From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f193.google.com ([209.85.208.193]:36148 "EHLO mail-lj1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727467AbfIGVIW (ORCPT ); Sat, 7 Sep 2019 17:08:22 -0400 Subject: Re: [PATCH] mostpost: don't warn about symbols from another file References: <20190906151059.1077708-1-arnd@arndb.de> From: Denis Efremov Message-ID: Date: Sun, 8 Sep 2019 00:08:14 +0300 MIME-Version: 1.0 In-Reply-To: <20190906151059.1077708-1-arnd@arndb.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Arnd Bergmann , Masahiro Yamada , Michal Marek Cc: Emil Velikov , Paul Walmsley , Sam Ravnborg , WANG Chao , Sami Tolvanen , linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org On 06.09.2019 18:10, Arnd Bergmann wrote: > On architectures such as ARM that have a list of symbols exported > from assembler in a separate C file, we get a lot of new warnings: > > WARNING: "__ashrdi3" [vmlinux] is a static (unknown) WARNING: > "__lshrdi3" [vmlinux] is a static (unknown) WARNING: "__aeabi_llsr" > [vmlinux] is a static (unknown) WARNING: "__aeabi_lasr" [vmlinux] is > a static (unknown) WARNING: "__aeabi_uidivmod" [vmlinux] is a static > (unknown) WARNING: "__udivsi3" [vmlinux] is a static (unknown) > WARNING: "_change_bit" [vmlinux] is a static (unknown) WARNING: > "__aeabi_idiv" [vmlinux] is a static (unknown) WARNING: "__umodsi3" > [vmlinux] is a static (unknown) WARNING: "__aeabi_uidiv" [vmlinux] is > a static (unknown) WARNING: "__aeabi_idivmod" [vmlinux] is a static > (unknown) WARNING: "__muldi3" [vmlinux] is a static (unknown) > WARNING: "__aeabi_ulcmp" [vmlinux] is a static (unknown) WARNING: > "__raw_writesb" [vmlinux] is a static (unknown) WARNING: > "__raw_readsb" [vmlinux] is a static (unknown) ... > > This is not helpful, as these are clearly not static symbols at all. > Suppress the warning in a case like this. > > Fixes: 15bfc2348d54 ("modpost: check for static EXPORT_SYMBOL* > functions") Signed-off-by: Arnd Bergmann Tested-by: Denis Efremov What I could add here is that all these symbols are: $ nm vmlinux | grep '__ashrdi3\|__lshrdi3\|__aeabi_llsr\|...' cd63c845 A __crc___aeabi_lasr 76cf47f6 A __crc___aeabi_llsl 8a4fa83b A __crc___aeabi_llsr 44643b93 A __crc___aeabi_lmul f564412a A __crc___aeabi_ulcmp 40f07981 A __crc___ashldi3 edd9106d A __crc___ashrdi3 389ecf9e A __crc___bswapdi2 f1ea6f1c A __crc___bswapsi2 14d4a9c5 A __crc__change_bit ff67b37f A __crc___lshrdi3 800e4ffa A __crc___muldi3 f7163ec9 A __crc___raw_readsb f0ed2ef4 A __crc___raw_writesb ffb94ef0 A __crc__test_and_change_bit 7cc035a7 A __crc___ucmpdi2 There is no ksymtab, kstrtab for them and there is no the exact symbols, only crc. Thus they get to the symbolhash table from handle_modversions() -> sym_update_crc(). Since there is no the exact symbols, e.g. like nm vmlinux | grep __kmalloc 2d6fcc06 A __crc___kmalloc c01c922d T __kmalloc <--- c0749192 r __kstrtab___kmalloc c073c7c4 r __ksymtab___kmalloc we can't check them in this cycle: // check for static EXPORT_SYMBOL_* functions && global vars for (sym = info.symtab_start; sym < info.symtab_stop; sym++) { and they are automatically marked as static. That's all so far, I don't know is it correct to have only __crc* or not for a symbol. Just a sidenote: arch/arm/kernel/armksyms.c states that these are /* * libgcc functions - functions that are used internally by the * compiler... Thanks, Denis > --- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1 > deletion(-) > > diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index > 76c221dd9b2b..4265dd924933 100644 --- a/scripts/mod/modpost.c +++ > b/scripts/mod/modpost.c @@ -2543,7 +2543,7 @@ int main(int argc, char > **argv) struct symbol *s = symbolhash[n]; > > while (s) { - if (s->is_static) + if (s->is_static && s->export > != export_unknown) warn("\"%s\" [%s] is a static %s\n", s->name, > s->module->name, export_str(s->export)); >