On Wed, 26 Jul 2017 14:31:53 -0700 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Wed, 26 Jul 2017 09:33:50 -0700 Shaohua Li <shli@xxxxxx> wrote: > > > On Wed, Jul 26, 2017 at 07:25:03PM +0900, Tetsuo Handa wrote: > > > When a thread is OOM-killed during swap_readpage() operation, an oops > > > occurs because end_swap_bio_read() is calling wake_up_process() based on > > > an assumption that the thread which called swap_readpage() is still alive. > > > > > > > ... > > > > > > > > Fix it by holding a reference to the thread. > > > > Ok, so the task is killed in the page fault retry time check, thanks! > > > > Reviewed-by: Shaohua Li <shli@xxxxxx> > > > > The original patch didn't appear in my inbox and marc.info doesn't > appear to have received it either. Can we please have a resend? Jens sent me a copy (thanks). A get_task_struct in the middle of readpage is very strange-looking. So a comment is needed. This? --- a/mm/page_io.c~swap-fix-oops-during-block-io-poll-in-swapin-path-fix +++ a/mm/page_io.c @@ -380,6 +380,10 @@ int swap_readpage(struct page *page, boo goto out; } bdev = bio->bi_bdev; + /* + * Keep this task valid during swap readpage because the oom killer may + * attempt to access it in the page fault retry time check. + */ get_task_struct(current); bio->bi_private = current; bio_set_op_attrs(bio, REQ_OP_READ, 0); _ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
