diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 971d0eda754..e7a5a68a9c2 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1030,6 +1030,10 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr, } else { switch (flags & MAP_TYPE) { case MAP_SHARED: + /* + * Ignore pgoff. + */ + pgoff = 0; vm_flags |= VM_SHARED | VM_MAYSHARE; break; case MAP_PRIVATE: @@ -2273,14 +2277,14 @@ int install_special_mapping(struct mm_struct *mm, static DEFINE_MUTEX(mm_all_locks_mutex); -static void vm_lock_anon_vma(struct anon_vma *anon_vma) +static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) { if (!test_bit(0, (unsigned long *) &anon_vma->head.next)) { /* * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. */ - spin_lock(&anon_vma->lock); + spin_lock_nest_lock(&anon_vma->lock, &mm->mmap_sem); /* * We can safely modify head.next after taking the * anon_vma->lock. If some other vma in this mm shares @@ -2296,7 +2300,7 @@ static void vm_lock_anon_vma(struct anon_vma *anon_vma) } } -static void vm_lock_mapping(struct address_space *mapping) +static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) { if (!test_bit(AS_MM_ALL_LOCKS, &mapping->flags)) { /* @@ -2310,7 +2314,7 @@ static void vm_lock_mapping(struct address_space *mapping) */ if (test_and_set_bit(AS_MM_ALL_LOCKS, &mapping->flags)) BUG(); - spin_lock(&mapping->i_mmap_lock); + spin_lock_nest_lock(&mapping->i_mmap_lock, &mm->mmap_sem); } } @@ -2358,11 +2362,17 @@ int mm_take_all_locks(struct mm_struct *mm) for (vma = mm->mmap; vma; vma = vma->vm_next) { if (signal_pending(current)) goto out_unlock; - if (vma->anon_vma) - vm_lock_anon_vma(vma->anon_vma); if (vma->vm_file && vma->vm_file->f_mapping) - vm_lock_mapping(vma->vm_file->f_mapping); + vm_lock_mapping(mm, vma->vm_file->f_mapping); + } + + for (vma = mm->mmap; vma; vma = vma->vm_next) { + if (signal_pending(current)) + goto out_unlock; + if (vma->anon_vma) + vm_lock_anon_vma(mm, vma->anon_vma); } + ret = 0; out_unlock: |