From patchwork Mon Oct 5 14:02:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 1376798 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=kernel.org Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=default header.b=ju6CVsNs; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4C4j3545l2z9ryj for ; Tue, 6 Oct 2020 01:02:25 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726018AbgJEOCY (ORCPT ); Mon, 5 Oct 2020 10:02:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:54056 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725954AbgJEOCY (ORCPT ); Mon, 5 Oct 2020 10:02:24 -0400 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AF4492085B; Mon, 5 Oct 2020 14:02:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601906543; bh=rxc3XhX1nx8QuYTrJNvWee/HrGELRzW/U/KzDS85YDg=; h=From:To:Cc:Subject:Date:From; b=ju6CVsNsFA93xbg1UKUxKjShRajQ/HLrcgiXnddy29nUbWxNnJRf7+J6mTVH6W+Rt w4m2JALHdxvEcrxSQKRqm0+Afzu7qww67afRDxpJwdAOzuIqI/6V4LISaXISHX3sUy nXGOo5NPECZ74QJ4T0P95XWd+tlbOdW3vLe18lWE= Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kPR4H-00HOH4-7u; Mon, 05 Oct 2020 15:02:21 +0100 From: Marc Zyngier To: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Linus Walleij , Bartosz Golaszewski , kernel-team@android.com Subject: [PATCH] gpio: pca953x: Survive spurious interrupts Date: Mon, 5 Oct 2020 15:02:17 +0100 Message-Id: <20201005140217.1390851-1-maz@kernel.org> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linus.walleij@linaro.org, bgolaszewski@baylibre.com, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The pca953x driver never checks the result of irq_find_mapping(), which returns 0 when no mapping is found. When a spurious interrupt is delivered (which can happen under obscure circumstances), the kernel explodes as it still tries to handle the error code as a real interrupt. Handle this particular case and warn on spurious interrupts. Signed-off-by: Marc Zyngier --- drivers/gpio/gpio-pca953x.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c index fb61f2fc6ed7..c2d6121c48c9 100644 --- a/drivers/gpio/gpio-pca953x.c +++ b/drivers/gpio/gpio-pca953x.c @@ -824,8 +824,21 @@ static irqreturn_t pca953x_irq_handler(int irq, void *devid) ret = pca953x_irq_pending(chip, pending); mutex_unlock(&chip->i2c_lock); - for_each_set_bit(level, pending, gc->ngpio) - handle_nested_irq(irq_find_mapping(gc->irq.domain, level)); + if (ret) { + ret = 0; + + for_each_set_bit(level, pending, gc->ngpio) { + int nested_irq = irq_find_mapping(gc->irq.domain, level); + + if (unlikely(nested_irq <= 0)) { + dev_warn_ratelimited(gc->parent, "unmapped interrupt %d\n", level); + continue; + } + + handle_nested_irq(nested_irq); + ret = 1; + } + } return IRQ_RETVAL(ret); }