From a90ae42ef550d0b945925b133e0f829806c78055 Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Tue, 21 Jan 2014 15:49:15 -0800 Subject: [PATCH] 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 Cc: Rik van Riel Reviewed-by: Michel Lespinasse Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 45 +++++++++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 22 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index ed6279cce642..b17f3102d36d 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1226,6 +1226,24 @@ 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; +} + static inline u64 file_mmap_size_max(struct file *file, struct inode *inode) { if (S_ISREG(inode->i_mode)) @@ -1316,16 +1334,8 @@ 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); @@ -2693,18 +2703,9 @@ 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