From f6507f83bccd4a5f7dc7091079bf58128dc56d66 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 10 Dec 2014 15:54:45 -0800 Subject: [PATCH] exit: wait: cleanup the ptrace_reparented() checks Now that EXIT_DEAD is the terminal state we can kill "int traced" variable and check "state == EXIT_DEAD" instead to cleanup the code. In particular, this way it is clear that the check obviously doesn't need tasklist_lock. Also fix the type of "unsigned long state", "long" was always wrong although this doesn't matter because cmpxchg/xchg uses typeof(*ptr). [akpm@linux-foundation.org: don't make me google the C Operator Precedence table] Signed-off-by: Oleg Nesterov Cc: Aaron Tomlin Cc: "Eric W. Biederman" Cc: Rik van Riel Cc: Sterling Alexander Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/exit.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/kernel/exit.c b/kernel/exit.c index 9c9526d87276..20875d6398ae 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -973,8 +973,7 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p, */ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) { - unsigned long state; - int retval, status, traced; + int state, retval, status; pid_t pid = task_pid_vnr(p); uid_t uid = from_kuid_munged(current_user_ns(), task_uid(p)); struct siginfo __user *infop; @@ -999,19 +998,18 @@ static int wait_task_zombie(struct wait_opts *wo, struct task_struct *p) } return wait_noreap_copyout(wo, p, pid, uid, why, status); } - - traced = ptrace_reparented(p); /* * Move the task's state to DEAD/TRACE, only one thread can do this. */ - state = traced && thread_group_leader(p) ? EXIT_TRACE : EXIT_DEAD; + state = (ptrace_reparented(p) && thread_group_leader(p)) ? + EXIT_TRACE : EXIT_DEAD; if (cmpxchg(&p->exit_state, EXIT_ZOMBIE, state) != EXIT_ZOMBIE) return 0; + /* - * It can be ptraced but not reparented, check - * thread_group_leader() to filter out sub-threads. + * Check thread_group_leader() to exclude the traced sub-threads. */ - if (likely(!traced) && thread_group_leader(p)) { + if (state == EXIT_DEAD && thread_group_leader(p)) { struct signal_struct *psig; struct signal_struct *sig; unsigned long maxrss; -- 2.34.1