From patchwork Mon Jan 6 08:18:46 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13927011 X-Patchwork-Delegate: bpf@iogearbox.net Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) (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 9119C1D6DC9; Mon, 6 Jan 2025 08:07:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.56 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736150823; cv=none; b=tLyTjpsG+zKQNpIR9NTqR45OU5OhxE5MjTncxkvwhCjfyb0mvOsgpEQf59w/UDrXzintRYvKiucT7VSE4Caknm5ov9nu4rqMApfu0eU/EtOfVTIqEllM/F5rWYdFUw+8O+qkKouiTrK1AvlJrIjknT4CcaimBPsF03ysO8Fhz8Y= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736150823; c=relaxed/simple; bh=7qzJ8Ksyo9MGJycen55qwiVKEUhRpzMhpfQoq1SLXtM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=Et5mr+x74Ss78bRhZxcwRkXBiWmhQRQTTjQrzAS+7fia2ucE45IYtUfhY4VmIIoD4fZbPIGg6n2pQieoB+Ud/kL8tJq2xOTE2PwBzj0lN/FX+z0/bUPG5EMtWZUy9k74nCurExZ48IsMLMCZxaQmtBYkbABq+HGjZQmzXYjwEYE= 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=45.249.212.56 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 dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4YRRbK1Dbwz4f3jRC; Mon, 6 Jan 2025 16:06:37 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 455DD1A1126; Mon, 6 Jan 2025 16:06:57 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgD3W2AZj3tnVG29AA--.29272S9; Mon, 06 Jan 2025 16:06:57 +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 05/19] bpf: Remove migrate_{disable|enable} from bpf_task_storage_lock helpers Date: Mon, 6 Jan 2025 16:18:46 +0800 Message-Id: <20250106081900.1665573-6-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--.29272S9 X-Coremail-Antispam: 1UD129KBjvJXoW7Zw48XF17Gr48Cr48CFy5XFb_yoW5JryUpr yxtF9xAr45J3ZYyrsxXws7AryUAwn3Ww47Krs0kF97Krs5XF93Wr1xt3ZrZFy3J34jqF43 ZFs0g3ZxCr1DJ3JanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPSb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E 14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2 AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAq x4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6r W5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_JFI_Gr1lIxAIcVC0I7IYx2IY6xkF 7I0E14v26F4j6r4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI 0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7I U1aLvJUUUUU== X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao Three callers of bpf_task_storage_lock() are ->map_lookup_elem, ->map_update_elem, ->map_delete_elem from bpf syscall. BPF syscall for these three operations of task storage has already disabled migration. Another two callers are bpf_task_storage_get() and bpf_task_storage_delete() helpers which will be used by BPF program. Two callers of bpf_task_storage_trylock() are bpf_task_storage_get() and bpf_task_storage_delete() helpers. The running contexts of these helpers have already disabled migration. Therefore, it is safe to remove migrate_{disable|enable} from task storage lock helpers for these call sites. However, bpf_task_storage_free() also invokes bpf_task_storage_lock() and its running context doesn't disable migration, therefore, add the missed migrate_{disable|enable} in bpf_task_storage_free(). Signed-off-by: Hou Tao --- kernel/bpf/bpf_task_storage.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c index bf7fa15fdcc6..1109475953c0 100644 --- a/kernel/bpf/bpf_task_storage.c +++ b/kernel/bpf/bpf_task_storage.c @@ -24,22 +24,20 @@ static DEFINE_PER_CPU(int, bpf_task_storage_busy); static void bpf_task_storage_lock(void) { - migrate_disable(); + cant_migrate(); this_cpu_inc(bpf_task_storage_busy); } static void bpf_task_storage_unlock(void) { this_cpu_dec(bpf_task_storage_busy); - migrate_enable(); } static bool bpf_task_storage_trylock(void) { - migrate_disable(); + cant_migrate(); if (unlikely(this_cpu_inc_return(bpf_task_storage_busy) != 1)) { this_cpu_dec(bpf_task_storage_busy); - migrate_enable(); return false; } return true; @@ -72,18 +70,19 @@ void bpf_task_storage_free(struct task_struct *task) { struct bpf_local_storage *local_storage; + migrate_disable(); rcu_read_lock(); local_storage = rcu_dereference(task->bpf_storage); - if (!local_storage) { - rcu_read_unlock(); - return; - } + if (!local_storage) + goto out; bpf_task_storage_lock(); bpf_local_storage_destroy(local_storage); bpf_task_storage_unlock(); +out: rcu_read_unlock(); + migrate_enable(); } static void *bpf_pid_task_storage_lookup_elem(struct bpf_map *map, void *key)