From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (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 6E65F3E8671 for ; Tue, 19 May 2026 21:59:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779227953; cv=none; b=cuIYVdQSuQPdnhOQIwECjgtHfL7EjlwvLofCuAf19b3UciVx7TGRbF1uRwBID+lKv/QFniPqhm4l0+OafLJ22buz+GEoSe7WPZxTD1ij1Lss/IMr7QccOtHeDQ5G1XEhjzvlZUHM6gwI5h81DPYRnk8qgJBzTcWXcTyDoeqKjx4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779227953; c=relaxed/simple; bh=H5zf7hyY5jhHjLE/Um6PIp4ND2nSLp3EuddCQZIZAwI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rlm+UOXDlTZYtW+7z1gAK5RQUWWNV1edgsVq7tjHxIGXgrSsRB2O97mY+xt65rtlAKx57PtWhIKEmstzGKe/vhVxKZG0tBCAaI3eVqNHsK/dPOVF+M7wAsqqg4UFUJuyOdb6xi9K0EPKjg2CUcBQU88mvYsPKgprG4ixN7S7ZgM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=L2lOC/3/; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="L2lOC/3/" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779227948; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U/I6S8Kw28BAahmP437WtXsPWiDEg/SpJL4HlJOaL8M=; b=L2lOC/3/L8+LUVnPOV/TD7LY9UayHbWUq6pU7DrtaGzDgC2nnsccBjOZ9+2HhskbA23HCS PRX9ubEmN53EyK9VP0LSPs8sPLCtFV9tw2SmMvU4hC8ZQgNOhIYcBUFc94mmUNMNE3q0d+ HGfZzy7jHqIXpVT/2h1M/LqHgZi9SPM= From: Martin KaFai Lau To: bpf@vger.kernel.org Cc: 'Alexei Starovoitov ' , 'Andrii Nakryiko ' , 'Daniel Borkmann ' , 'Shakeel Butt ' , 'Roman Gushchin ' , 'Amery Hung ' , netdev@vger.kernel.org Subject: [RFC PATCH bpf-next 03/12] bpf: Add bpf_struct_ops accessor helpers Date: Tue, 19 May 2026 14:58:10 -0700 Message-ID: <20260519215841.2984970-4-martin.lau@linux.dev> In-Reply-To: <20260519215841.2984970-1-martin.lau@linux.dev> References: <20260519215841.2984970-1-martin.lau@linux.dev> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: Martin KaFai Lau Add the helper functions bpf_struct_ops_map_kdata(), bpf_struct_ops_kdata_map_id(), and bpf_struct_ops_map_cfi_stubs() in bpf_struct_ops.c. They will be called from cgroup.c in the upcoming patch to create a struct_ops to cgroup attachment link. bpf_struct_ops_valid_to_reg() is also exposed for the upcoming caller in cgroup.c. The link update validation is also refactored into a new function bpf_struct_ops_link_update_check() such that it can be reused by the caller in cgroup.c in the upcoming patch. Signed-off-by: Martin KaFai Lau --- include/linux/bpf.h | 28 +++++++++++++++++ kernel/bpf/bpf_struct_ops.c | 63 ++++++++++++++++++++++++++++--------- 2 files changed, 77 insertions(+), 14 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a276eada19c4..dbf98741f15b 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2136,6 +2136,12 @@ int bpf_prog_assoc_struct_ops(struct bpf_prog *prog, struct bpf_map *map); void bpf_prog_disassoc_struct_ops(struct bpf_prog *prog); void *bpf_prog_get_assoc_struct_ops(const struct bpf_prog_aux *aux); u32 bpf_struct_ops_id(const void *kdata); +void *bpf_struct_ops_map_kdata(struct bpf_map *map); +u32 bpf_struct_ops_kdata_map_id(void *kdata); +void *bpf_struct_ops_map_cfi_stubs(struct bpf_map *map); +bool bpf_struct_ops_valid_to_reg(struct bpf_map *map); +int bpf_struct_ops_link_update_check(struct bpf_map *new_map, struct bpf_map *old_map, + struct bpf_map *expected_old_map); #ifdef CONFIG_NET /* Define it here to avoid the use of forward declaration */ @@ -2200,6 +2206,28 @@ static inline void bpf_map_struct_ops_info_fill(struct bpf_map_info *info, struc static inline void bpf_struct_ops_desc_release(struct bpf_struct_ops_desc *st_ops_desc) { } +static inline void *bpf_struct_ops_map_kdata(struct bpf_map *map) +{ + return NULL; +} +static inline u32 bpf_struct_ops_kdata_map_id(void *kdata) +{ + return 0; +} +static inline void *bpf_struct_ops_map_cfi_stubs(struct bpf_map *map) +{ + return NULL; +} +static inline bool bpf_struct_ops_valid_to_reg(struct bpf_map *map) +{ + return false; +} +static inline int bpf_struct_ops_link_update_check(struct bpf_map *new_map, + struct bpf_map *old_map, + struct bpf_map *expected_old_map) +{ + return -EOPNOTSUPP; +} #endif diff --git a/kernel/bpf/bpf_struct_ops.c b/kernel/bpf/bpf_struct_ops.c index 28eab24ef0ed..8650a3b88bf6 100644 --- a/kernel/bpf/bpf_struct_ops.c +++ b/kernel/bpf/bpf_struct_ops.c @@ -1199,7 +1199,33 @@ u32 bpf_struct_ops_id(const void *kdata) } EXPORT_SYMBOL_GPL(bpf_struct_ops_id); -static bool bpf_struct_ops_valid_to_reg(struct bpf_map *map) +void *bpf_struct_ops_map_kdata(struct bpf_map *map) +{ + struct bpf_struct_ops_map *st_map; + + st_map = container_of(map, struct bpf_struct_ops_map, map); + return st_map->kvalue.data; +} + +u32 bpf_struct_ops_kdata_map_id(void *kdata) +{ + struct bpf_struct_ops_value *kvalue = + container_of(kdata, struct bpf_struct_ops_value, data); + struct bpf_struct_ops_map *st_map = + container_of(kvalue, struct bpf_struct_ops_map, kvalue); + + return st_map->map.id; +} + +void *bpf_struct_ops_map_cfi_stubs(struct bpf_map *map) +{ + struct bpf_struct_ops_map *st_map; + + st_map = container_of(map, struct bpf_struct_ops_map, map); + return st_map->st_ops_desc->st_ops->cfi_stubs; +} + +bool bpf_struct_ops_valid_to_reg(struct bpf_map *map) { struct bpf_struct_ops_map *st_map = (struct bpf_struct_ops_map *)map; @@ -1252,6 +1278,26 @@ static int bpf_struct_ops_map_link_fill_link_info(const struct bpf_link *link, return 0; } +int bpf_struct_ops_link_update_check(struct bpf_map *new_map, + struct bpf_map *old_map, + struct bpf_map *expected_old_map) +{ + struct bpf_struct_ops_map *st_map, *old_st_map; + + if (!old_map) + return -ENOLINK; + if (expected_old_map && old_map != expected_old_map) + return -EPERM; + + st_map = container_of(new_map, struct bpf_struct_ops_map, map); + old_st_map = container_of(old_map, struct bpf_struct_ops_map, map); + /* The new and old struct_ops must be the same type. */ + if (st_map->st_ops_desc != old_st_map->st_ops_desc) + return -EINVAL; + + return 0; +} + static int bpf_struct_ops_map_link_update(struct bpf_link *link, struct bpf_map *new_map, struct bpf_map *expected_old_map) { @@ -1270,23 +1316,12 @@ static int bpf_struct_ops_map_link_update(struct bpf_link *link, struct bpf_map return -EOPNOTSUPP; mutex_lock(&update_mutex); - old_map = st_link->map; - if (!old_map) { - err = -ENOLINK; - goto err_out; - } - if (expected_old_map && old_map != expected_old_map) { - err = -EPERM; + err = bpf_struct_ops_link_update_check(new_map, old_map, expected_old_map); + if (err) goto err_out; - } old_st_map = container_of(old_map, struct bpf_struct_ops_map, map); - /* The new and old struct_ops must be the same type. */ - if (st_map->st_ops_desc != old_st_map->st_ops_desc) { - err = -EINVAL; - goto err_out; - } err = st_map->st_ops_desc->st_ops->update(st_map->kvalue.data, old_st_map->kvalue.data, link); if (err) -- 2.53.0-Meta