From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yb1-f201.google.com ([209.85.219.201]:52905 "EHLO mail-yb1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728086AbfHMMTc (ORCPT ); Tue, 13 Aug 2019 08:19:32 -0400 Received: by mail-yb1-f201.google.com with SMTP id n6so542054ybf.19 for ; Tue, 13 Aug 2019 05:19:31 -0700 (PDT) Date: Tue, 13 Aug 2019 13:17:03 +0100 In-Reply-To: <20190813121733.52480-1-maennich@google.com> Message-Id: <20190813121733.52480-7-maennich@google.com> Mime-Version: 1.0 References: <20180716122125.175792-1-maco@android.com> <20190813121733.52480-1-maennich@google.com> Subject: [PATCH v2 06/10] export: allow definition default namespaces in Makefiles or sources From: Matthias Maennich Content-Type: text/plain; charset="UTF-8" Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, maco@android.com Cc: kernel-team@android.com, maennich@google.com, arnd@arndb.de, geert@linux-m68k.org, gregkh@linuxfoundation.org, hpa@zytor.com, jeyu@kernel.org, joel@joelfernandes.org, kstewart@linuxfoundation.org, linux-arch@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-modules@vger.kernel.org, linux-scsi@vger.kernel.org, linux-usb@vger.kernel.org, lucas.de.marchi@gmail.com, maco@google.com, michal.lkml@markovi.net, mingo@redhat.com, oneukum@suse.com, pombredanne@nexb.com, sam@ravnborg.org, sboyd@codeaurora.org, sspatil@google.com, stern@rowland.harvard.edu, tglx@linutronix.de, usb-storage@lists.one-eyed-alien.net, x86@kernel.org, yamada.masahiro@socionext.com, Ard Biesheuvel , Michael Ellerman To avoid excessive usage of EXPORT_SYMBOL_NS(sym, MY_NAMESPACE), where MY_NAMESPACE will always be the namespace we are exporting to, allow exporting all definitions of EXPORT_SYMBOL() and friends by defining DEFAULT_SYMBOL_NAMESPACE. For example, to export all symbols defined in usb-common into the namespace USB_COMMON, add a line like this to drivers/usb/common/Makefile: ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=USB_COMMON That is equivalent to changing all EXPORT_SYMBOL(sym) definitions to EXPORT_SYMBOL_NS(sym, USB_COMMON). Subsequently all symbol namespaces functionality will apply. Another way of making use of this feature is to define the namespace within source or header files similar to how TRACE_SYSTEM defines are used: #undef DEFAULT_SYMBOL_NAMESPACE #define DEFAULT_SYMBOL_NAMESPACE USB_COMMON Please note that, as opposed to TRACE_SYSTEM, DEFAULT_SYMBOL_NAMESPACE has to be defined before including include/linux/export.h. If DEFAULT_SYMBOL_NAMESPACE is defined, a symbol can still be exported to another namespace by using EXPORT_SYMBOL_NS() and friends with explicitly specifying the namespace. Suggested-by: Arnd Bergmann Reviewed-by: Martijn Coenen Signed-off-by: Matthias Maennich --- include/linux/export.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/include/linux/export.h b/include/linux/export.h index 8e12e05444d1..1fb243abdbc4 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -166,6 +166,12 @@ struct kernel_symbol { #define __EXPORT_SYMBOL ___EXPORT_SYMBOL #endif +#ifdef DEFAULT_SYMBOL_NAMESPACE +#undef __EXPORT_SYMBOL +#define __EXPORT_SYMBOL(sym, sec) \ + __EXPORT_SYMBOL_NS(sym, sec, DEFAULT_SYMBOL_NAMESPACE) +#endif + #define EXPORT_SYMBOL(sym) __EXPORT_SYMBOL(sym, "") #define EXPORT_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_gpl") #define EXPORT_SYMBOL_GPL_FUTURE(sym) __EXPORT_SYMBOL(sym, "_gpl_future") -- 2.23.0.rc1.153.gdeed80330f-goog