From mboxrd@z Thu Jan 1 00:00:00 1970 From: mcgrof@kernel.org Date: Fri, 19 Aug 2016 21:33:59 +0000 Subject: [PATCH v4 01/16] x86: remove LTO_REFERENCE_INITCALL() Message-Id: <1471642454-5679-2-git-send-email-mcgrof@kernel.org> List-Id: References: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> In-Reply-To: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, jpoimboe@redhat.com, bp@alien8.de, linux@arm.linux.org.uk, mhiramat@kernel.org, masami.hiramatsu.pt@hitachi.com, jbaron@akamai.com, heiko.carstens@de.ibm.com, ananth@linux.vnet.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, realmz6@gmail.com Cc: x86@kernel.org, luto@amacapital.net, keescook@chromium.org, torvalds@linux-foundation.org, gregkh@linuxfoundation.org, rusty@rustcorp.com.au, gnomes@lxorguk.ukuu.org.uk, alan@linux.intel.com, dwmw2@infradead.org, arnd@arndb.de, ming.lei@canonical.com, linux-arch@vger.kernel.org, benh@kernel.crashing.org, ananth@in.ibm.com, pebolle@tiscali.nl, fontana@sharpeleven.org, david.vrabel@citrix.com, konrad.wilk@oracle.com, mcb30@ipxe.org, jgross@suse.com, andrew.cooper3@citrix.com, andriy.shevchenko@linux.intel.com, paul.gortmaker@windriver.com, xen-devel@lists.xensource.com, ak@linux.intel.com, pali.rohar@gmail.com, dvhart@infradead.org, platform-driver-x86@vger.kernel.org, mmarek@suse.com, linux@rasmusvillemoes.dk, jkosina@suse.cz, korea.drzix@gmail.com, linux-kbuild@vger.kernel.org, ton From: "Luis R. Rodriguez" The setup for LTO never made it upstream, and although this has some users, this is now really old stuff for a gcc 4.7 LTO problem. We know that at least LTO_REFERENCE_INITCALL() work around can be removed if LTO is not supported on v4.7 anymore. As per Andi the DISABLE_LTO and LTO_CFLAGS are still neeeded though. v3: added to this series, removing LTO_REFERENCE_INITCALL() justifies that other future similar macros do not need a respective LTO_REFERENCE_INITCALL() on them therefore simplifying new code. Acked-by: Andi Kleen Signed-off-by: Luis R. Rodriguez --- include/linux/init.h | 20 +------------------- 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index 1e5c131d5c9a..aa662ad80d9c 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -151,23 +151,6 @@ extern bool initcall_debug; #ifndef __ASSEMBLY__ -#ifdef CONFIG_LTO -/* Work around a LTO gcc problem: when there is no reference to a variable - * in a module it will be moved to the end of the program. This causes - * reordering of initcalls which the kernel does not like. - * Add a dummy reference function to avoid this. The function is - * deleted by the linker. - */ -#define LTO_REFERENCE_INITCALL(x) \ - ; /* yes this is needed */ \ - static __used __exit void *reference_##x(void) \ - { \ - return &x; \ - } -#else -#define LTO_REFERENCE_INITCALL(x) -#endif - /* initcalls are now grouped by functionality into separate * subsections. Ordering inside the subsections is determined * by link order. @@ -180,8 +163,7 @@ extern bool initcall_debug; #define __define_initcall(fn, id) \ static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(".initcall" #id ".init"))) = fn; \ - LTO_REFERENCE_INITCALL(__initcall_##fn##id) + __attribute__((__section__(".initcall" #id ".init"))) = fn; /* * Early initcalls run before initializing SMP. -- 2.9.2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: mcgrof@kernel.org Subject: [PATCH v4 01/16] x86: remove LTO_REFERENCE_INITCALL() Date: Fri, 19 Aug 2016 14:33:59 -0700 Message-ID: <1471642454-5679-2-git-send-email-mcgrof@kernel.org> References: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> Return-path: In-Reply-To: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> Sender: linux-sh-owner@vger.kernel.org To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, jpoimboe@redhat.com, bp@alien8.de, linux@arm.linux.org.uk, mhiramat@kernel.org, masami.hiramatsu.pt@hitachi.com, jbaron@akamai.com, heiko.carstens@de.ibm.com, ananth@linux.vnet.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, realmz6@gmail.com Cc: x86@kernel.org, luto@amacapital.net, keescook@chromium.org, torvalds@linux-foundation.org, gregkh@linuxfoundation.org, rusty@rustcorp.com.au, gnomes@lxorguk.ukuu.org.uk, alan@linux.intel.com, dwmw2@infradead.org, arnd@arndb.de, ming.lei@canonical.com, linux-arch@vger.kernel.org, benh@kernel.crashing.org, ananth@in.ibm.com, pebolle@tiscali.nl, fontana@sharpeleven.org, david.vrabel@citrix.com, konrad.wilk@oracle.com, mcb30@ipxe.org, jgross@suse.com, andrew.cooper3@citrix.com, andriy.shevchenko@linux.intel.com, paul.gortmaker@windriver.com, xen-devel@lists.xensource.com, ak@linux.intel.com, pali.rohar@gmail.com, dvhart@infradead.org, platform-driver-x86@vger.kernel.org, mmarek@suse.com, linux@rasmusvillemoes.dk, jkosina@suse.cz, korea.drzix@gmail.com, linux-kbuild@vger.kernel.org, ton List-Id: platform-driver-x86.vger.kernel.org From: "Luis R. Rodriguez" The setup for LTO never made it upstream, and although this has some users, this is now really old stuff for a gcc 4.7 LTO problem. We know that at least LTO_REFERENCE_INITCALL() work around can be removed if LTO is not supported on v4.7 anymore. As per Andi the DISABLE_LTO and LTO_CFLAGS are still neeeded though. v3: added to this series, removing LTO_REFERENCE_INITCALL() justifies that other future similar macros do not need a respective LTO_REFERENCE_INITCALL() on them therefore simplifying new code. Acked-by: Andi Kleen Signed-off-by: Luis R. Rodriguez --- include/linux/init.h | 20 +------------------- 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index 1e5c131d5c9a..aa662ad80d9c 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -151,23 +151,6 @@ extern bool initcall_debug; #ifndef __ASSEMBLY__ -#ifdef CONFIG_LTO -/* Work around a LTO gcc problem: when there is no reference to a variable - * in a module it will be moved to the end of the program. This causes - * reordering of initcalls which the kernel does not like. - * Add a dummy reference function to avoid this. The function is - * deleted by the linker. - */ -#define LTO_REFERENCE_INITCALL(x) \ - ; /* yes this is needed */ \ - static __used __exit void *reference_##x(void) \ - { \ - return &x; \ - } -#else -#define LTO_REFERENCE_INITCALL(x) -#endif - /* initcalls are now grouped by functionality into separate * subsections. Ordering inside the subsections is determined * by link order. @@ -180,8 +163,7 @@ extern bool initcall_debug; #define __define_initcall(fn, id) \ static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(".initcall" #id ".init"))) = fn; \ - LTO_REFERENCE_INITCALL(__initcall_##fn##id) + __attribute__((__section__(".initcall" #id ".init"))) = fn; /* * Early initcalls run before initializing SMP. -- 2.9.2 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:38854 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755223AbcHSVey (ORCPT ); Fri, 19 Aug 2016 17:34:54 -0400 From: mcgrof@kernel.org Subject: [PATCH v4 01/16] x86: remove LTO_REFERENCE_INITCALL() Date: Fri, 19 Aug 2016 14:33:59 -0700 Message-Id: <1471642454-5679-2-git-send-email-mcgrof@kernel.org> In-Reply-To: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> References: <1471642454-5679-1-git-send-email-mcgrof@kernel.org> Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: hpa@zytor.com, tglx@linutronix.de, mingo@redhat.com, jpoimboe@redhat.com, bp@alien8.de, linux@arm.linux.org.uk, mhiramat@kernel.org, masami.hiramatsu.pt@hitachi.com, jbaron@akamai.com, heiko.carstens@de.ibm.com, ananth@linux.vnet.ibm.com, anil.s.keshavamurthy@intel.com, davem@davemloft.net, realmz6@gmail.com Cc: x86@kernel.org, luto@amacapital.net, keescook@chromium.org, torvalds@linux-foundation.org, gregkh@linuxfoundation.org, rusty@rustcorp.com.au, gnomes@lxorguk.ukuu.org.uk, alan@linux.intel.com, dwmw2@infradead.org, arnd@arndb.de, ming.lei@canonical.com, linux-arch@vger.kernel.org, benh@kernel.crashing.org, ananth@in.ibm.com, pebolle@tiscali.nl, fontana@sharpeleven.org, david.vrabel@citrix.com, konrad.wilk@oracle.com, mcb30@ipxe.org, jgross@suse.com, andrew.cooper3@citrix.com, andriy.shevchenko@linux.intel.com, paul.gortmaker@windriver.com, xen-devel@lists.xensource.com, ak@linux.intel.com, pali.rohar@gmail.com, dvhart@infradead.org, platform-driver-x86@vger.kernel.org, mmarek@suse.com, linux@rasmusvillemoes.dk, jkosina@suse.cz, korea.drzix@gmail.com, linux-kbuild@vger.kernel.org, tony.luck@intel.com, akpm@linux-foundation.org, linux-ia64@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rostedt@goodmis.org, jani.nikula@intel.com, mchehab@osg.samsung.com, markus.heiser@darmarit.de, acme@redhat.com, jolsa@kernel.org, msalter@redhat.com, chris@zankel.net, jcmvbkbc@gmail.com, linux-xtensa@linux-xtensa.org, paulus@samba.org, mpe@ellerman.id.au, James.Bottomley@HansenPartnership.com, "Luis R. Rodriguez" From: "Luis R. Rodriguez" The setup for LTO never made it upstream, and although this has some users, this is now really old stuff for a gcc 4.7 LTO problem. We know that at least LTO_REFERENCE_INITCALL() work around can be removed if LTO is not supported on v4.7 anymore. As per Andi the DISABLE_LTO and LTO_CFLAGS are still neeeded though. v3: added to this series, removing LTO_REFERENCE_INITCALL() justifies that other future similar macros do not need a respective LTO_REFERENCE_INITCALL() on them therefore simplifying new code. Acked-by: Andi Kleen Signed-off-by: Luis R. Rodriguez --- include/linux/init.h | 20 +------------------- 1 file changed, 1 insertion(+), 19 deletions(-) diff --git a/include/linux/init.h b/include/linux/init.h index 1e5c131d5c9a..aa662ad80d9c 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -151,23 +151,6 @@ extern bool initcall_debug; #ifndef __ASSEMBLY__ -#ifdef CONFIG_LTO -/* Work around a LTO gcc problem: when there is no reference to a variable - * in a module it will be moved to the end of the program. This causes - * reordering of initcalls which the kernel does not like. - * Add a dummy reference function to avoid this. The function is - * deleted by the linker. - */ -#define LTO_REFERENCE_INITCALL(x) \ - ; /* yes this is needed */ \ - static __used __exit void *reference_##x(void) \ - { \ - return &x; \ - } -#else -#define LTO_REFERENCE_INITCALL(x) -#endif - /* initcalls are now grouped by functionality into separate * subsections. Ordering inside the subsections is determined * by link order. @@ -180,8 +163,7 @@ extern bool initcall_debug; #define __define_initcall(fn, id) \ static initcall_t __initcall_##fn##id __used \ - __attribute__((__section__(".initcall" #id ".init"))) = fn; \ - LTO_REFERENCE_INITCALL(__initcall_##fn##id) + __attribute__((__section__(".initcall" #id ".init"))) = fn; /* * Early initcalls run before initializing SMP. -- 2.9.2