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Commit 05873df9 authored by Carsten Otte's avatar Carsten Otte Committed by Martin Schwidefsky
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[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: default avatarCarsten Otte <cotte@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent f9783ec8

arch/s390/mm/pgtable.c

+4 −3
Original line number Diff line number Diff line
@@ -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);