From patchwork Thu Aug 13 10:52:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 258140 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 869C7C433E1 for ; Thu, 13 Aug 2020 10:59:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AEAE20771 for ; Thu, 13 Aug 2020 10:59:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726467AbgHMK77 (ORCPT ); Thu, 13 Aug 2020 06:59:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38172 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726072AbgHMK7s (ORCPT ); Thu, 13 Aug 2020 06:59:48 -0400 X-Greylist: delayed 420 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Thu, 13 Aug 2020 03:59:48 PDT Received: from mailout2.hostsharing.net (mailout2.hostsharing.net [IPv6:2a01:37:3000::53df:4ee9:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3D224C061757 for ; Thu, 13 Aug 2020 03:59:47 -0700 (PDT) Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.hostsharing.net", Issuer "COMODO RSA Domain Validation Secure Server CA" (not verified)) by mailout2.hostsharing.net (Postfix) with ESMTPS id C7E9D10189947; Thu, 13 Aug 2020 12:52:41 +0200 (CEST) Received: from localhost (unknown [89.246.108.87]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by h08.hostsharing.net (Postfix) with ESMTPSA id 8FAFF603DA32; Thu, 13 Aug 2020 12:52:41 +0200 (CEST) X-Mailbox-Line: From f827ff09da55b8c57d316a1b008a137677b58921 Mon Sep 17 00:00:00 2001 Message-Id: From: Lukas Wunner Date: Thu, 13 Aug 2020 12:52:40 +0200 Subject: [PATCH] serial: pl011: Fix oops on -EPROBE_DEFER To: Greg Kroah-Hartman , Jiri Slaby Cc: Russell King , linux-serial@vger.kernel.org, Aleksey Makarov , Peter Hurley , Christopher Covington Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org If probing of a pl011 gets deferred until after free_initmem(), an oops ensues because pl011_console_match() is called which has been freed. Fix by removing the __init attribute from the function and those it calls. Commit 10879ae5f12e ("serial: pl011: add console matching function") introduced pl011_console_match() not just for early consoles but regular preferred consoles, such as those added by acpi_parse_spcr(). Regular consoles may be registered after free_initmem() for various reasons, one being deferred probing, another being dynamic enablement of serial ports using a DeviceTree overlay. Thus, pl011_console_match() must not be declared __init and the functions it calls mustn't either. Stack trace for posterity: Unable to handle kernel paging request at virtual address 80c38b58 Internal error: Oops: 8000000d [#1] PREEMPT SMP ARM PC is at pl011_console_match+0x0/0xfc LR is at register_console+0x150/0x468 [<80187004>] (register_console) [<805a8184>] (uart_add_one_port) [<805b2b68>] (pl011_register_port) [<805b3ce4>] (pl011_probe) [<80569214>] (amba_probe) [<805ca088>] (really_probe) [<805ca2ec>] (driver_probe_device) [<805ca5b0>] (__device_attach_driver) [<805c8060>] (bus_for_each_drv) [<805c9dfc>] (__device_attach) [<805ca630>] (device_initial_probe) [<805c90a8>] (bus_probe_device) [<805c95a8>] (deferred_probe_work_func) Fixes: 10879ae5f12e ("serial: pl011: add console matching function") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v4.10+ Cc: Aleksey Makarov Cc: Peter Hurley Cc: Russell King Cc: Christopher Covington --- drivers/tty/serial/amba-pl011.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index c010f639298d..cd1ba8d8b0e6 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2241,9 +2241,8 @@ pl011_console_write(struct console *co, const char *s, unsigned int count) clk_disable(uap->clk); } -static void __init -pl011_console_get_options(struct uart_amba_port *uap, int *baud, - int *parity, int *bits) +static void pl011_console_get_options(struct uart_amba_port *uap, int *baud, + int *parity, int *bits) { if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) { unsigned int lcr_h, ibrd, fbrd; @@ -2276,7 +2275,7 @@ pl011_console_get_options(struct uart_amba_port *uap, int *baud, } } -static int __init pl011_console_setup(struct console *co, char *options) +static int pl011_console_setup(struct console *co, char *options) { struct uart_amba_port *uap; int baud = 38400; @@ -2344,8 +2343,8 @@ static int __init pl011_console_setup(struct console *co, char *options) * * Returns 0 if console matches; otherwise non-zero to use default matching */ -static int __init pl011_console_match(struct console *co, char *name, int idx, - char *options) +static int pl011_console_match(struct console *co, char *name, int idx, + char *options) { unsigned char iotype; resource_size_t addr;