Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760628AbZKZPru (ORCPT ); Thu, 26 Nov 2009 10:47:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756484AbZKZPrs (ORCPT ); Thu, 26 Nov 2009 10:47:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:13608 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756432AbZKZPrp (ORCPT ); Thu, 26 Nov 2009 10:47:45 -0500 Message-ID: <4B0EA3AA.5070003@redhat.com> Date: Thu, 26 Nov 2009 10:50:02 -0500 From: Masami Hiramatsu User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.4pre) Gecko/20090922 Fedora/3.0-2.7.b4.fc11 Thunderbird/3.0b4 MIME-Version: 1.0 To: KOSAKI Motohiro CC: linux-kernel@vger.kernel.org, dhowells@redhat.com, hidehiro.kawai.ez@hitachi.com, lethal@linux-sh.org, mingo@elte.hu, oleg@redhat.com, roland@redhat.com, vapier@gentoo.org, Takahiro Yasui Subject: Re: + binfmt-introduce-coredump-parameter-structure.patch added to -mm tree References: <200911202212.nAKMCF2v012068@imap1.linux-foundation.org> <20091126174835.5A73.A69D9226@jp.fujitsu.com> In-Reply-To: <20091126174835.5A73.A69D9226@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3218 Lines: 93 Hi Kosaki-san, KOSAKI Motohiro wrote: > Hi Hiramatsu-san, > >> >> The patch titled >> binfmt: introduce coredump parameter structure >> has been added to the -mm tree. Its filename is >> binfmt-introduce-coredump-parameter-structure.patch >> >> Before you just go and hit "reply", please: >> a) Consider who else should be cc'ed >> b) Prefer to cc a suitable mailing list as well >> c) Ideally: find the original patch on the mailing list and do a >> reply-to-all to that, adding suitable additional cc's >> >> *** Remember to use Documentation/SubmitChecklist when testing your code *** >> >> See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find >> out what to do about this >> >> The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ >> >> ------------------------------------------------------ >> Subject: binfmt: introduce coredump parameter structure >> From: Masami Hiramatsu >> >> These patches are for fixing coredump mm->flags consistency issue. >> >> --- >> 1787 if (mm->core_state || !get_dumpable(mm)) { <- (1) >> 1788 up_write(&mm->mmap_sem); >> 1789 put_cred(cred); >> 1790 goto fail; >> 1791 } >> 1792 >> [...] >> 1798 if (get_dumpable(mm) == 2) { /* Setuid core dump mode */ <-(2) >> 1799 flag = O_EXCL; /* Stop rewrite attacks */ >> 1800 cred->fsuid = 0; /* Dump root private */ >> 1801 } >> --- >> >> Since dumpable bits are not protected by lock, there is a chance to change >> these bits between (1) and (2). >> >> To solve this issue, this patch copies mm->flags to >> coredump_params.mm_flags at the beginning of do_coredump() and uses it >> instead of get_dumpable() while dumping core. This series also introduce >> coredump parameter structure for simplify bimfmt->core_dump interface. >> >> >> >> This patch: >> >> Introduce coredump parameter data structure (struct coredump_params) for >> simplifying binfmt->core_dump() arguments. This also cleanup DUMP_WRITE() >> in elf_core_dump() by style issue. > > > This patch break ia64 because arch specific ELF_CORE_EXTRA_PHDRS and > ELF_CORE_WRITE_EXTRA_DATA still use DUMP_WRITE. I expect this patch > break uml too. $ grep -r DUMP_WRITE arch/*/include arch/ia64/include/asm/elf.h: DUMP_WRITE(&phdr, sizeof(phdr)); \ arch/ia64/include/asm/elf.h: DUMP_WRITE((void *) gate_phdrs[\ Oops, certainly, that's a problem. IMHO, we should not do like that, all parameter required by a macro should be specified explicitly, since it reduces readability so much... I think we'd better make those macros inline function, check it's return value for error handling. What would you think about it? Thank you, -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America), Inc. Software Solutions Division e-mail: mhiramat@redhat.com -- 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/