From: Willy Tarreau <w@1wt.eu>
Date: Thu, 11 Aug 2022 11:56:42 +0000 (+0200)
Subject: BUILD: stconn: fix build warning at -O3 about possible null sc
X-Git-Tag: v2.7-dev4~60
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6a378d1677cbab31987a0979726b68b25612197a;p=thirdparty%2Fhaproxy.git

BUILD: stconn: fix build warning at -O3 about possible null sc

gcc-6.x and 7.x emit build warnings about sc possibly being null upon
return from sc_detach_endp(). This actually is not the case and the
compiler is a little bit overzealous there, but there exists code
paths that can make this analysis non-trivial so let's at least add
a similar BUG_ON() to let both the compiler and the deverloper know
this doesn't happen.

This should be backported to 2.6.
---

diff --git a/src/stconn.c b/src/stconn.c
index 3ffdf51812..36d19b46fe 100644
--- a/src/stconn.c
+++ b/src/stconn.c
@@ -459,6 +459,7 @@ int sc_reset_endp(struct stconn *sc)
 
 	/* The app is still attached, the sc will not be released */
 	sc_detach_endp(&sc);
+	BUG_ON(!sc);
 	BUG_ON(sc->sedesc);
 	sc->sedesc = new_sd;
 	sc->sedesc->sc = sc;
@@ -1977,5 +1978,6 @@ void sc_conn_commit_endp_upgrade(struct stconn *sc)
 		return;
 	sc_detach_endp(&sc);
 	/* Because it was already set as detached, the sedesc must be preserved */
+	BUG_ON(!sc);
 	BUG_ON(!sc->sedesc);
 }