[ Oops, forgot to CC lkml on this to Linus, and people might want to see ]
Linus, please apply.
Rather than have the module loader the module structure and
resolve the symbols __this_module to it, make __this_module a real
structure inside the module, using the linkonce trick we used for
module names.
This saves us an allocation (saving a page per module on
archs which need the module structure close by), and means we don't
have to fill in a few module fields.
Works fine here. Requires the previous "Overzealous permenant mark
removed" patch, otherwise you'll get some rejects.
Thanks,
Rusty.
-- Anyone who quotes me in their sig is an idiot. -- Rusty Russell.Name: Embedded __this_module Author: Rusty Russell Status: Tested in 2.5.52 Depends: Module/module-noexit.patch.gz
D: This makes __this_module a real symbol for modules, rather than D: allocating at load time. This makes things a little simpler, and D: also saves about a page on architectures which have their own D: module allocator (eg. Sparc64).
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1411-2.5.53-embedded-thismodule.pre/include/linux/init.h .1411-2.5.53-embedded-thismodule/include/linux/init.h --- .1411-2.5.53-embedded-thismodule.pre/include/linux/init.h 2002-12-17 08:10:38.000000000 +1100 +++ .1411-2.5.53-embedded-thismodule/include/linux/init.h 2002-12-27 21:05:37.000000000 +1100 @@ -147,14 +147,13 @@ struct obs_kernel_param { #define module_init(initfn) \ static inline initcall_t __inittest(void) \ { return initfn; } \ - int __initfn(void) __attribute__((alias(#initfn))); + int init_module(void) __attribute__((alias(#initfn))); /* This is only required if you want to be unloadable. */ #define module_exit(exitfn) \ static inline exitcall_t __exittest(void) \ { return exitfn; } \ - void __exitfn(void) __attribute__((alias(#exitfn))); - + void cleanup_module(void) __attribute__((alias(#exitfn))); #define __setup(str,func) /* nothing */ #endif diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1411-2.5.53-embedded-thismodule.pre/include/linux/module.h .1411-2.5.53-embedded-thismodule/include/linux/module.h --- .1411-2.5.53-embedded-thismodule.pre/include/linux/module.h 2002-12-17 08:10:39.000000000 +1100 +++ .1411-2.5.53-embedded-thismodule/include/linux/module.h 2002-12-27 21:05:37.000000000 +1100 @@ -40,12 +40,11 @@ struct kernel_symbol char name[MODULE_NAME_LEN]; }; -#ifdef MODULE +/* These are either module local, or the kernel's dummy ones. */ +extern int init_module(void); +extern void cleanup_module(void); -#ifdef KBUILD_MODNAME -static const char __module_name[MODULE_NAME_LEN] __attribute__((section(".gnu.linkonce.modname"))) = \ - __stringify(KBUILD_MODNAME); -#endif +#ifdef MODULE /* For replacement modutils, use an alias not a pointer. */ #define MODULE_GENERIC_TABLE(gtype,name) \ @@ -56,9 +55,6 @@ static const struct gtype##_id * __modul extern const struct gtype##_id __mod_##gtype##_table \ __attribute__ ((unused, alias(__stringify(name)))) -/* This is magically filled in by the linker, but THIS_MODULE must be - a constant so it works in initializers. */ -extern struct module __this_module; #define THIS_MODULE (&__this_module) #else /* !MODULE */ @@ -176,7 +172,7 @@ struct module /* The command line arguments (may be mangled). People like keeping pointers to this stuff */ - char args[0]; + char *args; }; /* FIXME: It'd be nice to isolate modules during init, too, so they @@ -289,6 +285,19 @@ static inline const char *module_address } #endif /* CONFIG_MODULES */ +#if defined(MODULE) && defined(KBUILD_MODNAME) +/* We make the linker do some of the work. */ +struct module __this_module +__attribute__((section(".gnu.linkonce.this_module"))) = { + .name = __stringify(KBUILD_MODNAME), + .symbols = { .owner = &__this_module }, + .init = init_module, +#ifdef CONFIG_MODULE_UNLOAD + .exit = cleanup_module, +#endif +}; +#endif /* MODULE && KBUILD_MODNAME */ + /* For archs to search exception tables */ extern struct list_head extables; extern spinlock_t modlist_lock; @@ -342,13 +351,6 @@ extern int module_dummy_usage; && __mod_between((p),(n),(m)->module_init,(m)->init_size)) \ || __mod_between((p),(n),(m)->module_core,(m)->core_size)) -/* Old-style "I'll just call it init_module and it'll be run at - insert". Use module_init(myroutine) instead. */ -#ifdef MODULE -#define init_module(voidarg) __initfn(void) -#define cleanup_module(voidarg) __exitfn(void) -#endif - /* * The exception and symbol tables, and the lock * to protect them. diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .1411-2.5.53-embedded-thismodule.pre/kernel/module.c .1411-2.5.53-embedded-thismodule/kernel/module.c --- .1411-2.5.53-embedded-thismodule.pre/kernel/module.c 2002-12-27 21:05:37.000000000 +1100 +++ .1411-2.5.53-embedded-thismodule/kernel/module.c 2002-12-27 21:05:37.000000000 +1100 @@ -60,6 +60,13 @@ struct sizes unsigned long core_size; }; +/* Stub function for modules which don't have an initfn */ +int init_module(void) +{ + return 0; +} +EXPORT_SYMBOL(init_module); + /* Find a symbol, return value and the symbol group */ static unsigned long __find_symbol(const char *name, struct kernel_symbol_group **group) @@ -357,6 +364,12 @@ static inline int try_force(unsigned int } #endif /* CONFIG_MODULE_FORCE_UNLOAD */ +/* Stub function for modules which don't have an exitfn */ +void cleanup_module(void) +{ +} +EXPORT_SYMBOL(cleanup_module); + asmlinkage long sys_delete_module(const char *name_user, unsigned int flags) { @@ -406,7 +419,8 @@ sys_delete_module(const char *name_user, } /* If it has an init func, it must have an exit func to unload */ - if ((mod->init && !mod->exit) || mod->unsafe) { + if ((mod->init != init_module && mod->exit == cleanup_module) + || mod->unsafe) { forced = try_force(flags); if (!forced) { /* This module can't be removed */ @@ -453,8 +467,7 @@ sys_delete_module(const char *name_user, destroy: /* Final destruction now noone is using it. */ - if (mod->exit) - mod->exit(); + mod->exit(); free_module(mod); out: @@ -474,7 +487,7 @@ static void print_unload_info(struct seq if (mod->unsafe) seq_printf(m, " [unsafe]"); - if (mod->init && !mod->exit) + if (mod->init != init_module && mod->exit == cleanup_module) seq_printf(m, " [permanent]"); seq_printf(m, "\n"); @@ -708,15 +721,15 @@ static void free_module(struct module *m list_del(&mod->extable.list); spin_unlock_irq(&modlist_lock); - /* These may be NULL, but that's OK */ - module_free(mod, mod->module_init); - module_free(mod, mod->module_core); - /* Module unload stuff */ module_unload_free(mod); - /* Finally, free the module structure */ - module_free(mod, mod); + /* This may be NULL, but that's OK */ + module_free(mod, mod->module_init); + kfree(mod->args); + + /* Finally, free the core (containing the module structure) */ + module_free(mod, mod->module_core); } void *__symbol_get(const char *symbol) @@ -771,27 +784,6 @@ static void *copy_section(const char *na return dest; } -/* Look for the special symbols */ -static int grab_private_symbols(Elf_Shdr *sechdrs, - unsigned int symbolsec, - const char *strtab, - struct module *mod) -{ - Elf_Sym *sym = (void *)sechdrs[symbolsec].sh_offset; - unsigned int i; - - for (i = 1; i < sechdrs[symbolsec].sh_size/sizeof(*sym); i++) { - if (symbol_is("__initfn", strtab + sym[i].st_name)) - mod->init = (void *)sym[i].st_value; -#ifdef CONFIG_MODULE_UNLOAD - if (symbol_is("__exitfn", strtab + sym[i].st_name)) - mod->exit = (void *)sym[i].st_value; -#endif - } - - return 0; -} - /* Deal with the given section */ static int handle_section(const char *name, Elf_Shdr *sechdrs, @@ -810,9 +802,6 @@ static int handle_section(const char *na case SHT_RELA: ret = apply_relocate_add(sechdrs, strtab, symindex, i, mod); break; - case SHT_SYMTAB: - ret = grab_private_symbols(sechdrs, i, strtab, mod); - break; default: DEBUGP("Ignoring section %u: %s\n", i, sechdrs[i].sh_type==SHT_NULL ? "NULL": @@ -920,9 +909,6 @@ static void simplify_symbols(Elf_Shdr *s strtab + sym[i].st_name, mod, &ksg); - /* We fake up "__this_module" */ - if (symbol_is("__this_module", strtab+sym[i].st_name)) - sym[i].st_value = (unsigned long)mod; } } } @@ -964,9 +950,9 @@ static struct module *load_module(void * { Elf_Ehdr *hdr; Elf_Shdr *sechdrs; - char *secstrings; + char *secstrings, *args; unsigned int i, symindex, exportindex, strindex, setupindex, exindex, - modnameindex, obsparmindex; + modindex, obsparmindex; long arglen; unsigned long common_length; struct sizes sizes, used; @@ -1007,7 +993,7 @@ static struct module *load_module(void * exportindex = setupindex = obsparmindex = 0; /* And these should exist, but gcc whinges if we don't init them */ - symindex = strindex = exindex = modnameindex = 0; + symindex = strindex = exindex = modindex = 0; /* Find where important sections are */ for (i = 1; i < hdr->e_shnum; i++) { @@ -1016,10 +1002,10 @@ static struct module *load_module(void * DEBUGP("Symbol table in section %u\n", i); symindex = i; } else if (strcmp(secstrings+sechdrs[i].sh_name, - ".gnu.linkonce.modname") == 0) { - /* This module's name */ - DEBUGP("Module name in section %u\n", i); - modnameindex = i; + ".gnu.linkonce.this_module") == 0) { + /* The module struct */ + DEBUGP("Module in section %u\n", i); + modindex = i; } else if (strcmp(secstrings+sechdrs[i].sh_name, "__ksymtab") == 0) { /* Exported symbols. */ @@ -1058,39 +1044,35 @@ static struct module *load_module(void * #endif } - if (!modnameindex) { - DEBUGP("Module has no name!\n"); + if (!modindex) { + printk(KERN_WARNING "No module found in object\n"); err = -ENOEXEC; goto free_hdr; } + mod = (void *)hdr + sechdrs[modindex].sh_offset; - /* Now allocate space for the module proper, and copy name and args. */ + /* Now copy in args */ err = strlen_user(uargs); if (err < 0) goto free_hdr; arglen = err; - mod = module_alloc(sizeof(*mod) + arglen+1); - if (!mod) { + args = kmalloc(arglen+1, GFP_KERNEL); + if (!args) { err = -ENOMEM; goto free_hdr; } - memset(mod, 0, sizeof(*mod) + arglen+1); - if (copy_from_user(mod->args, uargs, arglen) != 0) { + if (copy_from_user(args, uargs, arglen+1) != 0) { err = -EFAULT; goto free_mod; } - strncpy(mod->name, (char *)hdr + sechdrs[modnameindex].sh_offset, - sizeof(mod->name)-1); if (find_module(mod->name)) { err = -EEXIST; goto free_mod; } - mod->symbols.owner = mod; mod->state = MODULE_STATE_COMING; - module_unload_init(mod); /* How much space will we need? (Common area in first) */ common_length = read_commons(hdr, &sechdrs[symindex]); @@ -1139,6 +1121,9 @@ static struct module *load_module(void * if (IS_ERR(ptr)) goto cleanup; sechdrs[i].sh_offset = (unsigned long)ptr; + /* Have we just copied __this_module across? */ + if (i == modindex) + mod = ptr; } else { sechdrs[i].sh_offset += (unsigned long)hdr; } @@ -1147,6 +1132,9 @@ static struct module *load_module(void * if (used.init_size > mod->init_size || used.core_size > mod->core_size) BUG(); + /* Now we've moved module, initialize linked lists, etc. */ + module_unload_init(mod); + /* Fix up syms, so that st_value is a pointer to location. */ simplify_symbols(sechdrs, symindex, strindex, mod->module_core, mod); @@ -1183,6 +1171,7 @@ static struct module *load_module(void * if (err < 0) goto cleanup; + mod->args = args; if (obsparmindex) { err = obsolete_params(mod->name, mod->args, (struct obsolete_modparm *) @@ -1215,7 +1204,7 @@ static struct module *load_module(void * free_core: module_free(mod, mod->module_core); free_mod: - module_free(mod, mod); + kfree(args); free_hdr: vfree(hdr); if (err < 0) return ERR_PTR(err); @@ -1266,7 +1255,7 @@ sys_init_module(void *umod, up(&module_mutex); /* Start the module */ - ret = mod->init ? mod->init() : 0; + ret = mod->init(); if (ret < 0) { /* Init routine failed: abort. Try to protect us from buggy refcounters. */
-- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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