From patchwork Mon Jan 6 08:18:53 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13927017 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) (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 3C2F71D7E42; Mon, 6 Jan 2025 08:07:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.51 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736150828; cv=none; b=QeAR6HnH8N2Rnb8aIk9sEO1aF+1GqNAgelKNXo7hkrF2reOqSC2y/FnCvIfwogxIwHx9wmc8eVcqyAqyAK3ikrtENLIz8EAKCWWJli0FYo/VtZuN/n6Np1tKILgQKC1jNf2P2T9k5CgEY92EvBfw98OG/KC7RyjoZWAZWOFBgaM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736150828; c=relaxed/simple; bh=nokPECxiWnuJREYY086A3+hRWJ9OBOpS1uU++LBiyGs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ghsKPO58F2oSUADHHM8dzj0seJUqF02psFnQckotOfWXyz+4+HKtxhQM2SlRApmsxXlozhLGJkAlGnmXts7Camkt2b97wX6KYjiarGr1vL/4Q5utRqNrYg8ry/cYMxGMI792ub41szdxu0220PVoDWOnodC+LfK5v6CucN+MYSA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=pass smtp.mailfrom=huaweicloud.com; arc=none smtp.client-ip=45.249.212.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.163.235]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4YRRbN3ckJz4f3kvv; Mon, 6 Jan 2025 16:06:40 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id C424C1A0E7B; Mon, 6 Jan 2025 16:07:01 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgD3W2AZj3tnVG29AA--.29272S16; Mon, 06 Jan 2025 16:07:01 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org, netdev@vger.kernel.org Cc: Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Eduard Zingerman , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , houtao1@huawei.com, xukuohai@huawei.com Subject: [PATCH bpf-next 12/19] bpf: Disable migration for bpf_selem_unlink in bpf_local_storage_map_free() Date: Mon, 6 Jan 2025 16:18:53 +0800 Message-Id: <20250106081900.1665573-13-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20250106081900.1665573-1-houtao@huaweicloud.com> References: <20250106081900.1665573-1-houtao@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgD3W2AZj3tnVG29AA--.29272S16 X-Coremail-Antispam: 1UD129KBjvJXoW7Ar1fCFyrCrW8uF4UWFW8tFb_yoW8CrykpF 93GryUtr4vqFWkursrJw4xAry3Aw4rW343KayDK34FvrsxAr98Xw1IkF1Fqa45Krn7tr1f Zas0g3WjyrWUZFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPvb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E 14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2 AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAq x4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6r W5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Gr0_Xr1lIxAIcVC0I7IYx2IY6xkF 7I0E14v26r4UJVWxJr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14 v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuY vjxUF9NVUUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao bpf_local_storage_map_free() invokes bpf_selem_unlink() to unlink and free the element from the storage map. It may invoke bpf_obj_free_fields() to free the special fields in the map value. Since these special fields may be allocated from bpf memory allocator, migrate_{disable|enable} pairs are necessary for the freeing of these objects. To simplify reasoning about when migrate_disable() is needed for the freeing of these dynamically-allocated objects, let the caller to guarantee migration is disabled before invoking bpf_obj_free_fields(). Therefore, the patch moves migrate_{disable|enable} out of the busy_counter condition and calls migrate_disable() before invoking bpf_obj_free_fields(). The migrate_{disable|enable} pairs in the underlying implementation of bpf_obj_free_fields() will be removed by the following patch. Signed-off-by: Hou Tao --- kernel/bpf/bpf_local_storage.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index 615a3034baeb..b649cf736438 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -905,15 +905,13 @@ void bpf_local_storage_map_free(struct bpf_map *map, while ((selem = hlist_entry_safe( rcu_dereference_raw(hlist_first_rcu(&b->list)), struct bpf_local_storage_elem, map_node))) { - if (busy_counter) { - migrate_disable(); + migrate_disable(); + if (busy_counter) this_cpu_inc(*busy_counter); - } bpf_selem_unlink(selem, true); - if (busy_counter) { + if (busy_counter) this_cpu_dec(*busy_counter); - migrate_enable(); - } + migrate_enable(); cond_resched_rcu(); } rcu_read_unlock();