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 97A7D1F91C5 for ; Thu, 26 Jun 2025 16:20:50 +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=1750954850; cv=none; b=U9M8gykO8fYlDZXthcc/AhQA+AaC6EuCh6IoJ2j7Tzb37xu4HNuimbizECFJLxEvA/e5cQE0/xv+DNUaWOnmrgsIi6azu5o0QO40OfYJUWVuEmM/FAOVz67YxrF002kXuDeipNIRfp31lbBId6f64GRIoKiTPa7NwZlR9cqzag4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750954850; c=relaxed/simple; bh=JStSjlQQDp7gtmCjJev5xjoqgrBVYuEFp9xXfUPV2dI=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=kPP2vLKHyxa2qiKUg8T6IelppEZbqh1z8cxhF0xFReV5P1fC8fctV8Vt24bfp52R1DRQe3dptfhrOjZa7MONyOBjpQLkImHVhxAVJlmJR/koX/7Npnh12yPr0P1gbr9KO2kClciMRyCuRDCeqIWvO1HTNyspVj/OylF7Zi7il0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p3of0Bg8; 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="p3of0Bg8" Received: by smtp.kernel.org (Postfix) with ESMTPS id 77E7FC4CEEB for ; Thu, 26 Jun 2025 16:20:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750954850; bh=JStSjlQQDp7gtmCjJev5xjoqgrBVYuEFp9xXfUPV2dI=; h=From:To:Subject:Date:In-Reply-To:References:From; b=p3of0Bg8g9KQxPTyZJy8JunTZvtx9bl+CftXUQpJh7BTliGCSLOhw+oG+ZG5o+api 3TcKYKzKds74A1+tkSer+tpTHTtI+s2kxN0asvQTu+IV5a9EwC/L6oIeBQAaga2cHo Gofzs+5kbSpgpKL2whN2Cec1IIrEjKQlPiOmcgpD39wNKgE15lD0xCNM/ydZ97ButP BQlXrglnb5FF29CL2o3cHAeAr+nfw5riH//Z4/UTVarA/l4X/Pv9uoMfNjw/g8+oIC e4KG8joSTna2fe/01+GsdtQu2n2y5orMPSqTG2TTsp/qGurV99I5S1HGI11cOBR+im Auoq3E2LNZf+A== Received: by aws-us-west-2-korg-bugzilla-1.web.codeaurora.org (Postfix, from userid 48) id 63A38C3279F; Thu, 26 Jun 2025 16:20:50 +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: Thu, 26 Jun 2025 16:20:50 +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: m.seyfarth@gmail.com 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 #4 from Marcus Seyfarth (m.seyfarth@gmail.com) --- (In reply to Greg Kroah-Hartman from comment #1) > On Thu, Jun 26, 2025 at 11:39:35AM +0000, bugzilla-daemon@kernel.org wrot= e: > > Experimenting with AI to tune memset_64.S (see the attached file) for my > > Intel > > 14700KF-system unveiled a race condition in the USB code. >=20 > Odds are this is because your memset code is buggy :) >=20 > As this isn't an existing kernel issue, there's not much we can do about > this at the moment, sorry. @Greg and Alan Understood, I thought so, too. But maybe there is some truth to the AI analysis. I cannot tell anything myself as I do not bring any programming expertise to the table and am fully dependant on AI (which is far from perf= ect at this point in time, I know). However, AI analysis by O3 and Gemini 2.5 P= ro both claim that my custom memset is fine and pointed me towards multiple problems in the xhci_setup_device function of xhci.c. All attempts to fix the problem failed so far. Hence this could be a red herring, I cannot tell. If people are willing to spend some time on this, I have attached the customized memset_64.S as full file and as a patch. If people do not consid= er this actionable, that is totally fine with me, too. Kernel: 6.15.3 Distro: CachyOS --=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.=