From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x241.google.com (mail-wm0-x241.google.com [IPv6:2a00:1450:400c:c09::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 41Kcwl0rSMzF0X5 for ; Tue, 3 Jul 2018 18:38:59 +1000 (AEST) Received: by mail-wm0-x241.google.com with SMTP id l15-v6so9782759wmc.1 for ; Tue, 03 Jul 2018 01:38:59 -0700 (PDT) Sender: Ingo Molnar Date: Tue, 3 Jul 2018 10:38:53 +0200 From: Ingo Molnar To: Ard Biesheuvel Cc: Thomas Gleixner , the arch/x86 maintainers , Ingo Molnar , Linux Kernel Mailing List , Arnd Bergmann , Kees Cook , Michael Ellerman , Thomas Garnier , "Serge E. Hallyn" , Bjorn Helgaas , Benjamin Herrenschmidt , Russell King , Paul Mackerras , Catalin Marinas , Petr Mladek , James Morris , Andrew Morton , Nicolas Pitre , Josh Poimboeuf , Steven Rostedt , Sergey Senozhatsky , Linus Torvalds , Jessica Yu , linux-arm-kernel , linuxppc-dev , Will Deacon Subject: Re: [PATCH v9 0/6] add support for relative references in special sections Message-ID: <20180703083853.GA5369@gmail.com> References: <20180626182802.19932-1-ard.biesheuvel@linaro.org> <20180627151510.GE30631@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , * Ard Biesheuvel wrote: > On 27 June 2018 at 17:15, Will Deacon wrote: > > Hi Ard, > > > > On Tue, Jun 26, 2018 at 08:27:55PM +0200, Ard Biesheuvel wrote: > >> This adds support for emitting special sections such as initcall arrays, > >> PCI fixups and tracepoints as relative references rather than absolute > >> references. This reduces the size by 50% on 64-bit architectures, but > >> more importantly, it removes the need for carrying relocation metadata > >> for these sections in relocatable kernels (e.g., for KASLR) that needs > >> to be fixed up at boot time. On arm64, this reduces the vmlinux footprint > >> of such a reference by 8x (8 byte absolute reference + 24 byte RELA entry > >> vs 4 byte relative reference) > >> > >> Patch #3 was sent out before as a single patch. This series supersedes > >> the previous submission. This version makes relative ksymtab entries > >> dependent on the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS rather > >> than trying to infer from kbuild test robot replies for which architectures > >> it should be blacklisted. > >> > >> Patch #1 introduces the new Kconfig symbol HAVE_ARCH_PREL32_RELOCATIONS, > >> and sets it for the main architectures that are expected to benefit the > >> most from this feature, i.e., 64-bit architectures or ones that use > >> runtime relocations. > >> > >> Patch #2 add support for #define'ing __DISABLE_EXPORTS to get rid of > >> ksymtab/kcrctab sections in decompressor and EFI stub objects when > >> rebuilding existing C files to run in a different context. > > > > I had a small question on patch 3, but it's really for my understanding. > > So, for patches 1-3: > > > > Reviewed-by: Will Deacon > > > > Thanks all. > > Thomas, Ingo, > > Except for the below tweak against patch #3 for powerpc, which may > apparently get confused by an input section called .discard without > any suffixes, this series is good to go, but requires your ack to > proceed, so I would like to ask you to share your comments and/or > objections. Also, any suggestions or recommendations regarding the > route these patches should take are highly appreciated. LGTM: Acked-by: Ingo Molnar Regarding route - I suspect -mm would be good, or any other tree that does a lot of cross-arch testing? Thanks, Ingo