From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 63C7615F404; Mon, 27 May 2024 14:12:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716819141; cv=none; b=EuH62wZtmVPN0eLm8dT81SFR4RkWJVWQPXr8LKPiaZ5yAgZ0Z0N+vtkfzpA+3r/8tK+DRQunDbFPiZxvNI9JUzjV2GAdfEaznQsBVsJBnqwwmMdcK433Z88pWRdTTkbIzj1t8rT7yrMTY9IJOfY58WGThcloHWU9mZjCLtlIMXQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1716819141; c=relaxed/simple; bh=KYbDoBIOVemCSPjQliXQl6JYCRrMwP9/hPqHjp4Cy2I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oQ7e5XaGK88e72eiefOo3kO1dJAZvFQfVy4bp7RSOP3PGzJ1fraEUdk19oXQHiWH/xtcpP2Q4xdUAE0fzpoB9Jq8o8iTO9JcHGDYxVmj0fL9I/cAHSv++/t/iH57SkbIH4S/0YQvZHGXK1nb87oWZHmboPh2aJT2A7yXxex/ccs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WytU5Vf+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="WytU5Vf+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13F35C4AF08; Mon, 27 May 2024 14:12:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1716819141; bh=KYbDoBIOVemCSPjQliXQl6JYCRrMwP9/hPqHjp4Cy2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WytU5Vf+jwEGZqe3EiZ9CKJdmDmh6i0H5H03dacWaTGW/iCnOtg9MaE4UDnW/hNfz 4mscoadmc+PPEfCkVocu+dd3IIqFK5ne8j0S2a/Cf8LBh8Fo/Juikn1tzZkBpQiVcf 3fqqo0E3nDwF0jm8Q/roI6mj6osQ795S7e9VfmUfx+C8uhkONBssms2RTLRhYzpE81 foiNV73MDMPTsTpPGZ1gxcdonYIbS2WjJsIwXyIKO3DPxGqdBLi+xxqsNbBxlzi7+Z qOiGthnGueoCRk2A+FCjmAIlqcFUeM54K4/aWQwcmt1guervx2Hw4ob0j6SdHwUK38 T2dVfDOA4AgOw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yonghong Song , Daniel Borkmann , Sasha Levin , ast@kernel.org, andrii@kernel.org, eddyz87@gmail.com, shuah@kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH AUTOSEL 6.9 03/35] selftests/bpf: Fix flaky test btf_map_in_map/lookup_update Date: Mon, 27 May 2024 10:11:08 -0400 Message-ID: <20240527141214.3844331-3-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240527141214.3844331-1-sashal@kernel.org> References: <20240527141214.3844331-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.9.2 Content-Transfer-Encoding: 8bit From: Yonghong Song [ Upstream commit 14bb1e8c8d4ad5d9d2febb7d19c70a3cf536e1e5 ] Recently, I frequently hit the following test failure: [root@arch-fb-vm1 bpf]# ./test_progs -n 33/1 test_lookup_update:PASS:skel_open 0 nsec [...] test_lookup_update:PASS:sync_rcu 0 nsec test_lookup_update:FAIL:map1_leak inner_map1 leaked! #33/1 btf_map_in_map/lookup_update:FAIL #33 btf_map_in_map:FAIL In the test, after map is closed and then after two rcu grace periods, it is assumed that map_id is not available to user space. But the above assumption cannot be guaranteed. After zero or one or two rcu grace periods in different siturations, the actual freeing-map-work is put into a workqueue. Later on, when the work is dequeued, the map will be actually freed. See bpf_map_put() in kernel/bpf/syscall.c. By using workqueue, there is no ganrantee that map will be actually freed after a couple of rcu grace periods. This patch removed such map leak detection and then the test can pass consistently. Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20240322061353.632136-1-yonghong.song@linux.dev Signed-off-by: Sasha Levin --- .../selftests/bpf/prog_tests/btf_map_in_map.c | 26 +------------------ 1 file changed, 1 insertion(+), 25 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c index a8b53b8736f01..f66ceccd7029c 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_map_in_map.c @@ -25,7 +25,7 @@ static void test_lookup_update(void) int map1_fd, map2_fd, map3_fd, map4_fd, map5_fd, map1_id, map2_id; int outer_arr_fd, outer_hash_fd, outer_arr_dyn_fd; struct test_btf_map_in_map *skel; - int err, key = 0, val, i, fd; + int err, key = 0, val, i; skel = test_btf_map_in_map__open_and_load(); if (CHECK(!skel, "skel_open", "failed to open&load skeleton\n")) @@ -102,30 +102,6 @@ static void test_lookup_update(void) CHECK(map1_id == 0, "map1_id", "failed to get ID 1\n"); CHECK(map2_id == 0, "map2_id", "failed to get ID 2\n"); - test_btf_map_in_map__destroy(skel); - skel = NULL; - - /* we need to either wait for or force synchronize_rcu(), before - * checking for "still exists" condition, otherwise map could still be - * resolvable by ID, causing false positives. - * - * Older kernels (5.8 and earlier) freed map only after two - * synchronize_rcu()s, so trigger two, to be entirely sure. - */ - CHECK(kern_sync_rcu(), "sync_rcu", "failed\n"); - CHECK(kern_sync_rcu(), "sync_rcu", "failed\n"); - - fd = bpf_map_get_fd_by_id(map1_id); - if (CHECK(fd >= 0, "map1_leak", "inner_map1 leaked!\n")) { - close(fd); - goto cleanup; - } - fd = bpf_map_get_fd_by_id(map2_id); - if (CHECK(fd >= 0, "map2_leak", "inner_map2 leaked!\n")) { - close(fd); - goto cleanup; - } - cleanup: test_btf_map_in_map__destroy(skel); } -- 2.43.0