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 4561A171E70; Wed, 3 Jul 2024 11:21:07 +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=1720005668; cv=none; b=GjJDanzlCKSZS7gnR4ElI+JS8gV9M46Y7OBe+Ml3uZvDQDEyxNRXsaAk8b5lVLGK1nZRSeKdgOSOothYG/k6fLR+8pHaNlY88rmmSVIYA3hpYxV2/7NLu6pdQ7Evl9cp+PexAWVPdkLXJ9YZhaGMLbtMbHk3iWoiFh9EkV7CsHk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720005668; c=relaxed/simple; bh=BnYT32GPZrCyzO1P46RDr2tt8pDKm4NX+7tGxIRivrs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ntRrOe62DG78qg1Yxg8OudY4+muQZhixlLrvKGl2p+CUv3iYG63FJmCGs1PbviY5MNa46nwgE7f8jwIdvKWbQNMJJEweKoYOKDNMcnU6ZNgI+05NhyfPZ1RRYWsRm1Wrf4ih22ZAUduYjDhQgbXhTUlEifqejp3tfgG0d4N6WQ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dUAg0Gux; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dUAg0Gux" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 637F8C2BD10; Wed, 3 Jul 2024 11:21:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720005667; bh=BnYT32GPZrCyzO1P46RDr2tt8pDKm4NX+7tGxIRivrs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dUAg0GuxrM2ZZbB5xxLp93xxdD0x547H2KBPZPf8ebImT9sN9FEvgCV/YAaxQS1KE IULOQOPXYn7NsUyOJxlpqia12Dc6TXpJbiB5gqe6+5HByF1jV2OCteP77LL2KacQ5k qO2RRIyJiWvJ0ZXWFF/HPMXh/PALSi6j/FmjZKoI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yonghong Song , Daniel Borkmann , Sasha Levin Subject: [PATCH 5.15 157/356] selftests/bpf: Fix flaky test btf_map_in_map/lookup_update Date: Wed, 3 Jul 2024 12:38:13 +0200 Message-ID: <20240703102919.041842994@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102913.093882413@linuxfoundation.org> References: <20240703102913.093882413@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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 eb90a6b8850d2..f4d753185001a 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