From patchwork Thu Nov 14 08:43:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Song Liu X-Patchwork-Id: 13874747 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 9B1E81F7570; Thu, 14 Nov 2024 08:44:42 +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=1731573882; cv=none; b=m9kEul/kFrvozOfUDNGgQIzeWBmAWYpkXDWTAWvGSxMtyqniEqxUl57ZrrkJC1N+xUjfsPi+6O6DUKHP2UrfJUL3KNBucSLnc30G5y1g7tQ9JanoXYOKlNpy3abUFgUh0LITUGY+yutHi3chptMYcziqW7Iznsh+NEAkhzS5iko= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731573882; c=relaxed/simple; bh=vqv7nsoFBXs3JlMYaca6LaUZbsVJm6kN4tNuO7C36Xg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pTMOaD4uefmCSI57zT5Err2I/O8dea+twEpfAGSFbx91KOnnfOCRKNn/2ioJ//y9EIwph18BMR/8lYxcdJWU4y2YBLTw3oNFon0a0aOehuWLPGEztm8zaCsd1EWslR+Yj4bWcFMBD8kwxcNJ6ygxkcgb6llwwmv0s8qx10AYqlU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OMiAW2jZ; 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="OMiAW2jZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E191C4CED6; Thu, 14 Nov 2024 08:44:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731573882; bh=vqv7nsoFBXs3JlMYaca6LaUZbsVJm6kN4tNuO7C36Xg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OMiAW2jZ6sNdS7VmecsJKbiYAglOcU6SWUX5b+8sGA09GyeHdwreENhpB8dpBe5QC zbhoOH8VcqVbNqqU1PLyMWFMtnDCqiDtG4yTCuBJSshEpg52aunoBZfoTvY4No7C+O ifLK/nKc+GH4TPg/LWoIEsZdfTLm3ereJ6hlY9uS4UCWOPYIeWVHvdDamEnVLfnxi3 h1j6Hg/0aWEAktkB8ELaT2SiOXs4X9WCEDxO7Ixwg72p4fvVvlY64gTl/+Ex3w5v3U fj2nodsaB9FHgg+qNgGmDxs6vBipu1ZNzR1t6drCLbrnxEb0qBSJrFgbZ9270ToE0V /o8Z6455xWctQ== From: Song Liu To: bpf@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org Cc: kernel-team@meta.com, andrii@kernel.org, eddyz87@gmail.com, ast@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, kpsingh@kernel.org, mattbobrowski@google.com, amir73il@gmail.com, repnop@google.com, jlayton@kernel.org, josef@toxicpanda.com, mic@digikod.net, gnoack@google.com, Song Liu Subject: [RFC/PATCH v2 bpf-next fanotify 5/7] bpf: Allow bpf map hold reference on dentry Date: Thu, 14 Nov 2024 00:43:43 -0800 Message-ID: <20241114084345.1564165-6-song@kernel.org> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20241114084345.1564165-1-song@kernel.org> References: <20241114084345.1564165-1-song@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 To save a dentry in a bpf map, proper logic is needed to free the dentry properly on map termination. Signed-off-by: Song Liu --- kernel/bpf/helpers.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 1a43d06eab28..5e3bf2c188a8 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -3004,6 +3004,12 @@ __bpf_kfunc int bpf_copy_from_user_str(void *dst, u32 dst__sz, const void __user return ret + 1; } +__bpf_kfunc void bpf_dentry_release_dtor(struct dentry *dentry) +{ + dput(dentry); +} +CFI_NOSEAL(bpf_dentry_release_dtor); + __bpf_kfunc_end_defs(); BTF_KFUNCS_START(generic_btf_ids) @@ -3046,6 +3052,8 @@ static const struct btf_kfunc_id_set generic_kfunc_set = { BTF_ID_LIST(generic_dtor_ids) BTF_ID(struct, task_struct) BTF_ID(func, bpf_task_release_dtor) +BTF_ID(struct, dentry) +BTF_ID(func, bpf_dentry_release_dtor) #ifdef CONFIG_CGROUPS BTF_ID(struct, cgroup) BTF_ID(func, bpf_cgroup_release_dtor) @@ -3105,11 +3113,15 @@ static int __init kfunc_init(void) .btf_id = generic_dtor_ids[0], .kfunc_btf_id = generic_dtor_ids[1] }, -#ifdef CONFIG_CGROUPS { .btf_id = generic_dtor_ids[2], .kfunc_btf_id = generic_dtor_ids[3] }, +#ifdef CONFIG_CGROUPS + { + .btf_id = generic_dtor_ids[4], + .kfunc_btf_id = generic_dtor_ids[5] + }, #endif };