From: Michael Tremer <michael.tremer@ipfire.org>
Date: Tue, 21 Oct 2025 07:26:01 +0000 (+0000)
Subject: command: Defer cleaning up the command to avoid zombies
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=43e45d0b2ef880426bf33a6c65e9666527857a15;p=telemetry.git

command: Defer cleaning up the command to avoid zombies

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/daemon/command.c b/src/daemon/command.c
index d5d45cb..6d8a145 100644
--- a/src/daemon/command.c
+++ b/src/daemon/command.c
@@ -299,6 +299,22 @@ static int td_command_log_stderr(td_ctx* ctx, td_file* file,
 	return 0;
 }
 
+/*
+	This function simply drops a reference to the command.
+
+	It is being called after the command has exited, but cannot be called in the
+	same iteration because we will cleanup the command and prevent the event loop
+	from reaping the process. Therefore we will be left with lots of zombies.
+*/
+static int td_command_cleanup(sd_event_source* source, void* data) {
+	td_command* self = data;
+
+	// Drop the reference
+	td_command_unref(self);
+
+	return 0;
+}
+
 static int td_command_exited(sd_event_source* source, const siginfo_t* si, void* data) {
 	td_command* self = data;
 	td_file* stdout = NULL;
@@ -384,7 +400,7 @@ ERROR:
 		td_file_unref(stdout);
 
 	// Drop the extra reference
-	td_command_unref(self);
+	sd_event_add_defer(self->loop, NULL, td_command_cleanup, self);
 
 	return r;
 }