mm/memblock.c: reversed logic in memblock_discard()

commit 91b540f98872a206ea1c49e4aa6ea8eed0886644 upstream.

In recently introduced memblock_discard() there is a reversed logic bug.
Memory is freed of static array instead of dynamically allocated one.

Link: http://lkml.kernel.org/r/1503511441-95478-2-git-send-email-pasha.tatashin@oracle.com
Fixes: 3010f876500f ("mm: discard memblock data later")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reported-by: Woody Suwalski <terraluna977@gmail.com>
Tested-by: Woody Suwalski <terraluna977@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/memblock.c b/mm/memblock.c
index ccec42c12ba8612e7c8441aa905dcfe7ec384238..42b98af6a41586dd5eba8def1c12ac2d353e639c 100644 (file)
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -311,7 +311,7 @@ void __init memblock_discard(void)
                __memblock_free_late(addr, size);
        }
 
-       if (memblock.memory.regions == memblock_memory_init_regions) {
+       if (memblock.memory.regions != memblock_memory_init_regions) {
                addr = __pa(memblock.memory.regions);
                size = PAGE_ALIGN(sizeof(struct memblock_region) *
                                  memblock.memory.max);