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Subject[PATCH] Minor module cleanup 2/3
Date
Linus, please apply.

This removes the separate symbol list: it has a 1:1 mapping with the
module list anyway.

[ This is made trivial by the fact that noone accesses this list from
outside module.c any more. ]

Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.

Name: Symbol list removal
Author: Rusty Russell
Status: Tested on 2.5.66-bk2
Depends: Module/module-text-address.patch.gz

D: This removes the symbol list, and the concept of kernel symbol groups,
D: in favour of just iterating through the modules. Now all iteration is
D: within kernel/module.c, this is a fairly trivial cleanup.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .21809-linux-2.5.61-bk1/include/linux/module.h .21809-linux-2.5.61-bk1.updated/include/linux/module.h
--- .21809-linux-2.5.61-bk1/include/linux/module.h 2003-02-17 15:47:09.000000000 +1100
+++ .21809-linux-2.5.61-bk1.updated/include/linux/module.h 2003-02-17 15:47:42.000000000 +1100
@@ -115,22 +115,6 @@ extern const struct gtype##_id __mod_##g
#define MODULE_DEVICE_TABLE(type,name) \
MODULE_GENERIC_TABLE(type##_device,name)

-struct kernel_symbol_group
-{
- /* Links us into the global symbol list */
- struct list_head list;
-
- /* Module which owns it (if any) */
- struct module *owner;
-
- /* Are we internal use only? */
- int gplonly;
-
- unsigned int num_syms;
- const struct kernel_symbol *syms;
- const unsigned long *crcs;
-};
-
/* Given an address, look for it in the exception tables */
const struct exception_table_entry *search_exception_tables(unsigned long add);

@@ -214,10 +198,14 @@ struct module
char name[MODULE_NAME_LEN];

/* Exported symbols */
- struct kernel_symbol_group symbols;
+ const struct kernel_symbol *syms;
+ unsigned int num_ksyms;
+ const unsigned long *crcs;

/* GPL-only exported symbols. */
- struct kernel_symbol_group gpl_symbols;
+ const struct kernel_symbol *gpl_syms;
+ unsigned int num_gpl_syms;
+ const unsigned long *gpl_crcs;

/* Exception tables */
struct exception_table extable;
@@ -411,8 +399,6 @@ extern struct module __this_module;
struct module __this_module
__attribute__((section(".gnu.linkonce.this_module"))) = {
.name = __stringify(KBUILD_MODNAME),
- .symbols = { .owner = &__this_module },
- .gpl_symbols = { .owner = &__this_module, .gplonly = 1 },
.init = init_module,
#ifdef CONFIG_MODULE_UNLOAD
.exit = cleanup_module,
@@ -472,14 +458,6 @@ static inline void __deprecated _MOD_INC
#define EXPORT_NO_SYMBOLS
#define __MODULE_STRING(x) __stringify(x)

-/*
- * The exception and symbol tables, and the lock
- * to protect them.
- */
-extern spinlock_t modlist_lock;
-extern struct list_head extables;
-extern struct list_head symbols;
-
/* Use symbol_get and symbol_put instead. You'll thank me. */
#define HAVE_INTER_MODULE
extern void inter_module_register(const char *, struct module *, const void *);
diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal .21809-linux-2.5.61-bk1/kernel/module.c .21809-linux-2.5.61-bk1.updated/kernel/module.c
--- .21809-linux-2.5.61-bk1/kernel/module.c 2003-02-17 15:47:09.000000000 +1100
+++ .21809-linux-2.5.61-bk1.updated/kernel/module.c 2003-02-17 15:48:45.000000000 +1100
@@ -58,7 +58,6 @@ static spinlock_t modlist_lock = SPIN_LO
/* List of modules, protected by module_mutex AND modlist_lock */
static DECLARE_MUTEX(module_mutex);
static LIST_HEAD(modules);
-static LIST_HEAD(symbols);
static LIST_HEAD(extables);

/* We require a truly strong try_module_get() */
@@ -76,25 +75,60 @@ int init_module(void)
}
EXPORT_SYMBOL(init_module);

-/* Find a symbol, return value and the symbol group */
+/* Provided by the linker */
+extern const struct kernel_symbol __start___ksymtab[];
+extern const struct kernel_symbol __stop___ksymtab[];
+extern const struct kernel_symbol __start___ksymtab_gpl[];
+extern const struct kernel_symbol __stop___ksymtab_gpl[];
+extern const unsigned long __start___kcrctab[];
+extern const unsigned long __start___kcrctab_gpl[];
+
+#ifndef CONFIG_MODVERSIONS
+#define symversion(base, idx) NULL
+#else
+#define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
+#endif
+
+/* Find a symbol, return value, crc and module which owns it */
static unsigned long __find_symbol(const char *name,
- struct kernel_symbol_group **group,
- unsigned int *symidx,
+ struct module **owner,
+ const unsigned long **crc,
int gplok)
{
- struct kernel_symbol_group *ks;
-
- list_for_each_entry(ks, &symbols, list) {
- unsigned int i;
+ struct module *mod;
+ unsigned int i;

- if (ks->gplonly && !gplok)
- continue;
- for (i = 0; i < ks->num_syms; i++) {
- if (strcmp(ks->syms[i].name, name) == 0) {
- *group = ks;
- if (symidx)
- *symidx = i;
- return ks->syms[i].value;
+ /* Core kernel first. */
+ *owner = NULL;
+ for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++) {
+ if (strcmp(__start___ksymtab[i].name, name) == 0) {
+ *crc = symversion(__start___kcrctab, i);
+ return __start___ksymtab[i].value;
+ }
+ }
+ if (gplok) {
+ for (i = 0; __start___ksymtab_gpl+i<__stop___ksymtab_gpl; i++)
+ if (strcmp(__start___ksymtab_gpl[i].name, name) == 0) {
+ *crc = symversion(__start___kcrctab_gpl, i);
+ return __start___ksymtab_gpl[i].value;
+ }
+ }
+
+ /* Now try modules. */
+ list_for_each_entry(mod, &modules, list) {
+ *owner = mod;
+ for (i = 0; i < mod->num_ksyms; i++)
+ if (strcmp(mod->syms[i].name, name) == 0) {
+ *crc = symversion(mod->crcs, i);
+ return mod->syms[i].value;
+ }
+
+ if (gplok) {
+ for (i = 0; i < mod->num_gpl_syms; i++) {
+ if (strcmp(mod->gpl_syms[i].name, name) == 0) {
+ *crc = symversion(mod->crcs, i);
+ return mod->gpl_syms[i].value;
+ }
}
}
}
@@ -520,13 +554,14 @@ static void print_unload_info(struct seq

void __symbol_put(const char *symbol)
{
- struct kernel_symbol_group *ksg;
+ struct module *owner;
unsigned long flags;
+ const unsigned long *crc;

spin_lock_irqsave(&modlist_lock, flags);
- if (!__find_symbol(symbol, &ksg, NULL, 1))
+ if (!__find_symbol(symbol, &owner, &crc, 1))
BUG();
- module_put(ksg->owner);
+ module_put(owner);
spin_unlock_irqrestore(&modlist_lock, flags);
}
EXPORT_SYMBOL(__symbol_put);
@@ -724,19 +759,15 @@ static int check_version(Elf_Shdr *sechd
unsigned int versindex,
const char *symname,
struct module *mod,
- struct kernel_symbol_group *ksg,
- unsigned int symidx)
+ const unsigned long *crc)
{
- unsigned long crc;
unsigned int i, num_versions;
struct modversion_info *versions;

/* Exporting module didn't supply crcs? OK, we're already tainted. */
- if (!ksg->crcs)
+ if (!crc)
return 1;

- crc = ksg->crcs[symidx];
-
versions = (void *) sechdrs[versindex].sh_addr;
num_versions = sechdrs[versindex].sh_size
/ sizeof(struct modversion_info);
@@ -745,12 +776,12 @@ static int check_version(Elf_Shdr *sechd
if (strcmp(versions[i].name, symname) != 0)
continue;

- if (versions[i].crc == crc)
+ if (versions[i].crc == *crc)
return 1;
printk("%s: disagrees about version of symbol %s\n",
mod->name, symname);
DEBUGP("Found checksum %lX vs module %lX\n",
- crc, versions[i].crc);
+ *crc, versions[i].crc);
return 0;
}
/* Not in module's version table. OK, but that taints the kernel. */
@@ -786,8 +817,7 @@ static inline int check_version(Elf_Shdr
unsigned int versindex,
const char *symname,
struct module *mod,
- struct kernel_symbol_group *ksg,
- unsigned int symidx)
+ const unsigned long *crc)
{
return 1;
}
@@ -812,17 +842,16 @@ static unsigned long resolve_symbol(Elf_
const char *name,
struct module *mod)
{
- struct kernel_symbol_group *ksg;
+ struct module *owner;
unsigned long ret;
- unsigned int symidx;
+ const unsigned long *crc;

spin_lock_irq(&modlist_lock);
- ret = __find_symbol(name, &ksg, &symidx, mod->license_gplok);
+ ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
if (ret) {
/* use_module can fail due to OOM, or module unloading */
- if (!check_version(sechdrs, versindex, name, mod,
- ksg, symidx) ||
- !use_module(mod, ksg->owner))
+ if (!check_version(sechdrs, versindex, name, mod, crc) ||
+ !use_module(mod, owner))
ret = 0;
}
spin_unlock_irq(&modlist_lock);
@@ -835,8 +864,6 @@ static void free_module(struct module *m
/* Delete from various lists */
spin_lock_irq(&modlist_lock);
list_del(&mod->list);
- list_del(&mod->symbols.list);
- list_del(&mod->gpl_symbols.list);
list_del(&mod->extable.list);
spin_unlock_irq(&modlist_lock);

@@ -853,12 +880,13 @@ static void free_module(struct module *m

void *__symbol_get(const char *symbol)
{
- struct kernel_symbol_group *ksg;
+ struct module *owner;
unsigned long value, flags;
+ const unsigned long *crc;

spin_lock_irqsave(&modlist_lock, flags);
- value = __find_symbol(symbol, &ksg, NULL, 1);
- if (value && !strong_try_module_get(ksg->owner))
+ value = __find_symbol(symbol, &owner, &crc, 1);
+ if (value && !strong_try_module_get(owner))
value = 0;
spin_unlock_irqrestore(&modlist_lock, flags);

@@ -1297,21 +1325,17 @@ static struct module *load_module(void *
goto cleanup;

/* Set up EXPORTed & EXPORT_GPLed symbols (section 0 is 0 length) */
- mod->symbols.num_syms = (sechdrs[exportindex].sh_size
- / sizeof(*mod->symbols.syms));
- mod->symbols.syms = (void *)sechdrs[exportindex].sh_addr;
+ mod->num_syms = sechdrs[exportindex].sh_size / sizeof(*mod->syms);
+ mod->syms = (void *)sechdrs[exportindex].sh_addr;
if (crcindex)
- mod->symbols.crcs = (void *)sechdrs[crcindex].sh_addr;
-
- mod->gpl_symbols.num_syms = (sechdrs[gplindex].sh_size
- / sizeof(*mod->symbols.syms));
- mod->gpl_symbols.syms = (void *)sechdrs[gplindex].sh_addr;
+ mod->crcs = (void *)sechdrs[crcindex].sh_addr;
+ mod->num_gpl_syms = sechdrs[gplindex].sh_size / sizeof(*mod->gpl_syms);
+ mod->gpl_syms = (void *)sechdrs[gplindex].sh_addr;
if (gplcrcindex)
- mod->gpl_symbols.crcs = (void *)sechdrs[gplcrcindex].sh_addr;
+ mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr;

#ifdef CONFIG_MODVERSIONS
- if ((mod->symbols.num_syms && !crcindex)
- || (mod->gpl_symbols.num_syms && !gplcrcindex)) {
+ if ((mod->num_ksyms&&!crcindex) || (mod->num_gpl_syms&&!gplcrcindex)) {
printk(KERN_WARNING "%s: No versions for exported symbols."
" Tainting kernel.\n", mod->name);
tainted |= TAINT_FORCED_MODULE;
@@ -1420,8 +1444,6 @@ sys_init_module(void *umod,
strong_try_module_get() will fail. */
spin_lock_irq(&modlist_lock);
list_add(&mod->extable.list, &extables);
- list_add_tail(&mod->symbols.list, &symbols);
- list_add_tail(&mod->gpl_symbols.list, &symbols);
list_add(&mod->list, &modules);
spin_unlock_irq(&modlist_lock);

@@ -1614,39 +1636,6 @@ struct module *module_text_address(unsig
return NULL;
}

-/* Provided by the linker */
-extern const struct kernel_symbol __start___ksymtab[];
-extern const struct kernel_symbol __stop___ksymtab[];
-extern const struct kernel_symbol __start___ksymtab_gpl[];
-extern const struct kernel_symbol __stop___ksymtab_gpl[];
-extern const unsigned long __start___kcrctab[];
-extern const unsigned long __stop___kcrctab[];
-extern const unsigned long __start___kcrctab_gpl[];
-extern const unsigned long __stop___kcrctab_gpl[];
-
-static struct kernel_symbol_group kernel_symbols, kernel_gpl_symbols;
-
-static int __init symbols_init(void)
-{
- /* Add kernel symbols to symbol table */
- kernel_symbols.num_syms = (__stop___ksymtab - __start___ksymtab);
- kernel_symbols.syms = __start___ksymtab;
- kernel_symbols.crcs = __start___kcrctab;
- kernel_symbols.gplonly = 0;
- list_add(&kernel_symbols.list, &symbols);
-
- kernel_gpl_symbols.num_syms = (__stop___ksymtab_gpl
- - __start___ksymtab_gpl);
- kernel_gpl_symbols.syms = __start___ksymtab_gpl;
- kernel_gpl_symbols.crcs = __start___kcrctab_gpl;
- kernel_gpl_symbols.gplonly = 1;
- list_add(&kernel_gpl_symbols.list, &symbols);
-
- return 0;
-}
-
-__initcall(symbols_init);
-
#ifdef CONFIG_MODVERSIONS
/* Generate the signature for struct module here, too, for modversions. */
void struct_module(struct module *mod) { return; }
b_gpl;
- kernel_gpl_symbols.gplonly = 1;
- list_add(&kernel_gpl_symbols.list, &symbols);
-
- return 0;
+ return mod;
+ return NULL;
}
-
-__initcall(symbols_init);
-
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