From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4900630114C for ; Wed, 2 Jul 2025 17:20:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751476843; cv=none; b=JOATi8r0bAV+iBK6Wg7fedGOnIUkKp5ZnIxjhw32meT3HYnYrlG811NBKzrF+PBU9CpsLQDRm/L9mMTsoMyhSR1bEh2w++Jm2JcOtoNbJiqrpY6B1/MUc2wx/zcSyvnRNxLQQ8xbF4N2clVrjz0svHXyNuPx1A5wZ91H26L573Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751476843; c=relaxed/simple; bh=hBRsTaZN3yhbrtxDCnm/9im/m52mRlSQjlRRRmBUWFE=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=n2vNKRAc6q/ZpPdv8/26NsRzcmbc62nqFMDzpWJbLkiqyqU3qKs4qgEPNYvwj0msdCMN2P1OLR7BxR4hEB8lrYTg7whoCOqz5wdF1EH6aHT2fW2m0qRAehuOF5QlKdLrhYj+lZodwjkyIlOciW9d/VNgv21rRG0uRg0fdDKfNVI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TujIKPls; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TujIKPls" Received: by smtp.kernel.org (Postfix) with ESMTPS id E6C5EC4CEEF for ; Wed, 2 Jul 2025 17:20:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751476842; bh=hBRsTaZN3yhbrtxDCnm/9im/m52mRlSQjlRRRmBUWFE=; h=From:To:Subject:Date:In-Reply-To:References:From; b=TujIKPlsvwbH7vYeLkjjY/CR7TVp4JXWmgKpe0X7x0Pqlq+O/jJgr2nzhpmFX48dp ln0mET9cj9WtqmLoAwJwZ0j0wu+MaVvBNWYi7tM2WRjOTn2Ber8i0LtvJgukLPnCvO 7cfJIP4sksBTUHz1EfmhZgp1bX6ZkxsrVN40KOV9bvEEedeh25Wur2gemXMUUtMBa0 YQbbmeZhiQN8v2FfkfeOEM0fiurM9Sra0I5BZDqgwzW9jdvOyHdIXodcufaZdqXUz7 SysXHzK2pTLfHZvQKS+kkjDHpP6YYIOpwhNLeNA0gRMcMldJyoUgV+olLaq5Kut86T e91Z7t+dgk/vQ== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id DF572C3279F; Wed, 2 Jul 2025 17:20:42 +0000 (UTC) From: bugzilla-daemon@kernel.org To: linux-usb@vger.kernel.org Subject: [Bug 220272] Latent race condition in USB code unveiled with optimized memset_64.S Date: Wed, 02 Jul 2025 17:20:42 +0000 X-Bugzilla-Reason: None X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: AssignedTo drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Product: Drivers X-Bugzilla-Component: USB X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: oliver@neukum.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: drivers_usb@kernel-bugs.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 https://bugzilla.kernel.org/show_bug.cgi?id=3D220272 --- Comment #28 from Oliver Neukum (oliver@neukum.org) --- (In reply to Alan Stern from comment #27) > But if that's the explanation then why does the driver work properly some= of > the time? Memory pressure on the cache. Sometimes cache lines will be invalidated. If you want to stay with the theory that this is a cache issue. Your diagnosis in #23 is correct. The driver is operating on a zeroed buffe= r. If we are also taking #25 then we'd have to assume that two different mice = fail in the same way, but inconsistently and only if a specific memset is used. Not really likely. My first suspicion was that we are looking at an issue with HCD with short transfers, specifically that te buffer is not really used and the IO done to the rings, but I see no way how this would correlate with a change in memse= t. Do we need to memset the buffers to 0x00? How about a diagnostic patch that uses another value? --=20 You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.=