linux-kernel - [PATCH AUTOSEL 5.2 034/185] arm64: mm: free the initrd reserved memblock in a aligned manner

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Message-Id: <20190922184924.32534-34-sashal@kernel.org>
Date:   Sun, 22 Sep 2019 14:46:52 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Junhua Huang <huang.junhua@....com.cn>,
        Will Deacon <will@...nel.org>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 5.2 034/185] arm64: mm: free the initrd reserved memblock in a aligned manner

From: Junhua Huang <huang.junhua@....com.cn>

[ Upstream commit 13776f9d40a028a245bb766269e360f5b7a62721 ]

We should free the initrd reserved memblock in an aligned manner,
because the initrd reserves the memblock in an aligned manner
in arm64_memblock_init().
Otherwise there are some fragments in memblock_reserved regions
after free_initrd_mem(). e.g.:
/sys/kernel/debug/memblock # cat reserved
   0: 0x0000000080080000..0x00000000817fafff
   1: 0x0000000083400000..0x0000000083ffffff
   2: 0x0000000090000000..0x000000009000407f
   3: 0x00000000b0000000..0x00000000b000003f
   4: 0x00000000b26184ea..0x00000000b2618fff
The fragments like the ranges from b0000000 to b000003f and
from b26184ea to b2618fff should be freed.

And we can do free_reserved_area() after memblock_free(),
as free_reserved_area() calls __free_pages(), once we've done
that it could be allocated somewhere else,
but memblock and iomem still say this is reserved memory.

Fixes: 05c58752f9dc ("arm64: To remove initrd reserved area entry from memblock")
Signed-off-by: Junhua Huang <huang.junhua@....com.cn>
Signed-off-by: Will Deacon <will@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/arm64/mm/init.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index f3c795278def0..b1ee6cb4b17fc 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -570,8 +570,12 @@ void free_initmem(void)
 #ifdef CONFIG_BLK_DEV_INITRD
 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
+	unsigned long aligned_start, aligned_end;
+
+	aligned_start = __virt_to_phys(start) & PAGE_MASK;
+	aligned_end = PAGE_ALIGN(__virt_to_phys(end));
+	memblock_free(aligned_start, aligned_end - aligned_start);
 	free_reserved_area((void *)start, (void *)end, 0, "initrd");
-	memblock_free(__virt_to_phys(start), end - start);
 }
 #endif

-- 
2.20.1