From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757290AbZKEOYN (ORCPT ); Thu, 5 Nov 2009 09:24:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757155AbZKEOYM (ORCPT ); Thu, 5 Nov 2009 09:24:12 -0500 Received: from mail-bw0-f227.google.com ([209.85.218.227]:43474 "EHLO mail-bw0-f227.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756966AbZKEOYK (ORCPT ); Thu, 5 Nov 2009 09:24:10 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=sender:message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=lfmpTu3Yv2VAdg5wohNbo32/ywqYKQGvJ6VYM5Tvu+1jWVcEUgXGXjd26aDqKFlbSm obKgYkyNWXEA7MgIgo4wIKRARnjDDma0L/GCJ43s0nPi96zSBpdFpTbkWRFkQsnD/61J 78hrE5FzYUKsmrpWjsFWTSx+UlHrNHJ5gfFNc= Message-ID: <4AF2E00A.3010107@tuffmail.co.uk> Date: Thu, 05 Nov 2009 14:24:10 +0000 From: Alan Jenkins User-Agent: Thunderbird 2.0.0.23 (X11/20090817) MIME-Version: 1.0 To: Sam Ravnborg , Mike Frysinger CC: greg@kroah.com, linux-kbuild@vger.kernel.org, carmelo73@gmail.com, linux-kernel@vger.kernel.org, Rusty Russell Subject: Re: [PATCH 05/10] kbuild: sort the list of symbols exported by the kernel (__ksymtab) References: <9b2b86520911020852q49c55695rb05d87090fa9ad33@mail.gmail.com> <1257242782-10496-6-git-send-email-alan-jenkins@tuffmail.co.uk> <200911041849.43311.rusty@rustcorp.com.au> <4AF150D2.6000207@tuffmail.co.uk> <20091104171916.GA6323@merkur.ravnborg.org> In-Reply-To: <20091104171916.GA6323@merkur.ravnborg.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sam Ravnborg wrote: > On Wed, Nov 04, 2009 at 10:00:50AM +0000, Alan Jenkins wrote: > >> Rusty Russell wrote: >> >>> On Tue, 3 Nov 2009 08:36:17 pm Alan Jenkins wrote: >>> >>> >>>> +/* >>>> + * We use CPP macros since they are more familiar than assembly macros. >>>> + * Note that CPP macros eat newlines, so each statement must be terminated >>>> + * by a semicolon. >>>> + */ >>>> + >>>> +#ifdef CONFIG_HAVE_SYMBOL_PREFIX >>>> +#define __SYM(sym) _##sym >>>> +#else >>>> +#define __SYM(sym) sym >>>> +#endif >>>> >>>> >>> Ideally, you would used MODULE_SYMBOL_PREFIX here, but of course it's a >>> string. I don't think Kconfig can do arbitrary identifiers, so we can't >>> make CONFIG_SYMBOL_PREFIX empty or _. >>> >>> Perhaps clarify it to a bool CONFIG_HAVE_MODULE_UNDERSCORE_PREFIX then, >>> since that's what you're assuming here? >>> >>> Thanks, >>> Rusty. >>> >> I made the same assumption in patch 4. The arch defines >> CONFIG_HAVE_SYMBOL_PREFIX, which then causes init/Kconfig to define >> CONFIG_SYMBOL_PREFIX="_". >> >> Mike suggested that I hack kbuild instead, to do something like >> >> unquote = ... >> AFLAGS_.tmp_export-asm.o += -DSYMBOL_PREFIX=$(unquote CONFIG_SYMBOL_PREFIX) >> >> I'm experimenting with the idea, but I haven't managed to get it working >> > > Something like this: > unquote = $(patsubst "%",%,$($1)) > > AFLAGS_.tmp_export-asm.o += -DSYMBOL_PREFIX=$(call unquote,CONFIG_SYMBOL_PREFIX) > > But the readability is low so we could be better off doing it direct: > > AFLAGS_.tmp_export-asm.o += -DSYMBOL_PREFIX=$(patsubst "%",",$(CONFIG_SYMBOL_PREFIX)) > > Sam > Thanks to both of you, I have something that works now. Unfortunately I had to export the variable AFLAGS_.tmp_export-asm.o, otherwise it had no effect. I assume it's a limitation of the top-level Makefile. To make SYMBOL_PREFIX available for linker scripts, I also added it to "cpp_flags" in scripts/Makefile.lib. (As far as I can see, cpp_flags is _only_ used for preprocessing linker scripts). If this is all getting too brittle, I guess I could be less timid and add it to the global KBUILD_CPPFLAGS instead :). Here's the incremental diff: diff --git a/Makefile b/Makefile index d7e4ed9..dfd672b 100644 --- a/Makefile +++ b/Makefile @@ -912,6 +912,11 @@ vmlinux.o: $(modpost-init) $(vmlinux-main) FORCE # when loading modules. .tmp_exports-asm.S: vmlinux.o +ifneq ($(CONFIG_SYMBOL_PREFIX),) +export AFLAGS_.tmp_exports-asm.o += -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX)) +endif + + # The actual objects are generated when descending, # make sure no implicit rule kicks in $(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ; diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig index 6c99419..1983662 100644 --- a/arch/blackfin/Kconfig +++ b/arch/blackfin/Kconfig @@ -5,6 +5,10 @@ mainmenu "Blackfin Kernel Configuration" +config SYMBOL_PREFIX + string + default "_" + config MMU def_bool n @@ -26,7 +30,6 @@ config BLACKFIN select HAVE_KERNEL_BZIP2 select HAVE_KERNEL_LZMA select HAVE_OPROFILE - select HAVE_SYMBOL_PREFIX select ARCH_WANT_OPTIONAL_GPIOLIB config GENERIC_BUG diff --git a/arch/blackfin/kernel/vmlinux.lds.S b/arch/blackfin/kernel/vmlinux.lds.S index ffd90fb..1f585e8 100644 --- a/arch/blackfin/kernel/vmlinux.lds.S +++ b/arch/blackfin/kernel/vmlinux.lds.S @@ -27,8 +27,6 @@ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ -#define VMLINUX_SYMBOL(_sym_) _##_sym_ - #include #include #include diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig index cc03bbf..53cc669 100644 --- a/arch/h8300/Kconfig +++ b/arch/h8300/Kconfig @@ -9,7 +9,10 @@ config H8300 bool default y select HAVE_IDE - select HAVE_SYMBOL_PREFIX + +config SYMBOL_PREFIX + string + default "_" config MMU bool diff --git a/arch/h8300/kernel/vmlinux.lds.S b/arch/h8300/kernel/vmlinux.lds.S index b9e2490..03d356d 100644 --- a/arch/h8300/kernel/vmlinux.lds.S +++ b/arch/h8300/kernel/vmlinux.lds.S @@ -1,4 +1,3 @@ -#define VMLINUX_SYMBOL(_sym_) _##_sym_ #include #include diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 9feb474..4a0e9b2 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -52,10 +52,15 @@ #define LOAD_OFFSET 0 #endif -#ifndef VMLINUX_SYMBOL -#define VMLINUX_SYMBOL(_sym_) _sym_ +#ifndef SYMBOL_PREFIX +#define VMLINUX_SYMBOL(sym) sym +#else +#define PASTE2(x,y) x##y +#define PASTE(x,y) PASTE2(x,y) +#define VMLINUX_SYMBOL(sym) PASTE(SYMBOL_PREFIX, sym) #endif + /* Align . to a 8 byte boundary equals to maximum function alignment. */ #define ALIGN_FUNCTION() . = ALIGN(8) diff --git a/include/linux/mod_export.h b/include/linux/mod_export.h index 3bb14e9..f694ff5 100644 --- a/include/linux/mod_export.h +++ b/include/linux/mod_export.h @@ -18,7 +18,11 @@ #endif /* Some toolchains use a `_' prefix for all user symbols. */ +#ifdef CONFIG_SYMBOL_PREFIX #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX +#else +#define MODULE_SYMBOL_PREFIX "" +#endif #ifndef __GENKSYMS__ @@ -98,14 +102,14 @@ struct kernel_symbol { * by a semicolon. */ -#ifdef CONFIG_HAVE_SYMBOL_PREFIX -#define __SYM(sym) _##sym +#ifndef SYMBOL_PREFIX +#define SYM(sym) sym #else -#define __SYM(sym) sym +#define PASTE2(x,y) x##y +#define PASTE(x,y) PASTE2(x,y) +#define SYM(sym) PASTE(SYMBOL_PREFIX, sym) #endif -#define SYM(sym) __SYM(sym) - #ifdef CONFIG_MODVERSIONS #define __CRC_SYMBOL(sym, crcsec) \ diff --git a/init/Kconfig b/init/Kconfig index 7f4ddf6..bb4051c 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1176,17 +1176,6 @@ config MODULE_SRCVERSION_ALL endif # MODULES -config HAVE_SYMBOL_PREFIX - bool - help - Some arch toolchains use a `_' prefix for all user symbols. - This option will be taken into account when loading modules. - -config SYMBOL_PREFIX - string - default "_" if HAVE_SYMBOL_PREFIX - default "" - config INIT_ALL_POSSIBLE bool help diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 7a77787..f9f1f6c 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -127,6 +127,11 @@ _c_flags += $(if $(patsubst n%,, \ $(CFLAGS_GCOV)) endif +ifdef CONFIG_SYMBOL_PREFIX +_cpp_flags += -DSYMBOL_PREFIX=$(patsubst "%",%,$(CONFIG_SYMBOL_PREFIX)) +endif + + # If building the kernel in a separate objtree expand all occurrences # of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/'). diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 404b69a..b5a801d 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -19,7 +19,12 @@ #include "../../include/linux/license.h" /* Some toolchains use a `_' prefix for all user symbols. */ +#ifdef CONFIG_SYMBOL_PREFIX #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX +#else +#define MODULE_SYMBOL_PREFIX "" +#endif + /* Are we using CONFIG_MODVERSIONS? */ int modversions = 0;