module: refactor load_module part 5

1) Extract out the relocation loop into apply_relocations
2) Extract license and version checks into check_module_license_and_versions
3) Extract icache flushing into flush_module_icache
4) Move __obsparm warning into find_module_sections
5) Move license setting into check_modinfo.

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

diff --git a/kernel/module.c b/kernel/module.c
index 241bc41..b536db8 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1698,6 +1698,39 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
        return ret;
 }
 
+static int apply_relocations(struct module *mod,
+                            Elf_Ehdr *hdr,
+                            Elf_Shdr *sechdrs,
+                            unsigned int symindex,
+                            unsigned int strindex)
+{
+       unsigned int i;
+       int err = 0;
+
+       /* Now do relocations. */
+       for (i = 1; i < hdr->e_shnum; i++) {
+               const char *strtab = (char *)sechdrs[strindex].sh_addr;
+               unsigned int info = sechdrs[i].sh_info;
+
+               /* Not a valid relocation section? */
+               if (info >= hdr->e_shnum)
+                       continue;
+
+               /* Don't bother with non-allocated sections */
+               if (!(sechdrs[info].sh_flags & SHF_ALLOC))
+                       continue;
+
+               if (sechdrs[i].sh_type == SHT_REL)
+                       err = apply_relocate(sechdrs, strtab, symindex, i, mod);
+               else if (sechdrs[i].sh_type == SHT_RELA)
+                       err = apply_relocate_add(sechdrs, strtab, symindex, i,
+                                                mod);
+               if (err < 0)
+                       break;
+       }
+       return err;
+}
+
 /* Additional bytes needed by arch in front of individual sections */
 unsigned int __weak arch_mod_section_prepend(struct module *mod,
                                             unsigned int section)
@@ -2179,6 +2212,10 @@ static int check_modinfo(struct module *mod,
                       " the quality is unknown, you have been warned.\n",
                       mod->name);
        }
+
+       /* Set up license info based on the info section */
+       set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
+
        return 0;
 }
 
@@ -2245,6 +2282,10 @@ static void find_module_sections(struct module *mod, Elf_Ehdr *hdr,
                                             sizeof(*mod->ftrace_callsites),
                                             &mod->num_ftrace_callsites);
 #endif
+
+       if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
+               printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
+                      mod->name);
 }
 
 static struct module *move_module(struct module *mod,
@@ -2311,6 +2352,60 @@ static struct module *move_module(struct module *mod,
        return mod;
 }
 
+static int check_module_license_and_versions(struct module *mod,
+                                            Elf_Shdr *sechdrs)
+{
+       /*
+        * ndiswrapper is under GPL by itself, but loads proprietary modules.
+        * Don't use add_taint_module(), as it would prevent ndiswrapper from
+        * using GPL-only symbols it needs.
+        */
+       if (strcmp(mod->name, "ndiswrapper") == 0)
+               add_taint(TAINT_PROPRIETARY_MODULE);
+
+       /* driverloader was caught wrongly pretending to be under GPL */
+       if (strcmp(mod->name, "driverloader") == 0)
+               add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+
+#ifdef CONFIG_MODVERSIONS
+       if ((mod->num_syms && !mod->crcs)
+           || (mod->num_gpl_syms && !mod->gpl_crcs)
+           || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
+#ifdef CONFIG_UNUSED_SYMBOLS
+           || (mod->num_unused_syms && !mod->unused_crcs)
+           || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
+#endif
+               ) {
+               return try_to_force_load(mod,
+                                        "no versions for exported symbols");
+       }
+#endif
+       return 0;
+}
+
+static void flush_module_icache(const struct module *mod)
+{
+       mm_segment_t old_fs;
+
+       /* flush the icache in correct context */
+       old_fs = get_fs();
+       set_fs(KERNEL_DS);
+
+       /*
+        * Flush the instruction cache, since we've played with text.
+        * Do it before processing of module parameters, so the module
+        * can provide parameter accessor functions of its own.
+        */
+       if (mod->module_init)
+               flush_icache_range((unsigned long)mod->module_init,
+                                  (unsigned long)mod->module_init
+                                  + mod->init_size);
+       flush_icache_range((unsigned long)mod->module_core,
+                          (unsigned long)mod->module_core + mod->core_size);
+
+       set_fs(old_fs);
+}
+
 /* Allocate and load the module: note that size of section 0 is always
    zero, and we rely on this for optional sections. */
 static noinline struct module *load_module(void __user *umod,
@@ -2331,8 +2426,6 @@ static noinline struct module *load_module(void __user *umod,
        struct _ddebug *debug = NULL;
        unsigned int num_debug = 0;
 
-       mm_segment_t old_fs;
-
        DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
               umod, len, uargs);
 
@@ -2453,20 +2546,13 @@ static noinline struct module *load_module(void __user *umod,
        if (err)
                goto free_init;
 
-       /* Set up license info based on the info section */
-       set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
-
-       /*
-        * ndiswrapper is under GPL by itself, but loads proprietary modules.
-        * Don't use add_taint_module(), as it would prevent ndiswrapper from
-        * using GPL-only symbols it needs.
-        */
-       if (strcmp(mod->name, "ndiswrapper") == 0)
-               add_taint(TAINT_PROPRIETARY_MODULE);
+       /* Now we've got everything in the final locations, we can
+        * find optional sections. */
+       find_module_sections(mod, hdr, sechdrs, secstrings);
 
-       /* driverloader was caught wrongly pretending to be under GPL */
-       if (strcmp(mod->name, "driverloader") == 0)
-               add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
+       err = check_module_license_and_versions(mod, sechdrs);
+       if (err)
+               goto free_unload;
 
        /* Set up MODINFO_ATTR fields */
        setup_modinfo(mod, sechdrs, infoindex);
@@ -2477,47 +2563,9 @@ static noinline struct module *load_module(void __user *umod,
        if (err < 0)
                goto cleanup;
 
-       /* Now we've got everything in the final locations, we can
-        * find optional sections. */
-       find_module_sections(mod, hdr, sechdrs, secstrings);
-
-#ifdef CONFIG_MODVERSIONS
-       if ((mod->num_syms && !mod->crcs)
-           || (mod->num_gpl_syms && !mod->gpl_crcs)
-           || (mod->num_gpl_future_syms && !mod->gpl_future_crcs)
-#ifdef CONFIG_UNUSED_SYMBOLS
-           || (mod->num_unused_syms && !mod->unused_crcs)
-           || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
-#endif
-               ) {
-               err = try_to_force_load(mod,
-                                       "no versions for exported symbols");
-               if (err)
-                       goto cleanup;
-       }
-#endif
-
-       /* Now do relocations. */
-       for (i = 1; i < hdr->e_shnum; i++) {
-               const char *strtab = (char *)sechdrs[strindex].sh_addr;
-               unsigned int info = sechdrs[i].sh_info;
-
-               /* Not a valid relocation section? */
-               if (info >= hdr->e_shnum)
-                       continue;
-
-               /* Don't bother with non-allocated sections */
-               if (!(sechdrs[info].sh_flags & SHF_ALLOC))
-                       continue;
-
-               if (sechdrs[i].sh_type == SHT_REL)
-                       err = apply_relocate(sechdrs, strtab, symindex, i,mod);
-               else if (sechdrs[i].sh_type == SHT_RELA)
-                       err = apply_relocate_add(sechdrs, strtab, symindex, i,
-                                                mod);
-               if (err < 0)
-                       goto cleanup;
-       }
+       err = apply_relocations(mod, hdr, sechdrs, symindex, strindex);
+       if (err < 0)
+               goto cleanup;
 
        /* Set up and sort exception table */
        mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
@@ -2541,28 +2589,9 @@ static noinline struct module *load_module(void __user *umod,
        if (err < 0)
                goto cleanup;
 
-       /* flush the icache in correct context */
-       old_fs = get_fs();
-       set_fs(KERNEL_DS);
-
-       /*
-        * Flush the instruction cache, since we've played with text.
-        * Do it before processing of module parameters, so the module
-        * can provide parameter accessor functions of its own.
-        */
-       if (mod->module_init)
-               flush_icache_range((unsigned long)mod->module_init,
-                                  (unsigned long)mod->module_init
-                                  + mod->init_size);
-       flush_icache_range((unsigned long)mod->module_core,
-                          (unsigned long)mod->module_core + mod->core_size);
-
-       set_fs(old_fs);
+       flush_module_icache(mod);
 
        mod->args = args;
-       if (section_addr(hdr, sechdrs, secstrings, "__obsparm"))
-               printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
-                      mod->name);
 
        /* Now sew it into the lists so we can get lockdep and oops
         * info during argument parsing.  Noone should access us, since
@@ -2619,6 +2648,7 @@ static noinline struct module *load_module(void __user *umod,
        module_arch_cleanup(mod);
  cleanup:
        free_modinfo(mod);
+ free_unload:
        module_unload_free(mod);
  free_init:
        module_free(mod, mod->module_init);