[PATCH 4.8 112/125] powerpc/nvram: Fix an incorrect partition merge

[Greg Kroah-Hartman]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Pan Xinhui <xinhui.pan@xxxxxxxxxxxxxxxxxx>

commit 11b7e154b132232535befe51c55db048069c8461 upstream.

When we merge two contiguous partitions whose signatures are marked
NVRAM_SIG_FREE, We need update prev's length and checksum, then write it
to nvram, not cur's. So lets fix this mistake now.

Also use memset instead of strncpy to set the partition's name. It's
more readable if we want to fill up with duplicate chars .

Fixes: fa2b4e54d41f ("powerpc/nvram: Improve partition removal")
Signed-off-by: Pan Xinhui <xinhui.pan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/powerpc/kernel/nvram_64.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -956,7 +956,7 @@ int __init nvram_remove_partition(const
 
 		/* Make partition a free partition */
 		part->header.signature = NVRAM_SIG_FREE;
-		strncpy(part->header.name, "wwwwwwwwwwww", 12);
+		memset(part->header.name, 'w', 12);
 		part->header.checksum = nvram_checksum(&part->header);
 		rc = nvram_write_header(part);
 		if (rc <= 0) {
@@ -974,8 +974,8 @@ int __init nvram_remove_partition(const
 		}
 		if (prev) {
 			prev->header.length += part->header.length;
-			prev->header.checksum = nvram_checksum(&part->header);
-			rc = nvram_write_header(part);
+			prev->header.checksum = nvram_checksum(&prev->header);
+			rc = nvram_write_header(prev);
 			if (rc <= 0) {
 				printk(KERN_ERR "nvram_remove_partition: nvram_write failed (%d)\n", rc);
 				return rc;