From c3a6cf19e695c8b0a9bf8b5933f863e12d878b7c Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 18 Oct 2019 10:31:43 +0100 Subject: export: avoid code duplication in include/linux/export.h include/linux/export.h has lots of code duplication between EXPORT_SYMBOL and EXPORT_SYMBOL_NS. To improve the maintainability and readability, unify the implementation. When the symbol has no namespace, pass the empty string "" to the 'ns' parameter. The drawback of this change is, it grows the code size. When the symbol has no namespace, sym->namespace was previously NULL, but it is now an empty string "". So, it increases 1 byte for every no namespace EXPORT_SYMBOL. A typical kernel configuration has 10K exported symbols, so it increases 10KB in rough estimation. I did not come up with a good idea to refactor it without increasing the code size. I am not sure how big a deal it is, but at least include/linux/export.h looks nicer. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Masahiro Yamada [maennich: rebase on top of 3 fixes for the namespace feature] Signed-off-by: Matthias Maennich Signed-off-by: Jessica Yu --- include/linux/export.h | 91 ++++++++++++++++---------------------------------- 1 file changed, 28 insertions(+), 63 deletions(-) (limited to 'include/linux/export.h') diff --git a/include/linux/export.h b/include/linux/export.h index 941d075f03d6..201262793369 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -46,7 +46,7 @@ extern struct module __this_module; * absolute relocations that require runtime processing on relocatable * kernels. */ -#define __KSYMTAB_ENTRY_NS(sym, sec) \ +#define __KSYMTAB_ENTRY(sym, sec) \ __ADDRESSABLE(sym) \ asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ " .balign 4 \n" \ @@ -56,33 +56,17 @@ extern struct module __this_module; " .long __kstrtabns_" #sym "- . \n" \ " .previous \n") -#define __KSYMTAB_ENTRY(sym, sec) \ - __ADDRESSABLE(sym) \ - asm(" .section \"___ksymtab" sec "+" #sym "\", \"a\" \n" \ - " .balign 4 \n" \ - "__ksymtab_" #sym ": \n" \ - " .long " #sym "- . \n" \ - " .long __kstrtab_" #sym "- . \n" \ - " .long 0 \n" \ - " .previous \n") - struct kernel_symbol { int value_offset; int name_offset; int namespace_offset; }; #else -#define __KSYMTAB_ENTRY_NS(sym, sec) \ - static const struct kernel_symbol __ksymtab_##sym \ - __attribute__((section("___ksymtab" sec "+" #sym), used)) \ - __aligned(sizeof(void *)) \ - = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym } - #define __KSYMTAB_ENTRY(sym, sec) \ static const struct kernel_symbol __ksymtab_##sym \ __attribute__((section("___ksymtab" sec "+" #sym), used)) \ __aligned(sizeof(void *)) \ - = { (unsigned long)&sym, __kstrtab_##sym, NULL } + = { (unsigned long)&sym, __kstrtab_##sym, __kstrtabns_##sym } struct kernel_symbol { unsigned long value; @@ -93,28 +77,20 @@ struct kernel_symbol { #ifdef __GENKSYMS__ -#define ___EXPORT_SYMBOL(sym,sec) __GENKSYMS_EXPORT_SYMBOL(sym) -#define ___EXPORT_SYMBOL_NS(sym,sec,ns) __GENKSYMS_EXPORT_SYMBOL(sym) +#define ___EXPORT_SYMBOL(sym, sec, ns) __GENKSYMS_EXPORT_SYMBOL(sym) #else -#define ___export_symbol_common(sym, sec) \ +/* For every exported symbol, place a struct in the __ksymtab section */ +#define ___EXPORT_SYMBOL(sym, sec, ns) \ extern typeof(sym) sym; \ __CRC_SYMBOL(sym, sec); \ static const char __kstrtab_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ - = #sym \ - -/* For every exported symbol, place a struct in the __ksymtab section */ -#define ___EXPORT_SYMBOL_NS(sym, sec, ns) \ - ___export_symbol_common(sym, sec); \ + = #sym; \ static const char __kstrtabns_##sym[] \ __attribute__((section("__ksymtab_strings"), used, aligned(1))) \ - = #ns; \ - __KSYMTAB_ENTRY_NS(sym, sec) - -#define ___EXPORT_SYMBOL(sym, sec) \ - ___export_symbol_common(sym, sec); \ + = ns; \ __KSYMTAB_ENTRY(sym, sec) #endif @@ -126,8 +102,7 @@ struct kernel_symbol { * be reused in other execution contexts such as the UEFI stub or the * decompressor. */ -#define __EXPORT_SYMBOL_NS(sym, sec, ns) -#define __EXPORT_SYMBOL(sym, sec) +#define __EXPORT_SYMBOL(sym, sec, ns) #elif defined(CONFIG_TRIM_UNUSED_KSYMS) @@ -143,48 +118,38 @@ struct kernel_symbol { #define __ksym_marker(sym) \ static int __ksym_marker_##sym[0] __section(".discard.ksym") __used -#define __EXPORT_SYMBOL(sym, sec) \ - __ksym_marker(sym); \ - __cond_export_sym(sym, sec, __is_defined(__KSYM_##sym)) -#define __cond_export_sym(sym, sec, conf) \ - ___cond_export_sym(sym, sec, conf) -#define ___cond_export_sym(sym, sec, enabled) \ - __cond_export_sym_##enabled(sym, sec) -#define __cond_export_sym_1(sym, sec) ___EXPORT_SYMBOL(sym, sec) -#define __cond_export_sym_0(sym, sec) /* nothing */ - -#define __EXPORT_SYMBOL_NS(sym, sec, ns) \ +#define __EXPORT_SYMBOL(sym, sec, ns) \ __ksym_marker(sym); \ - __cond_export_ns_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) -#define __cond_export_ns_sym(sym, sec, ns, conf) \ - ___cond_export_ns_sym(sym, sec, ns, conf) -#define ___cond_export_ns_sym(sym, sec, ns, enabled) \ - __cond_export_ns_sym_##enabled(sym, sec, ns) -#define __cond_export_ns_sym_1(sym, sec, ns) ___EXPORT_SYMBOL_NS(sym, sec, ns) -#define __cond_export_ns_sym_0(sym, sec, ns) /* nothing */ + __cond_export_sym(sym, sec, ns, __is_defined(__KSYM_##sym)) +#define __cond_export_sym(sym, sec, ns, conf) \ + ___cond_export_sym(sym, sec, ns, conf) +#define ___cond_export_sym(sym, sec, ns, enabled) \ + __cond_export_sym_##enabled(sym, sec, ns) +#define __cond_export_sym_1(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns) +#define __cond_export_sym_0(sym, sec, ns) /* nothing */ #else -#define __EXPORT_SYMBOL_NS(sym,sec,ns) ___EXPORT_SYMBOL_NS(sym,sec,ns) -#define __EXPORT_SYMBOL(sym,sec) ___EXPORT_SYMBOL(sym,sec) +#define __EXPORT_SYMBOL(sym, sec, ns) ___EXPORT_SYMBOL(sym, sec, ns) #endif /* CONFIG_MODULES */ #ifdef DEFAULT_SYMBOL_NAMESPACE -#undef __EXPORT_SYMBOL -#define __EXPORT_SYMBOL(sym, sec) \ - __EXPORT_SYMBOL_NS(sym, sec, DEFAULT_SYMBOL_NAMESPACE) +#include +#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, __stringify(DEFAULT_SYMBOL_NAMESPACE)) +#else +#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "") #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") -#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL_NS(sym, "", ns) -#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL_NS(sym, "_gpl", ns) +#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") +#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns) +#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns) #ifdef CONFIG_UNUSED_SYMBOLS -#define EXPORT_UNUSED_SYMBOL(sym) __EXPORT_SYMBOL(sym, "_unused") -#define EXPORT_UNUSED_SYMBOL_GPL(sym) __EXPORT_SYMBOL(sym, "_unused_gpl") +#define EXPORT_UNUSED_SYMBOL(sym) _EXPORT_SYMBOL(sym, "_unused") +#define EXPORT_UNUSED_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_unused_gpl") #else #define EXPORT_UNUSED_SYMBOL(sym) #define EXPORT_UNUSED_SYMBOL_GPL(sym) -- cgit v1.2.3 From bf49d9dd6fef688733e2ddbd55f7bcb57df194e4 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 18 Oct 2019 13:50:53 +0900 Subject: export,module: add SPDX GPL-2.0 license identifier to headers with no license Commit b24413180f56 ("License cleanup: add SPDX GPL-2.0 license identifier to files with no license") took care of a lot of files without any license information. These headers were not processed by the tool perhaps because they contain "GPL" in the code. I do not see any license boilerplate in them, so they fall back to GPL version 2 only, which is the project default. Signed-off-by: Masahiro Yamada Link: https://lore.kernel.org/r/20191018045053.8424-1-yamada.masahiro@socionext.com Signed-off-by: Greg Kroah-Hartman --- include/asm-generic/export.h | 1 + include/linux/export.h | 1 + include/linux/license.h | 1 + include/linux/module.h | 7 +++++-- 4 files changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux/export.h') diff --git a/include/asm-generic/export.h b/include/asm-generic/export.h index fa577978fbbd..d0166115a825 100644 --- a/include/asm-generic/export.h +++ b/include/asm-generic/export.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef __ASM_GENERIC_EXPORT_H #define __ASM_GENERIC_EXPORT_H diff --git a/include/linux/export.h b/include/linux/export.h index 941d075f03d6..aee5c86ae350 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef _LINUX_EXPORT_H #define _LINUX_EXPORT_H diff --git a/include/linux/license.h b/include/linux/license.h index decdbf43cb5c..7cce390f120b 100644 --- a/include/linux/license.h +++ b/include/linux/license.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ #ifndef __LICENSE_H #define __LICENSE_H diff --git a/include/linux/module.h b/include/linux/module.h index 6d20895e7739..bd165ba68617 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -1,11 +1,14 @@ -#ifndef _LINUX_MODULE_H -#define _LINUX_MODULE_H +/* SPDX-License-Identifier: GPL-2.0-only */ /* * Dynamic loading of modules into the kernel. * * Rewritten by Richard Henderson Dec 1996 * Rewritten again by Rusty Russell, 2002 */ + +#ifndef _LINUX_MODULE_H +#define _LINUX_MODULE_H + #include #include #include -- cgit v1.2.3