[S390] memory leak with RCU_TABLE_FREE

The rcu page table free code uses a couple of bits in the page table
pointer passed to tlb_remove_table to discern the different page table
types. __tlb_remove_table extracts the type with an incorrect mask which
leads to memory leaks. The correct mask is ((FRAG_MASK << 4) | FRAG_MASK).

Cc: stable@kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2011-10-30 15:16:08 +01:00
parent a45aff5285
commit e73b7fffe4

View File

@ -662,8 +662,9 @@ void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table)
void __tlb_remove_table(void *_table)
{
void *table = (void *)((unsigned long) _table & PAGE_MASK);
unsigned type = (unsigned long) _table & ~PAGE_MASK;
const unsigned long mask = (FRAG_MASK << 4) | FRAG_MASK;
void *table = (void *)((unsigned long) _table & ~mask);
unsigned type = (unsigned long) _table & mask;
if (type)
__page_table_free_rcu(table, type);