[S390] gmap: always up mmap_sem properly

If gmap_unmap_segment figures that the segment was not mapped in the
first place, it need to up mmap_sem on exit.

Cc: <stable@kernel.org>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Carsten Otte 2011-09-26 16:40:34 +02:00 committed by Martin Schwidefsky
parent f9783ec862
commit 05873df981
1 changed files with 4 additions and 3 deletions

View File

@ -303,15 +303,15 @@ int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
/* Walk the guest addr space page table */
table = gmap->table + (((to + off) >> 53) & 0x7ff);
if (*table & _REGION_ENTRY_INV)
return 0;
goto out;
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
table = table + (((to + off) >> 42) & 0x7ff);
if (*table & _REGION_ENTRY_INV)
return 0;
goto out;
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
table = table + (((to + off) >> 31) & 0x7ff);
if (*table & _REGION_ENTRY_INV)
return 0;
goto out;
table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
table = table + (((to + off) >> 20) & 0x7ff);
@ -319,6 +319,7 @@ int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len)
flush |= gmap_unlink_segment(gmap, table);
*table = _SEGMENT_ENTRY_INV;
}
out:
up_read(&gmap->mm->mmap_sem);
if (flush)
gmap_flush_tlb(gmap);