Testers welcome,
Rusty.
Name: Embedded __this_module
Author: Rusty Russell
Status: Tested in 2.5.52
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 -urNp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.52/include/linux/module.h working-2.5.52-thismodule/include/linux/module.h
--- linux-2.5.52/include/linux/module.h Tue Dec 17 08:10:39 2002
+++ working-2.5.52-thismodule/include/linux/module.h Mon Dec 23 16:37:53 2002
@@ -42,11 +42,6 @@ struct kernel_symbol
#ifdef MODULE
-#ifdef KBUILD_MODNAME
-static const char __module_name[MODULE_NAME_LEN] __attribute__((section(".gnu.linkonce.modname"))) = \
- __stringify(KBUILD_MODNAME);
-#endif
-
/* For replacement modutils, use an alias not a pointer. */
#define MODULE_GENERIC_TABLE(gtype,name) \
static const unsigned long __module_##gtype##_size \
@@ -56,9 +51,6 @@ 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 +174,7 @@ 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
@@ -288,6 +286,11 @@ static inline const char *module_address
return NULL;
}
#endif /* CONFIG_MODULES */
+
+#ifdef MODULE
+/* This defines __this_module. */
+#include <linux/thismodule.h>
+#endif
/* For archs to search exception tables */
extern struct list_head extables;
diff -urNp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.52/include/linux/thismodule.h working-2.5.52-thismodule/include/linux/thismodule.h
--- linux-2.5.52/include/linux/thismodule.h Thu Jan 1 10:00:00 1970
+++ working-2.5.52-thismodule/include/linux/thismodule.h Mon Dec 23 16:10:04 2002
@@ -0,0 +1,19 @@
+#ifndef _LINUX_THISMODULE_H
+#define _LINUX_THISMODULE_H
+/* This stub is linked into every module. */
+
+/* These could be defined in the module, or will resolve to the kernel stubs */
+extern int __initfn(void);
+extern void __exitfn(void);
+
+/* We use the linker to do some of the work for us. */
+static struct module __this_module
+__attribute__((section(".gnu.linkonce.this_module"))) = {
+ .name = __stringify(KBUILD_MODNAME),
+ .symbols = { .owner = &__this_module },
+ .init = __initfn,
+#ifdef CONFIG_MODULE_UNLOAD
+ .exit = __exitfn,
+#endif
+};
+#endif /* MODULE */
diff -urNp --exclude TAGS -X /home/rusty/current-dontdiff --minimal linux-2.5.52/kernel/module.c working-2.5.52-thismodule/kernel/module.c
--- linux-2.5.52/kernel/module.c Tue Dec 17 08:11:03 2002
+++ working-2.5.52-thismodule/kernel/module.c Mon Dec 23 16:37:14 2002
@@ -32,7 +32,7 @@
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
-#if 0
+#if 1
#define DEBUGP printk
#else
#define DEBUGP(fmt , a...)
@@ -60,6 +60,13 @@ struct sizes
unsigned long core_size;
};
+/* Stub function for modules which don't have an initfn */
+int __initfn(void)
+{
+ return 0;
+}
+EXPORT_SYMBOL(__initfn);
+
/* 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 __exitfn(void)
+{
+}
+EXPORT_SYMBOL(__exitfn);
+
asmlinkage long
sys_delete_module(const char *name_user, unsigned int flags)
{
@@ -405,7 +418,7 @@ sys_delete_module(const char *name_user,
}
}
- if (!mod->exit || mod->unsafe) {
+ if (mod->exit == __exitfn || mod->unsafe) {
forced = try_force(flags);
if (!forced) {
/* This module can't be removed */
@@ -452,8 +465,7 @@ 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:
@@ -473,7 +485,7 @@ static void print_unload_info(struct seq
if (mod->unsafe)
seq_printf(m, " [unsafe]");
- if (!mod->exit)
+ if (mod->exit == __exitfn)
seq_printf(m, " [permanent]");
seq_printf(m, "\n");
@@ -715,6 +727,7 @@ static void free_module(struct module *m
module_unload_free(mod);
/* Finally, free the module structure */
+ kfree(mod->args);
module_free(mod, mod);
}
@@ -770,27 +783,6 @@ 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,
@@ -809,9 +801,6 @@ 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":
@@ -919,9 +908,6 @@ 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;
}
}
}
@@ -963,9 +949,9 @@ 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;
@@ -1006,7 +992,7 @@ 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++) {
@@ -1015,10 +1001,10 @@ 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. */
@@ -1057,30 +1043,28 @@ 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) != 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;
@@ -1089,7 +1073,6 @@ static struct module *load_module(void *
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]);
@@ -1138,6 +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;
}
@@ -1146,6 +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);
@@ -1182,6 +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 *)
@@ -1214,7 +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);
-- 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/