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-rw-r--r--kernel/signal.c79
1 files changed, 61 insertions, 18 deletions
diff --git a/kernel/signal.c b/kernel/signal.c
index b6b36768b758..d8034737db4c 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -55,10 +55,22 @@ static int sig_handler_ignored(void __user *handler, int sig)
(handler == SIG_DFL && sig_kernel_ignore(sig));
}
-static int sig_ignored(struct task_struct *t, int sig)
+static int sig_task_ignored(struct task_struct *t, int sig,
+ int from_ancestor_ns)
{
void __user *handler;
+ handler = sig_handler(t, sig);
+
+ if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) &&
+ handler == SIG_DFL && !from_ancestor_ns)
+ return 1;
+
+ return sig_handler_ignored(handler, sig);
+}
+
+static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns)
+{
/*
* Blocked signals are never ignored, since the
* signal handler may change by the time it is
@@ -67,14 +79,13 @@ static int sig_ignored(struct task_struct *t, int sig)
if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
return 0;
- handler = sig_handler(t, sig);
- if (!sig_handler_ignored(handler, sig))
+ if (!sig_task_ignored(t, sig, from_ancestor_ns))
return 0;
/*
* Tracers may want to know about even ignored signals.
*/
- return !tracehook_consider_ignored_signal(t, sig, handler);
+ return !tracehook_consider_ignored_signal(t, sig);
}
/*
@@ -318,7 +329,7 @@ int unhandled_signal(struct task_struct *tsk, int sig)
return 1;
if (handler != SIG_IGN && handler != SIG_DFL)
return 0;
- return !tracehook_consider_fatal_signal(tsk, sig, handler);
+ return !tracehook_consider_fatal_signal(tsk, sig);
}
@@ -624,7 +635,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
* Returns true if the signal should be actually delivered, otherwise
* it should be dropped.
*/
-static int prepare_signal(int sig, struct task_struct *p)
+static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns)
{
struct signal_struct *signal = p->signal;
struct task_struct *t;
@@ -708,7 +719,7 @@ static int prepare_signal(int sig, struct task_struct *p)
}
}
- return !sig_ignored(p, sig);
+ return !sig_ignored(p, sig, from_ancestor_ns);
}
/*
@@ -777,7 +788,7 @@ static void complete_signal(int sig, struct task_struct *p, int group)
!(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) &&
!sigismember(&t->real_blocked, sig) &&
(sig == SIGKILL ||
- !tracehook_consider_fatal_signal(t, sig, SIG_DFL))) {
+ !tracehook_consider_fatal_signal(t, sig))) {
/*
* This signal will be fatal to the whole group.
*/
@@ -813,8 +824,8 @@ static inline int legacy_queue(struct sigpending *signals, int sig)
return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
}
-static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
- int group)
+static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
+ int group, int from_ancestor_ns)
{
struct sigpending *pending;
struct sigqueue *q;
@@ -822,7 +833,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
trace_sched_signal_send(sig, t);
assert_spin_locked(&t->sighand->siglock);
- if (!prepare_signal(sig, t))
+
+ if (!prepare_signal(sig, t, from_ancestor_ns))
return 0;
pending = group ? &t->signal->shared_pending : &t->pending;
@@ -871,6 +883,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
break;
default:
copy_siginfo(&q->info, info);
+ if (from_ancestor_ns)
+ q->info.si_pid = 0;
break;
}
} else if (!is_si_special(info)) {
@@ -889,6 +903,20 @@ out_set:
return 0;
}
+static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
+ int group)
+{
+ int from_ancestor_ns = 0;
+
+#ifdef CONFIG_PID_NS
+ if (!is_si_special(info) && SI_FROMUSER(info) &&
+ task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0)
+ from_ancestor_ns = 1;
+#endif
+
+ return __send_signal(sig, info, t, group, from_ancestor_ns);
+}
+
int print_fatal_signals;
static void print_fatal_signal(struct pt_regs *regs, int signr)
@@ -1133,7 +1161,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid,
if (sig && p->sighand) {
unsigned long flags;
spin_lock_irqsave(&p->sighand->siglock, flags);
- ret = __group_send_sig_info(sig, info, p);
+ ret = __send_signal(sig, info, p, 1, 0);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
out_unlock:
@@ -1320,7 +1348,7 @@ int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group)
goto ret;
ret = 1; /* the signal is ignored */
- if (!prepare_signal(sig, t))
+ if (!prepare_signal(sig, t, 0))
goto out;
ret = 0;
@@ -1367,7 +1395,6 @@ int do_notify_parent(struct task_struct *tsk, int sig)
struct siginfo info;
unsigned long flags;
struct sighand_struct *psig;
- struct task_cputime cputime;
int ret = sig;
BUG_ON(sig == -1);
@@ -1397,9 +1424,10 @@ int do_notify_parent(struct task_struct *tsk, int sig)
info.si_uid = __task_cred(tsk)->uid;
rcu_read_unlock();
- thread_group_cputime(tsk, &cputime);
- info.si_utime = cputime_to_jiffies(cputime.utime);
- info.si_stime = cputime_to_jiffies(cputime.stime);
+ info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime,
+ tsk->signal->utime));
+ info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime,
+ tsk->signal->stime));
info.si_status = tsk->exit_code & 0x7f;
if (tsk->exit_code & 0x80)
@@ -1575,7 +1603,15 @@ static void ptrace_stop(int exit_code, int clear_code, siginfo_t *info)
read_lock(&tasklist_lock);
if (may_ptrace_stop()) {
do_notify_parent_cldstop(current, CLD_TRAPPED);
+ /*
+ * Don't want to allow preemption here, because
+ * sys_ptrace() needs this task to be inactive.
+ *
+ * XXX: implement read_unlock_no_resched().
+ */
+ preempt_disable();
read_unlock(&tasklist_lock);
+ preempt_enable_no_resched();
schedule();
} else {
/*
@@ -1836,9 +1872,16 @@ relock:
/*
* Global init gets no signals it doesn't want.
+ * Container-init gets no signals it doesn't want from same
+ * container.
+ *
+ * Note that if global/container-init sees a sig_kernel_only()
+ * signal here, the signal must have been generated internally
+ * or must have come from an ancestor namespace. In either
+ * case, the signal cannot be dropped.
*/
if (unlikely(signal->flags & SIGNAL_UNKILLABLE) &&
- !signal_group_exit(signal))
+ !sig_kernel_only(signr))
continue;
if (sig_kernel_stop(signr)) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-04 18:58:05 +0000