[PATCH] Clean up module.c symbol searching logic

[mv-sheeva.git] / kernel / module.c

diff --git a/kernel/module.c b/kernel/module.c
index f368812ac0e88b0ff87911df0ec29725a38c49e3..2a892b20d68f33a8291e8659bea60d4bfd245390 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -28,6 +28,7 @@
 #include <linux/syscalls.h>
 #include <linux/fcntl.h>
 #include <linux/rcupdate.h>
+#include <linux/capability.h>
 #include <linux/cpu.h>
 #include <linux/moduleparam.h>
 #include <linux/errno.h>
@@ -134,6 +135,18 @@ extern const unsigned long __start___kcrctab_gpl[];
 #define symversion(base, idx) ((base) ? ((base) + (idx)) : NULL)
 #endif
 
+/* lookup symbol in given range of kernel_symbols */
+static const struct kernel_symbol *lookup_symbol(const char *name,
+       const struct kernel_symbol *start,
+       const struct kernel_symbol *stop)
+{
+       const struct kernel_symbol *ks = start;
+       for (; ks < stop; ks++)
+               if (strcmp(ks->name, name) == 0)
+                       return ks;
+       return NULL;
+}
+
 /* Find a symbol, return value, crc and module which owns it */
 static unsigned long __find_symbol(const char *name,
                                   struct module **owner,
@@ -141,39 +154,41 @@ static unsigned long __find_symbol(const char *name,
                                   int gplok)
 {
        struct module *mod;
-       unsigned int i;
+       const struct kernel_symbol *ks;
 
        /* 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;
-               }
+       ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
+       if (ks) {
+               *crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
+               return ks->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;
-                       }
+               ks = lookup_symbol(name, __start___ksymtab_gpl,
+                                        __stop___ksymtab_gpl);
+               if (ks) {
+                       *crc = symversion(__start___kcrctab_gpl,
+                                         (ks - __start___ksymtab_gpl));
+                       return ks->value;
+               }
        }
 
        /* Now try modules. */ 
        list_for_each_entry(mod, &modules, list) {
                *owner = mod;
-               for (i = 0; i < mod->num_syms; i++)
-                       if (strcmp(mod->syms[i].name, name) == 0) {
-                               *crc = symversion(mod->crcs, i);
-                               return mod->syms[i].value;
-                       }
+               ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
+               if (ks) {
+                       *crc = symversion(mod->crcs, (ks - mod->syms));
+                       return ks->value;
+               }
 
                if (gplok) {
-                       for (i = 0; i < mod->num_gpl_syms; i++) {
-                               if (strcmp(mod->gpl_syms[i].name, name) == 0) {
-                                       *crc = symversion(mod->gpl_crcs, i);
-                                       return mod->gpl_syms[i].value;
-                               }
+                       ks = lookup_symbol(name, mod->gpl_syms,
+                                          mod->gpl_syms + mod->num_gpl_syms);
+                       if (ks) {
+                               *crc = symversion(mod->gpl_crcs,
+                                                 (ks - mod->gpl_syms));
+                               return ks->value;
                        }
                }
        }
@@ -958,7 +973,6 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
        unsigned long ret;
        const unsigned long *crc;
 
-       spin_lock_irq(&modlist_lock);
        ret = __find_symbol(name, &owner, &crc, mod->license_gplok);
        if (ret) {
                /* use_module can fail due to OOM, or module unloading */
@@ -966,7 +980,6 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
                    !use_module(mod, owner))
                        ret = 0;
        }
-       spin_unlock_irq(&modlist_lock);
        return ret;
 }
 
@@ -1445,18 +1458,13 @@ static void setup_modinfo(struct module *mod, Elf_Shdr *sechdrs,
 #ifdef CONFIG_KALLSYMS
 int is_exported(const char *name, const struct module *mod)
 {
-       unsigned int i;
-
-       if (!mod) {
-               for (i = 0; __start___ksymtab+i < __stop___ksymtab; i++)
-                       if (strcmp(__start___ksymtab[i].name, name) == 0)
-                               return 1;
-               return 0;
-       }
-       for (i = 0; i < mod->num_syms; i++)
-               if (strcmp(mod->syms[i].name, name) == 0)
+       if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
+               return 1;
+       else
+               if (lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
                        return 1;
-       return 0;
+               else
+                       return 0;
 }
 
 /* As per nm */
@@ -1671,6 +1679,9 @@ static struct module *load_module(void __user *umod,
                goto free_mod;
        }
 
+       /* Userspace could have altered the string after the strlen_user() */
+       args[arglen - 1] = '\0';
+
        if (find_module(mod->name)) {
                err = -EEXIST;
                goto free_mod;
@@ -2093,7 +2104,8 @@ static unsigned long mod_find_symname(struct module *mod, const char *name)
        unsigned int i;
 
        for (i = 0; i < mod->num_symtab; i++)
-               if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0)
+               if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
+                   mod->symtab[i].st_info != 'U')
                        return mod->symtab[i].st_value;
        return 0;
 }