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
04 May, 2017
1 commit
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On SPARSEMEM systems page poisoning is enabled after buddy is up,
because of the dependency on page extension init. This causes the pages
released by free_all_bootmem not to be poisoned. This either delays or
misses the identification of some issues because the pages have to
undergo another cycle of alloc-free-alloc for any corruption to be
detected.Enable page poisoning early by getting rid of the PAGE_EXT_DEBUG_POISON
flag. Since all the free pages will now be poisoned, the flag need not
be verified before checking the poison during an alloc.[vinmenon@codeaurora.org: fix Kconfig]
Link: http://lkml.kernel.org/r/1490878002-14423-1-git-send-email-vinmenon@codeaurora.org
Link: http://lkml.kernel.org/r/1490358246-11001-1-git-send-email-vinmenon@codeaurora.org
Signed-off-by: Vinayak Menon
Acked-by: Laura Abbott
Tested-by: Laura Abbott
Cc: Joonsoo Kim
Cc: Michal Hocko
Cc: Akinobu Mita
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jun, 2016
1 commit
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Per the discussion with Joonsoo Kim [1], we need check the return value
of lookup_page_ext() for all call sites since it might return NULL in
some cases, although it is unlikely, i.e. memory hotplug.Tested with ltp with "page_owner=0".
[1] http://lkml.kernel.org/r/20160519002809.GA10245@js1304-P5Q-DELUXE
[akpm@linux-foundation.org: fix build-breaking typos]
[arnd@arndb.de: fix build problems from lookup_page_ext]
Link: http://lkml.kernel.org/r/6285269.2CksypHdYp@wuerfel
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1464023768-31025-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi
Signed-off-by: Arnd Bergmann
Cc: Joonsoo Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 May, 2016
1 commit
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It's more convenient to use existing function helper to convert string
"on/off" to boolean.Link: http://lkml.kernel.org/r/1461908824-16129-1-git-send-email-mnghuan@gmail.com
Signed-off-by: Minfei Huang
Acked-by: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Mar, 2016
2 commits
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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: Laura Abbott
Acked-by: Rafael J. Wysocki
Cc: "Kirill A. Shutemov"
Cc: Vlastimil Babka
Cc: Michal Hocko
Cc: Kees Cook
Cc: Mathias Krause
Cc: Dave Hansen
Cc: Jianyu Zhan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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: Laura Abbott
Cc: Rafael J. Wysocki
Cc: "Kirill A. Shutemov"
Cc: Vlastimil Babka
Cc: Michal Hocko
Cc: Kees Cook
Cc: Mathias Krause
Cc: Dave Hansen
Cc: Jianyu Zhan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
