Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756731AbbGTRud (ORCPT ); Mon, 20 Jul 2015 13:50:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41556 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756162AbbGTRub (ORCPT ); Mon, 20 Jul 2015 13:50:31 -0400 Date: Mon, 20 Jul 2015 12:50:26 -0500 From: Josh Poimboeuf To: Namhyung Kim Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Michal Marek , Peter Zijlstra , Andy Lutomirski , Borislav Petkov , Linus Torvalds , Andi Kleen , Pedro Alves , x86@kernel.org, live-patching@vger.kernel.org, LKML Subject: Re: [PATCH v7 2/4] x86/stackvalidate: Compile-time stack validation Message-ID: <20150720175026.GC28075@treble.redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2557 Lines: 79 On Tue, Jul 21, 2015 at 01:53:25AM +0900, Namhyung Kim wrote: > Hi, > > Just nitpicks below.. Hi Namhyung, thanks for the review! > On Wed, Jul 15, 2015 at 2:14 AM, Josh Poimboeuf wrote: > > +void elf_close(struct elf *elf) > > +{ > > + struct section *sec, *tmpsec; > > + struct symbol *sym, *tmpsym; > > + > > + list_for_each_entry_safe(sec, tmpsec, &elf->sections, list) { > > + list_for_each_entry_safe(sym, tmpsym, &sec->symbols, list) { > > + list_del(&sym->list); > > + free(sym); > > + } > > It seems that it needs to free entries in sec->relas too here. I must confess that this program has some known memory leaks. I actually have a comment at the top of the file attempting to explain why, but I'll try to improve the comment a little bit. Many of the leaks are actually intentional, since it's a short running program that needs to run fast (though I haven't yet optimized it for speed). And most of the data structures are needed until it exits anyway. It's perhaps distasteful, but it improves performance. And I'm a pragmatist at heart ;-) That said, I will make your suggested change here, since maybe the elf.c code might someday be reused elsewhere, and freeing memory is actually the goal of this function. > > +int main(int argc, char *argv[]) > > +{ > > + struct elf *elf; > > + int ret = 0, warnings = 0; > > + > > + argp_parse(&argp, argc, argv, 0, 0, &args); > > + > > + elf = elf_open(args.args[0]); > > + if (!elf) { > > + fprintf(stderr, "error reading elf file %s\n", args.args[0]); > > + return 1; > > + } > > + > > + ret = decode_sections(elf); > > + if (ret < 0) > > + goto out; > > + warnings += ret; > > + > > + ret = validate_functions(elf); > > + if (ret < 0) > > + goto out; > > + warnings += ret; > > + > > + ret = validate_uncallable_instructions(elf); > > + if (ret < 0) > > + goto out; > > + warnings += ret; > > + > > +out: > > elf_close(elf); ?? I intentionally left out the call to elf_close() here, since this is the exit path and the kernel will free the memory anyway. -- Josh -- 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/