4 * (C) Copyright 1995 Linus Torvalds
5 * (C) Copyright 2002 Christoph Hellwig
8 #include <linux/mman.h>
12 static int mlock_fixup(struct vm_area_struct * vma,
13 unsigned long start, unsigned long end, unsigned int newflags)
15 struct mm_struct * mm = vma->vm_mm;
19 if (newflags == vma->vm_flags)
22 if (start != vma->vm_start) {
23 if (split_vma(mm, vma, start, 1)) {
29 if (end != vma->vm_end) {
30 if (split_vma(mm, vma, end, 0)) {
37 * vm_flags is protected by the mmap_sem held in write mode.
38 * It's okay if try_to_unmap_one unmaps a page just after we
39 * set VM_LOCKED, make_pages_present below will bring it back.
41 vma->vm_flags = newflags;
44 * Keep track of amount of locked VM.
46 pages = (end - start) >> PAGE_SHIFT;
47 if (newflags & VM_LOCKED) {
49 ret = make_pages_present(start, end);
52 vma->vm_mm->locked_vm -= pages;
57 static int do_mlock(unsigned long start, size_t len, int on)
59 unsigned long nstart, end, tmp;
60 struct vm_area_struct * vma, * next;
63 if (on && !capable(CAP_IPC_LOCK))
65 len = PAGE_ALIGN(len);
71 vma = find_vma(current->mm, start);
72 if (!vma || vma->vm_start > start)
75 for (nstart = start ; ; ) {
76 unsigned int newflags;
78 /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
80 newflags = vma->vm_flags | VM_LOCKED;
82 newflags &= ~VM_LOCKED;
84 if (vma->vm_end >= end) {
85 error = mlock_fixup(vma, nstart, end, newflags);
91 error = mlock_fixup(vma, nstart, tmp, newflags);
96 if (!vma || vma->vm_start != nstart) {
104 asmlinkage long sys_mlock(unsigned long start, size_t len)
106 unsigned long locked, grow;
107 unsigned long lock_limit;
110 down_write(¤t->mm->mmap_sem);
111 len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
114 grow = len >> PAGE_SHIFT;
115 if (!vx_vmlocked_avail(current->mm, grow))
117 locked = current->mm->locked_vm + grow;
119 lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
120 lock_limit >>= PAGE_SHIFT;
122 /* check against resource limits */
123 if (locked <= lock_limit)
124 error = do_mlock(start, len, 1);
126 up_write(¤t->mm->mmap_sem);
130 asmlinkage long sys_munlock(unsigned long start, size_t len)
134 down_write(¤t->mm->mmap_sem);
135 len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
137 ret = do_mlock(start, len, 0);
138 up_write(¤t->mm->mmap_sem);
142 static int do_mlockall(int flags)
145 unsigned int def_flags;
146 struct vm_area_struct * vma;
148 if (!capable(CAP_IPC_LOCK))
152 if (flags & MCL_FUTURE)
153 def_flags = VM_LOCKED;
154 current->mm->def_flags = def_flags;
157 for (vma = current->mm->mmap; vma ; vma = vma->vm_next) {
158 unsigned int newflags;
160 newflags = vma->vm_flags | VM_LOCKED;
161 if (!(flags & MCL_CURRENT))
162 newflags &= ~VM_LOCKED;
165 mlock_fixup(vma, vma->vm_start, vma->vm_end, newflags);
170 asmlinkage long sys_mlockall(int flags)
172 unsigned long lock_limit;
175 down_write(¤t->mm->mmap_sem);
176 if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE)))
179 lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
180 lock_limit >>= PAGE_SHIFT;
183 if (!vx_vmlocked_avail(current->mm, current->mm->total_vm))
185 /* check vserver lock limits? */
186 if (current->mm->total_vm <= lock_limit)
187 ret = do_mlockall(flags);
189 up_write(¤t->mm->mmap_sem);
193 asmlinkage long sys_munlockall(void)
197 down_write(¤t->mm->mmap_sem);
198 ret = do_mlockall(0);
199 up_write(¤t->mm->mmap_sem);