02 Nov, 2017
1 commit
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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
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
28 Aug, 2015
1 commit
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The current checkstack.pl script has a few problems, stemming from the
overly simplistic attempt at parsing objdump output with regular
expressions: For example, on x86_64 it doesn't take the push
instruction into account, making it consistently underestimate the
real stack use, and it also doesn't capture stack pointer adjustments
of exactly 128 bytes [1].Since newer gcc (>= 4.6) knows about -fstack-usage, we might as well
take the information straight from the horse's mouth. This patch
introduces scripts/stackusage, which is a simple wrapper for running
make with KCFLAGS set to -fstack-usage. Example use isscripts/stackusage -o out.su -j8 lib/
The script understands "-o foo" for writing to 'foo' and -h for a
trivial help text; anything else is passed to make.Afterwards, we find all newly created .su files, massage them a
little, sort by stack use and write the result to a single output
file.Note that the function names printed by (at least) gcc 4.7 are
sometimes useless. For example, the first three lines of out.su
generated above are./lib/decompress_bunzip2.c:155 get_next_block 448 static
./lib/decompress_unlzma.c:537 unlzma 336 static
./lib/vsprintf.c:616 8 304 staticThat function '8' is really the static symbol_string(), but it has
been subject to 'interprocedural scalar replacement of aggregates', so
its name in the object file is 'symbol_string.isra.8'. gcc 5.0 doesn't
have this problem; it uses the full name as seen in the object file.[1] Since gcc encodes that by
48 83 c4 80 add $0xffffffffffffff80,%rsp
and not
48 81 ec 80 00 00 00 sub $0x80,%rsp
since -128 fits in an imm8.
Signed-off-by: Rasmus Villemoes
Signed-off-by: Michal Marek
