From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-x22f.google.com (mail-wm0-x22f.google.com [IPv6:2a00:1450:400c:c09::22f]) (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 3v7CxH3N1tzDqCp for ; Wed, 25 Jan 2017 03:16:51 +1100 (AEDT) Received: by mail-wm0-x22f.google.com with SMTP id c206so217470563wme.0 for ; Tue, 24 Jan 2017 08:16:51 -0800 (PST) From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linuxppc-dev@lists.ozlabs.org, akpm@linux-foundation.org, torvalds@linux-foundation.org, arnd@arndb.de, rusty@rustcorp.com.au, jeyu@redhat.com, mpe@ellerman.id.au, viro@zeniv.linux.org.uk, linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk, linux-arch@vger.kernel.org, Ard Biesheuvel Subject: [PATCH v4 0/2] modversions: redefine kcrctab entries as 32-bit values Date: Tue, 24 Jan 2017 16:16:38 +0000 Message-Id: <1485274600-21976-1-git-send-email-ard.biesheuvel@linaro.org> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This v4 is a followup to [0] 'modversions: redefine kcrctab entries as relative CRC pointers', but since relative CRC pointers do not work in modules, and are actually only needed by powerpc with CONFIG_RELOCATABLE=y, I have made it a Kconfig selectable feature instead. Patch #1 introduces the MODULE_REL_CRCS Kconfig symbol, and adds the kbuild handling of it, i.e., modpost, genksyms and kallsyms. Patch #2 switches all architectures to 32-bit CRC entries in kcrctab, where all architectures except powerpc with CONFIG_RELOCATABLE=y use absolute ELF symbol references as before. v4: make relative CRCs kconfig selectable use absolute CRC symbols in modules regardless of kconfig selection split into two patches v3: emit CRCs into .rodata rather than .rodata.modver, given that the latter will be emitted with read-write permissions, making the CRCs end up in a writable module segment. fold the modpost fix to ensure that the section address is only substracted from the symbol address when the ELF object in question is fully linked (i.e., ET_DYN or ET_EXEC, and not ET_REL) v2: update modpost as well, so that genksyms no longer has to emit symbols for both the actual CRC value and the reference to where it is stored in the image [0] http://marc.info/?l=linux-arch&m=148493613415294&w=2 Ard Biesheuvel (2): kbuild: modversions: add infrastructure for emitting relative CRCs modversions: treat symbol CRCs as 32 bit quantities arch/powerpc/Kconfig | 1 + arch/powerpc/include/asm/module.h | 4 -- arch/powerpc/kernel/module_64.c | 8 ---- include/asm-generic/export.h | 11 ++--- include/linux/export.h | 14 ++++++ include/linux/module.h | 14 +++--- init/Kconfig | 4 ++ kernel/module.c | 45 ++++++++++---------- scripts/Makefile.build | 2 + scripts/genksyms/genksyms.c | 19 ++++++--- scripts/kallsyms.c | 12 ++++++ scripts/mod/modpost.c | 10 +++++ 12 files changed, 93 insertions(+), 51 deletions(-) -- 2.7.4