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generic debug pagealloc

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CONFIG_DEBUG_PAGEALLOC is now supported by x86, powerpc, sparc64, and
s390.  This patch implements it for the rest of the architectures by
filling the pages with poison byte patterns after free_pages() and
verifying the poison patterns before alloc_pages().

This generic one cannot detect invalid page accesses immediately but
invalid read access may cause invalid dereference by poisoned memory and
invalid write access can be detected after a long delay.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Akinobu Mita 2009-03-31 15:23:17 -07:00 • committed by Linus Torvalds
parent 610a77e04a
commit 6a11f75b6a
16 changed files with 202 additions and 19 deletions
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17
mm/Kconfig.debug Normal file
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config WANT_PAGE_DEBUG_FLAGS
bool
config PAGE_POISONING
bool "Debug page memory allocations"
depends on DEBUG_KERNEL && !ARCH_SUPPORTS_DEBUG_PAGEALLOC
depends on !HIBERNATION
select DEBUG_PAGEALLOC
select WANT_PAGE_DEBUG_FLAGS
help
Fill the pages with poison patterns after free_pages() and verify
the patterns before alloc_pages(). This results in a large slowdown,
but helps to find certain types of memory corruptions.
This option cannot enalbe with hibernation. Otherwise, it will get
wrong messages for memory corruption because the free pages are not
saved to the suspend image.