From: Miaohe Lin Date: Tue, 13 Oct 2020 23:54:10 +0000 (-0700) Subject: mm: use helper function mapping_allow_writable() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=cf508b58457cfe51b168d49ea6c79a221900d354;p=linux.git mm: use helper function mapping_allow_writable() Commit 4bb5f5d9395b ("mm: allow drivers to prevent new writable mappings") changed i_mmap_writable from unsigned int to atomic_t and add the helper function mapping_allow_writable() to atomic_inc i_mmap_writable. But it forgot to use this helper function in dup_mmap() and __vma_link_file(). Signed-off-by: Miaohe Lin Signed-off-by: Andrew Morton Cc: Christian Brauner Cc: Ingo Molnar Cc: Peter Zijlstra Cc: "Eric W. Biederman" Cc: Christian Kellner Cc: Suren Baghdasaryan Cc: Adrian Reber Cc: Shakeel Butt Cc: Aleksa Sarai Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20200917112736.7789-1-linmiaohe@huawei.com Signed-off-by: Linus Torvalds --- diff --git a/kernel/fork.c b/kernel/fork.c index a3795aaaab5c5..2dcb19a30650d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -559,7 +559,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm, atomic_dec(&inode->i_writecount); i_mmap_lock_write(mapping); if (tmp->vm_flags & VM_SHARED) - atomic_inc(&mapping->i_mmap_writable); + mapping_allow_writable(mapping); flush_dcache_mmap_lock(mapping); /* insert tmp into the share list, just after mpnt */ vma_interval_tree_insert_after(tmp, mpnt, diff --git a/mm/mmap.c b/mm/mmap.c index 19cd69524837d..7799a3f2e4838 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -621,7 +621,7 @@ static void __vma_link_file(struct vm_area_struct *vma) if (vma->vm_flags & VM_DENYWRITE) atomic_dec(&file_inode(file)->i_writecount); if (vma->vm_flags & VM_SHARED) - atomic_inc(&mapping->i_mmap_writable); + mapping_allow_writable(mapping); flush_dcache_mmap_lock(mapping); vma_interval_tree_insert(vma, &mapping->i_mmap);