From patchwork Fri Mar 22 14:56:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 781966 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 D78AC4D9FC; Fri, 22 Mar 2024 14:56:44 +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=1711119405; cv=none; b=ausBj2XWKSZ+6OLDZCU/Wg2EYbCzBsbIkMp4wP1a4LIm1aaEQbtsnGO/ZS8Xn6VTYlVQ1BOTQp3HD1Wd+GO8dlu+2TeqC/dTDYrPM8epf6b4WSb3B9oe5dtSTvGEjNxm7aV+4TGAxEcVt1cBX4cc9UvbugL84Kui/K96nfY+eHg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711119405; c=relaxed/simple; bh=AQM/MOBZQB8kTZ7hImM8LuYMO1/YVcBCsPzNl5BbNas=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Pfn7jZbW+2+uJe3qVSH8YK/bc0tieYrYNc4Ur3N4Hj9eAEkNgv28d6xuIUQiz/S2BSTSC1cia4wGrFWpz8PpEfWn7ABqju4bUvXN8Oc2wM7JnECJkCewganZV2o/brT5TABd1z141KKVYLhdKNKK/6sLRUASn0TaOD3xFkb1vyw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G1luBfHZ; 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="G1luBfHZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13846C433C7; Fri, 22 Mar 2024 14:56:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711119404; bh=AQM/MOBZQB8kTZ7hImM8LuYMO1/YVcBCsPzNl5BbNas=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=G1luBfHZ9od5gDb8aBwf1ryLkqwrToKwM2BnkM9QUYlvxtolFrHlio0SOPezNsUJ4 2gWcv1c66ZXQdxPS5dyIDH/6l93zbl96jby2j0CTNwtiOdOgLniftn9OELTeR5i03/ QiALqaDQBWmdV29JJmvxEXkJocLo4QgqMi6X4PBIZbgS7oM1TZWkxi3jBNgS6idukW o7b6NS4RnhsM6A8hcqXjQ1f6Snx2HeGzZe7w5Tz60h3+MxvHR41FyQUxRAXZvNsSV5 MXF3VyzKFM1j6V6Lat9aXU22FrICShFSUlZ10JA2xclNuXLM2en3AkeGOxozdvLH/u DRjfNrPUikgfQ== From: Benjamin Tissoires Date: Fri, 22 Mar 2024 15:56:22 +0100 Subject: [PATCH bpf-next v5 2/6] bpf/verifier: add bpf_timer as a kfunc capable type Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240322-hid-bpf-sleepable-v5-2-179c7b59eaaa@kernel.org> References: <20240322-hid-bpf-sleepable-v5-0-179c7b59eaaa@kernel.org> In-Reply-To: <20240322-hid-bpf-sleepable-v5-0-179c7b59eaaa@kernel.org> To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan Cc: Benjamin Tissoires , bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org X-Mailer: b4 0.12.4 X-Developer-Signature: v=1; a=ed25519-sha256; t=1711119393; l=2971; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=AQM/MOBZQB8kTZ7hImM8LuYMO1/YVcBCsPzNl5BbNas=; b=mdIx0Y9m0oTOKphQwoHaWo1J1w10dmVcMk1rrA6QvLWZD/2MdXCiLyOZMk0haK5DczelnwIJ8 7pHY2K0uTf5DzekTHDciOl9I8vMax5owXMXRLKjV4zx4YExqUf2P2W0 X-Developer-Key: i=bentiss@kernel.org; a=ed25519; pk=7D1DyAVh6ajCkuUTudt/chMuXWIJHlv2qCsRkIizvFw= We need to extend the bpf_timer API, but the way forward relies on kfuncs. So make bpf_timer known for kfuncs from the verifier PoV Signed-off-by: Benjamin Tissoires --- changes in v5: - also check for the reg offset changes in v4: - enforce KF_ARG_PTR_TO_TIMER to be of type PTR_TO_MAP_VALUE new in v3 (split from v2 02/10) --- kernel/bpf/verifier.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 63749ad5ac6b..24a604e26ec7 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -10826,6 +10826,7 @@ enum { KF_ARG_LIST_NODE_ID, KF_ARG_RB_ROOT_ID, KF_ARG_RB_NODE_ID, + KF_ARG_TIMER_ID, }; BTF_ID_LIST(kf_arg_btf_ids) @@ -10834,6 +10835,7 @@ BTF_ID(struct, bpf_list_head) BTF_ID(struct, bpf_list_node) BTF_ID(struct, bpf_rb_root) BTF_ID(struct, bpf_rb_node) +BTF_ID(struct, bpf_timer_kern) static bool __is_kfunc_ptr_arg_type(const struct btf *btf, const struct btf_param *arg, int type) @@ -10877,6 +10879,12 @@ static bool is_kfunc_arg_rbtree_node(const struct btf *btf, const struct btf_par return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_RB_NODE_ID); } +static bool is_kfunc_arg_timer(const struct btf *btf, const struct btf_param *arg) +{ + bool ret = __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_TIMER_ID); + return ret; +} + static bool is_kfunc_arg_callback(struct bpf_verifier_env *env, const struct btf *btf, const struct btf_param *arg) { @@ -10946,6 +10954,7 @@ enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_NULL, KF_ARG_PTR_TO_CONST_STR, KF_ARG_PTR_TO_MAP, + KF_ARG_PTR_TO_TIMER, }; enum special_kfunc_type { @@ -11102,6 +11111,9 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, if (is_kfunc_arg_map(meta->btf, &args[argno])) return KF_ARG_PTR_TO_MAP; + if (is_kfunc_arg_timer(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_TIMER; + if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { if (!btf_type_is_struct(ref_t)) { verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", @@ -11735,6 +11747,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_CALLBACK: case KF_ARG_PTR_TO_REFCOUNTED_KPTR: case KF_ARG_PTR_TO_CONST_STR: + case KF_ARG_PTR_TO_TIMER: /* Trusted by default */ break; default: @@ -12021,6 +12034,16 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ if (ret) return ret; break; + case KF_ARG_PTR_TO_TIMER: + if (reg->type != PTR_TO_MAP_VALUE) { + verbose(env, "arg#%d doesn't point to a map value\n", i); + return -EINVAL; + } + if (reg->off) { + verbose(env, "arg#%d offset can not be greater than 0\n", i); + return -EINVAL; + } + break; } }