From patchwork Mon Jan 6 08:19:00 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13927025 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 8B7F21DA0E1; Mon, 6 Jan 2025 08:07:12 +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=1736150836; cv=none; b=KVTyCsoBiP017BC5o6N0QGHEWI6dyckuBhqw1CrefYje2qjb4t7VY2uMMG/aiw/4ZQ2hEaShG9dgnakOE39t0Nz1mgi++tIPSZT5w0XQ3cbscE567WrR0Tu5pPF++g0i7HGoQEOASvSLGIW2o1uQqiLuDdL2+zVHvG79ar1SYmk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736150836; c=relaxed/simple; bh=XPAyxuEqoQ9kPmaRjBByoeA0kuBk23qq7DNXlnka/4c=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=DBsBqWg2MVVytdN+WWH9zwy6nOdbQbLg8F1WmTlzZDD6StLICc5ocWomxaRwP4W+/qvmnNRX/EVPcoXzJYuAtRP88zQA5jULrpUJ5Nm6XjyeFUrwlN6oa9PMAaTJAAA38OePcENY0Gs9Ox/quzd+kBJLx1foomdhEvQZeveNLLc= 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 [172.19.93.142]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4YRRbV1C8lz4f3jd9; Mon, 6 Jan 2025 16:06:46 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 44BB91A10C2; Mon, 6 Jan 2025 16:07:06 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgD3W2AZj3tnVG29AA--.29272S23; Mon, 06 Jan 2025 16:07:06 +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 19/19] bpf: Remove migrate_{disable|enable} from bpf_selem_free() Date: Mon, 6 Jan 2025 16:19:00 +0800 Message-Id: <20250106081900.1665573-20-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--.29272S23 X-Coremail-Antispam: 1UD129KBjvJXoW7Kr1fCr48CF1ftr1rtr48tFb_yoW8tFWfpF Z7Xr95Cr4Uta1F9FsrJF4fCryrXw48Wr17Kr4DA34rtrsxZF93Gr4IkF18Za43Gw1UXryf ZF1Yga4Uuw4UCFDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 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_selem_free() has the following three callers: (1) bpf_local_storage_update It will be invoked through ->map_update_elem syscall or helpers for storage map. Migration has already been disabled in these running contexts. (2) bpf_sk_storage_clone It has already disabled migration before invoking bpf_selem_free(). (3) bpf_selem_free_list bpf_selem_free_list() has three callers: bpf_selem_unlink_storage(), bpf_local_storage_update() and bpf_local_storage_destroy(). The callers of bpf_selem_unlink_storage() includes: storage map ->map_delete_elem syscall, storage map delete helpers and bpf_local_storage_map_free(). These contexts have already disabled migration when invoking bpf_selem_unlink() which invokes bpf_selem_unlink_storage() and bpf_selem_free_list() correspondingly. bpf_local_storage_update() has been analyzed as the first caller above. bpf_local_storage_destroy() is invoked when freeing the local storage for the kernel object. Now cgroup, task, inode and sock storage have already disabled migration before invoking bpf_local_storage_destroy(). After the analyses above, it is safe to remove migrate_{disable|enable} from bpf_selem_free(). Also add a cant_migrate() check in bpf_selem_free(). Signed-off-by: Hou Tao --- kernel/bpf/bpf_local_storage.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/bpf_local_storage.c b/kernel/bpf/bpf_local_storage.c index d67ba116aee8..f196093db0a0 100644 --- a/kernel/bpf/bpf_local_storage.c +++ b/kernel/bpf/bpf_local_storage.c @@ -235,6 +235,8 @@ void bpf_selem_free(struct bpf_local_storage_elem *selem, struct bpf_local_storage_map *smap, bool reuse_now) { + cant_migrate(); + if (!smap->bpf_ma) { /* Only task storage has uptrs and task storage * has moved to bpf_mem_alloc. Meaning smap->bpf_ma == true @@ -258,9 +260,7 @@ void bpf_selem_free(struct bpf_local_storage_elem *selem, * bpf_mem_cache_free will be able to reuse selem * immediately. */ - migrate_disable(); bpf_mem_cache_free(&smap->selem_ma, selem); - migrate_enable(); return; }