From patchwork Mon Mar 29 07:58:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 411629 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 E7C6DC433E2 for ; Mon, 29 Mar 2021 08:04:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0124961999 for ; Mon, 29 Mar 2021 08:03:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231570AbhC2IDa (ORCPT ); Mon, 29 Mar 2021 04:03:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:45412 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231441AbhC2ICt (ORCPT ); Mon, 29 Mar 2021 04:02:49 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AB82B6197F; Mon, 29 Mar 2021 08:02:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617004968; bh=DeVbnc7dhfifVTkUd8+aO2oWriYvvGDHDJ/iwaqX5Lw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=z7p8VOhYLsGlpMUfBXZvBbx6v0RyArxxGqfdvrK64JWB0udCvBssV0PjZ2rRkPQ40 9IDGraSuNNgZ7e4nfIqUf2ALddkfs656lZBU4gS8JgvxrFUdh/hDCBfA5z0W/4N+Vd hXFeH3v94qEq4At6jUGTB7xgUeP1EoXH6EaNH3K4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Rafael J. Wysocki" , Hans de Goede , Sasha Levin Subject: [PATCH 4.9 33/53] ACPI: scan: Rearrange memory allocation in acpi_device_add() Date: Mon, 29 Mar 2021 09:58:08 +0200 Message-Id: <20210329075608.605488641@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075607.561619583@linuxfoundation.org> References: <20210329075607.561619583@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rafael J. Wysocki [ Upstream commit c1013ff7a5472db637c56bb6237f8343398c03a7 ] The upfront allocation of new_bus_id is done to avoid allocating memory under acpi_device_lock, but it doesn't really help, because (1) it leads to many unnecessary memory allocations for _ADR devices, (2) kstrdup_const() is run under that lock anyway and (3) it complicates the code. Rearrange acpi_device_add() to allocate memory for a new struct acpi_device_bus_id instance only when necessary, eliminate a redundant local variable from it and reduce the number of labels in there. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Reviewed-by: Hans de Goede Signed-off-by: Sasha Levin --- drivers/acpi/scan.c | 57 +++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 31 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 5aa4a01f698f..c1066487c06b 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -622,12 +622,23 @@ void acpi_bus_put_acpi_device(struct acpi_device *adev) put_device(&adev->dev); } +static struct acpi_device_bus_id *acpi_device_bus_id_match(const char *dev_id) +{ + struct acpi_device_bus_id *acpi_device_bus_id; + + /* Find suitable bus_id and instance number in acpi_bus_id_list. */ + list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) { + if (!strcmp(acpi_device_bus_id->bus_id, dev_id)) + return acpi_device_bus_id; + } + return NULL; +} + int acpi_device_add(struct acpi_device *device, void (*release)(struct device *)) { + struct acpi_device_bus_id *acpi_device_bus_id; int result; - struct acpi_device_bus_id *acpi_device_bus_id, *new_bus_id; - int found = 0; if (device->handle) { acpi_status status; @@ -653,38 +664,26 @@ int acpi_device_add(struct acpi_device *device, INIT_LIST_HEAD(&device->del_list); mutex_init(&device->physical_node_lock); - new_bus_id = kzalloc(sizeof(struct acpi_device_bus_id), GFP_KERNEL); - if (!new_bus_id) { - pr_err(PREFIX "Memory allocation error\n"); - result = -ENOMEM; - goto err_detach; - } - mutex_lock(&acpi_device_lock); - /* - * Find suitable bus_id and instance number in acpi_bus_id_list - * If failed, create one and link it into acpi_bus_id_list - */ - list_for_each_entry(acpi_device_bus_id, &acpi_bus_id_list, node) { - if (!strcmp(acpi_device_bus_id->bus_id, - acpi_device_hid(device))) { - acpi_device_bus_id->instance_no++; - found = 1; - kfree(new_bus_id); - break; + + acpi_device_bus_id = acpi_device_bus_id_match(acpi_device_hid(device)); + if (acpi_device_bus_id) { + acpi_device_bus_id->instance_no++; + } else { + acpi_device_bus_id = kzalloc(sizeof(*acpi_device_bus_id), + GFP_KERNEL); + if (!acpi_device_bus_id) { + result = -ENOMEM; + goto err_unlock; } - } - if (!found) { - acpi_device_bus_id = new_bus_id; acpi_device_bus_id->bus_id = kstrdup_const(acpi_device_hid(device), GFP_KERNEL); if (!acpi_device_bus_id->bus_id) { - pr_err(PREFIX "Memory allocation error for bus id\n"); + kfree(acpi_device_bus_id); result = -ENOMEM; - goto err_free_new_bus_id; + goto err_unlock; } - acpi_device_bus_id->instance_no = 0; list_add_tail(&acpi_device_bus_id->node, &acpi_bus_id_list); } dev_set_name(&device->dev, "%s:%02x", acpi_device_bus_id->bus_id, acpi_device_bus_id->instance_no); @@ -719,13 +718,9 @@ int acpi_device_add(struct acpi_device *device, list_del(&device->node); list_del(&device->wakeup_list); - err_free_new_bus_id: - if (!found) - kfree(new_bus_id); - + err_unlock: mutex_unlock(&acpi_device_lock); - err_detach: acpi_detach_data(device->handle, acpi_scan_drop_device); return result; }