From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 29 Oct 2002 22:41:22 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 29 Oct 2002 22:41:21 -0500 Received: from dp.samba.org ([66.70.73.150]:11227 "EHLO lists.samba.org") by vger.kernel.org with ESMTP id ; Tue, 29 Oct 2002 22:41:19 -0500 From: Rusty Russell To: Jeff Garzik Cc: linux-kernel@vger.kernel.org, torvalds@transmeta.com, dhinds@zen.stanford.edu, alan@lxorguk.ukuu.org.uk Subject: Re: [PATCH] Get rid of check_resource() before it becomes a problem In-reply-to: Your message of "Tue, 29 Oct 2002 21:33:28 CDT." <3DBF44F8.8010307@pobox.com> Date: Wed, 30 Oct 2002 14:15:01 +1100 Message-Id: <20021030034743.A05AA2C0DD@lists.samba.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In message <3DBF44F8.8010307@pobox.com> you write: > Need to zap the export from kernel/ksyms.c too Ack. Here it is, fresh against 2.5.44. Rusty. -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. Name: Remove inherently racy check_resource Author: Rusty Russell Status: Trivial D: The new resource interface foolishly replicated the (obsolete, D: racy) spirit of the check_region call as check_resource. You D: should use request_resource/release_resource instead. diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .8919-linux-2.5.45/drivers/pcmcia/rsrc_mgr.c .8919-linux-2.5.45.updated/drivers/pcmcia/rsrc_mgr.c --- .8919-linux-2.5.45/drivers/pcmcia/rsrc_mgr.c 2002-10-15 15:29:59.000000000 +1000 +++ .8919-linux-2.5.45.updated/drivers/pcmcia/rsrc_mgr.c 2002-10-30 14:03:09.000000000 +1100 @@ -124,16 +124,36 @@ static struct resource *resource_parent( return &ioport_resource; } +/* FIXME: Fundamentally racy. */ static inline int check_io_resource(unsigned long b, unsigned long n, struct pci_dev *dev) { - return check_resource(resource_parent(b, n, IORESOURCE_IO, dev), b, n); + struct resource *region; + + region = __request_region(resource_parent(b, n, IORESOURCE_IO, dev), + b, n, "check_io_resource"); + if (!region) + return -EBUSY; + + release_resource(region); + kfree(region); + return 0; } +/* FIXME: Fundamentally racy. */ static inline int check_mem_resource(unsigned long b, unsigned long n, struct pci_dev *dev) { - return check_resource(resource_parent(b, n, IORESOURCE_MEM, dev), b, n); + struct resource *region; + + region = __request_region(resource_parent(b, n, IORESOURCE_MEM, dev), + b, n, "check_mem_resource"); + if (!region) + return -EBUSY; + + release_resource(region); + kfree(region); + return 0; } static struct resource *make_resource(unsigned long b, unsigned long n, diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .8919-linux-2.5.45/include/linux/ioport.h .8919-linux-2.5.45.updated/include/linux/ioport.h --- .8919-linux-2.5.45/include/linux/ioport.h 2002-05-09 12:40:19.000000000 +1000 +++ .8919-linux-2.5.45.updated/include/linux/ioport.h 2002-10-30 14:03:09.000000000 +1100 @@ -85,7 +85,6 @@ extern struct resource iomem_resource; extern int get_resource_list(struct resource *, char *buf, int size); -extern int check_resource(struct resource *root, unsigned long, unsigned long); extern int request_resource(struct resource *root, struct resource *new); extern int release_resource(struct resource *new); extern int allocate_resource(struct resource *root, struct resource *new, diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .8919-linux-2.5.45/kernel/ksyms.c .8919-linux-2.5.45.updated/kernel/ksyms.c --- .8919-linux-2.5.45/kernel/ksyms.c 2002-10-30 12:53:10.000000000 +1100 +++ .8919-linux-2.5.45.updated/kernel/ksyms.c 2002-10-30 14:06:18.000000000 +1100 @@ -445,7 +445,6 @@ EXPORT_SYMBOL(enable_hlt); EXPORT_SYMBOL(request_resource); EXPORT_SYMBOL(release_resource); EXPORT_SYMBOL(allocate_resource); -EXPORT_SYMBOL(check_resource); EXPORT_SYMBOL(__request_region); EXPORT_SYMBOL(__check_region); EXPORT_SYMBOL(__release_region); diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .8919-linux-2.5.45/kernel/resource.c .8919-linux-2.5.45.updated/kernel/resource.c --- .8919-linux-2.5.45/kernel/resource.c 2002-08-11 15:31:43.000000000 +1000 +++ .8919-linux-2.5.45.updated/kernel/resource.c 2002-10-30 14:03:09.000000000 +1100 @@ -131,20 +131,6 @@ int release_resource(struct resource *ol return retval; } -int check_resource(struct resource *root, unsigned long start, unsigned long len) -{ - struct resource *conflict, tmp; - - tmp.start = start; - tmp.end = start + len - 1; - write_lock(&resource_lock); - conflict = __request_resource(root, &tmp); - if (!conflict) - __release_resource(&tmp); - write_unlock(&resource_lock); - return conflict ? -EBUSY : 0; -} - /* * Find empty slot in the resource tree given range and alignment. */