From: Oleg Nesterov Now that my_ptrace_child() is trivial we can use the "p->ptrace & PT_PTRACED" inline and simplify the corresponding logic in do_wait: we can't find the child in TASK_TRACED state without PT_PTRACED flag set, ptrace_untrace() either sets TASK_STOPPED or wakes up the tracee. Signed-off-by: Oleg Nesterov Cc: Roland McGrath Cc: Christoph Hellwig Signed-off-by: Andrew Morton --- kernel/exit.c | 23 +++-------------------- 1 file changed, 3 insertions(+), 20 deletions(-) diff -puN kernel/exit.c~kill-my_ptrace_child kernel/exit.c --- a/kernel/exit.c~kill-my_ptrace_child +++ a/kernel/exit.c @@ -1509,12 +1509,6 @@ static int wait_task_continued(struct ta return retval; } - -static inline int my_ptrace_child(struct task_struct *p) -{ - return p->ptrace & PT_PTRACED; -} - static long do_wait(pid_t pid, int options, struct siginfo __user *infop, int __user *stat_addr, struct rusage __user *ru) { @@ -1553,22 +1547,11 @@ repeat: /* * It's stopped now, so it might later * continue, exit, or stop again. - * - * When we hit the race with PTRACE_ATTACH, we - * will not report this child. But the race - * means it has not yet been moved to our - * ptrace_children list, so we need to set the - * flag here to avoid a spurious ECHILD when - * the race happens with the only child. */ flag = 1; - - if (!my_ptrace_child(p)) { - if (is_task_traced(p)) - continue; - if (!(options & WUNTRACED)) - continue; - } + if (!(p->ptrace & PT_PTRACED) && + !(options & WUNTRACED)) + continue; retval = wait_task_stopped(p, ret == 2, (options & WNOWAIT), infop, _