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
