diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mlock.c | 51 |
1 files changed, 38 insertions, 13 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index ca3894113b97..339d9e0949b6 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -506,7 +506,8 @@ static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, if (newflags == vma->vm_flags || (vma->vm_flags & VM_SPECIAL) || is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm)) - goto out; /* don't set VM_LOCKED, don't count */ + /* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */ + goto out; pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); *prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma, @@ -577,7 +578,7 @@ static int apply_vma_lock_flags(unsigned long start, size_t len, prev = vma; for (nstart = start ; ; ) { - vm_flags_t newflags = vma->vm_flags & ~VM_LOCKED; + vm_flags_t newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; newflags |= flags; @@ -646,10 +647,15 @@ SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len) SYSCALL_DEFINE3(mlock2, unsigned long, start, size_t, len, int, flags) { - if (flags) + vm_flags_t vm_flags = VM_LOCKED; + + if (flags & ~MLOCK_ONFAULT) return -EINVAL; - return do_mlock(start, len, VM_LOCKED); + if (flags & MLOCK_ONFAULT) + vm_flags |= VM_LOCKONFAULT; + + return do_mlock(start, len, vm_flags); } SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) @@ -666,24 +672,43 @@ SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) return ret; } +/* + * Take the MCL_* flags passed into mlockall (or 0 if called from munlockall) + * and translate into the appropriate modifications to mm->def_flags and/or the + * flags for all current VMAs. + * + * There are a couple of subtleties with this. If mlockall() is called multiple + * times with different flags, the values do not necessarily stack. If mlockall + * is called once including the MCL_FUTURE flag and then a second time without + * it, VM_LOCKED and VM_LOCKONFAULT will be cleared from mm->def_flags. + */ static int apply_mlockall_flags(int flags) { struct vm_area_struct * vma, * prev = NULL; + vm_flags_t to_add = 0; - if (flags & MCL_FUTURE) + current->mm->def_flags &= VM_LOCKED_CLEAR_MASK; + if (flags & MCL_FUTURE) { current->mm->def_flags |= VM_LOCKED; - else - current->mm->def_flags &= ~VM_LOCKED; - if (flags == MCL_FUTURE) - goto out; + if (flags & MCL_ONFAULT) + current->mm->def_flags |= VM_LOCKONFAULT; + + if (!(flags & MCL_CURRENT)) + goto out; + } + + if (flags & MCL_CURRENT) { + to_add |= VM_LOCKED; + if (flags & MCL_ONFAULT) + to_add |= VM_LOCKONFAULT; + } for (vma = current->mm->mmap; vma ; vma = prev->vm_next) { vm_flags_t newflags; - newflags = vma->vm_flags & ~VM_LOCKED; - if (flags & MCL_CURRENT) - newflags |= VM_LOCKED; + newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; + newflags |= to_add; /* Ignore errors */ mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags); @@ -698,7 +723,7 @@ SYSCALL_DEFINE1(mlockall, int, flags) unsigned long lock_limit; int ret; - if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE))) + if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT))) return -EINVAL; if (!can_do_mlock()) |