linux-kernel - [PATCH 1/1] x86: also use debug_pagealloc_enabled() for free_init

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Date:	Fri, 29 Jan 2016 13:52:12 +0100
From:	Christian Borntraeger <borntraeger@...ibm.com>
To:	akpm@...ux-foundation.org
Cc:	linux-kernel@...r.kernel.org, linux-mm@...ck.org, x86@...nel.org,
	Joonsoo Kim <iamjoonsoo.kim@....com>, davej@...emonkey.org.uk,
	David Rientjes <rientjes@...gle.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Christian Borntraeger <borntraeger@...ibm.com>
Subject: [PATCH 1/1] x86: also use debug_pagealloc_enabled() for free_init_pages

we want to couple all debugging features with debug_pagealloc_enabled()
and not with the config option CONFIG_DEBUG_PAGEALLOC.

Suggested-by: David Rientjes <rientjes@...gle.com>
Signed-off-by: Christian Borntraeger <borntraeger@...ibm.com>
---
 arch/x86/mm/init.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 39823fd..9d56f27 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -667,21 +667,22 @@ void free_init_pages(char *what, unsigned long begin, unsigned long end)
 	 * mark them not present - any buggy init-section access will
 	 * create a kernel page fault:
 	 */
-#ifdef CONFIG_DEBUG_PAGEALLOC
-	printk(KERN_INFO "debug: unmapping init [mem %#010lx-%#010lx]\n",
-		begin, end - 1);
-	set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
-#else
-	/*
-	 * We just marked the kernel text read only above, now that
-	 * we are going to free part of that, we need to make that
-	 * writeable and non-executable first.
-	 */
-	set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
-	set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
+	if (debug_pagealloc_enabled()) {
+		pr_info("debug: unmapping init [mem %#010lx-%#010lx]\n",
+			begin, end - 1);
+		set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
+	} else {
+		/*
+		 * We just marked the kernel text read only above, now that
+		 * we are going to free part of that, we need to make that
+		 * writeable and non-executable first.
+		 */
+		set_memory_nx(begin, (end - begin) >> PAGE_SHIFT);
+		set_memory_rw(begin, (end - begin) >> PAGE_SHIFT);
 
-	free_reserved_area((void *)begin, (void *)end, POISON_FREE_INITMEM, what);
-#endif
+		free_reserved_area((void *)begin, (void *)end,
+				   POISON_FREE_INITMEM, what);
+	}
 }
 
 void free_initmem(void)
-- 
2.3.0