s390/mm: Fix crst upgrade of mmap with MAP_FIXED
Right now the page table upgrade does not happen if the end address
of a fixed mapping is greater than TASK_SIZE.
Enhance s390_mmap_check() to handle MAP_FIXED mappings correctly.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/mm/mmap.c b/arch/s390/mm/mmap.c
index c59a5ef..06bafec 100644
--- a/arch/s390/mm/mmap.c
+++ b/arch/s390/mm/mmap.c
@@ -101,12 +101,15 @@
#else
-int s390_mmap_check(unsigned long addr, unsigned long len)
+int s390_mmap_check(unsigned long addr, unsigned long len, unsigned long flags)
{
int rc;
- if (!is_compat_task() &&
- len >= TASK_SIZE && TASK_SIZE < (1UL << 53)) {
+ if (is_compat_task() || (TASK_SIZE >= (1UL << 53)))
+ return 0;
+ if (!(flags & MAP_FIXED))
+ addr = 0;
+ if ((addr + len) >= TASK_SIZE) {
rc = crst_table_upgrade(current->mm, 1UL << 53);
if (rc)
return rc;