module: move module args strndup_user to just before use

Instead of copying and allocating the args and storing it in
load_info, we can just allocate them right before we need them.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/kernel/module.c b/kernel/module.c
index 29dd232f818314fc3e278aecc86482a1536a95a5..cabafe228444ebc9ee84c7a3c57a9582464c7292 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -114,7 +114,7 @@ struct load_info {
        Elf_Ehdr *hdr;
        unsigned long len;
        Elf_Shdr *sechdrs;
-       char *secstrings, *args, *strtab;
+       char *secstrings, *strtab;
        unsigned long *strmap;
        unsigned long symoffs, stroffs;
        struct {
@@ -2096,7 +2096,7 @@ static inline void kmemleak_load_module(const struct module *mod,
 }
 #endif
 
-/* Sets info->hdr, info->len and info->args. */
+/* Sets info->hdr and info->len. */
 static int copy_and_check(struct load_info *info,
                          const void __user *umod, unsigned long len,
                          const char __user *uargs)
@@ -2132,13 +2132,6 @@ static int copy_and_check(struct load_info *info,
                goto free_hdr;
        }
 
-       /* Now copy in args */
-       info->args = strndup_user(uargs, ~0UL >> 1);
-       if (IS_ERR(info->args)) {
-               err = PTR_ERR(info->args);
-               goto free_hdr;
-       }
-
        info->hdr = hdr;
        info->len = len;
        return 0;
@@ -2150,7 +2143,6 @@ free_hdr:
 
 static void free_copy(struct load_info *info)
 {
-       kfree(info->args);
        vfree(info->hdr);
 }
 
@@ -2468,7 +2460,7 @@ static struct module *layout_and_allocate(struct load_info *info)
        err = module_frob_arch_sections(info->hdr, info->sechdrs,
                                        info->secstrings, mod);
        if (err < 0)
-               goto free_args;
+               goto out;
 
        pcpusec = &info->sechdrs[info->index.pcpu];
        if (pcpusec->sh_size) {
@@ -2476,7 +2468,7 @@ static struct module *layout_and_allocate(struct load_info *info)
                err = percpu_modalloc(mod,
                                      pcpusec->sh_size, pcpusec->sh_addralign);
                if (err)
-                       goto free_args;
+                       goto out;
                pcpusec->sh_flags &= ~(unsigned long)SHF_ALLOC;
        }
 
@@ -2507,8 +2499,7 @@ free_strmap:
        kfree(info->strmap);
 free_percpu:
        percpu_modfree(mod);
-free_args:
-       kfree(info->args);
+out:
        return ERR_PTR(err);
 }
 
@@ -2594,7 +2585,12 @@ static noinline struct module *load_module(void __user *umod,
 
        flush_module_icache(mod);
 
-       mod->args = info.args;
+       /* Now copy in args */
+       mod->args = strndup_user(uargs, ~0UL >> 1);
+       if (IS_ERR(mod->args)) {
+               err = PTR_ERR(mod->args);
+               goto free_arch_cleanup;
+       }
 
        mod->state = MODULE_STATE_COMING;
 
@@ -2648,6 +2644,8 @@ static noinline struct module *load_module(void __user *umod,
  unlock:
        mutex_unlock(&module_mutex);
        synchronize_sched();
+       kfree(mod->args);
+ free_arch_cleanup:
        module_arch_cleanup(mod);
  free_modinfo:
        free_modinfo(mod);