Subject: [PATCH 25/44] selftests: net: tcp_mmap: clear whole tcp_zerocopy_receive struct

From: Eric Dumazet <[email-masked]>
Date: Tue, 5 May 2020 20:51:06 -0700

[ Upstream commit bf5525f3a8e3248be5aa5defe5aaadd60e1c1ba1 ]

We added fields in tcp_zerocopy_receive structure,
so make sure to clear all fields to not pass garbage to the kernel.

We were lucky because recent additions added 'out' parameters,
still we need to clean our reference implementation, before folks
copy/paste it.

Fixes: c8856c051454 ("tcp-zerocopy: Return inq along with tcp receive zerocopy.")
Fixes: 33946518d493 ("tcp-zerocopy: Return sk_err (if set) along with tcp receive zerocopy.")
Signed-off-by: Eric Dumazet <[email-masked]>
Cc: Arjun Roy <[email-masked]>
Cc: Soheil Hassas Yeganeh <[email-masked]>
Acked-by: Soheil Hassas Yeganeh <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 tools/testing/selftests/net/tcp_mmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/tcp_mmap.c b/tools/testing/selftests/net/tcp_mmap.c
index 35505b31e5cc..62171fd638c8 100644
--- a/tools/testing/selftests/net/tcp_mmap.c
+++ b/tools/testing/selftests/net/tcp_mmap.c
@@ -165,9 +165,10 @@ void *child_thread(void *arg)
 			socklen_t zc_len = sizeof(zc);
 			int res;
 
+			memset(&zc, 0, sizeof(zc));
 			zc.address = (__u64)((unsigned long)addr);
 			zc.length = chunk_size;
-			zc.recv_skip_hint = 0;
+
 			res = getsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE,
 					 &zc, &zc_len);
 			if (res == -1)
-- 
2.26.2