Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753521AbdCFJWO (ORCPT ); Mon, 6 Mar 2017 04:22:14 -0500 Received: from mx2.suse.de ([195.135.220.15]:37305 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753026AbdCFJOG (ORCPT ); Mon, 6 Mar 2017 04:14:06 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Jiri Slaby Subject: [PATCH 3.12 087/113] goldfish: Sanitize the broken interrupt handler Date: Mon, 6 Mar 2017 10:11:51 +0100 Message-Id: <94e5bdac8a29138a96e560a8c8d4607e2d8d9e20.1488791431.git.jslaby@suse.cz> X-Mailer: git-send-email 2.12.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1898 Lines: 68 From: Thomas Gleixner 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 6cf18e6927c0b224f972e3042fb85770d63cb9f8 upstream. This interrupt handler is broken in several ways: - It loops forever when the op code is not decodeable - It never returns IRQ_HANDLED because the only way to exit the loop returns IRQ_NONE unconditionally. The whole concept of this is broken. Creating devices in an interrupt handler is beyond any point of sanity. Make it at least behave halfways sane so accidental users do not have to deal with a hard to debug lockup. Fixes: e809c22b8fb028 ("goldfish: add the goldfish virtual bus") Reported-by: Gabriel C Signed-off-by: Thomas Gleixner Acked-by: Linus Torvalds Signed-off-by: Jiri Slaby --- drivers/platform/goldfish/pdev_bus.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/platform/goldfish/pdev_bus.c b/drivers/platform/goldfish/pdev_bus.c index 92cc4cfafde5..6bcd57cb2f75 100644 --- a/drivers/platform/goldfish/pdev_bus.c +++ b/drivers/platform/goldfish/pdev_bus.c @@ -153,23 +153,26 @@ static int goldfish_new_pdev(void) static irqreturn_t goldfish_pdev_bus_interrupt(int irq, void *dev_id) { irqreturn_t ret = IRQ_NONE; + while (1) { u32 op = readl(pdev_bus_base + PDEV_BUS_OP); - switch (op) { - case PDEV_BUS_OP_DONE: - return IRQ_NONE; + switch (op) { case PDEV_BUS_OP_REMOVE_DEV: goldfish_pdev_remove(); + ret = IRQ_HANDLED; break; case PDEV_BUS_OP_ADD_DEV: goldfish_new_pdev(); + ret = IRQ_HANDLED; break; + + case PDEV_BUS_OP_DONE: + default: + return ret; } - ret = IRQ_HANDLED; } - return ret; } static int goldfish_pdev_bus_probe(struct platform_device *pdev) -- 2.12.0