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authorHeiko Carstens <heiko.carstens@de.ibm.com>2012-10-08 07:54:32 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2012-10-09 14:17:01 +0200
commitfc7e48aad35bf98c84cf21aed5c2f100c5ce009b (patch)
tree1d33f49ac9705e1939cbe122d5aafb57aa7af07a /arch/s390/mm
parentc972cc60c23f5a6309292bfcc91a441743ba027e (diff)
downloadlinux-fc7e48aad35bf98c84cf21aed5c2f100c5ce009b.tar.gz
s390/mm,vmem: fix vmem_add_mem()/vmem_remove_range()
vmem_add_mem() should only then insert a large page if pmd_none() is true
for the specific entry. We might have a leftover from a previous mapping.
In addition make vmem_remove_range()'s page table walk code more complete
and fix a couple of potential endless loops (which can never happen :).

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm')
-rw-r--r--arch/s390/mm/vmem.c16
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index d402b19f1df2..387c7c60b5b8 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -109,8 +109,8 @@ static int vmem_add_mem(unsigned long start, unsigned long size, int ro)
 		pm_dir = pmd_offset(pu_dir, address);
 
 #if defined(CONFIG_64BIT) && !defined(CONFIG_DEBUG_PAGEALLOC)
-		if (MACHINE_HAS_EDAT1 && address && !(address & ~PMD_MASK) &&
-		    (address + PMD_SIZE <= end)) {
+		if (MACHINE_HAS_EDAT1 && pmd_none(*pm_dir) && address &&
+		    !(address & ~PMD_MASK) && (address + PMD_SIZE <= end)) {
 			pte_val(pte) |= _SEGMENT_ENTRY_LARGE;
 			pmd_val(*pm_dir) = pte_val(pte);
 			address += PMD_SIZE;
@@ -151,12 +151,20 @@ static void vmem_remove_range(unsigned long start, unsigned long size)
 	pte_val(pte) = _PAGE_TYPE_EMPTY;
 	while (address < end) {
 		pg_dir = pgd_offset_k(address);
+		if (pgd_none(*pg_dir)) {
+			address += PGDIR_SIZE;
+			continue;
+		}
 		pu_dir = pud_offset(pg_dir, address);
-		if (pud_none(*pu_dir))
+		if (pud_none(*pu_dir)) {
+			address += PUD_SIZE;
 			continue;
+		}
 		pm_dir = pmd_offset(pu_dir, address);
-		if (pmd_none(*pm_dir))
+		if (pmd_none(*pm_dir)) {
+			address += PMD_SIZE;
 			continue;
+		}
 		if (pmd_large(*pm_dir)) {
 			pmd_clear(pm_dir);
 			address += PMD_SIZE;