From mboxrd@z Thu Jan 1 00:00:00 1970 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 A0D46C433E4 for ; Thu, 20 Aug 2020 12:30:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7AB3E208E4 for ; Thu, 20 Aug 2020 12:30:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597926659; bh=saIfEHG1GHEzf/+wjr30BPnCjZhXRuhKW1yiXlQKbAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zUAIOgkh4n6evQSRJSZEz6Zz494PtIP65eTpqMJpeVddSEtAMyCKjISpzJlMQXcDM LjDn46dTUuHz8cPvJ55Cxbc7cxntHl9eL+c9SEcUyFTE2CE1ibQT7JJG1+jPnhNWaG OnqvtWBnuNiJS12vpjB/VWItieP39oqYsN3X113w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727073AbgHTJvG (ORCPT ); Thu, 20 Aug 2020 05:51:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:59138 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729763AbgHTJuu (ORCPT ); Thu, 20 Aug 2020 05:50:50 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 B009E2075E; Thu, 20 Aug 2020 09:50:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597917050; bh=saIfEHG1GHEzf/+wjr30BPnCjZhXRuhKW1yiXlQKbAQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g5SayGW9hz+L/Xp5XyZvXl3sEgqmWiQujI0qMviylzopyBFvwMMMl9Yyx2iVXW7K7 B2qtuNZjRgfwp0BF7wwINCFYzzl7+thv36opDnt+uI7klfxlxwX4urJZye6St13eoC ZqhmL4Cg/7TVEblMkZC1bTbVHFBJvLFnu4QIPPtI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dhananjay Phadke , Florian Fainelli , Ray Jui , Wolfram Sang , Sasha Levin Subject: [PATCH 5.4 137/152] i2c: iproc: fix race between client unreg and isr Date: Thu, 20 Aug 2020 11:21:44 +0200 Message-Id: <20200820091600.827736817@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200820091553.615456912@linuxfoundation.org> References: <20200820091553.615456912@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dhananjay Phadke [ Upstream commit b1eef236f50ba6afea680da039ef3a2ca9c43d11 ] When i2c client unregisters, synchronize irq before setting iproc_i2c->slave to NULL. (1) disable_irq() (2) Mask event enable bits in control reg (3) Erase slave address (avoid further writes to rx fifo) (4) Flush tx and rx FIFOs (5) Clear pending event (interrupt) bits in status reg (6) enable_irq() (7) Set client pointer to NULL Unable to handle kernel NULL pointer dereference at virtual address 0000000000000318 [ 371.020421] pc : bcm_iproc_i2c_isr+0x530/0x11f0 [ 371.025098] lr : __handle_irq_event_percpu+0x6c/0x170 [ 371.030309] sp : ffff800010003e40 [ 371.033727] x29: ffff800010003e40 x28: 0000000000000060 [ 371.039206] x27: ffff800010ca9de0 x26: ffff800010f895df [ 371.044686] x25: ffff800010f18888 x24: ffff0008f7ff3600 [ 371.050165] x23: 0000000000000003 x22: 0000000001600000 [ 371.055645] x21: ffff800010f18888 x20: 0000000001600000 [ 371.061124] x19: ffff0008f726f080 x18: 0000000000000000 [ 371.066603] x17: 0000000000000000 x16: 0000000000000000 [ 371.072082] x15: 0000000000000000 x14: 0000000000000000 [ 371.077561] x13: 0000000000000000 x12: 0000000000000001 [ 371.083040] x11: 0000000000000000 x10: 0000000000000040 [ 371.088519] x9 : ffff800010f317c8 x8 : ffff800010f317c0 [ 371.093999] x7 : ffff0008f805b3b0 x6 : 0000000000000000 [ 371.099478] x5 : ffff0008f7ff36a4 x4 : ffff8008ee43d000 [ 371.104957] x3 : 0000000000000000 x2 : ffff8000107d64c0 [ 371.110436] x1 : 00000000c00000af x0 : 0000000000000000 [ 371.115916] Call trace: [ 371.118439] bcm_iproc_i2c_isr+0x530/0x11f0 [ 371.122754] __handle_irq_event_percpu+0x6c/0x170 [ 371.127606] handle_irq_event_percpu+0x34/0x88 [ 371.132189] handle_irq_event+0x40/0x120 [ 371.136234] handle_fasteoi_irq+0xcc/0x1a0 [ 371.140459] generic_handle_irq+0x24/0x38 [ 371.144594] __handle_domain_irq+0x60/0xb8 [ 371.148820] gic_handle_irq+0xc0/0x158 [ 371.152687] el1_irq+0xb8/0x140 [ 371.155927] arch_cpu_idle+0x10/0x18 [ 371.159615] do_idle+0x204/0x290 [ 371.162943] cpu_startup_entry+0x24/0x60 [ 371.166990] rest_init+0xb0/0xbc [ 371.170322] arch_call_rest_init+0xc/0x14 [ 371.174458] start_kernel+0x404/0x430 Fixes: c245d94ed106 ("i2c: iproc: Add multi byte read-write support for slave mode") Signed-off-by: Dhananjay Phadke Reviewed-by: Florian Fainelli Acked-by: Ray Jui Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-bcm-iproc.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c index 03475f1799730..dd9661c11782a 100644 --- a/drivers/i2c/busses/i2c-bcm-iproc.c +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -1037,7 +1037,7 @@ static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave) if (!iproc_i2c->slave) return -EINVAL; - iproc_i2c->slave = NULL; + disable_irq(iproc_i2c->irq); /* disable all slave interrupts */ tmp = iproc_i2c_rd_reg(iproc_i2c, IE_OFFSET); @@ -1050,6 +1050,17 @@ static int bcm_iproc_i2c_unreg_slave(struct i2c_client *slave) tmp &= ~BIT(S_CFG_EN_NIC_SMB_ADDR3_SHIFT); iproc_i2c_wr_reg(iproc_i2c, S_CFG_SMBUS_ADDR_OFFSET, tmp); + /* flush TX/RX FIFOs */ + tmp = (BIT(S_FIFO_RX_FLUSH_SHIFT) | BIT(S_FIFO_TX_FLUSH_SHIFT)); + iproc_i2c_wr_reg(iproc_i2c, S_FIFO_CTRL_OFFSET, tmp); + + /* clear all pending slave interrupts */ + iproc_i2c_wr_reg(iproc_i2c, IS_OFFSET, ISR_MASK_SLAVE); + + iproc_i2c->slave = NULL; + + enable_irq(iproc_i2c->irq); + return 0; } -- 2.25.1