From: Carsten Otte <cotte@de.ibm.com>
Date: Mon, 26 Sep 2011 14:40:34 +0000 (+0200)
Subject: [S390] gmap: always up mmap_sem properly
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=05873df981ca1dd32f398e7b4e19864de907e064;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[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>
---

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index f69ff3c13496..5d56c2b95b14 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -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);