From patchwork Fri Feb 14 16:45:16 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Amery Hung X-Patchwork-Id: 13975256 X-Patchwork-Delegate: bpf@iogearbox.net Received: from mail-pl1-f169.google.com (mail-pl1-f169.google.com [209.85.214.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7BBDB264FA9 for ; Fri, 14 Feb 2025 16:45:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.169 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739551533; cv=none; b=kdgSLBadNSIWPyzglAImQXz0vgdT/5d8X60/Q+2NCIwepvEAsQpgWtbDAnNokEKAXohQLo6L9MnZbS4IUAFE6/iqyZrT8mDZIDlxpJS8+8k9i6YQThezfvOVh0bxwF+eLPpxlqZHyApSDAE+bDFcM2L4g4nSpq8/hvzsJyf/xKI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739551533; c=relaxed/simple; bh=F1LqcDnRgUym3jCFdQfnlgIgsLietRoBiVkYd8ua0Wk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oA5hJ5zLCTiTk7808Qbxp5zGssvxXFlgbcQIZC//4yWY3jWwn4dWqrHkGhLST9Jjpv8By2hZnARZ08ufRfi3Ifb6W35+zfofip22fptQawhrTUccdAu0Gnu0oDZdL2Vc/IhNGB82zN3zGVyNs3v2RnjTgctctdwH/cPy/KL/1uk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=XJ1/1Ekx; arc=none smtp.client-ip=209.85.214.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XJ1/1Ekx" Received: by mail-pl1-f169.google.com with SMTP id d9443c01a7336-21f6d2642faso61428365ad.1 for ; Fri, 14 Feb 2025 08:45:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1739551530; x=1740156330; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=2VNl9RoDF4qcMk8lDzfqgVHsgyUHTU4tSw9Z2ZI42WM=; b=XJ1/1EkxLix55Ss6HA0qOu/01dQYuR8wY8ooQuTVtf4+aRvri+WqkmxeoMs2NgULkg /ur7hAQguAkXERc4vOmzpApSeQvrhquTW/WF+YDcad+JZBDU2IMLn+1GKwAYk+LfAeMS PyE/s5W20UxPtN7fjhBQXCxm4uTHt2vsHVDMwiKUHd7EpXWS8sYZf6et11+Af915U+M2 SiMquxkQpzxIM73/skaLQx1RbkFhlggnuoFWBQtQkxvDxZItO0YZOrAP9ySLQrOXxdAK 67cIqriwv3KBHNhqhtm8YWlX6TLFOXNFWV7o+ryrKjk7kMj5j0LZSJB2xGvI5C5V1HlC kO/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1739551530; x=1740156330; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2VNl9RoDF4qcMk8lDzfqgVHsgyUHTU4tSw9Z2ZI42WM=; b=VlliSAh/FYSInn10zKaYGGXyXXQLOrgJGJdKb4thuDq7f5JG4nlu6USEO7J2nmear6 eB5WCYWJ0AXPXyD4zTfVmPMBSmLNB6ozMnsPxgYceqdWFbOoVpl/Dpt/6MKwTy/PyTIX P1g6aycB3IvAFgKHg7+Up3T78H1sOrMWszl7ObwzT+IDEHPPiVAasAEEgaQWANwkCO0E djPM5vNEEgXKVl6DJuWZ5QlZGs6whmcOQWS8wAdC2M7WeJPQBtWY5f0u/NPwFeBIZHbN CsuRV3VTiMWn07rcqr45wNlSNbhYXNGvAgvFUQbieThgmTnq7fFuw2Av4kCncoP4McHo Ci4w== X-Gm-Message-State: AOJu0YxuEgW2PkGH1LmDs77BD7bzt8Mngp8SQaiVrSOxBdfNpDR1Yfi0 4wX1IA2WyRPVOyLH1a6tOoBRG/DAIiFYc7e3HEfSx/qoQH1OEM4w4d32sg== X-Gm-Gg: ASbGnct2mxyxX+fqUSg0/eXLm0kIBlWu/43EtBS8nNCij458Hoew9KKpD3syisARG1g g3MsWxoTwg52nnYAilfijA0Fy5lTUcP2K2Mz92CeN1lSjFFJuZPmQhvudu7vWpwBYjdQOfhbWlx CVptpIAv3qSa/WrZdQz1YbetDQLVF1lIk380X1Hu21ECkuiUsmG5tWPPLU+GiJ4/RInWKk2d/hi 1kYvtfa1EeLROvmfWZUEL2y5XCtY4dYx4lqNeEOJ6rgcYkw04eefxJWOVDHNNkUHKhFQnd3o96y p42GiF0Lsgmx8NV4ptTL8POpkKlELf/OLp6wcaVCXRefEQSnLIXcfr4zQl9WVETeJg== X-Google-Smtp-Source: AGHT+IHwEGCTLmHOB8cPiU3P95bHyn26BDUXZU68QjyVWNQAUIuZjvgBv6fREq2rhDG/MIj/HvMKQw== X-Received: by 2002:a05:6a21:6e47:b0:1ee:6fec:3e5c with SMTP id adf61e73a8af0-1ee8caab660mr304502637.7.1739551530378; Fri, 14 Feb 2025 08:45:30 -0800 (PST) Received: from localhost.localdomain (c-76-146-13-146.hsd1.wa.comcast.net. [76.146.13.146]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-adbf21517eesm2223346a12.13.2025.02.14.08.45.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Feb 2025 08:45:30 -0800 (PST) From: Amery Hung To: bpf@vger.kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, alexei.starovoitov@gmail.com, martin.lau@kernel.org, eddyz87@gmail.com, ameryhung@gmail.com, kernel-team@meta.com Subject: [PATCH bpf-next v1 1/5] bpf: Make every prog keep a copy of ctx_arg_info Date: Fri, 14 Feb 2025 08:45:16 -0800 Message-ID: <20250214164520.1001211-2-ameryhung@gmail.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250214164520.1001211-1-ameryhung@gmail.com> References: <20250214164520.1001211-1-ameryhung@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net Currently, ctx_arg_info is read-only in the view of the verifier since it is shared among programs of the same attach type. Make each program have their own copy of ctx_arg_info so that we can use it to store program specific information. In the next patch where we support acquiring a referenced kptr through a struct_ops argument tagged with "__ref", ctx_arg_info->ref_obj_id will be used to store the unique reference object id of the argument. This avoids creating a requirement in the verifier that "__ref" tagged arguments must be the first set of references acquired [0]. [0] https://lore.kernel.org/bpf/20241220195619.2022866-2-amery.hung@gmail.com/ Signed-off-by: Amery Hung Acked-by: Eduard Zingerman Acked-by: Martin KaFai Lau --- include/linux/bpf.h | 7 +++++-- kernel/bpf/bpf_iter.c | 13 ++++++------- kernel/bpf/syscall.c | 2 ++ kernel/bpf/verifier.c | 25 +++++++++++++++---------- 4 files changed, 28 insertions(+), 19 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f3f50e29d639..f4df39e8c735 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1507,7 +1507,7 @@ struct bpf_prog_aux { u32 max_rdonly_access; u32 max_rdwr_access; struct btf *attach_btf; - const struct bpf_ctx_arg_aux *ctx_arg_info; + struct bpf_ctx_arg_aux *ctx_arg_info; void __percpu *priv_stack_ptr; struct mutex dst_mutex; /* protects dst_* pointers below, *after* prog becomes visible */ struct bpf_prog *dst_prog; @@ -1945,6 +1945,9 @@ static inline void bpf_struct_ops_desc_release(struct bpf_struct_ops_desc *st_op #endif +int bpf_prog_ctx_arg_info_init(struct bpf_prog *prog, + const struct bpf_ctx_arg_aux *info, u32 cnt); + #if defined(CONFIG_CGROUP_BPF) && defined(CONFIG_BPF_LSM) int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog, int cgroup_atype); @@ -2546,7 +2549,7 @@ struct bpf_iter__bpf_map_elem { int bpf_iter_reg_target(const struct bpf_iter_reg *reg_info); void bpf_iter_unreg_target(const struct bpf_iter_reg *reg_info); -bool bpf_iter_prog_supported(struct bpf_prog *prog); +int bpf_iter_prog_supported(struct bpf_prog *prog); const struct bpf_func_proto * bpf_iter_get_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog); int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr, struct bpf_prog *prog); diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c index 106735145948..380e9a7cac75 100644 --- a/kernel/bpf/bpf_iter.c +++ b/kernel/bpf/bpf_iter.c @@ -335,7 +335,7 @@ static void cache_btf_id(struct bpf_iter_target_info *tinfo, tinfo->btf_id = prog->aux->attach_btf_id; } -bool bpf_iter_prog_supported(struct bpf_prog *prog) +int bpf_iter_prog_supported(struct bpf_prog *prog) { const char *attach_fname = prog->aux->attach_func_name; struct bpf_iter_target_info *tinfo = NULL, *iter; @@ -344,7 +344,7 @@ bool bpf_iter_prog_supported(struct bpf_prog *prog) int prefix_len = strlen(prefix); if (strncmp(attach_fname, prefix, prefix_len)) - return false; + return -EINVAL; mutex_lock(&targets_mutex); list_for_each_entry(iter, &targets, list) { @@ -360,12 +360,11 @@ bool bpf_iter_prog_supported(struct bpf_prog *prog) } mutex_unlock(&targets_mutex); - if (tinfo) { - prog->aux->ctx_arg_info_size = tinfo->reg_info->ctx_arg_info_size; - prog->aux->ctx_arg_info = tinfo->reg_info->ctx_arg_info; - } + if (!tinfo) + return -EINVAL; - return tinfo != NULL; + return bpf_prog_ctx_arg_info_init(prog, tinfo->reg_info->ctx_arg_info, + tinfo->reg_info->ctx_arg_info_size); } const struct bpf_func_proto * diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index c420edbfb7c8..598f19e6ebd2 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -2315,6 +2315,8 @@ static void __bpf_prog_put_noref(struct bpf_prog *prog, bool deferred) kfree(prog->aux->kfunc_tab); if (prog->aux->attach_btf) btf_put(prog->aux->attach_btf); + if (prog->aux->ctx_arg_info) + kfree(prog->aux->ctx_arg_info); if (deferred) { if (prog->sleepable) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9971c03adfd5..a41ba019780f 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -22377,6 +22377,18 @@ static void print_verification_stats(struct bpf_verifier_env *env) env->peak_states, env->longest_mark_read_walk); } +int bpf_prog_ctx_arg_info_init(struct bpf_prog *prog, + const struct bpf_ctx_arg_aux *info, u32 cnt) +{ + prog->aux->ctx_arg_info = kcalloc(cnt, sizeof(*info), GFP_KERNEL); + if (!prog->aux->ctx_arg_info) + return -ENOMEM; + + memcpy(prog->aux->ctx_arg_info, info, sizeof(*info) * cnt); + prog->aux->ctx_arg_info_size = cnt; + return 0; +} + static int check_struct_ops_btf_id(struct bpf_verifier_env *env) { const struct btf_type *t, *func_proto; @@ -22457,17 +22469,12 @@ static int check_struct_ops_btf_id(struct bpf_verifier_env *env) return -EACCES; } - /* btf_ctx_access() used this to provide argument type info */ - prog->aux->ctx_arg_info = - st_ops_desc->arg_info[member_idx].info; - prog->aux->ctx_arg_info_size = - st_ops_desc->arg_info[member_idx].cnt; - prog->aux->attach_func_proto = func_proto; prog->aux->attach_func_name = mname; env->ops = st_ops->verifier_ops; - return 0; + return bpf_prog_ctx_arg_info_init(prog, st_ops_desc->arg_info[member_idx].info, + st_ops_desc->arg_info[member_idx].cnt); } #define SECURITY_PREFIX "security_" @@ -22917,9 +22924,7 @@ static int check_attach_btf_id(struct bpf_verifier_env *env) prog->aux->attach_btf_trace = true; return 0; } else if (prog->expected_attach_type == BPF_TRACE_ITER) { - if (!bpf_iter_prog_supported(prog)) - return -EINVAL; - return 0; + return bpf_iter_prog_supported(prog); } if (prog->type == BPF_PROG_TYPE_LSM) {