From: Willy Tarreau <w@1wt.eu>
Date: Sat, 4 Nov 2023 07:12:17 +0000 (+0100)
Subject: MINOR: mux-h2: always use h2_send() in h2_done_ff(), not h2_process()
X-Git-Tag: v2.9-dev9~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0fa5adee3bb17814b80ddfb5e07f5e219efcfebd;p=thirdparty%2Fhaproxy.git

MINOR: mux-h2: always use h2_send() in h2_done_ff(), not h2_process()

By calling h2_process(), the code would theoretically make it possible
for a synchronous ->wake() call to provoke an indirect call to h2_snd_buf()
while we're in h2_done_ff(), which could be quite bad. The current
conditions do not permit it right now but this could easily break by
accident. Better use h2_send() and wake the task up if needed. Precise
performance tests showed no change.
---

diff --git a/src/mux_h2.c b/src/mux_h2.c
index 785fbd9cdc..d0ab3c8a01 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -7070,7 +7070,8 @@ static void h2_done_ff(struct stconn *sc)
 	b_add(mbuf, 9);
 	h2s->sws -= sd->iobuf.data;
 	h2c->mws -= sd->iobuf.data;
-	h2_process(h2c);
+	if (h2_send(h2s->h2c))
+		tasklet_wakeup(h2s->h2c->wait_event.tasklet);
 
  end:
 	sd->iobuf.buf = NULL;