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Commit f7f5b675 authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Rusty Russell
Browse files

Shrink struct module: CONFIG_UNUSED_SYMBOLS ifdefs 



module.c and module.h conatains code for finding
exported symbols which are declared with EXPORT_UNUSED_SYMBOL,
and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set
and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway
(because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then).

This patch adds required #ifdefs.

Signed-off-by: default avatarDenys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent af540689

include/linux/module.h

+2 −0
Original line number Diff line number Diff line
@@ -257,6 +257,7 @@ struct module 
	const struct kernel_symbol *gpl_syms;

	const unsigned long *gpl_crcs;



#ifdef CONFIG_UNUSED_SYMBOLS

	/* unused exported symbols. */

	const struct kernel_symbol *unused_syms;

	const unsigned long *unused_crcs;
@@ -266,6 +267,7 @@ struct module 
	unsigned int num_unused_gpl_syms;

	const struct kernel_symbol *unused_gpl_syms;

	const unsigned long *unused_gpl_crcs;

#endif



	/* symbols that will be GPL-only in the near future. */

	const struct kernel_symbol *gpl_future_syms;

init/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -856,8 +856,8 @@ config MODULE_UNLOAD 
	help

	  Without this option you will not be able to unload any

	  modules (note that some modules may not be unloadable

	  anyway), which makes your kernel slightly smaller and

	  simpler.  If unsure, say Y.

	  anyway), which makes your kernel smaller, faster

	  and simpler.  If unsure, say Y.



config MODULE_FORCE_UNLOAD

	bool "Forced module unloading"

kernel/module.c

+34 −15
Original line number Diff line number Diff line
@@ -134,17 +134,19 @@ extern const struct kernel_symbol __start___ksymtab_gpl[]; 
extern const struct kernel_symbol __stop___ksymtab_gpl[];

extern const struct kernel_symbol __start___ksymtab_gpl_future[];

extern const struct kernel_symbol __stop___ksymtab_gpl_future[];

extern const struct kernel_symbol __start___ksymtab_unused[];

extern const struct kernel_symbol __stop___ksymtab_unused[];

extern const struct kernel_symbol __start___ksymtab_unused_gpl[];

extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];

extern const struct kernel_symbol __start___ksymtab_gpl_future[];

extern const struct kernel_symbol __stop___ksymtab_gpl_future[];

extern const unsigned long __start___kcrctab[];

extern const unsigned long __start___kcrctab_gpl[];

extern const unsigned long __start___kcrctab_gpl_future[];

#ifdef CONFIG_UNUSED_SYMBOLS

extern const struct kernel_symbol __start___ksymtab_unused[];

extern const struct kernel_symbol __stop___ksymtab_unused[];

extern const struct kernel_symbol __start___ksymtab_unused_gpl[];

extern const struct kernel_symbol __stop___ksymtab_unused_gpl[];

extern const unsigned long __start___kcrctab_unused[];

extern const unsigned long __start___kcrctab_unused_gpl[];

#endif



#ifndef CONFIG_MODVERSIONS

#define symversion(base, idx) NULL
@@ -198,12 +200,14 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, 
		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,

		  __start___kcrctab_gpl_future,

		  WILL_BE_GPL_ONLY, false },

#ifdef CONFIG_UNUSED_SYMBOLS

		{ __start___ksymtab_unused, __stop___ksymtab_unused,

		  __start___kcrctab_unused,

		  NOT_GPL_ONLY, true },

		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,

		  __start___kcrctab_unused_gpl,

		  GPL_ONLY, true },

#endif

	};



	if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data))
@@ -220,6 +224,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, 
			  mod->gpl_future_syms + mod->num_gpl_future_syms,

			  mod->gpl_future_crcs,

			  WILL_BE_GPL_ONLY, false },

#ifdef CONFIG_UNUSED_SYMBOLS

			{ mod->unused_syms,

			  mod->unused_syms + mod->num_unused_syms,

			  mod->unused_crcs,
@@ -228,6 +233,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, 
			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,

			  mod->unused_gpl_crcs,

			  GPL_ONLY, true },

#endif

		};



		if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data))
@@ -270,6 +276,7 @@ static bool find_symbol_in_section(const struct symsearch *syms, 
		}

	}



#ifdef CONFIG_UNUSED_SYMBOLS

	if (syms->unused && fsa->warn) {

		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "

		       "however this module is using it.\n", fsa->name);
@@ -281,6 +288,7 @@ static bool find_symbol_in_section(const struct symsearch *syms, 
		       "mailinglist together with submitting your code for "

		       "inclusion.\n");

	}

#endif



	fsa->owner = owner;

	fsa->crc = symversion(syms->crcs, symnum);
@@ -1476,8 +1484,10 @@ static int verify_export_symbols(struct module *mod) 
		{ mod->syms, mod->num_syms },

		{ mod->gpl_syms, mod->num_gpl_syms },

		{ mod->gpl_future_syms, mod->num_gpl_future_syms },

#ifdef CONFIG_UNUSED_SYMBOLS

		{ mod->unused_syms, mod->num_unused_syms },

		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },

#endif

	};



	for (i = 0; i < ARRAY_SIZE(arr); i++) {
@@ -1795,10 +1805,12 @@ static struct module *load_module(void __user *umod, 
	unsigned int gplfutureindex;

	unsigned int gplfuturecrcindex;

	unsigned int unwindex = 0;

#ifdef CONFIG_UNUSED_SYMBOLS

	unsigned int unusedindex;

	unsigned int unusedcrcindex;

	unsigned int unusedgplindex;

	unsigned int unusedgplcrcindex;

#endif

	unsigned int markersindex;

	unsigned int markersstringsindex;

	struct module *mod;
@@ -1881,13 +1893,15 @@ static struct module *load_module(void __user *umod, 
	exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");

	gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");

	gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future");

	unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");

	unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");

	crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");

	gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");

	gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future");

#ifdef CONFIG_UNUSED_SYMBOLS

	unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused");

	unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl");

	unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused");

	unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl");

#endif

	setupindex = find_sec(hdr, sechdrs, secstrings, "__param");

	exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");

	obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
@@ -2049,14 +2063,15 @@ static struct module *load_module(void __user *umod, 
		mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;

	mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size /

					sizeof(*mod->gpl_future_syms);

	mod->num_unused_syms = sechdrs[unusedindex].sh_size /

					sizeof(*mod->unused_syms);

	mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /

					sizeof(*mod->unused_gpl_syms);

	mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr;

	if (gplfuturecrcindex)

		mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr;



#ifdef CONFIG_UNUSED_SYMBOLS

	mod->num_unused_syms = sechdrs[unusedindex].sh_size /

					sizeof(*mod->unused_syms);

	mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size /

					sizeof(*mod->unused_gpl_syms);

	mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr;

	if (unusedcrcindex)

		mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
@@ -2064,13 +2079,17 @@ static struct module *load_module(void __user *umod, 
	if (unusedgplcrcindex)

		mod->unused_gpl_crcs

			= (void *)sechdrs[unusedgplcrcindex].sh_addr;

#endif



#ifdef CONFIG_MODVERSIONS

	if ((mod->num_syms && !crcindex) ||

	    (mod->num_gpl_syms && !gplcrcindex) ||

	    (mod->num_gpl_future_syms && !gplfuturecrcindex) ||

	    (mod->num_unused_syms && !unusedcrcindex) ||

	    (mod->num_unused_gpl_syms && !unusedgplcrcindex)) {

	if ((mod->num_syms && !crcindex)

	    || (mod->num_gpl_syms && !gplcrcindex)

	    || (mod->num_gpl_future_syms && !gplfuturecrcindex)

#ifdef CONFIG_UNUSED_SYMBOLS

	    || (mod->num_unused_syms && !unusedcrcindex)

	    || (mod->num_unused_gpl_syms && !unusedgplcrcindex)

#endif

		) {

		printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);

		err = try_to_force_load(mod, "nocrc");

		if (err)