From patchwork Wed Nov 1 20:45:14 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kui-Feng Lee X-Patchwork-Id: 13443052 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 B1789182AE for ; Wed, 1 Nov 2023 20:45:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="cGXydJOA" Received: from mail-yb1-xb2a.google.com (mail-yb1-xb2a.google.com [IPv6:2607:f8b0:4864:20::b2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCE9B111 for ; Wed, 1 Nov 2023 13:45:34 -0700 (PDT) Received: by mail-yb1-xb2a.google.com with SMTP id 3f1490d57ef6-da0344eb3fdso192878276.3 for ; Wed, 01 Nov 2023 13:45:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1698871533; x=1699476333; 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=lcF9QhsGznHlT8/5sJj7dpWmuOGGzYn8hgOUQia2MvM=; b=cGXydJOA6VmekErDzHqoBXjw+hLSM9MBs104teilYHIXY4sTQTHdMO0iinh/STlbvk jHx4Xoig8m3ch8yELPN9ViXXR+7dmm3j/Fgl976dUVkAhL9BuA2MpbNSiwhQLi1uBnCr guQE+yR9ZLZRqfNIPhBnFNowgHeCnTrJPRh5Gb36902YQpLd2gHAJRYw8Bgb/6IHGjay JslNdfzkSO2FMn8X8mNVHFONnKn6FvVhxJ8u/CQ8mOSKtC07SWO6KGT+tXfiQC3nseFF uKp1dZcywSZyCqBT0fd+oQKqhYwJKqyx5VKg43VFSjKNP5lYjL8SnJbIjEmmWm7emURR eccg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698871533; x=1699476333; 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=lcF9QhsGznHlT8/5sJj7dpWmuOGGzYn8hgOUQia2MvM=; b=Pzv9RKrXKi4J9HafDyyarD/i7mTe2BGFUmM6NTv7Uz3nGu5RM7hj8rxVvsTNuh9txC I1wKFSwxBpTdLr2DhXv5XaSN4rJMVkMH1/aj0oGxXNZW944XgCs2K/xh3FlHDSLL0QLA tCKcYkk6npOITGhdaErje84iULfECfsJMGrR9tgSevwES31MaKrx5v8fiMLZeqHgePAz Yw82JacRAH8vMkGdQpVue73r4z4ZBtub/BtTmsBRiXDhczHajUnIKDmRI37pi4r+9ZXe QzaEXkp8LN/kOlPFbkQEcCsTwDJs2OnwbZqEOZXxtgD4ZnzctQpmvtLllmXAEw2+DvTU K8ng== X-Gm-Message-State: AOJu0Yy0EkZ1m42rjCkZkBtvvF6IeUTVj0SkSdp4JmuRD6SzvVsF64bo dziQBuqKSGqUEh5XNNqCGzFaMQt3yT0= X-Google-Smtp-Source: AGHT+IHA6oUgNlOz7ejEimBHigF7fgDB/ahoeicCJ49VL5b8TodO3U1ACQA5lF9jm1GDt4DQYFBdIA== X-Received: by 2002:a5b:49:0:b0:da0:c7e7:cf80 with SMTP id e9-20020a5b0049000000b00da0c7e7cf80mr14912769ybp.57.1698871533446; Wed, 01 Nov 2023 13:45:33 -0700 (PDT) Received: from kickker.attlocal.net ([2600:1700:6cf8:1240:eea0:6f66:c57d:6b7c]) by smtp.gmail.com with ESMTPSA id o83-20020a25d756000000b00da086d6921fsm342386ybg.50.2023.11.01.13.45.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Nov 2023 13:45:33 -0700 (PDT) From: thinker.li@gmail.com To: bpf@vger.kernel.org, ast@kernel.org, martin.lau@linux.dev, song@kernel.org, kernel-team@meta.com, andrii@kernel.org, drosen@google.com Cc: sinquersw@gmail.com, kuifeng@meta.com, Kui-Feng Lee Subject: [PATCH bpf-next v9 07/12] bpf: validate value_type Date: Wed, 1 Nov 2023 13:45:14 -0700 Message-Id: <20231101204519.677870-8-thinker.li@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231101204519.677870-1-thinker.li@gmail.com> References: <20231101204519.677870-1-thinker.li@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 From: Kui-Feng Lee A value_type should consist of three components: refcnt, state, and data. refcnt and state has been move to struct bpf_struct_ops_common_value to make it easier to check the value type. Signed-off-by: Kui-Feng Lee --- include/linux/bpf.h | 12 +++++ kernel/bpf/bpf_struct_ops.c | 93 ++++++++++++++++++++++++------------- 2 files changed, 72 insertions(+), 33 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c287f42b2e48..2a9bc482d85e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -3231,4 +3231,16 @@ static inline bool bpf_is_subprog(const struct bpf_prog *prog) return prog->aux->func_idx != 0; } +enum bpf_struct_ops_state { + BPF_STRUCT_OPS_STATE_INIT, + BPF_STRUCT_OPS_STATE_INUSE, + BPF_STRUCT_OPS_STATE_TOBEFREE, + BPF_STRUCT_OPS_STATE_READY, +}; + +struct bpf_struct_ops_common_value { + refcount_t refcnt; + enum bpf_struct_ops_state state; +}; + #endif /* _LINUX_BPF_H */ diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index be9bee970c9c..bc855b2ef97e 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -13,19 +13,8 @@ #include #include -enum bpf_struct_ops_state { - BPF_STRUCT_OPS_STATE_INIT, - BPF_STRUCT_OPS_STATE_INUSE, - BPF_STRUCT_OPS_STATE_TOBEFREE, - BPF_STRUCT_OPS_STATE_READY, -}; - -#define BPF_STRUCT_OPS_COMMON_VALUE \ - refcount_t refcnt; \ - enum bpf_struct_ops_state state - struct bpf_struct_ops_value { - BPF_STRUCT_OPS_COMMON_VALUE; + struct bpf_struct_ops_common_value common; char data[] ____cacheline_aligned_in_smp; }; @@ -80,8 +69,8 @@ static DEFINE_MUTEX(update_mutex); #define BPF_STRUCT_OPS_TYPE(_name) \ extern struct bpf_struct_ops bpf_##_name; \ \ -struct bpf_struct_ops_##_name { \ - BPF_STRUCT_OPS_COMMON_VALUE; \ +struct bpf_struct_ops_##_name { \ + struct bpf_struct_ops_common_value common; \ struct _name data ____cacheline_aligned_in_smp; \ }; #include "bpf_struct_ops_types.h" @@ -112,11 +101,49 @@ const struct bpf_prog_ops bpf_struct_ops_prog_ops = { BTF_ID_LIST(st_ops_ids) BTF_ID(struct, module) +BTF_ID(struct, bpf_struct_ops_common_value) enum { IDX_MODULE_ID, + IDX_ST_OPS_COMMON_VALUE_ID, }; +extern struct btf *btf_vmlinux; + +static bool is_valid_value_type(struct btf *btf, s32 value_id, + const struct btf_type *type, + const char *value_name) +{ + const struct btf_type *common_value_type; + const struct btf_member *member; + const struct btf_type *vt, *mt; + + vt = btf_type_by_id(btf, value_id); + if (btf_vlen(vt) != 2) { + pr_warn("The number of %s's members should be 2, but we get %d\n", + value_name, btf_vlen(vt)); + return false; + } + member = btf_type_member(vt); + mt = btf_type_by_id(btf, member->type); + common_value_type = btf_type_by_id(btf_vmlinux, + st_ops_ids[IDX_ST_OPS_COMMON_VALUE_ID]); + if (mt != common_value_type) { + pr_warn("The first member of %s should be bpf_struct_ops_common_value\n", + value_name); + return false; + } + member++; + mt = btf_type_by_id(btf, member->type); + if (mt != type) { + pr_warn("The second member of %s should be %s\n", + value_name, btf_name_by_offset(btf, type->name_off)); + return false; + } + + return true; +} + static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, struct btf *btf, struct bpf_verifier_log *log) @@ -137,14 +164,6 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, } sprintf(value_name, "%s%s", VALUE_PREFIX, st_ops->name); - value_id = btf_find_by_name_kind(btf, value_name, - BTF_KIND_STRUCT); - if (value_id < 0) { - pr_warn("Cannot find struct %s in btf_vmlinux\n", - value_name); - return; - } - type_id = btf_find_by_name_kind(btf, st_ops->name, BTF_KIND_STRUCT); if (type_id < 0) { @@ -159,6 +178,16 @@ static void bpf_struct_ops_desc_init(struct bpf_struct_ops_desc *st_ops_desc, return; } + value_id = btf_find_by_name_kind(btf, value_name, + BTF_KIND_STRUCT); + if (value_id < 0) { + pr_warn("Cannot find struct %s in btf_vmlinux\n", + value_name); + return; + } + if (!is_valid_value_type(btf, value_id, t, value_name)) + return; + for_each_member(i, t, member) { const struct btf_type *func_proto; @@ -218,8 +247,6 @@ void bpf_struct_ops_init(struct btf *btf, struct bpf_verifier_log *log) } } -extern struct btf *btf_vmlinux; - static const struct bpf_struct_ops_desc * bpf_struct_ops_find_value(struct btf *btf, u32 value_id) { @@ -275,7 +302,7 @@ int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key, kvalue = &st_map->kvalue; /* Pair with smp_store_release() during map_update */ - state = smp_load_acquire(&kvalue->state); + state = smp_load_acquire(&kvalue->common.state); if (state == BPF_STRUCT_OPS_STATE_INIT) { memset(value, 0, map->value_size); return 0; @@ -286,7 +313,7 @@ int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key, */ uvalue = value; memcpy(uvalue, st_map->uvalue, map->value_size); - uvalue->state = state; + uvalue->common.state = state; /* This value offers the user space a general estimate of how * many sockets are still utilizing this struct_ops for TCP @@ -294,7 +321,7 @@ int bpf_struct_ops_map_sys_lookup_elem(struct bpf_map *map, void *key, * should sufficiently meet our present goals. */ refcnt = atomic64_read(&map->refcnt) - atomic64_read(&map->usercnt); - refcount_set(&uvalue->refcnt, max_t(s64, refcnt, 0)); + refcount_set(&uvalue->common.refcnt, max_t(s64, refcnt, 0)); return 0; } @@ -408,7 +435,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, if (err) return err; - if (uvalue->state || refcount_read(&uvalue->refcnt)) + if (uvalue->common.state || refcount_read(&uvalue->common.refcnt)) return -EINVAL; tlinks = kcalloc(BPF_TRAMP_MAX, sizeof(*tlinks), GFP_KERNEL); @@ -420,7 +447,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, mutex_lock(&st_map->lock); - if (kvalue->state != BPF_STRUCT_OPS_STATE_INIT) { + if (kvalue->common.state != BPF_STRUCT_OPS_STATE_INIT) { err = -EBUSY; goto unlock; } @@ -542,7 +569,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, * * Pair with smp_load_acquire() during lookup_elem(). */ - smp_store_release(&kvalue->state, BPF_STRUCT_OPS_STATE_READY); + smp_store_release(&kvalue->common.state, BPF_STRUCT_OPS_STATE_READY); goto unlock; } @@ -560,7 +587,7 @@ static long bpf_struct_ops_map_update_elem(struct bpf_map *map, void *key, * It ensures the above udata updates (e.g. prog->aux->id) * can be seen once BPF_STRUCT_OPS_STATE_INUSE is set. */ - smp_store_release(&kvalue->state, BPF_STRUCT_OPS_STATE_INUSE); + smp_store_release(&kvalue->common.state, BPF_STRUCT_OPS_STATE_INUSE); /* Hold the owner module until the struct_ops is * unregistered */ @@ -596,7 +623,7 @@ static long bpf_struct_ops_map_delete_elem(struct bpf_map *map, void *key) if (st_map->map.map_flags & BPF_F_LINK) return -EOPNOTSUPP; - prev_state = cmpxchg(&st_map->kvalue.state, + prev_state = cmpxchg(&st_map->kvalue.common.state, BPF_STRUCT_OPS_STATE_INUSE, BPF_STRUCT_OPS_STATE_TOBEFREE); switch (prev_state) { @@ -829,7 +856,7 @@ static bool bpf_struct_ops_valid_to_reg(struct bpf_map *map) return map->map_type == BPF_MAP_TYPE_STRUCT_OPS && map->map_flags & BPF_F_LINK && /* Pair with smp_store_release() during map_update */ - smp_load_acquire(&st_map->kvalue.state) == BPF_STRUCT_OPS_STATE_READY; + smp_load_acquire(&st_map->kvalue.common.state) == BPF_STRUCT_OPS_STATE_READY; } static void bpf_struct_ops_map_link_dealloc(struct bpf_link *link)