• Laura Abbott's avatar
    mm/page_poison.c: enable PAGE_POISONING as a separate option · 8823b1db
    Laura Abbott authored
    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: default avatarLaura 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: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
kernel-parameters.txt 152 KB