Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936364AbXLRAc1 (ORCPT ); Mon, 17 Dec 2007 19:32:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1763038AbXLRAcS (ORCPT ); Mon, 17 Dec 2007 19:32:18 -0500 Received: from smtp2.linux-foundation.org ([207.189.120.14]:32823 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761109AbXLRAcR (ORCPT ); Mon, 17 Dec 2007 19:32:17 -0500 Date: Mon, 17 Dec 2007 16:21:12 -0800 (PST) From: Linus Torvalds To: Arjan van de Ven cc: Tony Luck , Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton , protasnb@gmail.com, tytso@thunk.org Subject: Re: Top kernel oopses/warnings this week In-Reply-To: <20071217154727.404e4bc4@laptopd505.fenrus.org> Message-ID: References: <4762CF8C.90808@linux.intel.com> <20071217172331.GA23070@elte.hu> <20071217133631.5bbc5842@laptopd505.fenrus.org> <12c511ca0712171458n1bc05b40nab6b4b7c92433c8d@mail.gmail.com> <476703A4.7000401@linux.intel.com> <12c511ca0712171526h242a7de8vadec78cd48747bd@mail.gmail.com> <20071217154727.404e4bc4@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1441 Lines: 54 On Mon, 17 Dec 2007, Arjan van de Ven wrote: > > +char *get_boot_uuid(void) > +{ > + static char target[38]; > + unsigned char *uuid; > + > + if (sysctl_bootid[8] == 0) > + generate_random_uuid(sysctl_bootid); > + /* sysctl_bootid is signed, to print we need unsigned .. */ > + uuid = sysctl_bootid; > + > + if (target[0] == 0) { > + sprintf(target, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-" > + "%02x%02x%02x%02x%02x%02x", Why isn't *everything* inside that "if (target[0] == 0" check? IOW, that function should look something like const char *get_boot_uuid(void) { static char target[38]; if (!target[0]) fill_boot_uid(target) return target; } which also allows you to clean it up a bit. I'd _also_ suggest that you'd actually try to avoid that horrid sequence of "%02x..", and instead just make sure that sysctl_bootid[] is 4-byte aligned, and then you can do sprintf("%08x-%04x-%04x-%04x-%04x%08x", ntohl(0[(u32 *)uuid]), ntohs(2[(u16 *)uuid]), ntohs(3[(u16 *)uuid]), ntohs(4[(u16 *)uuid]), ntohs(5[(u16 *)uuid]), ntohl(3[(u32 *)uuid])); which also gets bonus points for being totally unreadable, and thus 100% in the spirit of uuid's. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/