lib/genalloc.c: fix overflow of ending address of memory chunk

In struct gen_pool_chunk, end_addr means the end address of memory chunk
(inclusive), but in the implementation it is treated as address + size of
memory chunk (exclusive), so it points to the address plus one instead of
correct ending address.

The ending address of memory chunk plus one will cause overflow on the
memory chunk including the last address of memory map, e.g.  when starting
address is 0xFFF00000 and size is 0x100000 on 32bit machine, ending
address will be 0x100000000.

Use correct ending address like starting address + size - 1.

[akpm@linux-foundation.org: add comment to struct gen_pool_chunk:end_addr]
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 661d374aeb2d..f8d41cb1cbe0 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -66,8 +66,8 @@ struct gen_pool_chunk {
 	struct list_head next_chunk;	/* next chunk in pool */
 	atomic_t avail;
 	phys_addr_t phys_addr;		/* physical starting address of memory chunk */
-	unsigned long start_addr;	/* starting address of memory chunk */
-	unsigned long end_addr;		/* ending address of memory chunk */
+	unsigned long start_addr;	/* start address of memory chunk */
+	unsigned long end_addr;		/* end address of memory chunk (inclusive) */
 	unsigned long bits[0];		/* bitmap for allocating memory chunk */
 };