From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from abb.hmeau.com (abb.hmeau.com [180.181.231.80]) (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 B15DCC2FB; Wed, 3 Sep 2025 04:23:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=180.181.231.80 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756873440; cv=none; b=rATNGFR8vmY2YaZVK0MgbQa2XNi9kq5SvSVK/k4nIsF8b8dS5oJQHaNfDVjWB2Vixjv1H9GscGvXUVqSsqsjt0NomREHmLsY2vkNGgQ78PxtbiGUWmDIBColh2Zdub6iOnnttZqTmywQbId6Aovjh128gPDi08JKvSA08MsO/tE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756873440; c=relaxed/simple; bh=svNKh6v9xSbreRbIN5AHavHDnFJA4RcUXkK5blEmANo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VAgzzEBETtrJhYAE7PiReG/Dtq3My4V91SVD5kISwYh5xKj8I8GRFzelI463Cqq/M7pVf1sFWzCYta69TjJ5tvTqdBNmsjwT9kmznh1Cv0TNMWq3zDL2el8X36JnicOJ8uYQHo0/whe38XuOXJZKmdwf5jWhQJOYLATNs9ofrLc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gondor.apana.org.au; spf=pass smtp.mailfrom=gondor.apana.org.au; dkim=pass (2048-bit key) header.d=hmeau.com header.i=@hmeau.com header.b=rkHbc0bj; arc=none smtp.client-ip=180.181.231.80 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gondor.apana.org.au Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gondor.apana.org.au Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=hmeau.com header.i=@hmeau.com header.b="rkHbc0bj" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=hmeau.com; s=formenos; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=pp1cKx0IjF5K66uP8QvoXn/uM1IyZZrNOlgAlK7jAEg=; b=rkHbc0bjzoSGPLg8QowyCMDRa2 mDiMogQN8ftzE/WLFgxcQ5Npq8Fy1+YXuO+LOTraNb/8WwS2xIuS4dVTl99kK9fI4V6k25n2ZUV8N C+MK5H2GALbw5e6ku9TGmYbINza7l9Va0foMrr37d41gdte2weocoxDSuXagfZdLpYz/6q6qMlxka XX1I0m6MP+908gmfdxj7RYUBoBoBQMQRWjHEelmKv5cWuYx4jbbKkFy837JbsJ5hHCKpRhZehhFtj IRDhREp0+vEn1TWLbxnPqg/F1kl1VOypqBo84EG7eiePL2Lmiww4uPKkzSNasH2difB74s8n1gCqg UftTNCQQ==; Received: from loth.rohan.me.apana.org.au ([192.168.167.2]) by formenos.hmeau.com with smtp (Exim 4.96 #2 (Debian)) id 1utemj-002CsD-2t; Wed, 03 Sep 2025 12:23:47 +0800 Received: by loth.rohan.me.apana.org.au (sSMTP sendmail emulation); Wed, 03 Sep 2025 12:23:46 +0800 Date: Wed, 3 Sep 2025 12:23:46 +0800 From: Herbert Xu To: Steven Rostedt Cc: Menglong Dong , mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, oliver.sang@intel.com Subject: Re: [PATCH] tracing: fprobe: fix suspicious rcu usage in fprobe_entry Message-ID: References: <20250829021436.19982-1-dongml2@chinatelecom.cn> <20250902105757.16a78aea@batman.local.home> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250902105757.16a78aea@batman.local.home> On Tue, Sep 02, 2025 at 10:57:57AM -0400, Steven Rostedt wrote: > > And then have: > > quiet_rcu_read_lock_check(); > head = rhltable_lookup(&fprobe_ip_table, &func, fprobe_rht_params); > quiet_rcu_read_unlock_check(); The thing is that rhl_for_each_entry_rcu which is called right after your unlock above should have created the same warning as rhltable_lookup. The fact that it doesn't appears to be a bug: it's using rcu_dereference_raw and I don't see why that's safe at all. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt