From nobody Sun Feb 8 11:43:19 2026 Received: from out-172.mta1.migadu.com (out-172.mta1.migadu.com [95.215.58.172]) (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 75CCE236A8B for ; Wed, 7 Jan 2026 02:26:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767752775; cv=none; b=Xt3QK6fsrahDfKQQ5zOImZeyjYN62WA6VuUp8AtOFzWTs0rpq0bHZtGBeQiUVVkEdd7O5U9QJIqoIKI9Ceh69tkeQ34UZo7HNdnr1YhnFePAC8Gje0Tz0JN15XeKEEwFTMWQkF7mYGaXQYWGW21lhvhx+7BgBo7dKnNz5KrvSZA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767752775; c=relaxed/simple; bh=f14hxeSmP0E/KQpY12Hvr761MvcVsF/1TGkOCNfMxxo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=annxS9oLFdNkvsth2B8CxhNeNU/35cvn5Lwdaht7S5a84xi5ab1w+PJ9ExBYR+FZvBXVdp8Gm3t7FcA1R+AlG3RT+bOoiSTJUqNfUcX+2gUZ3xxDffeAsVr9CGMldyuTty19YT5OUIU9pLg0wtsGvQl67OMal5qKuuR99K/8UqU= 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=Kt3Mmqhz; arc=none smtp.client-ip=95.215.58.172 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="Kt3Mmqhz" 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=1767752770; 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=2W48jz1P7h4RXym2RZ4cSXG9fjmInfEAzpFscwvOLQ4=; b=Kt3MmqhzwrxD7NOdUhj902ebP9caCGGpZQoq7MrnNpCTilphr34VhKLEdvn0SRHziGHwJi 5DL5WusvqI4nnJ80g17IOXXr0/8BFB2x+hFdqj9Fw9aJ8gUz8zJPyvb12RMqyQEhJW4g+a TCyZdChCONnyHfqtU2JYzy3D3eSdOY4= From: Leon Hwang To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Jiri Olsa , Yonghong Song , Song Liu , Eduard Zingerman , Martin KaFai Lau , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Shuah Khan , Jason Xing , Willem de Bruijn , Mykyta Yatsenko , Tao Chen , Kumar Kartikeya Dwivedi , Anton Protopopov , Amery Hung , Tobias Klauser , Rong Tao , dxu@dxuuu.xyz, deso@posteo.net, Leon Hwang , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v13 5/7] bpf: Add BPF_F_CPU and BPF_F_ALL_CPUS flags support for percpu_cgroup_storage maps Date: Wed, 7 Jan 2026 10:20:20 +0800 Message-ID: <20260107022022.12843-6-leon.hwang@linux.dev> In-Reply-To: <20260107022022.12843-1-leon.hwang@linux.dev> References: <20260107022022.12843-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Introduce BPF_F_ALL_CPUS flag support for percpu_cgroup_storage maps to allow updating values for all CPUs with a single value for update_elem API. Introduce BPF_F_CPU flag support for percpu_cgroup_storage maps to allow: * update value for specified CPU for update_elem API. * lookup value for specified CPU for lookup_elem API. The BPF_F_CPU flag is passed via map_flags along with embedded cpu info. Signed-off-by: Leon Hwang --- include/linux/bpf-cgroup.h | 4 ++-- include/linux/bpf.h | 1 + kernel/bpf/local_storage.c | 23 ++++++++++++++++++----- kernel/bpf/syscall.c | 2 +- 4 files changed, 22 insertions(+), 8 deletions(-) diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h index d1eb5c7729cb..2f535331f926 100644 --- a/include/linux/bpf-cgroup.h +++ b/include/linux/bpf-cgroup.h @@ -172,7 +172,7 @@ void bpf_cgroup_storage_link(struct bpf_cgroup_storage = *storage, void bpf_cgroup_storage_unlink(struct bpf_cgroup_storage *storage); int bpf_cgroup_storage_assign(struct bpf_prog_aux *aux, struct bpf_map *ma= p); =20 -int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, void *v= alue); +int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void *key, void *v= alue, u64 flags); int bpf_percpu_cgroup_storage_update(struct bpf_map *map, void *key, void *value, u64 flags); =20 @@ -470,7 +470,7 @@ static inline struct bpf_cgroup_storage *bpf_cgroup_sto= rage_alloc( static inline void bpf_cgroup_storage_free( struct bpf_cgroup_storage *storage) {} static inline int bpf_percpu_cgroup_storage_copy(struct bpf_map *map, void= *key, - void *value) { + void *value, u64 flags) { return 0; } static inline int bpf_percpu_cgroup_storage_update(struct bpf_map *map, diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f5c259dcc425..5936f8e2996f 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -3921,6 +3921,7 @@ static inline bool bpf_map_supports_cpu_flags(enum bp= f_map_type map_type) case BPF_MAP_TYPE_PERCPU_ARRAY: case BPF_MAP_TYPE_PERCPU_HASH: case BPF_MAP_TYPE_LRU_PERCPU_HASH: + case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE: return true; default: return false; diff --git a/kernel/bpf/local_storage.c b/kernel/bpf/local_storage.c index 2ab4b60ffe61..1ccbf28b2ad9 100644 --- a/kernel/bpf/local_storage.c +++ b/kernel/bpf/local_storage.c @@ -180,7 +180,7 @@ static long cgroup_storage_update_elem(struct bpf_map *= map, void *key, } =20 int bpf_percpu_cgroup_storage_copy(struct bpf_map *_map, void *key, - void *value) + void *value, u64 map_flags) { struct bpf_cgroup_storage_map *map =3D map_to_storage(_map); struct bpf_cgroup_storage *storage; @@ -198,11 +198,17 @@ int bpf_percpu_cgroup_storage_copy(struct bpf_map *_m= ap, void *key, * access 'value_size' of them, so copying rounded areas * will not leak any kernel data */ + if (map_flags & BPF_F_CPU) { + cpu =3D map_flags >> 32; + copy_map_value(_map, value, per_cpu_ptr(storage->percpu_buf, cpu)); + goto unlock; + } size =3D round_up(_map->value_size, 8); for_each_possible_cpu(cpu) { copy_map_value_long(_map, value + off, per_cpu_ptr(storage->percpu_buf, = cpu)); off +=3D size; } +unlock: rcu_read_unlock(); return 0; } @@ -212,10 +218,11 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *= _map, void *key, { struct bpf_cgroup_storage_map *map =3D map_to_storage(_map); struct bpf_cgroup_storage *storage; - int cpu, off =3D 0; + void *val; u32 size; + int cpu; =20 - if (map_flags !=3D BPF_ANY && map_flags !=3D BPF_EXIST) + if ((u32)map_flags & ~(BPF_ANY | BPF_EXIST | BPF_F_CPU | BPF_F_ALL_CPUS)) return -EINVAL; =20 rcu_read_lock(); @@ -231,11 +238,17 @@ int bpf_percpu_cgroup_storage_update(struct bpf_map *= _map, void *key, * returned or zeros which were zero-filled by percpu_alloc, * so no kernel data leaks possible */ + if (map_flags & BPF_F_CPU) { + cpu =3D map_flags >> 32; + copy_map_value(_map, per_cpu_ptr(storage->percpu_buf, cpu), value); + goto unlock; + } size =3D round_up(_map->value_size, 8); for_each_possible_cpu(cpu) { - copy_map_value_long(_map, per_cpu_ptr(storage->percpu_buf, cpu), value += off); - off +=3D size; + val =3D (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; + copy_map_value(_map, per_cpu_ptr(storage->percpu_buf, cpu), val); } +unlock: rcu_read_unlock(); return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 5e3b5d828856..ecc0929ce462 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -320,7 +320,7 @@ static int bpf_map_copy_value(struct bpf_map *map, void= *key, void *value, } else if (map->map_type =3D=3D BPF_MAP_TYPE_PERCPU_ARRAY) { err =3D bpf_percpu_array_copy(map, key, value, flags); } else if (map->map_type =3D=3D BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { - err =3D bpf_percpu_cgroup_storage_copy(map, key, value); + err =3D bpf_percpu_cgroup_storage_copy(map, key, value, flags); } else if (map->map_type =3D=3D BPF_MAP_TYPE_STACK_TRACE) { err =3D bpf_stackmap_extract(map, key, value, false); } else if (IS_FD_ARRAY(map) || IS_FD_PROG_ARRAY(map)) { --=20 2.52.0