From patchwork Wed Feb 14 08:48:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13556074 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 32D18B64A for ; Wed, 14 Feb 2024 08:48:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707900517; cv=none; b=YIGdn/BQNzDMA/EXRoo59Lcs9MN2Mh0RV3xlev2uAyz8P9USAzFdlRrTpM6prfC+vuRAXwGYorSdnfq27MAZGxyNp0+1SjWlnonsjdz5S3O2DPuRapDREo9myWjojblyU1QEvJQt6KNqQVQ/TMSLQ3BiQPcOKog/t9Gh+yMHBHY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707900517; c=relaxed/simple; bh=qi5Bs7Cf2a/XS99tp48PJPpELPUcFcpZoHc9zokTEC4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=UhPbeYRfc6JnZ12pGjsMtz0g0MZ4HqkDtUMsjQOfO2LnR76F9/E/BW9NXYKtA0QaTQwBdWhHUJaKt/B0dsy0FJHZMeDMPH1eiP91WQ34ZhWpH8rFI1OYi995qQYlesjiNxYKazWJbyZR2da0eyPJYYkUxz2p61Vh5T+5vqNZIXQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=Z0eRummk; arc=none smtp.client-ip=209.85.128.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="Z0eRummk" Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-5efe82b835fso118116377b3.0 for ; Wed, 14 Feb 2024 00:48:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1707900515; x=1708505315; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=vgH6jFYJlZcCO1muBwFlEgXGTqXSIAVOsixhgGigIv4=; b=Z0eRummkMIUk2E9fnjJZQdU8B79u2qa/JnVHPOhX4Qehn04035XMfLPxHE0hQgeGzq tTQi0UZfPFR9+kEM70ivoty+G6oh6RG1iGTzIxXOd1IPe8/KjBnvcVrSaGtNbChUr/FE 90Iud7KZX586YdIUFMmOPrv3e8NNYf26LnXBmPyGm/Lksu09nIH9JFtq2WQYlzDCAyCW 8N2x1IeU3H/igMm+hcbs02EDF314naiAo7OKSI1SV+XgUEOM1ZcCEm6hwBlUGt6Sh5UE iZB1EvB4i5H3rF/5h8y/ckxrMCO0SDVPgGfx6+04wLYlTpEIRzUkaLareE6fv6OuSoa0 Pw7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1707900515; x=1708505315; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=vgH6jFYJlZcCO1muBwFlEgXGTqXSIAVOsixhgGigIv4=; b=qnthdHRD0MCNVQGCUU0c8hXPt9OOccn2HuGPpHDVGwy9iBqG4pNVx2rTivPKV3JwNJ ptEoNhERwkkwo+/Yjug91nwJXEVBqVBXB3vZ/W8drBZuDIsKQOj2VssKR2+3jakcONCz BhccNcU7Vul6nv8v4JeV/ZSQBy24DnAYec4eFl4FK5gT1aaMwMwgAXbptC23/0F04Tdj CRZAlLdxniTwpevTIcgwG4ylek7KD8nd5AkjfwSgChyNTECCNYoEQUzvmv+SZl9O9CZj O41ud0delalPS0KiQfyZAatMGOqTKZzWcRd3ATiT/6okk/33rPuLBf6u66MtXGeJMOeL FQHA== X-Forwarded-Encrypted: i=1; AJvYcCVUaH9CyIImGRhvu3UwzhoP3Osq0OABhpjT8DLLE/zXF5h0f2mGUOh4wfpiAE09BNwMypt844snNfG57WlhpU3ybBBMXdyv X-Gm-Message-State: AOJu0Yx8FPBEplwMyobM9INExaodym94IjX9TDFiu42a6YL8yGzlMIeu dscYkRc/z+LijyPU6p0lxPmLohfnI12FmbuXIghJjBpfIr8QQiYrP/n9Yp+jBAT+AYXjvNYMcYr e0vLarumCjA== X-Google-Smtp-Source: AGHT+IELTMuQWEVV+IdSL9R1xizsS+OgXyKRcKJaDe+k6pK9UnxJHdzgSNBBRhcMXnwspNDYDODWTVgTed52oA== X-Received: from edumazet1.c.googlers.com ([fda3:e722:ac3:cc00:2b:7d90:c0a8:395a]) (user=edumazet job=sendgmr) by 2002:a05:6902:70b:b0:dc6:dfd9:d431 with SMTP id k11-20020a056902070b00b00dc6dfd9d431mr391163ybt.1.1707900515291; Wed, 14 Feb 2024 00:48:35 -0800 (PST) Date: Wed, 14 Feb 2024 08:48:29 +0000 In-Reply-To: <20240214084829.684541-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240214084829.684541-1-edumazet@google.com> X-Mailer: git-send-email 2.43.0.687.g38aa6559b0-goog Message-ID: <20240214084829.684541-3-edumazet@google.com> Subject: [PATCH 2/2] kobject: reduce uevent_sock_mutex scope From: Eric Dumazet To: Greg Kroah-Hartman , Christian Brauner Cc: linux-kernel , "Rafael J . Wysocki" , Andrew Morton , netdev@vger.kernel.org, "David S . Miller" , Jakub Kicinski , Paolo Abeni , Eric Dumazet , Eric Dumazet This is a followup of commit a3498436b3a0 ("netns: restrict uevents") - uevent_sock_mutex no longer protects uevent_seqnum thanks to prior patch in the series. - uevent_net_broadcast() can run without holding uevent_sock_mutex. - Instead of grabbing uevent_sock_mutex before calling kobject_uevent_net_broadcast(), we can move the mutex_lock(&uevent_sock_mutex) to the place we iterate over uevent_sock_list : uevent_net_broadcast_untagged(). After this patch, typical netdevice creations and destructions calling uevent_net_broadcast_tagged() no longer need to acquire uevent_sock_mutex. Signed-off-by: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Christian Brauner Reviewed-by: Christian Brauner --- lib/kobject_uevent.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 9cb1a7fdaeba4fc5c698fbe84f359fb305345be1..03b427e2707e357ab12abeb9da234432c4bc0fb3 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -42,10 +42,9 @@ struct uevent_sock { #ifdef CONFIG_NET static LIST_HEAD(uevent_sock_list); -#endif - /* This lock protects uevent_sock_list */ static DEFINE_MUTEX(uevent_sock_mutex); +#endif /* the strings here must match the enum in include/linux/kobject.h */ static const char *kobject_actions[] = { @@ -315,6 +314,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env, int retval = 0; /* send netlink message */ + mutex_lock(&uevent_sock_mutex); list_for_each_entry(ue_sk, &uevent_sock_list, list) { struct sock *uevent_sock = ue_sk->sk; @@ -334,6 +334,7 @@ static int uevent_net_broadcast_untagged(struct kobj_uevent_env *env, if (retval == -ENOBUFS || retval == -ESRCH) retval = 0; } + mutex_unlock(&uevent_sock_mutex); consume_skb(skb); return retval; @@ -589,10 +590,8 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, if (retval) goto exit; - mutex_lock(&uevent_sock_mutex); retval = kobject_uevent_net_broadcast(kobj, env, action_string, devpath); - mutex_unlock(&uevent_sock_mutex); #ifdef CONFIG_UEVENT_HELPER /* call uevent_helper, usually only enabled during early boot */ @@ -743,9 +742,7 @@ static int uevent_net_rcv_skb(struct sk_buff *skb, struct nlmsghdr *nlh, return -EPERM; } - mutex_lock(&uevent_sock_mutex); ret = uevent_net_broadcast(net->uevent_sock->sk, skb, extack); - mutex_unlock(&uevent_sock_mutex); return ret; }