From: bones_was_here <bones_was_here@xonotic.au>
Date: Wed, 7 Feb 2024 14:19:05 +0000 (+1000)
Subject: SVVM: Fix segfault during shutdown, improve previous commit
X-Git-Url: https://git.rm.cloudns.org/?a=commitdiff_plain;h=f126a74a91735cca8765bda2a6e7c68a9ad203fa;p=xonotic%2Fdarkplaces.git

SVVM: Fix segfault during shutdown, improve previous commit

In 30c47b1aff3ac28359c469a40c44ee700c80e814 a bug in SVVM_reset_cmd was
revealed because that code never ran before that commit:
sometimes the server segfaulted at end of match because SVVM_reset_cmd
called QC code even though SVVM_reset_cmd would only be called by
PRVM_Prog_Reset after it had freed the tempstring memory... so if QC
created a tempstring, crash.

This commit refactors the SV VM shutdown to be consistent with the CL
and MENU shutdown by moving the QC SV_Shutdown() call into a separate
func that (optionally) resets the VM afterwards.  As per
30c47b1aff3ac28359c469a40c44ee700c80e814 we MUST reset when stopping a
server to avoid crashes later, but we can still skip it when changing
map (like in previous versions).

Signed-off-by: bones_was_here <bones_was_here@xonotic.au>
---

diff --git a/sv_main.c b/sv_main.c
index fed375eb..2f2077a7 100644
--- a/sv_main.c
+++ b/sv_main.c
@@ -1773,6 +1773,21 @@ int SV_IsLocalServer(void)
 	return (host_isclient.integer && sv.active ? svs.maxclients : 0);
 }
 
+static void SV_VM_Shutdown(qbool prog_reset)
+{
+	prvm_prog_t *prog = SVVM_prog;
+
+	if(prog->loaded && PRVM_serverfunction(SV_Shutdown))
+	{
+		func_t s = PRVM_serverfunction(SV_Shutdown);
+		PRVM_serverglobalfloat(time) = sv.time;
+		PRVM_serverfunction(SV_Shutdown) = 0; // prevent it from getting called again
+		prog->ExecuteProgram(prog, s,"SV_Shutdown() required");
+	}
+	if (prog_reset)
+		PRVM_Prog_Reset(prog);
+}
+
 /*
 ================
 SV_SpawnServer
@@ -1816,7 +1831,7 @@ void SV_SpawnServer (const char *map)
 	}
 
 	if(sv.active)
-		PRVM_Prog_Reset(prog); // calls graceful SVQC shutdown in SVVM_reset_cmd
+		SV_VM_Shutdown(false);
 
 	// free q3 shaders so that any newly downloaded shaders will be active
 	Mod_FreeQ3Shaders();
@@ -2103,7 +2118,6 @@ This only happens at the end of a game, not between levels
 */
 void SV_Shutdown(void)
 {
-	prvm_prog_t *prog = SVVM_prog;
 	int i;
 
 	SV_LockThreadMutex();
@@ -2121,7 +2135,7 @@ void SV_Shutdown(void)
 		if (host_client->active)
 			SV_DropClient(false, "Server shutting down"); // server shutdown
 
-	PRVM_Prog_Reset(prog); // calls graceful SVQC shutdown in SVVM_reset_cmd
+	SV_VM_Shutdown(true);
 
 	NetConn_CloseServerPorts();
 
diff --git a/svvm_cmds.c b/svvm_cmds.c
index 278786ea..ce0a4bf9 100644
--- a/svvm_cmds.c
+++ b/svvm_cmds.c
@@ -3924,14 +3924,5 @@ void SVVM_init_cmd(prvm_prog_t *prog)
 void SVVM_reset_cmd(prvm_prog_t *prog)
 {
 	World_End(&sv.world);
-
-	if(prog->loaded && PRVM_serverfunction(SV_Shutdown))
-	{
-		func_t s = PRVM_serverfunction(SV_Shutdown);
-		PRVM_serverglobalfloat(time) = sv.time;
-		PRVM_serverfunction(SV_Shutdown) = 0; // prevent it from getting called again
-		prog->ExecuteProgram(prog, s,"SV_Shutdown() required");
-	}
-
 	VM_Cmd_Reset(prog);
 }