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authorDavidlohr Bueso <davidlohr@hp.com>2014-01-21 15:49:15 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-21 16:19:44 -0800
commit363ee17f0f405faff74d9aaf93d21d5f41d5102d (patch)
tree4ff07b1b36a024b455467ac78e07fec6f18a6780
parent49f0ce5f92321cdcf741e35f385669a421013cb7 (diff)
mm/mmap.c: add mlock_future_check() helper
Both do_brk and do_mmap_pgoff verify that we are actually capable of locking future pages if the corresponding VM_LOCKED flags are used. Encapsulate this logic into a single mlock_future_check() helper function. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/mmap.c45
1 files changed, 23 insertions, 22 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 39552de6e1db..a0e7153a79e6 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1191,6 +1191,24 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
return hint;
}
+static inline int mlock_future_check(struct mm_struct *mm,
+ unsigned long flags,
+ unsigned long len)
+{
+ unsigned long locked, lock_limit;
+
+ /* mlock MCL_FUTURE? */
+ if (flags & VM_LOCKED) {
+ locked = len >> PAGE_SHIFT;
+ locked += mm->locked_vm;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
+ lock_limit >>= PAGE_SHIFT;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ return -EAGAIN;
+ }
+ return 0;
+}
+
/*
* The caller must hold down_write(&current->mm->mmap_sem).
*/
@@ -1252,16 +1270,8 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (!can_do_mlock())
return -EPERM;
- /* mlock MCL_FUTURE? */
- if (vm_flags & VM_LOCKED) {
- unsigned long locked, lock_limit;
- locked = len >> PAGE_SHIFT;
- locked += mm->locked_vm;
- lock_limit = rlimit(RLIMIT_MEMLOCK);
- lock_limit >>= PAGE_SHIFT;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- return -EAGAIN;
- }
+ if (mlock_future_check(mm, vm_flags, len))
+ return -EAGAIN;
if (file) {
struct inode *inode = file_inode(file);
@@ -2592,18 +2602,9 @@ static unsigned long do_brk(unsigned long addr, unsigned long len)
if (error & ~PAGE_MASK)
return error;
- /*
- * mlock MCL_FUTURE?
- */
- if (mm->def_flags & VM_LOCKED) {
- unsigned long locked, lock_limit;
- locked = len >> PAGE_SHIFT;
- locked += mm->locked_vm;
- lock_limit = rlimit(RLIMIT_MEMLOCK);
- lock_limit >>= PAGE_SHIFT;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- return -EAGAIN;
- }
+ error = mlock_future_check(mm, mm->def_flags, len);
+ if (error)
+ return error;
/*
* mm->mmap_sem is required to protect against another thread