* (C) Copyright 2002 Christoph Hellwig
*/
+#include <linux/capability.h>
#include <linux/mman.h>
#include <linux/mm.h>
+#include <linux/mempolicy.h>
+#include <linux/syscalls.h>
+#include <linux/vs_memory.h>
-static int mlock_fixup(struct vm_area_struct * vma,
+static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev,
unsigned long start, unsigned long end, unsigned int newflags)
{
struct mm_struct * mm = vma->vm_mm;
+ pgoff_t pgoff;
int pages;
int ret = 0;
- if (newflags == vma->vm_flags)
+ if (newflags == vma->vm_flags) {
+ *prev = vma;
goto out;
+ }
+
+ pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
+ *prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma,
+ vma->vm_file, pgoff, vma_policy(vma));
+ if (*prev) {
+ vma = *prev;
+ goto success;
+ }
+
+ *prev = vma;
if (start != vma->vm_start) {
- if (split_vma(mm, vma, start, 1)) {
- ret = -EAGAIN;
+ ret = split_vma(mm, vma, start, 1);
+ if (ret)
goto out;
- }
}
if (end != vma->vm_end) {
- if (split_vma(mm, vma, end, 0)) {
- ret = -EAGAIN;
+ ret = split_vma(mm, vma, end, 0);
+ if (ret)
goto out;
- }
}
-
- spin_lock(&mm->page_table_lock);
+
+success:
+ /*
+ * vm_flags is protected by the mmap_sem held in write mode.
+ * It's okay if try_to_unmap_one unmaps a page just after we
+ * set VM_LOCKED, make_pages_present below will bring it back.
+ */
vma->vm_flags = newflags;
- spin_unlock(&mm->page_table_lock);
/*
* Keep track of amount of locked VM.
pages = (end - start) >> PAGE_SHIFT;
if (newflags & VM_LOCKED) {
pages = -pages;
- ret = make_pages_present(start, end);
+ if (!(newflags & VM_IO))
+ ret = make_pages_present(start, end);
}
- vma->vm_mm->locked_vm -= pages;
+ vx_vmlocked_sub(mm, pages);
out:
+ if (ret == -ENOMEM)
+ ret = -EAGAIN;
return ret;
}
static int do_mlock(unsigned long start, size_t len, int on)
{
unsigned long nstart, end, tmp;
- struct vm_area_struct * vma, * next;
+ struct vm_area_struct * vma, * prev;
int error;
- if (on && !capable(CAP_IPC_LOCK))
- return -EPERM;
len = PAGE_ALIGN(len);
end = start + len;
if (end < start)
return -EINVAL;
if (end == start)
return 0;
- vma = find_vma(current->mm, start);
+ vma = find_vma_prev(current->mm, start, &prev);
if (!vma || vma->vm_start > start)
return -ENOMEM;
+ if (start > vma->vm_start)
+ prev = vma;
+
for (nstart = start ; ; ) {
unsigned int newflags;
if (!on)
newflags &= ~VM_LOCKED;
- if (vma->vm_end >= end) {
- error = mlock_fixup(vma, nstart, end, newflags);
- break;
- }
-
tmp = vma->vm_end;
- next = vma->vm_next;
- error = mlock_fixup(vma, nstart, tmp, newflags);
+ if (tmp > end)
+ tmp = end;
+ error = mlock_fixup(vma, &prev, nstart, tmp, newflags);
if (error)
break;
nstart = tmp;
- vma = next;
+ if (nstart < prev->vm_end)
+ nstart = prev->vm_end;
+ if (nstart >= end)
+ break;
+
+ vma = prev->vm_next;
if (!vma || vma->vm_start != nstart) {
error = -ENOMEM;
break;
asmlinkage long sys_mlock(unsigned long start, size_t len)
{
- unsigned long locked;
+ unsigned long locked, grow;
unsigned long lock_limit;
int error = -ENOMEM;
+ if (!can_do_mlock())
+ return -EPERM;
+
down_write(¤t->mm->mmap_sem);
len = PAGE_ALIGN(len + (start & ~PAGE_MASK));
start &= PAGE_MASK;
- locked = len >> PAGE_SHIFT;
- locked += current->mm->locked_vm;
+ grow = len >> PAGE_SHIFT;
+ if (!vx_vmlocked_avail(current->mm, grow))
+ goto out;
+ locked = current->mm->locked_vm + grow;
- lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
lock_limit >>= PAGE_SHIFT;
/* check against resource limits */
- if (locked <= lock_limit)
+ if ((locked <= lock_limit) || capable(CAP_IPC_LOCK))
error = do_mlock(start, len, 1);
+out:
up_write(¤t->mm->mmap_sem);
return error;
}
static int do_mlockall(int flags)
{
- int error;
- unsigned int def_flags;
- struct vm_area_struct * vma;
+ struct vm_area_struct * vma, * prev = NULL;
+ unsigned int def_flags = 0;
- if (!capable(CAP_IPC_LOCK))
- return -EPERM;
-
- def_flags = 0;
if (flags & MCL_FUTURE)
def_flags = VM_LOCKED;
current->mm->def_flags = def_flags;
+ if (flags == MCL_FUTURE)
+ goto out;
- error = 0;
- for (vma = current->mm->mmap; vma ; vma = vma->vm_next) {
+ for (vma = current->mm->mmap; vma ; vma = prev->vm_next) {
unsigned int newflags;
newflags = vma->vm_flags | VM_LOCKED;
newflags &= ~VM_LOCKED;
/* Ignore errors */
- mlock_fixup(vma, vma->vm_start, vma->vm_end, newflags);
+ mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags);
}
- return error;
+out:
+ return 0;
}
asmlinkage long sys_mlockall(int flags)
unsigned long lock_limit;
int ret = -EINVAL;
- down_write(¤t->mm->mmap_sem);
if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE)))
goto out;
- lock_limit = current->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ ret = -EPERM;
+ if (!can_do_mlock())
+ goto out;
+
+ down_write(¤t->mm->mmap_sem);
+
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
lock_limit >>= PAGE_SHIFT;
ret = -ENOMEM;
- if (current->mm->total_vm <= lock_limit)
+ if (!vx_vmlocked_avail(current->mm, current->mm->total_vm))
+ goto out;
+ if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) ||
+ capable(CAP_IPC_LOCK))
ret = do_mlockall(flags);
-out:
up_write(¤t->mm->mmap_sem);
+out:
return ret;
}
up_write(¤t->mm->mmap_sem);
return ret;
}
+
+/*
+ * Objects with different lifetime than processes (SHM_LOCK and SHM_HUGETLB
+ * shm segments) get accounted against the user_struct instead.
+ */
+static DEFINE_SPINLOCK(shmlock_user_lock);
+
+int user_shm_lock(size_t size, struct user_struct *user)
+{
+ unsigned long lock_limit, locked;
+ int allowed = 0;
+
+ locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit >>= PAGE_SHIFT;
+ spin_lock(&shmlock_user_lock);
+ if (locked + user->locked_shm > lock_limit && !capable(CAP_IPC_LOCK))
+ goto out;
+ get_uid(user);
+ user->locked_shm += locked;
+ allowed = 1;
+out:
+ spin_unlock(&shmlock_user_lock);
+ return allowed;
+}
+
+void user_shm_unlock(size_t size, struct user_struct *user)
+{
+ spin_lock(&shmlock_user_lock);
+ user->locked_shm -= (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ spin_unlock(&shmlock_user_lock);
+ free_uid(user);
+}
git://git.onelab.eu / linux-2.6.git / blobdiff