--- zzzz-none-000/linux-4.9.279/kernel/signal.c	2021-08-08 06:38:54.000000000 +0000
+++ puma7-arm-6591-750/linux-4.9.279/kernel/signal.c	2023-02-08 10:58:16.000000000 +0000
@@ -34,6 +34,7 @@
 #include <linux/compat.h>
 #include <linux/cn_proc.h>
 #include <linux/compiler.h>
+#include <linux/mm.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
@@ -1035,6 +1036,37 @@
 }
 #endif
 
+static void avm_trace_critical_init_signals(siginfo_t *info,
+					    struct task_struct *t)
+{
+	/*
+	 * HAX: Busybox init shuts down the system on some signals.
+	 * Take note of processes that are sending such signals.
+	 *
+	 * This really should be handled in user space, but... user space on a
+	 * Fritzbox has currently no means by itself to write persistent logs,
+	 * traversing parent processes is a pain outside the kernel, and it's
+	 * just simpler to maintain here rather than in the busybox init.
+	 */
+
+	if (!IS_ENABLED(CONFIG_AVM_TRACE_INIT_SIGNALS))
+		return;
+
+	if (likely(!is_global_init(t)))
+		return;
+
+	switch (info->si_signo) {
+	case SIGTERM:
+	case SIGUSR1:
+	case SIGUSR2:
+	case SIGPWR:
+		pr_notice("Task (pid %d) is sending signal #%d to init!\n",
+				task_pid_nr(current),
+				info->si_signo);
+		show_parent_tasks_cmdlines(current);
+	}
+}
+
 static int __send_signal(int sig, struct siginfo *info, struct task_struct *t,
 			int group, int from_ancestor_ns)
 {
@@ -1136,6 +1168,7 @@
 	complete_signal(sig, t, group);
 ret:
 	trace_signal_generate(sig, info, t, group, result);
+	avm_trace_critical_init_signals(info, t);
 	return ret;
 }
 
@@ -1627,6 +1660,7 @@
 	result = TRACE_SIGNAL_DELIVERED;
 out:
 	trace_signal_generate(sig, &q->info, t, group, result);
+	avm_trace_critical_init_signals(&q->info, t);
 	unlock_task_sighand(t, &flags);
 ret:
 	return ret;