diff options
| author | Laura Abbott <labbott@fedoraproject.org> | 2016-03-15 14:56:27 -0700 |
|---|---|---|
| committer | Vinayak Menon <vinmenon@codeaurora.org> | 2017-04-14 23:43:04 +0530 |
| commit | 5c69adad61e27f467fa8e1671633e455741e3fae (patch) | |
| tree | 579bd7cf1d021d6729da1ffaceed4227c3148712 /include | |
| parent | 406ab7d2d4f3a72f3ef1dd10f894e6c88ee3ac01 (diff) | |
mm/page_poison.c: enable PAGE_POISONING as a separate option
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
Change-Id: I77a36f844ddae54695089c98a97bf0a6e226a025
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jianyu Zhan <nasa4836@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 8823b1dbc05fab1a8bec275eeae4709257c2661d
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 186d2ab9cd13..8e4e3debce84 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2146,6 +2146,15 @@ static inline void vm_stat_account(struct mm_struct *mm, } #endif /* CONFIG_PROC_FS */ +#ifdef CONFIG_PAGE_POISONING +extern bool page_poisoning_enabled(void); +extern void kernel_poison_pages(struct page *page, int numpages, int enable); +#else +static inline bool page_poisoning_enabled(void) { return false; } +static inline void kernel_poison_pages(struct page *page, int numpages, + int enable) { } +#endif + #ifdef CONFIG_DEBUG_PAGEALLOC extern bool _debug_pagealloc_enabled; extern void __kernel_map_pages(struct page *page, int numpages, int enable); |