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authorAkinobu Mita <akinobu.mita@gmail.com>2009-04-01 00:23:17 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-01 17:59:13 +0200
commit6a11f75b6a17b5d9ac5025f8d048382fd1f47377 (patch)
treea3415cd897823975b927f89a233d2703bf97ba2b /arch/sparc
parentmemdup_user(): introduce (diff)
downloadlinux-6a11f75b6a17b5d9ac5025f8d048382fd1f47377.tar.xz
linux-6a11f75b6a17b5d9ac5025f8d048382fd1f47377.zip
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/sparc')
-rw-r--r--arch/sparc/Kconfig3
-rw-r--r--arch/sparc/Kconfig.debug3
2 files changed, 5 insertions, 1 deletions
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index c3ea215334f6..cc12cd48bbc5 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -124,6 +124,9 @@ config ARCH_NO_VIRT_TO_BUS
config OF
def_bool y
+config ARCH_SUPPORTS_DEBUG_PAGEALLOC
+ def_bool y if SPARC64
+
source "init/Kconfig"
source "kernel/Kconfig.freezer"
diff --git a/arch/sparc/Kconfig.debug b/arch/sparc/Kconfig.debug
index b8a15e271bfa..d001b42041a5 100644
--- a/arch/sparc/Kconfig.debug
+++ b/arch/sparc/Kconfig.debug
@@ -24,7 +24,8 @@ config STACK_DEBUG
config DEBUG_PAGEALLOC
bool "Debug page memory allocations"
- depends on SPARC64 && DEBUG_KERNEL && !HIBERNATION
+ 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