From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Date: Mon, 04 Jan 2016 18:15:28 +0000 Subject: Re: [PATCH 0/6] generic relative extable support Message-Id: <568AB6C0.4060502@zytor.com> List-Id: References: <1451837157-447-1-git-send-email-ard.biesheuvel@linaro.org> <20160104112026.GC4179@osiris> In-Reply-To: <20160104112026.GC4179@osiris> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Heiko Carstens , Ard Biesheuvel Cc: linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, mingo@redhat.com, schwidefsky@de.ibm.com, mattst88@gmail.com, ink@jurassic.park.msu.ru, rth@twiddle.net, tony.luck@intel.com, fenghua.yu@intel.com, catalin.marinas@arm.com, will.deacon@arm.com, arnd@arndb.de, akpm@linux-foundation.org, mark.rutland@arm.com, marc.zyngier@arm.com On 01/04/2016 03:20 AM, Heiko Carstens wrote: > On Sun, Jan 03, 2016 at 05:05:51PM +0100, Ard Biesheuvel wrote: >> There are currently four architectures (x86, ia64, alpha and s390) whose >> user-access exception tables are relative to the table entry address rather >> than absolute. Each of these architectures has its own search_extable() and >> sort_extable() implementation, which are not only mostly identical to each >> other, but also deviate very little from the generic absolute implementations >> in lib/extable.c that they override. >> >> So before making arm64 the fifth architecture that reimplements this, let's >> refactor the existing code so that all of these architectures use common code >> for searching and sorting the relative extables. Archs may set >> ARCH_HAS_RELATIVE_EXTABLE to indicate that the table consists of a pair of >> relative ints, and may define swap_ex_entry_fixup() if the fixup member needs >> special treatment in the swapping step of the sorting routine (such as alpha). >> >> Note that the s390 patch applies on top of the following patch: >> >> http://article.gmane.org/gmane.linux.kernel/2117036 >> >> which fixes a bug I spotted while working on this code. Since that probably >> needs to go to -stable, I broke it out and posted it separately. >> >> Ard Biesheuvel (6): >> extable: add support for relative extables to search and sort routines >> alpha/extable: use generic search and sort routines >> s390/extable: use generic search and sort routines >> x86/extable: use generic search and sort routines >> ia64/extable: use generic search and sort routines >> arm64: switch to relative exception tables > > For the s390 bits: > > Acked-by: Heiko Carstens > For the x86 bits: Acked-by: H. Peter Anvin *However*, please see my comment about generalizing _ASM_EXTABLE() for the non-x86 architectures. -hpa