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: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/include/linux/module.h b/include/linux/module.h
index 63f0eb6..a860a2c 100644 (file)
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -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;

diff --git a/init/Kconfig b/init/Kconfig
index 6199d11..c8578f9 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -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"

diff --git a/kernel/module.c b/kernel/module.c
index c51c089..ea95805 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -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)