Messages in this thread | | | Date | Wed, 21 Nov 2018 18:16:50 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] ptrace: take into account saved_sigmask in PTRACE_{GET,SET}SIGMASK |
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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).
> --- 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.
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