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. 17 Mar, 2016 1 commit
    • Denys Vlasenko's avatar
      include/linux/unaligned: force inlining of byteswap operations · e3bde956
      Denys Vlasenko authored
      Sometimes gcc mysteriously doesn't inline
      very small functions we expect to be inlined. See
      
          https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122
      
      With this .config:
      http://busybox.net/~vda/kernel_config_OPTIMIZE_INLINING_and_Os,
      the following functions get deinlined many times.
      Examples of disassembly:
      
      <get_unaligned_be16> (24 copies, 108 calls):
             66 8b 07                mov    (%rdi),%ax
             55                      push   %rbp
             48 89 e5                mov    %rsp,%rbp
             86 e0                   xchg   %ah,%al
             5d                      pop    %rbp
             c3                      retq
      
      <get_unaligned_be32> (25 copies, 181 calls):
             8b 07                   mov    (%rdi),%eax
             55                      push   %rbp
             48 89 e5                mov    %rsp,%rbp
             0f c8                   bswap  %eax
             5d                      pop    %rbp
             c3                      retq
      
      <get_unaligned_be64> (23 copies, 94 calls):
             48 8b 07                mov    (%rdi),%rax
             55                      push   %rbp
             48 89 e5                mov    %rsp,%rbp
             48 0f c8                bswap  %rax
             5d                      pop    %rbp
             c3                      retq
      
      <put_unaligned_be16> (2 copies, 11 calls):
             89 f8                   mov    %edi,%eax
             55                      push   %rbp
             c1 ef 08                shr    $0x8,%edi
             c1 e0 08                shl    $0x8,%eax
             09 c7                   or     %eax,%edi
             48 89 e5                mov    %rsp,%rbp
             66 89 3e                mov    %di,(%rsi)
      
      <put_unaligned_be32> (8 copies, 43 calls):
             55                      push   %rbp
             0f cf                   bswap  %edi
             89 3e                   mov    %edi,(%rsi)
             48 89 e5                mov    %rsp,%rbp
             5d                      pop    %rbp
             c3                      retq
      
      <put_unaligned_be64> (26 copies, 157 calls):
             55                      push   %rbp
             48 0f cf                bswap  %rdi
             48 89 3e                mov    %rdi,(%rsi)
             48 89 e5                mov    %rsp,%rbp
             5d                      pop    %rbp
             c3                      retq
      
      This patch fixes this via s/inline/__always_inline/.
      
      It only affects arches with efficient unaligned access insns, such as x86.
      (arched which lack such ops do not include linux/unaligned/access_ok.h)
      
      Code size decrease after the patch is ~8.5k:
      
          text     data      bss       dec     hex filename
      92197848 20826112 36417536 149441496 8e84bd8 vmlinux
      92189231 20826144 36417536 149432911 8e82a4f vmlinux6_unaligned_be_after
      Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
      Acked-by: default avatarIngo Molnar <mingo@kernel.org>
      Cc: Thomas Graf <tgraf@suug.ch>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      e3bde956
  3. 13 Jan, 2011 1 commit
  4. 23 Dec, 2010 1 commit
    • Will Newton's avatar
      include/linux/unaligned: pack the whole struct rather than just the field · 4e06fd14
      Will Newton authored
      The current packed struct implementation of unaligned access adds the
      packed attribute only to the field within the unaligned struct rather than
      to the struct as a whole.  This is not sufficient to enforce proper
      behaviour on architectures with a default struct alignment of more than
      one byte.
      
      For example, the current implementation of __get_unaligned_cpu16 when
      compiled for arm with gcc -O1 -mstructure-size-boundary=32 assumes the
      struct is on a 4 byte boundary so performs the load of the 16bit packed
      field as if it were on a 4 byte boundary:
      
      __get_unaligned_cpu16:
              ldrh    r0, [r0, #0]
              bx      lr
      
      Moving the packed attribute to the struct rather than the field causes the
      proper unaligned access code to be generated:
      
      __get_unaligned_cpu16:
      	ldrb	r3, [r0, #0]	@ zero_extendqisi2
      	ldrb	r0, [r0, #1]	@ zero_extendqisi2
      	orr	r0, r3, r0, asl #8
      	bx	lr
      Signed-off-by: Will Newton's avatarWill Newton <will.newton@gmail.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e06fd14
  5. 24 Sep, 2009 1 commit
    • Albin Tonnerre's avatar
      include/linux/unaligned/{l,b}e_byteshift.h: fix usage for compressed kernels · 2fa43410
      Albin Tonnerre authored
      When unaligned accesses are required for uncompressing a kernel (such as
      for LZO decompression on ARM in a patch that follows), including
      <linux/kernel.h> causes issues as it brings in a lot of things that are
      not available in the decompression environment.
      
      linux/kernel.h brings at least:
      extern int console_printk[];
      extern const char hex_asc[];
      which causes errors at link-time as they are not available when
      compiling the pre-boot environement. There are also a few others:
      
        arch/arm/boot/compressed/misc.o: In function `valid_user_regs':
         arch/arm/include/asm/ptrace.h:158: undefined reference to `elf_hwcap'
        arch/arm/boot/compressed/misc.o: In function `console_silent':
         include/linux/kernel.h:292: undefined reference to `console_printk'
        arch/arm/boot/compressed/misc.o: In function `console_verbose':
         include/linux/kernel.h:297: undefined reference to `console_printk'
        arch/arm/boot/compressed/misc.o: In function `pack_hex_byte':
         include/linux/kernel.h:360: undefined reference to `hex_asc'
        arch/arm/boot/compressed/misc.o: In function `hweight_long':
         include/linux/bitops.h:45: undefined reference to `hweight32'
        arch/arm/boot/compressed/misc.o: In function `__cmpxchg_local_generic':
         include/asm-generic/cmpxchg-local.h:21: undefined reference to `wrong_size_cmpxchg'
         include/asm-generic/cmpxchg-local.h:42: undefined reference to `wrong_size_cmpxchg'
        arch/arm/boot/compressed/misc.o: In function `__xchg':
         arch/arm/include/asm/system.h:309: undefined reference to `__bad_xchg'
      
      However, those files apparently use nothing from <linux/kernel.h>, all
      they need is the declaration of types such as u32 or u64, so
      <linux/types.h> should be enough
      Signed-off-by: default avatarAlbin Tonnerre <albin.tonnerre@free-electrons.com>
      Cc: Sam Ravnborg <sam@ravnborg.org>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      2fa43410
  6. 29 Apr, 2008 1 commit
    • Harvey Harrison's avatar
      kernel: add common infrastructure for unaligned access · 064106a9
      Harvey Harrison authored
      Create a linux/unaligned directory similar in spirit to the linux/byteorder
      folder to hold generic implementations collected from various arches.
      
      Currently there are five implementations:
      1) packed_struct.h: C-struct based, from asm-generic/unaligned.h
      2) le_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
      3) be_byteshift.h: Open coded byte-swapping, heavily based on asm-arm
      4) memmove.h: taken from multiple implementations in tree
      5) access_ok.h: taken from x86 and others, unaligned access is ok.
      
      All of the new implementations checks for sizes not equal to 1,2,4,8
      and will fail to link.
      
      API additions:
      
      get_unaligned_{le16|le32|le64|be16|be32|be64}(p) which is meant to replace
      code of the form:
      le16_to_cpu(get_unaligned((__le16 *)p));
      
      put_unaligned_{le16|le32|le64|be16|be32|be64}(val, pointer) which is meant to
      replace code of the form:
      put_unaligned(cpu_to_le16(val), (__le16 *)p);
      
      The headers that arches should include from their asm/unaligned.h:
      
      access_ok.h : Wrappers of the byteswapping functions in asm/byteorder
      
      Choose a particular implementation for little-endian access:
      le_byteshift.h
      le_memmove.h (arch must be LE)
      le_struct.h (arch must be LE)
      
      Choose a particular implementation for big-endian access:
      be_byteshift.h
      be_memmove.h (arch must be BE)
      be_struct.h (arch must be BE)
      
      After including as needed from the above, include unaligned/generic.h and
      define your arch's get/put_unaligned as (for LE):
      Signed-off-by: Harvey Harrison's avatarHarvey Harrison <harvey.harrison@gmail.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>
      064106a9