From: Stanislav Fomichev <sdf@fomichev.me>
Date: Thu, 4 Sep 2025 18:27:10 +0000 (-0700)
Subject: selftests: ncdevmem: don't retry EFAULT
X-Git-Tag: v6.17.8~390
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e2e2a093eecd41e0706d316a6b03b247658cca6b;p=thirdparty%2Fkernel%2Fstable.git

selftests: ncdevmem: don't retry EFAULT

[ Upstream commit 8c0b9ed2401b9b3f164c8c94221899a1ace6e9ab ]

devmem test fails on NIPA. Most likely we get skb(s) with readable
frags (why?) but the failure manifests as an OOM. The OOM happens
because ncdevmem spams the following message:

  recvmsg ret=-1
  recvmsg: Bad address

As of today, ncdevmem can't deal with various reasons of EFAULT:
- falling back to regular recvmsg for non-devmem skbs
- increasing ctrl_data size (can't happen with ncdevmem's large buffer)

Exit (cleanly) with error when recvmsg returns EFAULT. This should at
least cause the test to cleanup its state.

Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Link: https://patch.msgid.link/20250904182710.1586473-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/tools/testing/selftests/drivers/net/hw/ncdevmem.c b/tools/testing/selftests/drivers/net/hw/ncdevmem.c
index 72f828021f832..147976e55dac2 100644
--- a/tools/testing/selftests/drivers/net/hw/ncdevmem.c
+++ b/tools/testing/selftests/drivers/net/hw/ncdevmem.c
@@ -631,6 +631,10 @@ static int do_server(struct memory_buffer *mem)
 			continue;
 		if (ret < 0) {
 			perror("recvmsg");
+			if (errno == EFAULT) {
+				pr_err("received EFAULT, won't recover");
+				goto err_close_client;
+			}
 			continue;
 		}
 		if (ret == 0) {