From patchwork Thu Mar 14 10:49:30 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Hogan X-Patchwork-Id: 2269661 Return-Path: X-Original-To: patchwork-linux-kbuild@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id C70063FC8A for ; Thu, 14 Mar 2013 10:50:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757085Ab3CNKtu (ORCPT ); Thu, 14 Mar 2013 06:49:50 -0400 Received: from multi.imgtec.com ([194.200.65.239]:62245 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756977Ab3CNKtr (ORCPT ); Thu, 14 Mar 2013 06:49:47 -0400 Message-ID: <5141AB3A.2060705@imgtec.com> Date: Thu, 14 Mar 2013 10:49:30 +0000 From: James Hogan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Rusty Russell CC: Sam Ravnborg , Stephen Rothwell , Al Viro , Michal Marek , "Andrew Morton" , Guenter Roeck , Jean Delvare , , , Mike Frysinger , , , Paul Gortmaker , Subject: Re: [RFC -next] linux/linkage.h: fix symbol prefix handling References: <1362656642-2693-1-git-send-email-james.hogan@imgtec.com> <87sj46wyf2.fsf@rustcorp.com.au> <5139AC39.90805@imgtec.com> <874ngiwije.fsf@rustcorp.com.au> <20130311230731.0c610d86569d09f6e23b8e61@canb.auug.org.au> <87ppz5usts.fsf@rustcorp.com.au> <20130312233300.9d86d47bb5369923ad520a21@canb.auug.org.au> <87ehfkuq27.fsf@rustcorp.com.au> <20130313063157.GB19681@merkur.ravnborg.org> <87zjy6tytz.fsf@rustcorp.com.au> In-Reply-To: <87zjy6tytz.fsf@rustcorp.com.au> X-Enigmail-Version: 1.4.6 X-Originating-IP: [192.168.154.65] X-SEF-Processed: 7_3_0_01181__2013_03_14_10_49_30 Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org On 14/03/13 04:00, Rusty Russell wrote: > From: Rusty Russell > Subject: CONFIG_SYMBOL_PREFIX: cleanup. > > We have CONFIG_SYMBOL_PREFIX, which three archs define to the string > "_". But Al Viro broke this in "consolidate cond_syscall and > SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to > do so. > > Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to > prefix it so something. So various places define helpers which are > defined to nothing if CONFIG_SYMBOL_PREFIX isn't set: > > 1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX. > 2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym) > 3) include/linux/export.h defines MODULE_SYMBOL_PREFIX. > 4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7) > 5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym) > 6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX > 7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if > CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version > for pasting. > > (arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too). > > Let's solve this properly: > 1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX. > 2) Make linux/export.h usable from asm. > 3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR(). > 4) Make everyone use them. > > Signed-off-by: Rusty Russell Reviewed-by: James Hogan Tested-by: James Hogan (metag) The only other special case of symbol prefixing I'm aware of is in scripts/genksyms/genksyms.c. It makes the decision at runtime based on the --arch=$ARCH argument, and is the only use of the arch argument: > if ((strcmp(arch, "h8300") == 0) || (strcmp(arch, "blackfin") == 0) || > (strcmp(arch, "metag") == 0)) > mod_prefix = "_"; Does the patch below look reasonable in addition to your patch? (Note: I'm not sure if genksyms is only used internally or whether it's API should be kept stable?). Thanks James Subject: [PATCH] genksyms: pass symbol-prefix instead of arch Pass symbol-prefix to genksyms instead of arch, so that the decision what symbol prefix to use is kept in one place. Basically genksyms used to take a -a $ARCH argument and it used that to determine whether to add an underscore symbol prefix. It's now changed to take a -s $SYMBOL_PREFIX argument so that the caller decides whether a symbol prefix is required. The build system then uses CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX to determine whether to pass the argument. Signed-off-by: James Hogan --- scripts/Makefile.build | 3 ++- scripts/genksyms/genksyms.c | 18 +++++++----------- 2 files changed, 9 insertions(+), 12 deletions(-) diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 0e801c3..d5d859c 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -211,7 +211,8 @@ $(obj)/%.i: $(src)/%.c FORCE cmd_gensymtypes = \ $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ - $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \ + $(GENKSYMS) $(if $(1), -T $(2)) \ + $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ $(if $(KBUILD_PRESERVE),-p) \ -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) diff --git a/scripts/genksyms/genksyms.c b/scripts/genksyms/genksyms.c index d25e4a1..88632df 100644 --- a/scripts/genksyms/genksyms.c +++ b/scripts/genksyms/genksyms.c @@ -45,7 +45,6 @@ int in_source_file; static int flag_debug, flag_dump_defs, flag_reference, flag_dump_types, flag_preserve, flag_warnings; -static const char *arch = ""; static const char *mod_prefix = ""; static int errors; @@ -731,7 +730,7 @@ static void genksyms_usage(void) { fputs("Usage:\n" "genksyms [-adDTwqhV] > /path/to/.tmp_obj.ver\n" "\n" #ifdef __GNU_LIBRARY__ - " -a, --arch Select architecture\n" + " -s, --symbol-prefix Select symbol prefix\n" " -d, --debug Increment the debug level (repeatable)\n" " -D, --dump Dump expanded symbol defs (for debugging only)\n" " -r, --reference file Read reference symbols from a file\n" @@ -742,7 +741,7 @@ static void genksyms_usage(void) " -h, --help Print this message\n" " -V, --version Print the release version\n" #else /* __GNU_LIBRARY__ */ - " -a Select architecture\n" + " -s Select symbol prefix\n" " -d Increment the debug level (repeatable)\n" " -D Dump expanded symbol defs (for debugging only)\n" " -r file Read reference symbols from a file\n" @@ -763,7 +762,7 @@ int main(int argc, char **argv) #ifdef __GNU_LIBRARY__ struct option long_opts[] = { - {"arch", 1, 0, 'a'}, + {"symbol-prefix", 1, 0, 's'}, {"debug", 0, 0, 'd'}, {"warnings", 0, 0, 'w'}, {"quiet", 0, 0, 'q'}, @@ -776,14 +775,14 @@ int main(int argc, char **argv) {0, 0, 0, 0} }; - while ((o = getopt_long(argc, argv, "a:dwqVDr:T:ph", + while ((o = getopt_long(argc, argv, "s:dwqVDr:T:ph", &long_opts[0], NULL)) != EOF) #else /* __GNU_LIBRARY__ */ - while ((o = getopt(argc, argv, "a:dwqVDr:T:ph")) != EOF) + while ((o = getopt(argc, argv, "s:dwqVDr:T:ph")) != EOF) #endif /* __GNU_LIBRARY__ */ switch (o) { - case 'a': - arch = optarg; + case 's': + mod_prefix = optarg; break; case 'd': flag_debug++; @@ -826,9 +825,6 @@ int main(int argc, char **argv) genksyms_usage(); return 1; } - if ((strcmp(arch, "h8300") == 0) || (strcmp(arch, "blackfin") == 0) || - (strcmp(arch, "metag") == 0)) - mod_prefix = "_"; { extern int yydebug; extern int yy_flex_debug;