Subject: Re: [PATCH net-next v10 08/16] tls: Inline do_tcp_sendpages()

From: Jakub Kicinski <[email-masked]>
Date: Tue, 25 Jul 2023 17:30:36 -0700

On Sun, 23 Jul 2023 09:35:56 +0300 Tariq Toukan wrote:
> Hi Jakub, David,
> 
> We repro the issue on the server side using this client command:
> $ wrk -b2.2.2.2 -t4 -c1000 -d5 --timeout 5s 
> https://2.2.2.3:20443/256000b.img
> 
> Port 20443 is configured with:
>      ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256;
>      sendfile    off;
> 
> 
> Important:
> 1. Couldn't repro with files smaller than 40KB.
> 2. Couldn't repro with "sendfile    on;"
> 
> In addition, we collected the vmcore (forced by panic_on_warn), it can 
> be downloaded from here:
> https://drive.google.com/file/d/1Fi2dzgq6k2hb2L_kwyntRjfLF6_RmbxB/view?usp=sharing

This has no symbols :(

There is a small bug in this commit, we should always set SPLICE.
But I don't see how that'd cause the warning you're seeing.
Does your build have CONFIG_DEBUG_VM enabled?

-->8-------------------------

From: Jakub Kicinski <[email-masked]>
Date: Tue, 25 Jul 2023 17:03:25 -0700
Subject: net: tls: set MSG_SPLICE_PAGES consistently

We used to change the flags for the last segment, because
non-last segments had the MSG_SENDPAGE_NOTLAST flag set.
That flag is no longer a thing so remove the setting.

Since flags most likely don't have MSG_SPLICE_PAGES set
this avoids passing parts of the sg as splice and parts
as non-splice.

... tags ...
Signed-off-by: Jakub Kicinski <[email-masked]>
---
 net/tls/tls_main.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
index b6896126bb92..4a8ee2f6badb 100644
--- a/net/tls/tls_main.c
+++ b/net/tls/tls_main.c
@@ -139,9 +139,6 @@ int tls_push_sg(struct sock *sk,
 
 	ctx->splicing_pages = true;
 	while (1) {
-		if (sg_is_last(sg))
-			msg.msg_flags = flags;
-
 		/* is sending application-limited? */
 		tcp_rate_check_app_limited(sk);
 		p = sg_page(sg);
-- 
2.41.0