From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 7170B13C9C4 for ; Wed, 27 Aug 2025 16:45:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756313146; cv=none; b=We/6inQ5sA1+fTzl01uxizH6KqIQPyV+MSnp9Yo8dRlzGkQykEkq8bCVxiHvWUNLtn6lxFBKzGw73oucUtbKshsUqcwgD6nn36xGAmdBkbwj4lG4d79nPEGrxCjRf6KpsOXR1oI+Vz8G0jB52cxagqkZoa4frqtFW5q8XhPSelE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756313146; c=relaxed/simple; bh=nhlu+/fiiXttNPBr+WrZMtEGbzYDTAO05I0tx3NgHSs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IAkk1iTt++2DKrjkXztkDqntZtQTFouu5LNb3JJ4anGU8QV1bGQi1Km2e8ZrGZSRhq0PqweXFGa2No852R/PoEfMoFJYZcs/WX9fpJmVPvw2VdGOkiw7jFdkUK1xWvw4+H85avj2IEmbWGeHlws6m4r0UgH8W3Iw1hoMUpVmZKs= 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=vxwPkEx9; arc=none smtp.client-ip=91.218.175.177 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="vxwPkEx9" 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=1756313142; 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=meyB+p7p/BFzs+SCa6nFQf46ZDAzDXmSodviDakKOcI=; b=vxwPkEx9OW2pRJc4AaINigLJQCKc35/kBrtKlVgN509ZJmMAncdfuT8PNQHeZ+eqPnyNs2 Z+W/Z56mm7RsKUuMzcUodf6l2WKN1tTwZw0umKgVuCl4yb2ayfDl18bHjUIHSXQXRJMwWW m0hgw07qt/LTG04TrUpWab84JAxnNdM= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, jolsa@kernel.org, yonghong.song@linux.dev, song@kernel.org, eddyz87@gmail.com, dxu@dxuuu.xyz, deso@posteo.net, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v4 3/7] bpf: Introduce BPF_F_CPU and BPF_F_ALL_CPUS flags for percpu_array maps Date: Thu, 28 Aug 2025 00:45:05 +0800 Message-ID: <20250827164509.7401-4-leon.hwang@linux.dev> In-Reply-To: <20250827164509.7401-1-leon.hwang@linux.dev> References: <20250827164509.7401-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Introduce support for the BPF_F_ALL_CPUS flag in percpu_array maps to allow updating values for all CPUs with a single value for both update_elem and update_batch APIs. Introduce support for the BPF_F_CPU flag in percpu_array maps to allow: * update value for specified CPU for both update_elem and update_batch APIs. * lookup value for specified CPU for both lookup_elem and lookup_batch APIs. The BPF_F_CPU flag is passed via: * map_flags of lookup_elem and update_elem APIs along with embedded cpu info. * elem_flags of lookup_batch and update_batch APIs along with embedded cpu info. Signed-off-by: Leon Hwang --- include/linux/bpf.h | 10 ++++++++-- kernel/bpf/arraymap.c | 28 ++++++++++++---------------- kernel/bpf/syscall.c | 2 +- 3 files changed, 21 insertions(+), 19 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a83364949b64c..bc44b72129e59 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2746,7 +2746,8 @@ int map_set_for_each_callback_args(struct bpf_verifier_env *env, struct bpf_func_state *callee); int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); -int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); +int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, + u64 flags); int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, u64 flags); int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, @@ -3760,7 +3761,12 @@ struct bpf_prog *bpf_prog_find_from_stack(void); static inline bool bpf_map_supports_cpu_flags(enum bpf_map_type map_type) { - return false; + switch (map_type) { + case BPF_MAP_TYPE_PERCPU_ARRAY: + return true; + default: + return false; + } } static inline int bpf_map_check_op_flags(struct bpf_map *map, u64 flags, u64 extra_flags_mask) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 3d080916faf97..42a75fbc588a1 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -295,17 +295,21 @@ static void *percpu_array_map_lookup_percpu_elem(struct bpf_map *map, void *key, return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu); } -int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) +int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64 flags) { struct bpf_array *array = container_of(map, struct bpf_array, map); u32 index = *(u32 *)key; void __percpu *pptr; - int cpu, off = 0; u32 size; + int err; if (unlikely(index >= array->map.max_entries)) return -ENOENT; + err = bpf_map_check_cpu_flags(flags, false); + if (unlikely(err)) + return err; + /* per_cpu areas are zero-filled and bpf programs can only * access 'value_size' of them, so copying rounded areas * will not leak any kernel data @@ -313,11 +317,7 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) size = array->elem_size; rcu_read_lock(); pptr = array->pptrs[index & array->index_mask]; - for_each_possible_cpu(cpu) { - copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu)); - check_and_init_map_value(map, value + off); - off += size; - } + bpf_percpu_copy_to_user(map, pptr, value, size, flags); rcu_read_unlock(); return 0; } @@ -387,12 +387,12 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, struct bpf_array *array = container_of(map, struct bpf_array, map); u32 index = *(u32 *)key; void __percpu *pptr; - int cpu, off = 0; u32 size; + int err; - if (unlikely(map_flags > BPF_EXIST)) - /* unknown flags */ - return -EINVAL; + err = bpf_map_check_cpu_flags(map_flags, true); + if (unlikely(err)) + return err; if (unlikely(index >= array->map.max_entries)) /* all elements were pre-allocated, cannot insert a new one */ @@ -411,11 +411,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, size = array->elem_size; rcu_read_lock(); pptr = array->pptrs[index & array->index_mask]; - for_each_possible_cpu(cpu) { - copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off); - bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu)); - off += size; - } + bpf_percpu_copy_from_user(map, pptr, value, size, map_flags); rcu_read_unlock(); return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index dbd21484d7a4d..2ee2cf5a8cedf 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -316,7 +316,7 @@ static int bpf_map_copy_value(struct bpf_map *map, void *key, void *value, map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH) { err = bpf_percpu_hash_copy(map, key, value); } else if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) { - err = bpf_percpu_array_copy(map, key, value); + err = bpf_percpu_array_copy(map, key, value, flags); } else if (map->map_type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { err = bpf_percpu_cgroup_storage_copy(map, key, value); } else if (map->map_type == BPF_MAP_TYPE_STACK_TRACE) { -- 2.50.1