syscalls: killthread

kernel-src/sys/syscalls/killthread.c

@@ -0,0 +1,58 @@
+#include <kernel/syscalls.h>
+#include <arch/cpu.h>
+#include <logging.h>
+#include <kernel/jobctl.h>
+#include <kernel/auth.h>
+
+syscallret_t syscall_killthread(context_t *context, int pid, int tid, int signal) {
+	syscallret_t ret = {
+		.ret = -1
+	};
+
+	if (pid < 1 || tid < 1 || signal < 0 || signal > NSIG) {
+		ret.errno = EINVAL;
+		return ret;
+	}
+
+	proc_t *sender = _cpu()->thread->proc;
+	proc_t *target = sched_getprocfrompid(pid);
+	if (target == NULL) {
+		ret.errno = ESRCH;
+		return ret;
+	}
+
+	// permission check
+	if (signal != SIGCONT || jobctl_getpgid(target) != jobctl_getpgid(sender)) {
+		ret.errno = auth_process_check(&sender->cred, AUTH_ACTIONS_PROCESS_SIGNAL, target);
+		if (ret.errno)
+			goto leave;
+	}
+
+	bool ok = false;
+	bool intstatus = spinlock_acquireirqclear(&target->threadlistlock);
+
+	thread_t *thread = target->threadlist;
+	while (thread) {
+		if (thread->tid == tid) {
+			signal_signalthread(thread, signal, false);
+			ok = true;
+			break;
+		}
+
+		thread = thread->procnext;
+	}
+
+	spinlock_releaseirqrestore(&target->threadlistlock, intstatus);
+
+	if (ok == false) {
+		ret.errno = ESRCH;
+		ret.ret = -1;
+	} else {
+		ret.errno = 0;
+		ret.ret = 0;
+	}
+
+	leave:
+	PROC_RELEASE(target);
+	return ret;
+}