From patchwork Wed Feb 21 16:25:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Tissoires X-Patchwork-Id: 774699 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 58AB38175F; Wed, 21 Feb 2024 16:25:33 +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=1708532733; cv=none; b=FE3tUlZHFnFFkkTYddBpnSmZpoXdKNp8RB6t+1Bn/AkPmqpfPptW19VfaKpHA0IX9ngHVOp7MIwapL+U5nO8ZoNIQcB6g2qmY7nC4BCZbPWN9CRAdn+ZSmopAV5nBqJDiUsHmq1M/vNSIIyJK2wPmUo9J5PWzn5h00nQxtU95Zc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708532733; c=relaxed/simple; bh=Mms2ysexNAwTlu0ixVh3mQvJfR7XVQbK1/6OpHHyNTk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=QmUlzTYsvtNRf2T2e0GPVJVUWv0CqVf1jPqGYqe1oSEABMFpN6TsnGFUkIoLJ30yg1Lgrc6s2fIHB79n+HWwQ1yVWl/LnxpNm9KherVyhFJ5NydeIsQub+Ih7uGhCETxdUzjXd+m0JivRimMxTN8Rj2mu4rhtBbFWyNNmP/N2M4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BzgkSWxx; 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="BzgkSWxx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1AE3C43399; Wed, 21 Feb 2024 16:25:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708532732; bh=Mms2ysexNAwTlu0ixVh3mQvJfR7XVQbK1/6OpHHyNTk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=BzgkSWxxL1yVpA3AP40UL1iNJt7dhFRqcnWwkIr9MhcBPn87wDNPRJnBCO/sMFhuO B6DsLTtCrQvFeP2jMEm94SzdbUK6wIM9gu1zajvLf2RkqYsFIAgWwWzGrn7BvwABer hhELTbOnO72g9IDIM8LRdYl+ojzy/l4B7Up77tcxToMoKVxAFmZCv3V1Tf8QdRjWF8 Ptc+V8oI0gAnaaWlOL5dr2tuPABx+Sf9U1vYxhRNKCHYmUS8FurcVf1aV2TU8Wbs36 x8BV/kfrthAlqGX0OqI5BIFSZ8ilAk5VqLniB0nW6DKV9meDGnDUZVcZnksdc9r+66 RHUoEN+lQKB/g== From: Benjamin Tissoires Date: Wed, 21 Feb 2024 17:25:18 +0100 Subject: [PATCH RFC bpf-next v3 02/16] bpf/verifier: introduce in_sleepable() helper Precedence: bulk X-Mailing-List: linux-input@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240221-hid-bpf-sleepable-v3-2-1fb378ca6301@kernel.org> References: <20240221-hid-bpf-sleepable-v3-0-1fb378ca6301@kernel.org> In-Reply-To: <20240221-hid-bpf-sleepable-v3-0-1fb378ca6301@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=1708532719; l=3279; i=bentiss@kernel.org; s=20230215; h=from:subject:message-id; bh=Mms2ysexNAwTlu0ixVh3mQvJfR7XVQbK1/6OpHHyNTk=; b=ubFCIPswBRFz/abxhmIcawSwTVPZa0JGnBDjJfGIMEOXWj8HHjtDgLFSPl40V+M9vub1naeZk 2KcPMrYv1mfB+/yBHNtNvw7/HK9cipJeTmWu+mfNNkZwmPmF3NuzTNN 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 --- no changes in v3 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 88e9d2e4c29f..7a4b19bea2ac 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 */ @@ -10164,7 +10169,7 @@ 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; } @@ -10194,7 +10199,7 @@ 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; } @@ -11535,7 +11540,7 @@ 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); } } @@ -12056,7 +12061,7 @@ 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; } @@ -18193,7 +18198,7 @@ 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 @@ -19669,7 +19674,7 @@ 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