From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yosry Ahmed Subject: [PATCH bpf-next v3 1/8] btf: Add a new kfunc set which allows to mark a function to be sleepable Date: Sat, 9 Jul 2022 00:04:32 +0000 Message-ID: <20220709000439.243271-2-yosryahmed@google.com> References: <20220709000439.243271-1-yosryahmed@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Q9FL6WxsRkjxyh1yae/tVcFdnxYyUSpDQ2F41fjmbF0=; b=jUf7c6YoaaMSoKC3BzGDRElpUL1MBXHu3HTb8RdVhRCb9f/DnJoiC27UnqjXk14m1j xF7v2kw5Cz/bksp7MeouwdKTi8UkpOmRc/cA63UZIx9TllIDKOdpntym4huATJVKYqn4 jZlNKh/X2D5woBeHtNXySysNlP1TXkXH7jDkoKE4zbNeeBqk0Cl1bG1X9Ym3K+O6922n N9I7HCRQXgbGzPhOFD/mlfV8zr+Sjelb03+XNmOuOE8qi9/6SxPY0ekAoUW5oT1DEZRb 2XaW7xzSPNKyvjceTCKRZX8NwBd7EKXFkqYf486Zt8eZxCmhBFlTJpVm90EduvckS8xT ZJsw== In-Reply-To: <20220709000439.243271-1-yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , Hao Luo , Tejun Heo , Zefan Li Cc: Johannes Weiner , Shuah Khan , Michal Hocko , KP Singh , Benjamin Tissoires , John Fastabend , =?UTF-8?q?Michal=20Koutn=C3=BD?= , Roman Gushchin , David Rientjes , Stanislav Fomichev , Greg Thelen , Shakeel Butt , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bpf-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Yosry Ahmed From: Benjamin Tissoires This allows to declare a kfunc as sleepable and prevents its use in a non sleepable program. Signed-off-by: Benjamin Tissoires Signed-off-by: Yosry Ahmed --- include/linux/btf.h | 2 ++ kernel/bpf/btf.c | 13 +++++++++++-- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/include/linux/btf.h b/include/linux/btf.h index 1bfed7fa04287..6e7517573d9e4 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -18,6 +18,7 @@ enum btf_kfunc_type { BTF_KFUNC_TYPE_RELEASE, BTF_KFUNC_TYPE_RET_NULL, BTF_KFUNC_TYPE_KPTR_ACQUIRE, + BTF_KFUNC_TYPE_SLEEPABLE, BTF_KFUNC_TYPE_MAX, }; @@ -37,6 +38,7 @@ struct btf_kfunc_id_set { struct btf_id_set *release_set; struct btf_id_set *ret_null_set; struct btf_id_set *kptr_acquire_set; + struct btf_id_set *sleepable_set; }; struct btf_id_set *sets[BTF_KFUNC_TYPE_MAX]; }; diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 4f2408a4df08b..2a4b4e50b6fb7 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6172,7 +6172,7 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, struct bpf_verifier_log *log = &env->log; u32 i, nargs, ref_id, ref_obj_id = 0; bool is_kfunc = btf_is_kernel(btf); - bool rel = false, kptr_get = false; + bool rel = false, kptr_get = false, sleepable = false; const char *func_name, *ref_tname; const struct btf_type *t, *ref_t; const struct btf_param *args; @@ -6203,11 +6203,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, } if (is_kfunc) { - /* Only kfunc can be release func */ + /* Only kfunc can be release, kptr acquire, or sleepable func */ rel = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), BTF_KFUNC_TYPE_RELEASE, func_id); kptr_get = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), BTF_KFUNC_TYPE_KPTR_ACQUIRE, func_id); + sleepable = btf_kfunc_id_set_contains(btf, resolve_prog_type(env->prog), + BTF_KFUNC_TYPE_SLEEPABLE, func_id); } /* check that BTF function arguments match actual types that the @@ -6405,6 +6407,13 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, func_name); return -EINVAL; } + + if (sleepable && !env->prog->aux->sleepable) { + bpf_log(log, "kernel function %s is sleepable but the program is not\n", + func_name); + return -EINVAL; + } + /* returns argument register number > 0 in case of reference release kfunc */ return rel ? ref_regno : 0; } -- 2.37.0.rc0.161.g10f37bed90-goog