From patchwork Tue Apr 26 08:20:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 567933 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7241FC433F5 for ; Tue, 26 Apr 2022 08:44:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236497AbiDZIrM (ORCPT ); Tue, 26 Apr 2022 04:47:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56552 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347072AbiDZIpq (ORCPT ); Tue, 26 Apr 2022 04:45:46 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB87843AD7; Tue, 26 Apr 2022 01:37:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 04B67CE1BC9; Tue, 26 Apr 2022 08:37:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E9F68C385A0; Tue, 26 Apr 2022 08:37:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650962234; bh=jESHIf0DUJpfwTSjPeAvmSihahXEUxYM6R7jE+M0Y+o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1nQL5YtCsmBzsWMit+yQR3rwoCOnf6R/sna8YBx/5msxl87fLrjhHxwGHqtCx+rvD CzYaQv2k87ex04K23b+rtztNu8Tv/BSCdpekeGm4/seGl3ZKH4qAYrxQWwX0w3GE3/ zgFjXsD+0qWQ40Ll1KE5Q08wHj637GebFPQKLNSk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dima Ruinskiy , Sasha Neftin , Naama Meir , Tony Nguyen , Sasha Levin Subject: [PATCH 5.15 029/124] igc: Fix infinite loop in release_swfw_sync Date: Tue, 26 Apr 2022 10:20:30 +0200 Message-Id: <20220426081748.132334626@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081747.286685339@linuxfoundation.org> References: <20220426081747.286685339@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sasha Neftin [ Upstream commit 907862e9aef75bf89e2b265efcc58870be06081e ] An infinite loop may occur if we fail to acquire the HW semaphore, which is needed for resource release. This will typically happen if the hardware is surprise-removed. At this stage there is nothing to do, except log an error and quit. Fixes: c0071c7aa5fe ("igc: Add HW initialization code") Suggested-by: Dima Ruinskiy Signed-off-by: Sasha Neftin Tested-by: Naama Meir Signed-off-by: Tony Nguyen Signed-off-by: Sasha Levin --- drivers/net/ethernet/intel/igc/igc_i225.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/igc/igc_i225.c b/drivers/net/ethernet/intel/igc/igc_i225.c index b6807e16eea9..a0e2a404d535 100644 --- a/drivers/net/ethernet/intel/igc/igc_i225.c +++ b/drivers/net/ethernet/intel/igc/igc_i225.c @@ -156,8 +156,15 @@ void igc_release_swfw_sync_i225(struct igc_hw *hw, u16 mask) { u32 swfw_sync; - while (igc_get_hw_semaphore_i225(hw)) - ; /* Empty */ + /* Releasing the resource requires first getting the HW semaphore. + * If we fail to get the semaphore, there is nothing we can do, + * except log an error and quit. We are not allowed to hang here + * indefinitely, as it may cause denial of service or system crash. + */ + if (igc_get_hw_semaphore_i225(hw)) { + hw_dbg("Failed to release SW_FW_SYNC.\n"); + return; + } swfw_sync = rd32(IGC_SW_FW_SYNC); swfw_sync &= ~mask;