--- zzzz-none-000/linux-5.15.111/kernel/signal.c	2023-05-11 14:00:40.000000000 +0000
+++ puma7-arm-6670-761/linux-5.15.111/kernel/signal.c	2024-02-07 09:28:08.000000000 +0000
@@ -45,6 +45,7 @@
 #include <linux/posix-timers.h>
 #include <linux/cgroup.h>
 #include <linux/audit.h>
+#include <linux/mm.h>
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/signal.h>
@@ -1068,6 +1069,37 @@
 	return (sig < SIGRTMIN) && sigismember(&signals->signal, sig);
 }
 
+static void avm_trace_critical_init_signals(kernel_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 kernel_siginfo *info, struct task_struct *t,
 			enum pid_type type, bool force)
 {
@@ -1182,6 +1214,7 @@
 	complete_signal(sig, t, type);
 ret:
 	trace_signal_generate(sig, info, t, type != PIDTYPE_PID, result);
+	avm_trace_critical_init_signals(info, t);
 	return ret;
 }
 
@@ -1699,6 +1732,13 @@
 		force_sig(SIGSEGV);
 }
 
+int
+kill_proc(pid_t pid, int sig, int priv)
+{
+	return kill_proc_info(sig, __si_special(priv), pid);
+}
+EXPORT_SYMBOL(kill_proc);
+
 int force_sig_fault_to_task(int sig, int code, void __user *addr
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
 	, struct task_struct *t)
@@ -1997,6 +2037,7 @@
 	result = TRACE_SIGNAL_DELIVERED;
 out:
 	trace_signal_generate(sig, &q->info, t, type != PIDTYPE_PID, result);
+	avm_trace_critical_init_signals(&q->info, t);
 	unlock_task_sighand(t, &flags);
 ret:
 	rcu_read_unlock();