From f71d20e961474dde77e6558396efb93d6ac80a4b Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Wed, 28 Jun 2006 04:26:45 -0700 Subject: [PATCH] Add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL Temporarily add EXPORT_UNUSED_SYMBOL and EXPORT_UNUSED_SYMBOL_GPL. These will be used as a transition measure for symbols that aren't used in the kernel and are on the way out. When a module uses such a symbol, a warning is printk'd at modprobe time. The main reason for removing unused exports is size: eacho export takes roughly between 100 and 150 bytes of kernel space in the binary. This patch gives users the option to immediately get this size gain via a config option. Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-generic/vmlinux.lds.h | 28 ++++++++++++++++++++++++++++ include/linux/module.h | 20 ++++++++++++++++++++ 2 files changed, 48 insertions(+) (limited to 'include') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 9d11550b4818..db5a3732f106 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -58,6 +58,20 @@ VMLINUX_SYMBOL(__stop___ksymtab_gpl) = .; \ } \ \ + /* Kernel symbol table: Normal unused symbols */ \ + __ksymtab_unused : AT(ADDR(__ksymtab_unused) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__start___ksymtab_unused) = .; \ + *(__ksymtab_unused) \ + VMLINUX_SYMBOL(__stop___ksymtab_unused) = .; \ + } \ + \ + /* Kernel symbol table: GPL-only unused symbols */ \ + __ksymtab_unused_gpl : AT(ADDR(__ksymtab_unused_gpl) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__start___ksymtab_unused_gpl) = .; \ + *(__ksymtab_unused_gpl) \ + VMLINUX_SYMBOL(__stop___ksymtab_unused_gpl) = .; \ + } \ + \ /* Kernel symbol table: GPL-future-only symbols */ \ __ksymtab_gpl_future : AT(ADDR(__ksymtab_gpl_future) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__start___ksymtab_gpl_future) = .; \ @@ -79,6 +93,20 @@ VMLINUX_SYMBOL(__stop___kcrctab_gpl) = .; \ } \ \ + /* Kernel symbol table: Normal unused symbols */ \ + __kcrctab_unused : AT(ADDR(__kcrctab_unused) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__start___kcrctab_unused) = .; \ + *(__kcrctab_unused) \ + VMLINUX_SYMBOL(__stop___kcrctab_unused) = .; \ + } \ + \ + /* Kernel symbol table: GPL-only unused symbols */ \ + __kcrctab_unused_gpl : AT(ADDR(__kcrctab_unused_gpl) - LOAD_OFFSET) { \ + VMLINUX_SYMBOL(__start___kcrctab_unused_gpl) = .; \ + *(__kcrctab_unused_gpl) \ + VMLINUX_SYMBOL(__stop___kcrctab_unused_gpl) = .; \ + } \ + \ /* Kernel symbol table: GPL-future-only symbols */ \ __kcrctab_gpl_future : AT(ADDR(__kcrctab_gpl_future) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__start___kcrctab_gpl_future) = .; \ diff --git a/include/linux/module.h b/include/linux/module.h index 9ebbb74b7b72..9e9dc7c24d95 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -203,6 +203,15 @@ void *__symbol_get_gpl(const char *symbol); #define EXPORT_SYMBOL_GPL_FUTURE(sym) \ __EXPORT_SYMBOL(sym, "_gpl_future") + +#ifdef CONFIG_UNUSED_SYMBOLS +#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) +#endif + #endif struct module_ref @@ -261,6 +270,15 @@ struct module unsigned int num_gpl_syms; const unsigned long *gpl_crcs; + /* unused exported symbols. */ + const struct kernel_symbol *unused_syms; + unsigned int num_unused_syms; + const unsigned long *unused_crcs; + /* GPL-only, unused exported symbols. */ + const struct kernel_symbol *unused_gpl_syms; + unsigned int num_unused_gpl_syms; + const unsigned long *unused_gpl_crcs; + /* symbols that will be GPL-only in the near future. */ const struct kernel_symbol *gpl_future_syms; unsigned int num_gpl_future_syms; @@ -456,6 +474,8 @@ void module_remove_driver(struct device_driver *); #define EXPORT_SYMBOL(sym) #define EXPORT_SYMBOL_GPL(sym) #define EXPORT_SYMBOL_GPL_FUTURE(sym) +#define EXPORT_UNUSED_SYMBOL(sym) +#define EXPORT_UNUSED_SYMBOL_GPL(sym) /* Given an address, look for it in the exception tables. */ static inline const struct exception_table_entry * -- cgit v1.2.3