From patchwork Wed Feb 14 17:18:30 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 772765 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 005358405C; Wed, 14 Feb 2024 17:19:04 +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=1707931145; cv=none; b=dSRUj3zt1xxvCCiKewZ6coO/IaLts2iB7nzKY4VEcZCnIesYWaFF5G781+g0Fyb3JknyprhVHpRAfoROSQtDYZ/S7yS8Snp6/4pBH0D8ccd1o4tnmaW2d54d3X8LFFIGv2kKJDFUPAPqWGy+C/c6kedXaeqwcbvLaVDUraL665Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707931145; c=relaxed/simple; bh=ZuS+7v5Dfl5IafHw0MgYCYKa9AW++myTFw0GViRRpYM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=AO2OJJ+ZogPCs4yRP6c+vyzwdUcu6l1w4wKITYa9+GqlF1sbiw8HZx12wP6mdAiMAkXsOe6/Z07QZipNTFNuJw8eLTmFpC6xiLoYl9EMlrMmyPtoe7denNng0pVNIG2Ws8YV2TxdBSymiLNSPvYErUAG6BZHT5ocr+MjmXAXXKE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QC12kdg4; 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="QC12kdg4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74061C43601; Wed, 14 Feb 2024 17:19:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707931144; bh=ZuS+7v5Dfl5IafHw0MgYCYKa9AW++myTFw0GViRRpYM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=QC12kdg4Aib5AcPh49e2/LK8jJLkgUAruYKDOwNQaopd+pga/EDbxFgh3ojIhfczu HXg6GquX+hye+mvEnKHqn1lMPHgJUrbdk7h3TSO3+RVznexX/Wwj7SuYd2FKyGeFLM sRgVVFHhveH5Tr2z1J//ugH1iSil5213Fyh16blTxF0YnL1yjNTganARWQjG2HPPmq xklI4xCwY80G7dw1cjP2FWdDRIPKtbiZ0zmRFhtQrUJgNcCKbn8H95/F7TDXil2YDf p98Qxk3Oe4tF1Mju5PRRQr192/xJ6xEO0M+LjhkLpxJ9uNcYEGx93PaJtXQvMq1Veq SXQqZxyh5u7+A== From: Benjamin Tissoires Date: Wed, 14 Feb 2024 18:18:30 +0100 Subject: [PATCH RFC bpf-next v2 01/10] bpf/verifier: introduce in_sleepable() helper Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240214-hid-bpf-sleepable-v2-1-5756b054724d@kernel.org> References: <20240214-hid-bpf-sleepable-v2-0-5756b054724d@kernel.org> In-Reply-To: <20240214-hid-bpf-sleepable-v2-0-5756b054724d@kernel.org> To: Alexei Starovoitov , Daniel Borkmann , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Jiri Kosina , Benjamin Tissoires , Jonathan Corbet , Shuah Khan Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, Benjamin Tissoires X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=ed25519-sha256; t=1707931135; l=3259; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=ZuS+7v5Dfl5IafHw0MgYCYKa9AW++myTFw0GViRRpYM=; b=37Ow3DoMrOPm0yj/WYnsJcZ0R+oyH5zub8WYF+eRcYwPZ/8PMJA2pgnCX/cG5KdlJnzEDvfZi cd3R+/0JvARDrWnnyoK+ZqKtuRsCmOHN5BmrAb/Ol6jjgL5wMgD7s2q X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= No code change, but it'll allow to have only one place to change everything when we add in_sleepable in cur_state. Signed-off-by: Benjamin Tissoires --- changes in v2 (compared to the one attaches to v1 0/9): - dropped the cur_state flag, so it can be put first --- kernel/bpf/verifier.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 64fa188d00ad..7831adba9abf 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5255,6 +5255,11 @@ static int map_kptr_match_type(struct bpf_verifier_env *env, return -EINVAL; } +static bool in_sleepable(struct bpf_verifier_env *env) +{ + return env->prog->aux->sleepable; +} + /* The non-sleepable programs and sleepable programs with explicit bpf_rcu_read_lock() * can dereference RCU protected pointers and result is PTR_TRUSTED. */ @@ -5262,7 +5267,7 @@ static bool in_rcu_cs(struct bpf_verifier_env *env) { return env->cur_state->active_rcu_lock || env->cur_state->active_lock.ptr || - !env->prog->aux->sleepable; + !in_sleepable(env); } /* Once GCC supports btf_type_tag the following mechanism will be replaced with tag check */ @@ -10149,7 +10154,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn return -EINVAL; } - if (!env->prog->aux->sleepable && fn->might_sleep) { + if (!in_sleepable(env) && fn->might_sleep) { verbose(env, "helper call might sleep in a non-sleepable prog\n"); return -EINVAL; } @@ -10179,7 +10184,7 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn return -EINVAL; } - if (env->prog->aux->sleepable && is_storage_get_function(func_id)) + if (in_sleepable(env) && is_storage_get_function(func_id)) env->insn_aux_data[insn_idx].storage_get_func_atomic = true; } @@ -11538,7 +11543,7 @@ static bool check_css_task_iter_allowlist(struct bpf_verifier_env *env) return true; fallthrough; default: - return env->prog->aux->sleepable; + return in_sleepable(env); } } @@ -12059,7 +12064,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, } sleepable = is_kfunc_sleepable(&meta); - if (sleepable && !env->prog->aux->sleepable) { + if (sleepable && !in_sleepable(env)) { verbose(env, "program must be sleepable to call sleepable kfunc %s\n", func_name); return -EACCES; } @@ -18197,7 +18202,7 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env) return -E2BIG; } - if (env->prog->aux->sleepable) + if (in_sleepable(env)) atomic64_inc(&map->sleepable_refcnt); /* hold the map. If the program is rejected by verifier, * the map will be released by release_maps() or it @@ -19673,7 +19678,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) } if (is_storage_get_function(insn->imm)) { - if (!env->prog->aux->sleepable || + if (!in_sleepable(env) || env->insn_aux_data[i + delta].storage_get_func_atomic) insn_buf[0] = BPF_MOV64_IMM(BPF_REG_5, (__force __s32)GFP_ATOMIC); else