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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2011-10-30 15:16:08 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-11-11 09:36:08 -0800 |
| commit | cd1ee66bb5156203711560ee73b00e70bb8450b5 (patch) | |
| tree | afa56c9e28806fa34e550dc300f34e3bcba86cbd | |
| parent | 0a85ef94c2af8630deb851e559c9d3bdf5530802 (diff) | |
| download | lwn-cd1ee66bb5156203711560ee73b00e70bb8450b5.tar.gz lwn-cd1ee66bb5156203711560ee73b00e70bb8450b5.zip | |
memory leak with RCU_TABLE_FREE
commit e73b7fffe487c315fd1a4fa22282e3362b440a06 upstream.
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).
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | arch/s390/mm/pgtable.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index 37a23c223705..458893f5f6b8 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -291,8 +291,9 @@ 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); |