Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.38 as permitted sender) client-ip=23.128.96.38;
From:   =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Date:   Thu, 23 Nov 2023 00:21:27 +0100
Subject: [PATCH 3/3] selftests/nolibc: disable coredump via setrlimit
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 8bit
Message-Id: <20231123-nolibc-rlimit-v1-3-a428b131de2a@weissschuh.net>
References: <20231123-nolibc-rlimit-v1-0-a428b131de2a@weissschuh.net>
In-Reply-To: <20231123-nolibc-rlimit-v1-0-a428b131de2a@weissschuh.net>
To:     Willy Tarreau <w@1wt.eu>, Shuah Khan <shuah@kernel.org>
Cc:     linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
        =?utf-8?q?Thomas_Wei=C3=9Fschuh?= <linux@weissschuh.net>
Precedence: bulk

qemu-user does has its own implementation of coredumping.
That implementation does not respect the call to
prctl(PR_SET_DUMPABLE, 0) in run_protection().
This leads to a coredump for every test run under qemu-user.

Use also setrlimit() to inhibit coredump creation which is respected by
qemu-user.

Link: https://lore.kernel.org/qemu-devel/20231115-qemu-user-dumpable-v1-2-edbe7f0fbb02@t-8ch.de/
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
---
 tools/testing/selftests/nolibc/nolibc-test.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index d07cebace107..ccb8d017a3e7 100644
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1167,6 +1167,7 @@ static int run_protection(int min __attribute__((unused)),
 {
 	pid_t pid;
 	int llen = 0, status;
+	struct rlimit rlimit = { 0, 0 };
 
 	llen += printf("0 -fstackprotector ");
 
@@ -1198,6 +1199,7 @@ static int run_protection(int min __attribute__((unused)),
 		close(STDERR_FILENO);
 
 		prctl(PR_SET_DUMPABLE, 0, 0, 0, 0);
+		setrlimit(RLIMIT_CORE, &rlimit);
 		smash_stack();
 		return 1;
 

-- 
2.43.0