}
EXPORT_SYMBOL(can_do_mlock);
-#ifdef CONFIG_UNEVICTABLE_LRU
/*
* Mlocked pages are marked with PageMlocked() flag for efficient testing
* in vmscan and, possibly, the fault path; and to support semi-accurate
return retval;
}
-#else /* CONFIG_UNEVICTABLE_LRU */
-
-/*
- * Just make pages present if VM_LOCKED. No-op if unlocking.
- */
-static long __mlock_vma_pages_range(struct vm_area_struct *vma,
- unsigned long start, unsigned long end,
- int mlock)
-{
- if (mlock && (vma->vm_flags & VM_LOCKED))
- return make_pages_present(start, end);
- return 0;
-}
-
-static inline int __mlock_posix_error_return(long retval)
-{
- return 0;
-}
-
-#endif /* CONFIG_UNEVICTABLE_LRU */
-
/**
* mlock_vma_pages_range() - mlock pages in specified vma range.
* @vma - the vma containing the specfied address range
*
* return number of pages [> 0] to be removed from locked_vm on success
* of "special" vmas.
- *
- * return negative error if vma spanning @start-@range disappears while
- * mmap semaphore is dropped. Unlikely?
*/
long mlock_vma_pages_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
- struct mm_struct *mm = vma->vm_mm;
int nr_pages = (end - start) / PAGE_SIZE;
BUG_ON(!(vma->vm_flags & VM_LOCKED));
if (!((vma->vm_flags & (VM_DONTEXPAND | VM_RESERVED)) ||
is_vm_hugetlb_page(vma) ||
vma == get_gate_vma(current))) {
- long error;
- downgrade_write(&mm->mmap_sem);
-
- error = __mlock_vma_pages_range(vma, start, end, 1);
- up_read(&mm->mmap_sem);
- /* vma can change or disappear */
- down_write(&mm->mmap_sem);
- vma = find_vma(mm, start);
- /* non-NULL vma must contain @start, but need to check @end */
- if (!vma || end > vma->vm_end)
- return -ENOMEM;
+ __mlock_vma_pages_range(vma, start, end, 1);
- return 0; /* hide other errors from mmap(), et al */
+ /* Hide errors from mmap() and other callers */
+ return 0;
}
/*
vma->vm_flags = newflags;
if (lock) {
- /*
- * mmap_sem is currently held for write. Downgrade the write
- * lock to a read lock so that other faults, mmap scans, ...
- * while we fault in all pages.
- */
- downgrade_write(&mm->mmap_sem);
-
ret = __mlock_vma_pages_range(vma, start, end, 1);
- /*
- * Need to reacquire mmap sem in write mode, as our callers
- * expect this. We have no support for atomically upgrading
- * a sem to write, so we need to check for ranges while sem
- * is unlocked.
- */
- up_read(&mm->mmap_sem);
- /* vma can change or disappear */
- down_write(&mm->mmap_sem);
- *prev = find_vma(mm, start);
- /* non-NULL *prev must contain @start, but need to check @end */
- if (!(*prev) || end > (*prev)->vm_end)
- ret = -ENOMEM;
- else if (ret > 0) {
+ if (ret > 0) {
mm->locked_vm -= ret;
ret = 0;
} else
ret = __mlock_posix_error_return(ret); /* translate if needed */
} else {
- /*
- * TODO: for unlocking, pages will already be resident, so
- * we don't need to wait for allocations/reclaim/pagein, ...
- * However, unlocking a very large region can still take a
- * while. Should we downgrade the semaphore for both lock
- * AND unlock ?
- */
__mlock_vma_pages_range(vma, start, end, 0);
}
return 0;
}
-asmlinkage long sys_mlockall(int flags)
+SYSCALL_DEFINE1(mlockall, int, flags)
{
unsigned long lock_limit;
int ret = -EINVAL;
return ret;
}
-asmlinkage long sys_munlockall(void)
+SYSCALL_DEFINE0(munlockall)
{
int ret;
free_uid(user);
}
-void *alloc_locked_buffer(size_t size)
+int account_locked_memory(struct mm_struct *mm, struct rlimit *rlim,
+ size_t size)
{
- unsigned long rlim, vm, pgsz;
- void *buffer = NULL;
+ unsigned long lim, vm, pgsz;
+ int error = -ENOMEM;
pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
- down_write(¤t->mm->mmap_sem);
-
- rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
- vm = current->mm->total_vm + pgsz;
- if (rlim < vm)
- goto out;
+ down_write(&mm->mmap_sem);
- rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
- vm = current->mm->locked_vm + pgsz;
- if (rlim < vm)
+ lim = rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
+ vm = mm->total_vm + pgsz;
+ if (lim < vm)
goto out;
- buffer = kzalloc(size, GFP_KERNEL);
- if (!buffer)
+ lim = rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
+ vm = mm->locked_vm + pgsz;
+ if (lim < vm)
goto out;
- current->mm->total_vm += pgsz;
- current->mm->locked_vm += pgsz;
+ mm->total_vm += pgsz;
+ mm->locked_vm += pgsz;
+ error = 0;
out:
- up_write(¤t->mm->mmap_sem);
- return buffer;
+ up_write(&mm->mmap_sem);
+ return error;
}
-void free_locked_buffer(void *buffer, size_t size)
+void refund_locked_memory(struct mm_struct *mm, size_t size)
{
unsigned long pgsz = PAGE_ALIGN(size) >> PAGE_SHIFT;
- down_write(¤t->mm->mmap_sem);
-
- current->mm->total_vm -= pgsz;
- current->mm->locked_vm -= pgsz;
+ down_write(&mm->mmap_sem);
- up_write(¤t->mm->mmap_sem);
+ mm->total_vm -= pgsz;
+ mm->locked_vm -= pgsz;
- kfree(buffer);
+ up_write(&mm->mmap_sem);
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff