Messages in this thread | | | Date | Sat, 2 Feb 2019 02:04:40 -0800 | From | Andrei Vagin <> | Subject | Re: [PATCH] ptrace: take into account saved_sigmask in PTRACE_{GET,SET}SIGMASK |
| |
On Wed, Nov 21, 2018 at 06:16:50PM -0800, Andrew Morton wrote: > On Mon, 19 Nov 2018 22:06:16 -0800 Andrei Vagin <avagin@gmail.com> wrote: > > > There are a few system calls (pselect, ppoll, etc) which replace a task > > sigmask while they are running in a kernel-space > > > > When a task calls one of these syscalls, the kernel saves a current > > sigmask in task->saved_sigmask and sets a syscall sigmask. > > > > On syscall-exit-stop, ptrace traps a task before restoring the > > saved_sigmask, so PTRACE_GETSIGMASK returns the syscall sigmask and > > PTRACE_SETSIGMASK does nothing, because its sigmask is replaced by > > saved_sigmask, when the task returns to user-space. > > > > This patch fixes this problem. PTRACE_GET_SIGMASK returns saved_sigmask > > is it's set. PTRACE_SETSIGMASK drops the TIF_RESTORE_SIGMASK flag. > > Looks good to me, but what would I know. I'll await input from Eric > and/or Oleg (please).
Hi Andrew,
What is your plan for this patch? In the ~akpm/mmotm/series, I see a comment of waiting for ack from Oleg.
Here was a feedback from Oleg: https://www.spinics.net/lists/kernel/msg2972154.html
where he said: "Ok, I think the patch is fine".
Is it enough or should I convince him to send a "real" ack?
Thanks, Andrei
> > > --- a/include/linux/sched/signal.h > > +++ b/include/linux/sched/signal.h > > @@ -417,10 +417,20 @@ static inline void set_restore_sigmask(void) > > set_thread_flag(TIF_RESTORE_SIGMASK); > > WARN_ON(!test_thread_flag(TIF_SIGPENDING)); > > } > > + > > +static inline void clear_tsk_restore_sigmask(struct task_struct *tsk) > > +{ > > + clear_tsk_thread_flag(tsk, TIF_RESTORE_SIGMASK); > > +} > > How irritating is it that this file uses "task" 85 times and "tsk" 19 > times? What did that gain us? This patch worsens things. > > Oh well.
| |