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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 0CDE7C468C6 for ; Tue, 17 Jul 2018 21:30:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD0A82075E for ; Tue, 17 Jul 2018 21:30:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jOX2W2e4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD0A82075E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730869AbeGQWEq (ORCPT ); Tue, 17 Jul 2018 18:04:46 -0400 Received: from mail-vk0-f68.google.com ([209.85.213.68]:32887 "EHLO mail-vk0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729742AbeGQWEq (ORCPT ); Tue, 17 Jul 2018 18:04:46 -0400 Received: by mail-vk0-f68.google.com with SMTP id y70-v6so1397965vkc.0; Tue, 17 Jul 2018 14:30:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=ePT1hv7iWzZgRWhg3eMMNq4TEXwmNCubXlnVUnxU2Rw=; b=jOX2W2e4jw/ObrtQAgG9qdFfL9e3OpQoXMNlhGKopzGB4pg9I2C8Ew2giWyBzuj1cf 4uSkc7IM9xqLgccC+JwjZfXXzOEZK1S7sO3kzV+P0o3oJluDwz+/ZY50xDFkUe6aT/fU D4wtBetW2bNfMYG1RP0uysbRtniakTnwf7P8bPOf8qjYlSABE4MLIPcC23F3y/rF1z8p RQ55U2zl5kj9bfORAbtaHekTkKAGWrwoYZglTD/kbpjBGRKXv5ytO78WScPfpuPa/8Oq 3NDIHjaJYttBe85dGpxxabPfdehhPpO5/g79uT7/bMGG1J7reLXG1rGnR6HlVZDML1V9 tU6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=ePT1hv7iWzZgRWhg3eMMNq4TEXwmNCubXlnVUnxU2Rw=; b=W3MOwlwMqPRqK2jZONKLDvNm6aDOdC7BLU2faSRnXH6osf425Y7yIr9KmbuR5uWEsN /0XQiyNU/mCopCDqpOUPM24Hlae+wQMzCdXqs62rL178qTCZShkHNI7Dcud3oo8KiZCq amgx8RlpRUKQDuTLW2F9l61bNRMk7DfRe1SNkL1GQZeMB9oq8pWgftmEKNiss/QE8t+Y RtwGWqigI50yDvL9vlKiNfBSkci4dJ4NsN0bePPLkpcWhnOei6Ak9+z3M7s70osGZCQ3 h1oyLPYANJhflJ23zV+uhillYTkvxgOTs0XwHv76fv4hZiO5LW0tcA5QgMJG8lPJPkAG pUTQ== X-Gm-Message-State: AOUpUlEbA7Xn7r5nMHtOT58VICNziWJnslNiADUSEWOnEXPnd8Cc+Nr7 zxRLp3Ixem28p8uHFl25JrSC7EXHW5xxbN7hY0g= X-Google-Smtp-Source: AAOMgpds2pqSKsUp0uht1mnLgHHkYkAQg67SgI7J1wRAVZs92pUiZFX26Kyq0UrjjZOD+r/wTgCIBzIKoZEnCM3w6rA= X-Received: by 2002:a1f:8e4d:: with SMTP id q74-v6mr2029446vkd.161.1531863011909; Tue, 17 Jul 2018 14:30:11 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a67:2149:0:0:0:0:0 with HTTP; Tue, 17 Jul 2018 14:30:11 -0700 (PDT) In-Reply-To: <20180717142314.32337-2-alexandre.belloni@bootlin.com> References: <20180717142314.32337-1-alexandre.belloni@bootlin.com> <20180717142314.32337-2-alexandre.belloni@bootlin.com> From: Andy Shevchenko Date: Wed, 18 Jul 2018 00:30:11 +0300 Message-ID: Subject: Re: [PATCH 1/5] spi: dw: fix possible race condition To: Alexandre Belloni Cc: Mark Brown , James Hogan , Paul Burton , linux-spi , devicetree , Linux Kernel Mailing List , Linux MIPS Mailing List , Thomas Petazzoni , Allan Nielsen Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 17, 2018 at 5:23 PM, Alexandre Belloni wrote: > It is possible to get an interrupt as soon as it is requested. dw_spi_irq > does spi_controller_get_devdata(master) and expects it to be different than > NULL. However, spi_controller_set_devdata() is called after request_irq(), > resulting in the following crash: > > CPU 0 Unable to handle kernel paging request at virtual address 00000030, epc == 8058e09c, ra == 8018ff90 > [...] > Call Trace: > [<8058e09c>] dw_spi_irq+0x8/0x64 > [<8018ff90>] __handle_irq_event_percpu+0x70/0x1d4 > [<80190128>] handle_irq_event_percpu+0x34/0x8c > [<801901c4>] handle_irq_event+0x44/0x80 > [<801951a8>] handle_level_irq+0xdc/0x194 > [<8018f580>] generic_handle_irq+0x38/0x50 > [<804c6924>] ocelot_irq_handler+0x104/0x1c0 > [<8018f580>] generic_handle_irq+0x38/0x50 > [<8075c1d8>] do_IRQ+0x18/0x24 > [<804c4714>] plat_irq_dispatch+0xa4/0x150 > [<80106ba8>] except_vec_vi_end+0xb8/0xc4 > [<8075ba5c>] _raw_spin_unlock_irqrestore+0x14/0x20 > [<801926c8>] __setup_irq+0x53c/0x8e0 > [<80192e28>] request_threaded_irq+0xf4/0x1e8 > [<8058ed18>] dw_spi_add_host+0x264/0x2c4 > [<8058f2ec>] dw_spi_mmio_probe+0x258/0x27c > [<8051f4a4>] platform_drv_probe+0x58/0xbc > [<8051daa8>] driver_probe_device+0x308/0x40c > [<8051dc9c>] __driver_attach+0xf0/0xf8 > [<8051b698>] bus_for_each_dev+0x78/0xcc > [<8051c2c0>] bus_add_driver+0x1b4/0x228 > [<8051e840>] driver_register+0x84/0x154 > [<801001d8>] do_one_initcall+0x54/0x1ac > [<80880e90>] kernel_init_freeable+0x1ec/0x2ac > [<80755310>] kernel_init+0x14/0x110 > [<80106698>] ret_from_kernel_thread+0x14/0x1c > Code: 00000000 8ca40050 8c820008 <8c420030> 0000000f 3042003f 10400007 00000000 8ca20230 > Good catch! Reviewed-by: Andy Shevchenko > Signed-off-by: Alexandre Belloni > --- > drivers/spi/spi-dw.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c > index f693bfe95ab9..a087464efdd7 100644 > --- a/drivers/spi/spi-dw.c > +++ b/drivers/spi/spi-dw.c > @@ -485,6 +485,8 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws) > dws->dma_inited = 0; > dws->dma_addr = (dma_addr_t)(dws->paddr + DW_SPI_DR); > > + spi_controller_set_devdata(master, dws); > + > ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, dev_name(dev), > master); > if (ret < 0) { > @@ -518,7 +520,6 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws) > } > } > > - spi_controller_set_devdata(master, dws); > ret = devm_spi_register_controller(dev, master); > if (ret) { > dev_err(&master->dev, "problem registering spi master\n"); > -- > 2.18.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-spi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- With Best Regards, Andy Shevchenko