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: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There wasn't an LKDTM test to distinguish between -fstack-protector and
-fstack-protector-strong in use. This adds CORRUPT_STACK_STRONG to see
the difference. Also adjusts the stack-clobber value to 0xff so execution
won't potentially jump into userspace when the stack protector is missing.
Signed-off-by: Kees Cook <keescook@chromium.org>
Two new tests STACK_GUARD_PAGE_LEADING and STACK_GUARD_PAGE_TRAILING
attempt to read the byte before and after, respectively, of the current
stack frame, which should fault.
Signed-off-by: Kees Cook <keescook@chromium.org>
While not a crash test, this does provide two tight atomic_t and
refcount_t loops for performance comparisons:
cd /sys/kernel/debug/provoke-crash
perf stat -B -- cat <(echo ATOMIC_TIMING) > DIRECT
perf stat -B -- cat <(echo REFCOUNT_TIMING) > DIRECT
Looking a CPU cycles is the best way to example the fast-path (rather
than instruction counts, since conditional jumps will be executed but
will be negligible due to branch-prediction).
Signed-off-by: Kees Cook <keescook@chromium.org>
The existing REFCOUNT_* LKDTM tests were designed only for testing a narrow
portion of CONFIG_REFCOUNT_FULL. This moves the tests to their own file and
expands their testing to poke each boundary condition.
Since the protections (CONFIG_REFCOUNT_FULL and x86-fast) use different
saturation values and reach-zero behavior, those have to be build-time
set so the tests can actually validate things are happening at the
right places.
Notably, the x86-fast protection will fail REFCOUNT_INC_ZERO and
REFCOUNT_ADD_ZERO since those conditions are not checked (only overflow
is critical to protecting refcount_t). CONFIG_REFCOUNT_FULL will warn for
each REFCOUNT_*_NEGATIVE test since it provides zero-pinning behaviors
(which allows it to pass REFCOUNT_INC_ZERO and REFCOUNT_ADD_ZERO).
Signed-off-by: Kees Cook <keescook@chromium.org>
This adds CORRUPT_USER_DS to check that the get_fs() test on syscall
return (via __VERIFY_PRE_USERMODE_STATE) still sees USER_DS. Since
trying to deal with values other than USER_DS and KERNEL_DS across all
architectures in a safe way is not sensible, this sets KERNEL_DS, but
since that could be extremely dangerous if the protection is not present,
it also raises SIGKILL for current, so that no matter what, the process
will die. A successful test will be visible with a BUG(), like all the
other LKDTM tests.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When building under CONFIG_DEBUG_LIST, list addition and removal will be
sanity-checked. This validates that the check is working as expected by
setting up classic corruption attacks against list manipulations, available
with the new lkdtm tests CORRUPT_LIST_ADD and CORRUPT_LIST_DEL.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
When building under W=1, the lack of lkdtm.h in lkdtm_usercopy.c and
lkdtm_rodata.c was discovered. This fixes the issue and consolidates
the common header and the pr_fmt macro for simplicity and regularity
across each test source file.
Signed-off-by: Kees Cook <keescook@chromium.org>
This splits all the remaining tests from lkdtm_core.c into the new
lkdtm_bugs.c file to help separate things better for readability.
Signed-off-by: Kees Cook <keescook@chromium.org>
This splits the *_AFTER_FREE and related tests into the new lkdtm_heap.c
file to help separate things better for readability.
Signed-off-by: Kees Cook <keescook@chromium.org>
This splits the EXEC_*, WRITE_* and related tests into the new lkdtm_perms.c
file to help separate things better for readability.
Signed-off-by: Kees Cook <keescook@chromium.org>
This splits the USERCOPY_* tests into the new lkdtm_usercopy.c file to
help separate things better for readability.
Signed-off-by: Kees Cook <keescook@chromium.org>
This adds a function that lives in the .rodata section. The section
flags are corrected using objcopy since there is no way with gcc to
declare section flags in an architecture-agnostic way.
Signed-off-by: Kees Cook <keescook@chromium.org>
