From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-176.mta1.migadu.com (out-176.mta1.migadu.com [95.215.58.176]) (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 E44252BB1D for ; Wed, 5 Nov 2025 02:14:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762308903; cv=none; b=O3zpMBMA556jmvXqis14ALmLZJJsizBD+tfdq0ukWn84wmk4aoM5nHxoM9DWyJgXV0Q+4dG6R2ASbejmiN/Hk/gNlZY+BJ745a6Rq0VhdjqSNdPt3Skr/l7WX+2zVLQ6oF0/kZkbi/OSy794Wvipj7DccjcMWbd/NaagYlcLL84= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762308903; c=relaxed/simple; bh=RXDWshm6Ex7MNL5cVbopmcYhAaNsDnmZWnc7+Ob5r9g=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=PaUxLq9UOLRq2TySsCJCIuefVOBU9MTvgnpgU5IG6GZu2mYi1+zdzxnZA6hMwp63V1a/R/1TV4m6u8SBG2qkWczKa8xr2XaLmusIHe+nNt5GFsBbDpjbNLAoqdVT8kKu4+6yxckQuCGXJ0jkoTC/PhWQHVPGmtkNJKOXIi/lFZ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=K/MnzXtg; arc=none smtp.client-ip=95.215.58.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="K/MnzXtg" Message-ID: <697dc64e-8707-44ba-8cda-ba48747f2973@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1762308897; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0v5bIKUko3vv2CrNyaHGGFDSMjC9KVNlTvQ9aEKd2Vg=; b=K/MnzXtgAAmStJjRw/4nBcq0PtRg7On7jB3oQbBRj4pcHZnuhPiYyEqwYErAVwbsgBgHF8 JiETZCObVdY4/m9HFhGwFQjGfxtzWRiiSX8crjVJ9AOznoklNZZ8MHRAYzmHukg6o3cx7+ ullmW0uAFJaFFG+/rf+s5dUUS3kFr9Q= Date: Wed, 5 Nov 2025 10:14:40 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next v4 4/4] selftests/bpf: Add tests to verify freeing the special fields when update hash and local storage maps Content-Language: en-US To: Yonghong Song , bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, memxor@gmail.com, ameryhung@gmail.com, linux-kernel@vger.kernel.org, kernel-patches-bot@fb.com References: <20251030152451.62778-1-leon.hwang@linux.dev> <20251030152451.62778-5-leon.hwang@linux.dev> <02b8c4ba-eb24-41e2-813c-98b83561ef9d@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Leon Hwang In-Reply-To: <02b8c4ba-eb24-41e2-813c-98b83561ef9d@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 5/11/25 01:30, Yonghong Song wrote: > > > On 10/30/25 8:24 AM, Leon Hwang wrote: >> Add tests to verify that updating hash and local storage maps decrements >> refcount when BPF_KPTR_REF objects are involved. >> >> The tests perform the following steps: >> >> 1. Call update_elem() to insert an initial value. >> 2. Use bpf_refcount_acquire() to increment the refcount. >> 3. Store the node pointer in the map value. >> 4. Add the node to a linked list. >> 5. Probe-read the refcount and verify it is *2*. >> 6. Call update_elem() again to trigger refcount decrement. >> 7. Probe-read the refcount and verify it is *1*. >> >> Signed-off-by: Leon Hwang > > I applied this patch only (i.e., not including patches 1/2/3) to master > branch and do bpf selftest and all tests succeeded. > > [root@arch-fb-vm1 bpf]# ./test_progs -t refcounted_kptr > #294/1   refcounted_kptr/insert_read_both: remove from tree + list:OK > ... > #294/18  refcounted_kptr/pcpu_hash_refcount_leak:OK > #294/19  refcounted_kptr/check_pcpu_hash_refcount:OK > #294/20  refcounted_kptr/hash_lock_refcount_leak:OK > #294/21  refcounted_kptr/check_hash_lock_refcount:OK > #294/22  refcounted_kptr/rbtree_sleepable_rcu:OK > #294/23  refcounted_kptr/rbtree_sleepable_rcu_no_explicit_rcu_lock:OK > #294/24  refcounted_kptr/cgroup_storage_lock_refcount_leak:OK > #294/25  refcounted_kptr/check_cgroup_storage_lock_refcount:OK > ... > > Did I miss anything? > Oops. You should run: ./test_progs -t kptr_refcount The results are as follows: test_percpu_hash_refcount_leak:PASS:libbpf_num_possible_cpus 0 nsec test_percpu_hash_refcount_leak:PASS:calloc values 0 nsec test_percpu_hash_refcount_leak:PASS:refcounted_kptr__open_and_load 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem init 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:PASS:refcount 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem dec refcount 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:FAIL:refcount unexpected refcount: actual 2 != expected 1 #158/1 kptr_refcount_leak/percpu_hash_refcount_leak:FAIL test_hash_lock_refcount_leak:PASS:refcounted_kptr__open_and_load 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem init 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:PASS:refcount 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem dec refcount 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:FAIL:refcount unexpected refcount: actual 2 != expected 1 #158/2 kptr_refcount_leak/hash_lock_refcount_leak:FAIL test_cgroup_storage_lock_refcount_leak:PASS:setup_cgroup_environment 0 nsec test_cgroup_storage_lock_refcount_leak:PASS:get_root_cgroup 0 nsec test_cgroup_storage_lock_refcount_leak:PASS:refcounted_kptr__open_and_load 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem init 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:PASS:refcount 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem dec refcount 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:FAIL:refcount unexpected refcount: actual 2 != expected 1 #158/3 kptr_refcount_leak/cgroup_storage_lock_refcount_leak:FAIL #158 kptr_refcount_leak:FAIL All error logs: test_percpu_hash_refcount_leak:PASS:libbpf_num_possible_cpus 0 nsec test_percpu_hash_refcount_leak:PASS:calloc values 0 nsec test_percpu_hash_refcount_leak:PASS:refcounted_kptr__open_and_load 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem init 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:PASS:refcount 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem dec refcount 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:FAIL:refcount unexpected refcount: actual 2 != expected 1 #158/1 kptr_refcount_leak/percpu_hash_refcount_leak:FAIL test_hash_lock_refcount_leak:PASS:refcounted_kptr__open_and_load 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem init 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:PASS:refcount 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem dec refcount 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:FAIL:refcount unexpected refcount: actual 2 != expected 1 #158/2 kptr_refcount_leak/hash_lock_refcount_leak:FAIL test_cgroup_storage_lock_refcount_leak:PASS:setup_cgroup_environment 0 nsec test_cgroup_storage_lock_refcount_leak:PASS:get_root_cgroup 0 nsec test_cgroup_storage_lock_refcount_leak:PASS:refcounted_kptr__open_and_load 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem init 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:PASS:refcount 0 nsec test_refcnt_leak:PASS:bpf_map__update_elem dec refcount 0 nsec test_refcnt_leak:PASS:bpf_prog_test_run_opts 0 nsec test_refcnt_leak:FAIL:refcount unexpected refcount: actual 2 != expected 1 #158/3 kptr_refcount_leak/cgroup_storage_lock_refcount_leak:FAIL #158 kptr_refcount_leak:FAIL Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED All three tests failed because the refcount remained 2 instead of decreasing to 1 after the second update_elem() call. The CI result [1] also demonstrates this issue. Sorry for the misleading test name earlier. Links: [1] https://github.com/kernel-patches/bpf/pull/10203 Thanks, Leon [...]