow: 384
       [<c0106b64>] show_trace_log_lvl+0x1a/0x30
       [<c01075e6>] show_trace+0x12/0x14
       [<c010763f>] dump_stack+0x16/0x18
       [<c0107ca4>] do_IRQ+0x6d/0xd9
       [<c010202b>] xen_evtchn_do_upcall+0x6e/0xa2
       [<c0106781>] xen_hypervisor_callback+0x25/0x2c
       [<c010116c>] xen_restore_fl+0x27/0x29
       [<c0330f63>] _spin_unlock_irqrestore+0x4a/0x50
       [<c0117aab>] change_page_attr+0x577/0x584
       [<c0117b45>] kernel_map_pages+0x8d/0xb4
       [<c016a314>] cache_alloc_refill+0x53f/0x632
       [<c016a6c2>] __kmalloc+0xc1/0x10d
       [<c0463d34>] malloc+0x10/0x12
       [<c04641c1>] huft_build+0x2a7/0x5fa
       [<c04645a5>] inflate_fixed+0x91/0x136
       [<c04657e2>] unpack_to_rootfs+0x5f2/0x8c1
       [<c0465acf>] populate_rootfs+0x1e/0xe4
      
      (This was under Xen, but there's no reason it couldn't happen on bare
        hardware.)
      
      This patch mallocs the local variables, thereby reducing the stack
      usage to sane levels.
      
      Also, up the heap size for the kernel decompressor to deal with the
      extra allocation.
      Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
      Signed-off-by: default avatarAndi Kleen <ak@suse.de>
      Cc: Tim Yamin <plasmaroo@gentoo.org>
      Cc: Andi Kleen <ak@suse.de>
      Cc: Matt Mackall <mpm@selenic.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ian Molton <spyro@f2s.com>
      35c74226
  16. 03 Jul, 2006 1 commit
    • Sam Ravnborg's avatar
      kbuild: introduce utsrelease.h · 63104eec
      Sam Ravnborg authored
      include/linux/version.h contained both actual KERNEL version
      and UTS_RELEASE that contains a subset from git SHA1 for when
      kernel was compiled as part of a git repository.
      This had the unfortunate side-effect that all files including version.h
      would be recompiled when some git changes was made due to changes SHA1.
      Split it out so we keep independent parts in separate files.
      
      Also update checkversion.pl script to no longer check for UTS_RELEASE.
      Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
      63104eec
  17. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4