diff options
author | Eric W. Biederman <ebiederm@xmission.com> | 2021-06-24 02:14:30 -0500 |
---|---|---|
committer | Eric W. Biederman <ebiederm@xmission.com> | 2022-01-08 12:43:57 -0600 |
commit | 49697335e0b441b0553598c1b48ee9ebb053d2f1 (patch) | |
tree | 87f8bbaeb9f274055e4bf8bb84e8aef77038f39f /kernel | |
parent | 60700e38fb68e800607ca7a027060d5419fc5798 (diff) | |
download | linux-49697335e0b441b0553598c1b48ee9ebb053d2f1.tar.bz2 |
signal: Remove the helper signal_group_exit
This helper is misleading. It tests for an ongoing exec as well as
the process having received a fatal signal.
Sometimes it is appropriate to treat an on-going exec differently than
a process that is shutting down due to a fatal signal. In particular
taking the fast path out of exit_signals instead of retargeting
signals is not appropriate during exec, and not changing the the exit
code in do_group_exit during exec.
Removing the helper makes it more obvious what is going on as both
cases must be coded for explicitly.
While removing the helper fix the two cases where I have observed
using signal_group_exit resulted in the wrong result.
In exit_signals only test for SIGNAL_GROUP_EXIT so that signals are
retargetted during an exec.
In do_group_exit use 0 as the exit code during an exec as de_thread
does not set group_exit_code. As best as I can determine
group_exit_code has been is set to 0 most of the time during
de_thread. During a thread group stop group_exit_code is set to the
stop signal and when the thread group receives SIGCONT group_exit_code
is reset to 0.
Link: https://lkml.kernel.org/r/20211213225350.27481-8-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/exit.c | 8 | ||||
-rw-r--r-- | kernel/signal.c | 8 |
2 files changed, 11 insertions, 5 deletions
diff --git a/kernel/exit.c b/kernel/exit.c index b05578abbf26..861cfb1e2f77 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -914,15 +914,19 @@ do_group_exit(int exit_code) BUG_ON(exit_code & 0x80); /* core dumps don't get here */ - if (signal_group_exit(sig)) + if (sig->flags & SIGNAL_GROUP_EXIT) exit_code = sig->group_exit_code; + else if (sig->group_exec_task) + exit_code = 0; else if (!thread_group_empty(current)) { struct sighand_struct *const sighand = current->sighand; spin_lock_irq(&sighand->siglock); - if (signal_group_exit(sig)) + if (sig->flags & SIGNAL_GROUP_EXIT) /* Another thread got here before we took the lock. */ exit_code = sig->group_exit_code; + else if (sig->group_exec_task) + exit_code = 0; else { sig->group_exit_code = exit_code; sig->flags = SIGNAL_GROUP_EXIT; diff --git a/kernel/signal.c b/kernel/signal.c index bae231bc2f4a..167b8e196a79 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2386,7 +2386,8 @@ static bool do_signal_stop(int signr) WARN_ON_ONCE(signr & ~JOBCTL_STOP_SIGMASK); if (!likely(current->jobctl & JOBCTL_STOP_DEQUEUED) || - unlikely(signal_group_exit(sig))) + unlikely(sig->flags & SIGNAL_GROUP_EXIT) || + unlikely(sig->group_exec_task)) return false; /* * There is no group stop already in progress. We must @@ -2693,7 +2694,8 @@ relock: enum pid_type type; /* Has this task already been marked for death? */ - if (signal_group_exit(signal)) { + if ((signal->flags & SIGNAL_GROUP_EXIT) || + signal->group_exec_task) { ksig->info.si_signo = signr = SIGKILL; sigdelset(¤t->pending.signal, SIGKILL); trace_signal_deliver(SIGKILL, SEND_SIG_NOINFO, @@ -2949,7 +2951,7 @@ void exit_signals(struct task_struct *tsk) */ cgroup_threadgroup_change_begin(tsk); - if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { + if (thread_group_empty(tsk) || (tsk->signal->flags & SIGNAL_GROUP_EXIT)) { tsk->flags |= PF_EXITING; cgroup_threadgroup_change_end(tsk); return; |