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Subject[PATCH] memblock: Make sure reserved.regions is freed really
Date
memblock_free() would double reserved.regions too, so we could free
old range for reserved.regions.

So need to check that regions get doubled. If it is doubled, we need to
free it.

Cc: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>

---
mm/memblock.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)

Index: linux-2.6/mm/memblock.c
===================================================================
--- linux-2.6.orig/mm/memblock.c
+++ linux-2.6/mm/memblock.c
@@ -148,11 +148,26 @@ phys_addr_t __init_memblock memblock_fin
*/
int __init_memblock memblock_free_reserved_regions(void)
{
+ struct memblock_region *r;
+ int ret;
+
if (memblock.reserved.regions == memblock_reserved_init_regions)
return 0;

- return memblock_free(__pa(memblock.reserved.regions),
- sizeof(struct memblock_region) * memblock.reserved.max);
+ /*
+ * During memblock_free, reserved.regions could be doubled,
+ * try to check with old one for checking, and need to free the new one.
+ */
+ do {
+ r = memblock.reserved.regions;
+ ret = memblock_free(__pa(memblock.reserved.regions),
+ sizeof(struct memblock_region) * memblock.reserved.max);
+
+ if (ret)
+ break;
+ } while (memblock.reserved.regions != r);
+
+ return ret;
}

/*
@@ -163,6 +178,10 @@ int __init_memblock memblock_reserve_res
if (memblock.reserved.regions == memblock_reserved_init_regions)
return 0;

+ /*
+ * Don't need to worry about if reserved.regions get updated later,
+ * and it is big enough after memblock_free_reserved_regions().
+ */
return memblock_reserve(__pa(memblock.reserved.regions),
sizeof(struct memblock_region) * memblock.reserved.max);
}

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