From: Todd Kjos <[email protected]> This reverts commit 33c6b9ca70a8b066a613e2a3d0331ae8f82aa31a.
The commit message is for a different patch. Reverting and then adding the same patch back with the correct commit message. Reported-by: Ben Hutchings <[email protected]> Cc: stable <[email protected]> # 4.14 Signed-off-by: Todd Kjos <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/android/binder_alloc.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -945,13 +945,14 @@ enum lru_status binder_alloc_free_page(s index = page - alloc->pages; page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; - - mm = alloc->vma_vm_mm; - if (!mmget_not_zero(mm)) - goto err_mmget; - if (!down_write_trylock(&mm->mmap_sem)) - goto err_down_write_mmap_sem_failed; vma = binder_alloc_get_vma(alloc); + if (vma) { + if (!mmget_not_zero(alloc->vma_vm_mm)) + goto err_mmget; + mm = alloc->vma_vm_mm; + if (!down_write_trylock(&mm->mmap_sem)) + goto err_down_write_mmap_sem_failed; + } list_lru_isolate(lru, item); spin_unlock(lock); @@ -964,9 +965,10 @@ enum lru_status binder_alloc_free_page(s PAGE_SIZE); trace_binder_unmap_user_end(alloc, index); + + up_write(&mm->mmap_sem); + mmput(mm); } - up_write(&mm->mmap_sem); - mmput(mm); trace_binder_unmap_kernel_start(alloc, index);
