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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 527BEC56202 for ; Wed, 25 Nov 2020 15:20:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF0F12067D for ; Wed, 25 Nov 2020 15:20:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730123AbgKYPUu (ORCPT ); Wed, 25 Nov 2020 10:20:50 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:42098 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729738AbgKYPUt (ORCPT ); Wed, 25 Nov 2020 10:20:49 -0500 Received: from mail-wr1-f72.google.com ([209.85.221.72]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1khwb9-0007Kr-PN for linux-kernel@vger.kernel.org; Wed, 25 Nov 2020 15:20:47 +0000 Received: by mail-wr1-f72.google.com with SMTP id w17so878520wrp.11 for ; Wed, 25 Nov 2020 07:20:47 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=1MLMHISOaIgeTutRvpuwhXxO602bfmP5K9rHz4FiRbk=; b=XRRt2UhNydJn0rv9RdSeZa4k382fX5ghit41uJDCyY1J8J2UWq/FH6F6LqsRra0XrS 91I6z1wRYAnscV0Ler4mm8aQUX6q2ND7fe/SOIrrYkTw025cmA7trSQLkAIsuyd7Uztx qtWP4hoQSUc8cLliPk2DWLUg1z2tyk4B26DSkaYxgHWagm0GrpmC7UAXTefQ2I2NgeIb Ne8/v58Yq7ex96ycMpHFEFF4T7OUd+wOb0g/+ieH5TVz3SGe1AdnBxnhhhiVtP9xvoKZ 23HrVRVEsYYW+ds835hNzUOCfwNZoMUjDlfJZf3z62fOYLV3/TLZrTZgLfcP1QumCYQv r5Jg== X-Gm-Message-State: AOAM5308ov8s+Gw9d+bE0BFUa3QMUWjmF3JyYHcWshW1pQIqMsqypBZN x9NEPOcSzIBsgvxExxs1CwpX2v2cCIKj3B3vbgbb4MTnNvgHJw/8l6ILet0w0y/oQryt9d/av0C PSCjTBYQC3X12NaHOZBNZRes3Kh83tJb17IhyBqsJMg== X-Received: by 2002:a1c:21c1:: with SMTP id h184mr4622244wmh.106.1606317644471; Wed, 25 Nov 2020 07:20:44 -0800 (PST) X-Google-Smtp-Source: ABdhPJxNl3QW6kYs2TIKJGqJ7Hpd3zDYSdJfygEszsCEVOuPl+mFLvTEXyKWiO90gc5dVPV8CMfqbQ== X-Received: by 2002:a1c:21c1:: with SMTP id h184mr4622220wmh.106.1606317644221; Wed, 25 Nov 2020 07:20:44 -0800 (PST) Received: from localhost (host-79-35-122-236.retail.telecomitalia.it. [79.35.122.236]) by smtp.gmail.com with ESMTPSA id i11sm5262891wrm.1.2020.11.25.07.20.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Nov 2020 07:20:43 -0800 (PST) Date: Wed, 25 Nov 2020 16:20:42 +0100 From: Andrea Righi To: Pavel Machek Cc: Boqun Feng , Dan Murphy , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] leds: trigger: fix potential deadlock with libata Message-ID: <20201125152042.GC73489@xps-13-7390> References: <20201102104152.GG9930@xps-13-7390> <20201125124648.GJ29328@amd> <20201125141517.GA73489@xps-13-7390> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201125141517.GA73489@xps-13-7390> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 25, 2020 at 03:15:18PM +0100, Andrea Righi wrote: ... > > I'd hate to see this in stable 3 days after Linus merges it... > > > > Do these need _irqsave, too? > > > > drivers/leds/led-triggers.c: read_lock(&trig->leddev_list_lock); > > drivers/leds/led-triggers.c: read_unlock(&trig->leddev_list_lock); > > drivers/leds/led-triggers.c: read_lock(&trig->leddev_list_lock); > > drivers/leds/led-triggers.c: read_unlock(&trig->leddev_list_lock); > > > > Best regards, > > I think also led_trigger_blink_setup() needs to use irqsave/irqrestore, > in fact: > > $ git grep "led_trigger_blink(" > drivers/leds/led-triggers.c:void led_trigger_blink(struct led_trigger *trig, > drivers/power/supply/power_supply_leds.c: led_trigger_blink(psy->charging_blink_full_solid_trig, > include/linux/leds.h:void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on, > include/linux/leds.h:static inline void led_trigger_blink(struct led_trigger *trigger, > > power_supply_leds.c is using led_trigger_blink() from a workqueue > context, so potentially the same deadlock condition can also happen. > > Let me know if you want me to send a new patch to include also this > case. Just sent (and tested) a v2 of this patch that changes also led_trigger_blink_setup(). -Andrea