From patchwork Wed Jan 8 01:07:15 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13929735 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 C385670838; Wed, 8 Jan 2025 00:55:25 +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=1736297727; cv=none; b=F2IjaeN2a8yG0KlrSCj0IYtbnaD88eDs1Jkh5Mhk+yzgPTAz71IasjI4kOERaQtaEHwXrPYoAK78YIY3MtVyaOS4SKsdXlgsgY7AmnvlOx+A7kgNHNxWa6F1B783ZPhwGqhteSROee999rvFUbaBQAUQuqzBbhJHkOushMRzeBc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736297727; c=relaxed/simple; bh=fkyBxiRi2sr7bsoSwRLptQZoQl8iofy0FvvYQagRNKQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=WT4sSCEvabOF2cqFRvWNo06oQI66AdDu9hgUfbLDNPWtEJTwGTqfOsS5Fm2wPn9b8zwJuHvPeCKewkWHbjolsUi287HVnuI2BxzTCXKgBinTNx7RXcl290aBq7WrMfqssLWtBr+Jh5+bi07OR1lVfxJEe80HukJwxo6VlwQhP04= 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 [172.19.93.142]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4YSTwP1rmYz4f3lfd; Wed, 8 Jan 2025 08:55:01 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id 98CF61A101B; Wed, 8 Jan 2025 08:55:22 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgBHq1_1zH1nBtZdAQ--.51859S7; Wed, 08 Jan 2025 08:55:22 +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 v2 03/16] bpf: Remove migrate_{disable|enable} in htab_elem_free Date: Wed, 8 Jan 2025 09:07:15 +0800 Message-Id: <20250108010728.207536-4-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20250108010728.207536-1-houtao@huaweicloud.com> References: <20250108010728.207536-1-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: gCh0CgBHq1_1zH1nBtZdAQ--.51859S7 X-Coremail-Antispam: 1UD129KBjvJXoW7Ar1kCrW3AF1UCw4DAF43Wrg_yoW8Xw47pF WkGr4xGw40qFyqvw43Xr4xKrWUXrn3Kr13AayDG34rt3s8ur97Jw4fAFyIqF1FvryUAr4f X39Fvw1xta18GrDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUP2b4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV W8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v2 6rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r1j6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AFwI 0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG 67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MI IYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E 14v26F4j6r4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr 0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU14x RDUUUUU== X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao htab_elem_free() has two call-sites: delete_all_elements() has already disabled migration, free_htab_elem() is invoked by other 4 functions: __htab_map_lookup_and_delete_elem, __htab_map_lookup_and_delete_batch, htab_map_update_elem and htab_map_delete_elem. BPF syscall has already disabled migration before invoking ->map_update_elem, ->map_delete_elem, and ->map_lookup_and_delete_elem callbacks for hash map. __htab_map_lookup_and_delete_batch() also disables migration before invoking free_htab_elem(). ->map_update_elem() and ->map_delete_elem() of hash map may be invoked by BPF program and the running context of BPF program has already disabled migration. Therefore, it is safe to remove the migration_{disable|enable} pair in htab_elem_free() Signed-off-by: Hou Tao --- kernel/bpf/hashtab.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c index 3c1122281d986..7f09943c6ee22 100644 --- a/kernel/bpf/hashtab.c +++ b/kernel/bpf/hashtab.c @@ -898,11 +898,9 @@ static void htab_elem_free(struct bpf_htab *htab, struct htab_elem *l) { check_and_free_fields(htab, l); - migrate_disable(); if (htab->map.map_type == BPF_MAP_TYPE_PERCPU_HASH) bpf_mem_cache_free(&htab->pcpu_ma, l->ptr_to_pptr); bpf_mem_cache_free(&htab->ma, l); - migrate_enable(); } static void htab_put_fd_value(struct bpf_htab *htab, struct htab_elem *l)