4 * (C) Copyright 1995 Linus Torvalds
5 * (C) Copyright 2002 Christoph Hellwig
8 #include <linux/mman.h>
10 #include <linux/vs_memory.h>
13 static int mlock_fixup(struct vm_area_struct * vma,
14 unsigned long start, unsigned long end, unsigned int newflags)
16 struct mm_struct * mm = vma->vm_mm;
20 if (newflags == vma->vm_flags)
23 if (start != vma->vm_start) {
24 if (split_vma(mm, vma, start, 1)) {
30 if (end != vma->vm_end) {
31 if (split_vma(mm, vma, end, 0)) {
38 * vm_flags is protected by the mmap_sem held in write mode.
39 * It's okay if try_to_unmap_one unmaps a page just after we
40 * set VM_LOCKED, make_pages_present below will bring it back.
42 vma->vm_flags = newflags;
45 * Keep track of amount of locked VM.
47 pages = (end - start) >> PAGE_SHIFT;
48 if (newflags & VM_LOCKED) {
50 ret = make_pages_present(start, end);
53 // vma->vm_mm->locked_vm -= pages;
54 vx_vmlocked_sub(vma->vm_mm, pages);
59 static int do_mlock(unsigned long start, size_t len, int on)
61 unsigned long nstart, end, tmp;
62 struct vm_area_struct * vma, * next;
65 if (on && !can_do_mlock())
67 len = PAGE_ALIGN(len);
73 vma = find_vma(current->mm, start);
74 if (!vma || vma->vm_start > start)
77 for (nstart = start ; ; ) {
78 unsigned int newflags;
80 /* Here we know that vma->vm_start <= nstart < vma->vm_end. */
82 newflags = vma->vm_flags | VM_LOCKED;
84 newflags &= ~VM_LOCKED;
86 if (vma->vm_end >= end) {
87 error = mlock_fixup(vma, nstart, end, newflags);
93 error = mlock_fixup(vma, nstart, tmp, newflags);
98 if (!vma || vma->vm_start != nstart) {
106 asmlinkage long sys_mlock(unsigned long start, size_t len)
108 unsigned long locked, grow;
109 unsigned long lock_limit;
112 down_write(¤t->mm->mmap_sem);
113 len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
116 grow = len >> PAGE_SHIFT;
117 if (!vx_vmlocked_avail(current->mm, grow))
119 locked = current->mm->locked_vm + grow;
121 lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
122 lock_limit >>= PAGE_SHIFT;
124 /* check against resource limits */
125 if ( (locked <= lock_limit) || capable(CAP_IPC_LOCK))
126 error = do_mlock(start, len, 1);
128 up_write(¤t->mm->mmap_sem);
132 asmlinkage long sys_munlock(unsigned long start, size_t len)
136 down_write(¤t->mm->mmap_sem);
137 len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
139 ret = do_mlock(start, len, 0);
140 up_write(¤t->mm->mmap_sem);
144 static int do_mlockall(int flags)
147 unsigned int def_flags;
148 struct vm_area_struct * vma;
154 if (flags & MCL_FUTURE)
155 def_flags = VM_LOCKED;
156 current->mm->def_flags = def_flags;
159 for (vma = current->mm->mmap; vma ; vma = vma->vm_next) {
160 unsigned int newflags;
162 newflags = vma->vm_flags | VM_LOCKED;
163 if (!(flags & MCL_CURRENT))
164 newflags &= ~VM_LOCKED;
167 mlock_fixup(vma, vma->vm_start, vma->vm_end, newflags);
172 asmlinkage long sys_mlockall(int flags)
174 unsigned long lock_limit;
177 down_write(¤t->mm->mmap_sem);
178 if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE)))
181 lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
182 lock_limit >>= PAGE_SHIFT;
185 if (!vx_vmlocked_avail(current->mm, current->mm->total_vm))
187 if ((current->mm->total_vm <= lock_limit) || capable(CAP_IPC_LOCK))
188 ret = do_mlockall(flags);
190 up_write(¤t->mm->mmap_sem);
194 asmlinkage long sys_munlockall(void)
198 down_write(¤t->mm->mmap_sem);
199 ret = do_mlockall(0);
200 up_write(¤t->mm->mmap_sem);