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-rw-r--r--include/linux/mm.h1
-rw-r--r--mm/mmap.c3
-rw-r--r--mm/mprotect.c6
3 files changed, 6 insertions, 4 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 196924b657bc..df322fb4df31 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -100,6 +100,7 @@ extern unsigned int kobjsize(const void *objp);
#define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
#define VM_RESERVED 0x00080000 /* Count as reserved_vm like IO */
#define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
+#define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
#define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
#define VM_NONLINEAR 0x00800000 /* Is non-linear (remap_file_pages) */
#define VM_MAPPED_COPY 0x01000000 /* T if mapped copy of data (nommu mmap) */
diff --git a/mm/mmap.c b/mm/mmap.c
index 75e0d0673d78..57d3b6097deb 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1110,6 +1110,9 @@ munmap_back:
if (!may_expand_vm(mm, len >> PAGE_SHIFT))
return -ENOMEM;
+ if (flags & MAP_NORESERVE)
+ vm_flags |= VM_NORESERVE;
+
if (accountable && (!(flags & MAP_NORESERVE) ||
sysctl_overcommit_memory == OVERCOMMIT_NEVER)) {
if (vm_flags & VM_SHARED) {
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 360d9cc8b38c..abd645a3b0a0 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -153,12 +153,10 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
* If we make a private mapping writable we increase our commit;
* but (without finer accounting) cannot reduce our commit if we
* make it unwritable again.
- *
- * FIXME? We haven't defined a VM_NORESERVE flag, so mprotecting
- * a MAP_NORESERVE private mapping to writable will now reserve.
*/
if (newflags & VM_WRITE) {
- if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED))) {
+ if (!(oldflags & (VM_ACCOUNT|VM_WRITE|
+ VM_SHARED|VM_NORESERVE))) {
charged = nrpages;
if (security_vm_enough_memory(charged))
return -ENOMEM;