From patchwork Mon Jan 6 08:18:59 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13927023 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 169FE1D79B6; Mon, 6 Jan 2025 08:07:09 +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=1736150834; cv=none; b=Rl2YiXrLEMs2N7LbwkRpd52Nw+2UaBDoc9f7dmsS0fylEqRmS98omhZQd7OYj4aeHwV2BNj4JVwfa6DR1GkxsGEKE1+pk4vs4o1vDNv4Ugv2mdgezOE9R15ueSFCL0c8EwdE+P/usZGdy+7jJfdwZjfwtHf1CUBcmOZ9BItT9YU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736150834; c=relaxed/simple; bh=ERV+dNS62FMiq+IIL3K7+YwHjYuSiJlg0VXFGZe3uzQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ocfOBIzTCLdNIEWiFR/tB5ckRU/Dml6HBHQsoQD8XZYmFaMxkFRe/5Cboc4HC/30EsFSCyd9QCelHV8AbMRT5+EHKSMblT2Px32Bc1E6ZyV/8qapLwefL44pGzLdrXpchG4S4M7F65PNwDh4GTHcLfwqrp7rLaWNNMLwYr1WEOA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=huaweicloud.com; spf=none 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=none smtp.mailfrom=huaweicloud.com Received: from mail.maildlp.com (unknown [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4YRRbS2Vl0z4f3kvs; Mon, 6 Jan 2025 16:06:44 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 9DF731A14E3; Mon, 6 Jan 2025 16:07:05 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgD3W2AZj3tnVG29AA--.29272S22; Mon, 06 Jan 2025 16:07:05 +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 18/19] bpf: Remove migrate_{disable|enable} from bpf_local_storage_free() Date: Mon, 6 Jan 2025 16:18:59 +0800 Message-Id: <20250106081900.1665573-19-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--.29272S22 X-Coremail-Antispam: 1UD129KBjvJXoW7Ar4DCrW3Ww13JFWktFykAFb_yoW8ZF43pF 92gr93Cr4Ut3WF9FsrXF4fAr9xXw45Gr1jkws8ArySyrZxZrZ8Gr42kF47uFy3Gw1UXF4S vFn0gF1UCr1UAFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 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_free() has three callers: 1) bpf_local_storage_alloc() Its caller must have disabled migration. 2) bpf_local_storage_destroy() Its four callers (bpf_{cgrp|inode|task|sk}_storage_free()) have already invoked migrate_disable() before invoking bpf_local_storage_destroy(). 3) bpf_selem_unlink() Its callers include: cgrp/inode/task/sk storage ->map_delete_elem callbacks, bpf_{cgrp|inode|task|sk}_storage_delete() helpers and bpf_local_storage_map_free(). All of these callers have already disabled migration before invoking bpf_selem_unlink(). Therefore, it is OK to remove migrate_{disable|enable} pair from bpf_local_storage_free(). Also add a cant_migrate() check in bpf_local_storage_free() to ensure the guarantee isn't broken. Signed-off-by: Hou Tao --- kernel/bpf/bpf_local_storage.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index 0970766278f7..d67ba116aee8 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -163,6 +163,8 @@ static void bpf_local_storage_free(struct bpf_local_storage *local_storage, if (!local_storage) return; + cant_migrate(); + if (!bpf_ma) { __bpf_local_storage_free(local_storage, reuse_now); return; @@ -174,17 +176,14 @@ static void bpf_local_storage_free(struct bpf_local_storage *local_storage, return; } - if (smap) { - migrate_disable(); + if (smap) bpf_mem_cache_free(&smap->storage_ma, local_storage); - migrate_enable(); - } else { + else /* smap could be NULL if the selem that triggered * this 'local_storage' creation had been long gone. * In this case, directly do call_rcu(). */ call_rcu(&local_storage->rcu, bpf_local_storage_free_rcu); - } } /* rcu tasks trace callback for bpf_ma == false */