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authorAkinobu Mita <akinobu.mita@gmail.com>2009-03-31 15:23:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-01 08:59:13 -0700
commit6a11f75b6a17b5d9ac5025f8d048382fd1f47377 (patch)
treea3415cd897823975b927f89a233d2703bf97ba2b /arch/powerpc
parent610a77e04a8d9fe8764dc484e2182fa251ce1cc2 (diff)
generic debug pagealloc
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>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/Kconfig3
-rw-r--r--arch/powerpc/Kconfig.debug1
2 files changed, 4 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index ad6b1c084fe..45192dce65c 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -228,6 +228,9 @@ config PPC_OF_PLATFORM_PCI
depends on PPC64 # not supported on 32 bits yet
default n
+config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ def_bool y
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"
diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index 22091bbfdc9..6aa0b5e087c 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -30,6 +30,7 @@ config DEBUG_STACK_USAGE
config DEBUG_PAGEALLOC
bool "Debug page memory allocations"
depends on DEBUG_KERNEL && !HIBERNATION
+ depends on ARCH_SUPPORTS_DEBUG_PAGEALLOC
help
Unmap pages from the kernel linear mapping after free_pages().
This results in a large slowdown, but helps to find certain types