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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 845D8C433F5 for ; Fri, 14 Jan 2022 10:10:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239349AbiANKKH (ORCPT ); Fri, 14 Jan 2022 05:10:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237721AbiANKKG (ORCPT ); Fri, 14 Jan 2022 05:10:06 -0500 Received: from mail-wr1-x42c.google.com (mail-wr1-x42c.google.com [IPv6:2a00:1450:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C8FB5C06161C for ; Fri, 14 Jan 2022 02:10:05 -0800 (PST) Received: by mail-wr1-x42c.google.com with SMTP id s1so14727942wra.6 for ; Fri, 14 Jan 2022 02:10:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=L+CN0gq3pLA6121ynnyAoFcRb1N4uFyFb+K1IzpWX/o=; b=Sxqfvyrg7X1JdLYtF4p7qZ9Lr/i6nC1UdCzXNxywNQGigjq+CXu96nOBxtzAMpVtDG MBCL6wEVeY7/2TpvwRdkENTR142OZemjnMcA679PtpRL7rQKOgTIvleawheeGfLM4akj +e+w6wK30D2BV+nx0sdUIayktQ4PZojXpBmUAz1lA4TMaa4wC/XX6ZPVKDdcP83a6n5c BDxjKAhvGOgQptQAk7FktsXGCsUImFhuMyBkLpoAcwTU9Rg5Q3RqVY6Ah7mVpj9CQMHS xqXYVe8ipNH2vERX5X58G1h/9PXJ4nSC1aO9lk612K69zrIHJLAoffCHoa5sZ4ujF76J ibeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=L+CN0gq3pLA6121ynnyAoFcRb1N4uFyFb+K1IzpWX/o=; b=7uds8lo2W1K18asN3zscQlhcDuyUvSYZ4K5q4L621kvJrUNrPrCSK/CORs+sEaCPiR WzVJ4HatgVk1oH//3SpfuOafGuCAO48f5mME/vcW5o9FbO8MCPOI410zNAYws9WsyLEG e01tFlZuNaT3WgBcI+tqjelt21PQU45u4+o1H8wbIwKQWtRaJL1ACi8fytlBmF8g9ZCE izjbN8xnnAE4EpW8V/JZwiEVqP9kR0alclulRvPQ4QX0CW1n1VWO3ltn9Sh35X4Nimnt /r1FLu4qZBKCoLQF3QqIh/AYjrDZbA5mRHurG+B2mK4moiTM06niXB/UEZvlOZomUxKb Ch2w== X-Gm-Message-State: AOAM531/DUYcD9xlV6GOOWmMxIpgq6usFLtdZbV//lPA9hf0TVzZHrgK 3voDv+SoRa36Ml4tzOq0DxuPEkU/DP0+yQ== X-Google-Smtp-Source: ABdhPJwwmp3enXaurDy1M0y2dns9KYDg6m61xUfowYASjv4QdrVtXmbWWVc2AucaYUoYGfMi4PIGag== X-Received: by 2002:a5d:64eb:: with SMTP id g11mr7765372wri.135.1642155004435; Fri, 14 Jan 2022 02:10:04 -0800 (PST) Received: from google.com ([31.124.24.179]) by smtp.gmail.com with ESMTPSA id j13sm11345704wmq.11.2022.01.14.02.10.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Jan 2022 02:10:04 -0800 (PST) Date: Fri, 14 Jan 2022 10:10:02 +0000 From: Lee Jones To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , Pavel Machek , Len Brown , linux-pm@vger.kernel.org Subject: Re: [PATCH] pm / wakeup: simplify the output logic of pm_show_wakelocks() Message-ID: References: <20220113184420.2504545-1-gregkh@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220113184420.2504545-1-gregkh@linuxfoundation.org> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, 13 Jan 2022, Greg Kroah-Hartman wrote: > The buffer handling in pm_show_wakelocks() is tricky, and hopefully > correct. Ensure it really is correct by using sysfs_emit_at() which > handles all of the tricky string handling logic in a PAGE_SIZE buffer > for us automatically as this is a sysfs file being read from. > > Cc: "Rafael J. Wysocki" > Cc: Pavel Machek > Cc: Len Brown > Cc: linux-pm@vger.kernel.org > Cc: Lee Jones > Signed-off-by: Greg Kroah-Hartman > --- > kernel/power/wakelock.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) Reviewed-by: Lee Jones > diff --git a/kernel/power/wakelock.c b/kernel/power/wakelock.c > index 105df4dfc783..52571dcad768 100644 > --- a/kernel/power/wakelock.c > +++ b/kernel/power/wakelock.c > @@ -39,23 +39,20 @@ ssize_t pm_show_wakelocks(char *buf, bool show_active) > { > struct rb_node *node; > struct wakelock *wl; > - char *str = buf; > - char *end = buf + PAGE_SIZE; > + int len = 0; > > mutex_lock(&wakelocks_lock); > > for (node = rb_first(&wakelocks_tree); node; node = rb_next(node)) { > wl = rb_entry(node, struct wakelock, node); > if (wl->ws->active == show_active) > - str += scnprintf(str, end - str, "%s ", wl->name); > + len += sysfs_emit_at(buf, len, "%s ", wl->name); > } > - if (str > buf) > - str--; > > - str += scnprintf(str, end - str, "\n"); > + len += sysfs_emit_at(buf, len, "\n"); > > mutex_unlock(&wakelocks_lock); > - return (str - buf); > + return len; > } > > #if CONFIG_PM_WAKELOCKS_LIMIT > 0 -- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog