On Fri, Apr 25, 2025 at 4:10 PM Kees Cook <[email protected]> wrote: > > On Fri, Apr 25, 2025 at 04:41:22PM -0400, Steven Rostedt wrote: > > From: Steven Rostedt <[email protected]> > > > > Getting the check if a task is a kernel thread or a user thread can be > > error prone as it's not easy to see the difference. > > > > if (!(task->flags & PF_KTHREAD)) > > > > Is not immediately obvious that it's checking for a user thread. > > > > if (is_user_thread(task)) > > > > Is much easier to review, as it is obvious that it is checking if the task > > is a user thread. > > > > Using a coccinelle script, convert these checks over to using either > > is_user_thread() or is_kernel_thread(). > > > > $ cat kthread.cocci > > @@ > > identifier task; > > @@ > > - !(task->flags & PF_KTHREAD) > > + is_user_thread(task) > > @@ > > identifier task; > > @@ > > - (task->flags & PF_KTHREAD) == 0 > > + is_user_thread(task) > > @@ > > identifier task; > > @@ > > - (task->flags & PF_KTHREAD) != 0 > > + is_kernel_thread(task) > > @@ > > identifier task; > > @@ > > - task->flags & PF_KTHREAD > > + is_kernel_thread(task) > > > > $ spatch --dir --include-headers kthread.cocci . > /tmp/t.patch > > $ patch -p1 < /tmp/t.patch > > > > Make sure to undo the conversion of the helper functions themselves! > > > > $ git show include/linux/sched.h | patch -p1 -R > > FYI, the "file in" test can be helpful. I use it to exclude tools and > samples regularly, and *I think* it would work for excluding individual > files too: > > @name_of_rule depends !(file in "tools") && !(file in "samples")@ > > I've been collecting random notes like this here: > > https://github.com/kees/kernel-tools/tree/trunk/coccinelle > > > tools/sched_ext/scx_central.bpf.c | 2 +- > > tools/sched_ext/scx_flatcg.bpf.c | 2 +- > > tools/sched_ext/scx_qmap.bpf.c | 2 +- > > I think these are fine. The Makefile is pulling in standard kbuild > Makefiles, so I think the correct include directories (outside of > tools/) are being used.
I suspect they are not fine. I don't think they #include linux/sched.h I would drop them for now. Tejun, please double check.
