linux-kernel - [RFC v3] arm:extend the reserved mrmory for initrd to be page aligned

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Date:	Tue, 16 Sep 2014 09:34:49 +0800
From:	"Wang, Yalin" <Yalin.Wang@...ymobile.com>
To:	'Will Deacon' <will.deacon@....com>,
	"'linux-kernel@...r.kernel.org'" <linux-kernel@...r.kernel.org>,
	"'linux-arm-kernel@...ts.infradead.org'" 
	<linux-arm-kernel@...ts.infradead.org>,
	"'linux-mm@...ck.org'" <linux-mm@...ck.org>,
	"'linux-arm-msm@...r.kernel.org'" <linux-arm-msm@...r.kernel.org>,
	'Russell King - ARM Linux' <linux@....linux.org.uk>
Subject: [RFC v3] arm:extend the reserved mrmory for initrd to be page
 aligned

this patch extend the start and end address of initrd to be page aligned,
so that we can free all memory including the un-page aligned head or tail
page of initrd, if the start or end address of initrd are not page
aligned, the page can't be freed by free_initrd_mem() function.

Signed-off-by: Yalin Wang <yalin.wang@...ymobile.com>
---
 arch/arm/mm/init.c   | 5 +++++
 arch/arm64/mm/init.c | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 659c75d..9221645 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -636,6 +636,11 @@ static int keep_initrd;
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
 	if (!keep_initrd) {
+		if (start == initrd_start)
+			start = round_down(start, PAGE_SIZE);
+		if (end == initrd_end)
+			end = round_up(end, PAGE_SIZE);
+
 		poison_init_mem((void *)start, PAGE_ALIGN(end) - start);
 		free_reserved_area((void *)start, (void *)end, -1, "initrd");
 	}
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 5472c24..c5512f6 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -334,8 +334,14 @@ static int keep_initrd;
 
 void free_initrd_mem(unsigned long start, unsigned long end)
 {
-	if (!keep_initrd)
+	if (!keep_initrd) {
+		if (start == initrd_start)
+			start = round_down(start, PAGE_SIZE);
+		if (end == initrd_end)
+			end = round_up(end, PAGE_SIZE);
+
 		free_reserved_area((void *)start, (void *)end, 0, "initrd");
+	}
 }
 
 static int __init keepinitrd_setup(char *__unused)
-- 
2.1.0
--
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