[PATCH 2.6.18-rc6 08/10] Keep the __init functions after initialization

[Catalin Marinas <catalin.marinas@gmail.com>]

From: Catalin Marinas <catalin.marinas@arm.com>

This patch adds the CONFIG_DEBUG_KEEP_INIT option which preserves the
.init.text section after initialization. Memory leaks happening during this
phase can be more easily tracked.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---

 include/linux/init.h |    5 +++++
 lib/Kconfig.debug    |   12 ++++++++++++
 2 files changed, 17 insertions(+), 0 deletions(-)

diff --git a/include/linux/init.h b/include/linux/init.h
index 6667785..4b2df24 100644
--- a/include/linux/init.h
+++ b/include/linux/init.h
@@ -40,8 +40,13 @@ #include <linux/compiler.h>
 
 /* These are for everybody (although not all archs will actually
    discard it in modules) */
+#ifdef CONFIG_DEBUG_KEEP_INIT
+#define __init
+#define __initdata
+#else
 #define __init		__attribute__ ((__section__ (".init.text")))
 #define __initdata	__attribute__ ((__section__ (".init.data")))
+#endif
 #define __exitdata	__attribute__ ((__section__(".exit.data")))
 #define __exit_call	__attribute_used__ __attribute__ ((__section__ (".exitcall.exit")))
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 1786cb5..b36ac64 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -195,6 +195,18 @@ config DEBUG_MEMLEAK_REPORTS_NR
 	  reading the /sys/kernel/debug/memleak file could lead to
 	  some soft-locks.
 
+config DEBUG_KEEP_INIT
+	bool "Do not free the __init code/data"
+	default n
+	depends on DEBUG_MEMLEAK
+	help
+	  This option moves the __init code/data out of the
+	  .init.text/.init.data sections. It is useful for identifying
+	  memory leaks happening during the kernel or modules
+	  initialization.
+
+	  If unsure, say N.
+
 config DEBUG_PREEMPT
 	bool "Debug preemptible kernel"
 	depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT