The patch titled Subject: mm: use helper function mapping_allow_writable() has been added to the -mm tree. Its filename is mm-use-helper-function-mapping_allow_writable.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-use-helper-function-mapping_allow_writable.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-use-helper-function-mapping_allow_writable.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: 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(). Link: https://lkml.kernel.org/r/20200917112736.7789-1-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Christian Brauner <christian.brauner@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Cc: Christian Kellner <christian@xxxxxxxxxx> Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx> Cc: Adrian Reber <areber@xxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Aleksa Sarai <cyphar@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/fork.c | 2 +- mm/mmap.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/kernel/fork.c~mm-use-helper-function-mapping_allow_writable +++ a/kernel/fork.c @@ -558,7 +558,7 @@ static __latent_entropy int dup_mmap(str 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, --- a/mm/mmap.c~mm-use-helper-function-mapping_allow_writable +++ a/mm/mmap.c @@ -621,7 +621,7 @@ static void __vma_link_file(struct vm_ar 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); _ Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are mm-swap-fix-confusing-comment-in-release_pages.patch mm-memcontrol-correct-the-comment-of-mem_cgroup_iter.patch mm-page_counter-correct-the-obsolete-func-name-in-the-comment-of-page_counter_try_charge.patch mm-use-helper-function-mapping_allow_writable.patch mm-vmstat-use-helper-macro-abs.patch mm-fix-some-broken-comments.patch mm-migrate-avoid-possible-unnecessary-process-right-check-in-kernel_move_pages.patch