1 files changed, 125 insertions, 103 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 79545bda358a..cb40a4e64a0e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2148,8 +2148,17 @@ static inline void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr,
 }
 #endif
 
-static int copy_and_check(Elf_Ehdr **hdrp,
-                          const void __user *umod, unsigned long len)
+struct load_info {
+        Elf_Ehdr *hdr;
+        unsigned long len;
+        Elf_Shdr *sechdrs;
+        char *secstrings, *args, *strtab;
+        struct {
+                unsigned int sym, str, mod, vers, info, pcpu;
+        } index;
+};
+
+static int copy_and_check(struct load_info *info, const void __user *umod, unsigned long len)
 {
         int err;
         Elf_Ehdr *hdr;
@@ -2159,7 +2168,7 @@ static int copy_and_check(Elf_Ehdr **hdrp,
 
         /* Suck in entire file: we'll want most of it. */
         /* vmalloc barfs on "unusual" numbers.  Check here */
-        if (len > 64 * 1024 * 1024 || (hdr = *hdrp = vmalloc(len)) == NULL)
+        if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
                 return -ENOMEM;
 
         if (copy_from_user(hdr, umod, len) != 0) {
@@ -2181,6 +2190,8 @@ static int copy_and_check(Elf_Ehdr **hdrp,
                 err = -ENOEXEC;
                 goto free_hdr;
         }
+        info->hdr = hdr;
+        info->len = len;
         return 0;
 
 free_hdr:
@@ -2188,6 +2199,80 @@ free_hdr:
         return err;
 }
 
+/*
+ * Set up our basic convenience variables (pointers to section headers,
+ * search for module section index etc), and do some basic section
+ * verification.
+ *
+ * Return the temporary module pointer (we'll replace it with the final
+ * one when we move the module sections around).
+ */
+static struct module *setup_load_info(struct load_info *info)
+{
+        unsigned int i;
+        struct module *mod;
+
+        /* Set up the convenience variables */
+        info->sechdrs = (void *)info->hdr + info->hdr->e_shoff;
+        info->secstrings = (void *)info->hdr + info->sechdrs[info->hdr->e_shstrndx].sh_offset;
+        info->sechdrs[0].sh_addr = 0;
+
+        for (i = 1; i < info->hdr->e_shnum; i++) {
+                if (info->sechdrs[i].sh_type != SHT_NOBITS
+                    && info->len < info->sechdrs[i].sh_offset + info->sechdrs[i].sh_size)
+                        goto truncated;
+
+                /* Mark all sections sh_addr with their address in the
+                   temporary image. */
+                info->sechdrs[i].sh_addr = (size_t)info->hdr + info->sechdrs[i].sh_offset;
+
+                /* Internal symbols and strings. */
+                if (info->sechdrs[i].sh_type == SHT_SYMTAB) {
+                        info->index.sym = i;
+                        info->index.str = info->sechdrs[i].sh_link;
+                        info->strtab = (char *)info->hdr + info->sechdrs[info->index.str].sh_offset;
+                }
+#ifndef CONFIG_MODULE_UNLOAD
+                /* Don't load .exit sections */
+                if (strstarts(info->secstrings+info->sechdrs[i].sh_name, ".exit"))
+                        info->sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
+#endif
+        }
+
+        info->index.mod = find_sec(info->hdr, info->sechdrs, info->secstrings,
+                            ".gnu.linkonce.this_module");
+        if (!info->index.mod) {
+                printk(KERN_WARNING "No module found in object\n");
+                return ERR_PTR(-ENOEXEC);
+        }
+        /* This is temporary: point mod into copy of data. */
+        mod = (void *)info->sechdrs[info->index.mod].sh_addr;
+
+        if (info->index.sym == 0) {
+                printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
+                       mod->name);
+                return ERR_PTR(-ENOEXEC);
+        }
+
+        info->index.vers = find_sec(info->hdr, info->sechdrs, info->secstrings, "__versions");
+        info->index.info = find_sec(info->hdr, info->sechdrs, info->secstrings, ".modinfo");
+        info->index.pcpu = find_pcpusec(info->hdr, info->sechdrs, info->secstrings);
+
+        /* Don't keep modinfo and version sections. */
+        info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
+        info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
+
+        /* Check module struct version now, before we try to use module. */
+        if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
+                return ERR_PTR(-ENOEXEC);
+
+        return mod;
+
+ truncated:
+        printk(KERN_ERR "Module len %lu truncated\n", info->len);
+        return ERR_PTR(-ENOEXEC);
+}
+
 static int check_modinfo(struct module *mod,
                          const Elf_Shdr *sechdrs,
                          unsigned int infoindex, unsigned int versindex)
@@ -2412,13 +2497,7 @@ static noinline struct module *load_module(void __user *umod,
                                   unsigned long len,
                                   const char __user *uargs)
 {
-        Elf_Ehdr *hdr;
-        Elf_Shdr *sechdrs;
-        char *secstrings, *args, *strtab = NULL;
-        unsigned int i;
-        unsigned int symindex = 0;
-        unsigned int strindex = 0;
-        unsigned int modindex, versindex, infoindex, pcpuindex;
+        struct load_info info = { NULL, };
         struct module *mod;
         long err;
         unsigned long symoffs, stroffs, *strmap;
@@ -2429,80 +2508,28 @@ static noinline struct module *load_module(void __user *umod,
         DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
                umod, len, uargs);
 
-        err = copy_and_check(&hdr, umod, len);
+        err = copy_and_check(&info, umod, len);
         if (err)
                 return ERR_PTR(err);
 
-        /* Convenience variables */
-        sechdrs = (void *)hdr + hdr->e_shoff;
-        secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
-        sechdrs[0].sh_addr = 0;
-
-        for (i = 1; i < hdr->e_shnum; i++) {
-                if (sechdrs[i].sh_type != SHT_NOBITS
-                    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size)
-                        goto truncated;
-
-                /* Mark all sections sh_addr with their address in the
-                   temporary image. */
-                sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;
-
-                /* Internal symbols and strings. */
-                if (sechdrs[i].sh_type == SHT_SYMTAB) {
-                        symindex = i;
-                        strindex = sechdrs[i].sh_link;
-                        strtab = (char *)hdr + sechdrs[strindex].sh_offset;
-                }
-#ifndef CONFIG_MODULE_UNLOAD
-                /* Don't load .exit sections */
-                if (strstarts(secstrings+sechdrs[i].sh_name, ".exit"))
-                        sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
-#endif
-        }
-
-        modindex = find_sec(hdr, sechdrs, secstrings,
-                            ".gnu.linkonce.this_module");
-        if (!modindex) {
-                printk(KERN_WARNING "No module found in object\n");
-                err = -ENOEXEC;
-                goto free_hdr;
-        }
-        /* This is temporary: point mod into copy of data. */
-        mod = (void *)sechdrs[modindex].sh_addr;
-
-        if (symindex == 0) {
-                printk(KERN_WARNING "%s: module has no symbols (stripped?)\n",
-                       mod->name);
-                err = -ENOEXEC;
-                goto free_hdr;
-        }
-
-        versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
-        infoindex = find_sec(hdr, sechdrs, secstrings, ".modinfo");
-        pcpuindex = find_pcpusec(hdr, sechdrs, secstrings);
-
-        /* Don't keep modinfo and version sections. */
-        sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
-        sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
-
-        /* Check module struct version now, before we try to use module. */
-        if (!check_modstruct_version(sechdrs, versindex, mod)) {
-                err = -ENOEXEC;
+        mod = setup_load_info(&info);
+        if (IS_ERR(mod)) {
+                err = PTR_ERR(mod);
                 goto free_hdr;
         }
 
-        err = check_modinfo(mod, sechdrs, infoindex, versindex);
+        err = check_modinfo(mod, info.sechdrs, info.index.info, info.index.vers);
         if (err)
                 goto free_hdr;
 
         /* Now copy in args */
-        args = strndup_user(uargs, ~0UL >> 1);
-        if (IS_ERR(args)) {
-                err = PTR_ERR(args);
+        info.args = strndup_user(uargs, ~0UL >> 1);
+        if (IS_ERR(info.args)) {
+                err = PTR_ERR(info.args);
                 goto free_hdr;
         }
 
-        strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
+        strmap = kzalloc(BITS_TO_LONGS(info.sechdrs[info.index.str].sh_size)
                          * sizeof(long), GFP_KERNEL);
         if (!strmap) {
                 err = -ENOMEM;
@@ -2512,17 +2539,17 @@ static noinline struct module *load_module(void __user *umod,
         mod->state = MODULE_STATE_COMING;
 
         /* Allow arches to frob section contents and sizes.  */
-        err = module_frob_arch_sections(hdr, sechdrs, secstrings, mod);
+        err = module_frob_arch_sections(info.hdr, info.sechdrs, info.secstrings, mod);
         if (err < 0)
                 goto free_mod;
 
-        if (pcpuindex) {
+        if (info.index.pcpu) {
                 /* We have a special allocation for this section. */
-                err = percpu_modalloc(mod, sechdrs[pcpuindex].sh_size,
-                                      sechdrs[pcpuindex].sh_addralign);
+                err = percpu_modalloc(mod, info.sechdrs[info.index.pcpu].sh_size,
+                                      info.sechdrs[info.index.pcpu].sh_addralign);
                 if (err)
                         goto free_mod;
-                sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
+                info.sechdrs[info.index.pcpu].sh_flags &= ~(unsigned long)SHF_ALLOC;
         }
         /* Keep this around for failure path. */
         percpu = mod_percpu(mod);
@@ -2530,12 +2557,12 @@ static noinline struct module *load_module(void __user *umod,
         /* Determine total sizes, and put offsets in sh_entsize.  For now
            this is done generically; there doesn't appear to be any
            special cases for the architectures. */
-        layout_sections(mod, hdr, sechdrs, secstrings);
-        symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
-                                secstrings, &stroffs, strmap);
+        layout_sections(mod, info.hdr, info.sechdrs, info.secstrings);
+        symoffs = layout_symtab(mod, info.sechdrs, info.index.sym, info.index.str, info.hdr,
+                                info.secstrings, &stroffs, strmap);
 
         /* Allocate and move to the final place */
-        mod = move_module(mod, hdr, sechdrs, secstrings, modindex);
+        mod = move_module(mod, info.hdr, info.sechdrs, info.secstrings, info.index.mod);
         if (IS_ERR(mod)) {
                 err = PTR_ERR(mod);
                 goto free_percpu;
@@ -2548,50 +2575,50 @@ static noinline struct module *load_module(void __user *umod,
 
         /* Now we've got everything in the final locations, we can
          * find optional sections. */
-        find_module_sections(mod, hdr, sechdrs, secstrings);
+        find_module_sections(mod, info.hdr, info.sechdrs, info.secstrings);
 
-        err = check_module_license_and_versions(mod, sechdrs);
+        err = check_module_license_and_versions(mod, info.sechdrs);
         if (err)
                 goto free_unload;
 
         /* Set up MODINFO_ATTR fields */
-        setup_modinfo(mod, sechdrs, infoindex);
+        setup_modinfo(mod, info.sechdrs, info.index.info);
 
         /* Fix up syms, so that st_value is a pointer to location. */
-        err = simplify_symbols(sechdrs, symindex, strtab, versindex, pcpuindex,
+        err = simplify_symbols(info.sechdrs, info.index.sym, info.strtab, info.index.vers, info.index.pcpu,
                                mod);
         if (err < 0)
                 goto cleanup;
 
-        err = apply_relocations(mod, hdr, sechdrs, symindex, strindex);
+        err = apply_relocations(mod, info.hdr, info.sechdrs, info.index.sym, info.index.str);
         if (err < 0)
                 goto cleanup;
 
         /* Set up and sort exception table */
-        mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
+        mod->extable = section_objs(info.hdr, info.sechdrs, info.secstrings, "__ex_table",
                                     sizeof(*mod->extable), &mod->num_exentries);
         sort_extable(mod->extable, mod->extable + mod->num_exentries);
 
         /* Finally, copy percpu area over. */
-        percpu_modcopy(mod, (void *)sechdrs[pcpuindex].sh_addr,
-                       sechdrs[pcpuindex].sh_size);
+        percpu_modcopy(mod, (void *)info.sechdrs[info.index.pcpu].sh_addr,
+                       info.sechdrs[info.index.pcpu].sh_size);
 
-        add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
-                     symoffs, stroffs, secstrings, strmap);
+        add_kallsyms(mod, info.sechdrs, info.hdr->e_shnum, info.index.sym, info.index.str,
+                     symoffs, stroffs, info.secstrings, strmap);
         kfree(strmap);
         strmap = NULL;
 
         if (!mod->taints)
-                debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
+                debug = section_objs(info.hdr, info.sechdrs, info.secstrings, "__verbose",
                                      sizeof(*debug), &num_debug);
 
-        err = module_finalize(hdr, sechdrs, mod);
+        err = module_finalize(info.hdr, info.sechdrs, mod);
         if (err < 0)
                 goto cleanup;
 
         flush_module_icache(mod);
 
-        mod->args = args;
+        mod->args = info.args;
 
         /* Now sew it into the lists so we can get lockdep and oops
          * info during argument parsing.  Noone should access us, since
@@ -2625,11 +2652,11 @@ static noinline struct module *load_module(void __user *umod,
         if (err < 0)
                 goto unlink;
 
-        add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
-        add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
+        add_sect_attrs(mod, info.hdr->e_shnum, info.secstrings, info.sechdrs);
+        add_notes_attrs(mod, info.hdr->e_shnum, info.secstrings, info.sechdrs);
 
         /* Get rid of temporary copy */
-        vfree(hdr);
+        vfree(info.hdr);
 
         trace_module_load(mod);
 
@@ -2657,16 +2684,11 @@ static noinline struct module *load_module(void __user *umod,
  free_percpu:
         free_percpu(percpu);
  free_mod:
-        kfree(args);
+        kfree(info.args);
         kfree(strmap);
  free_hdr:
-        vfree(hdr);
+        vfree(info.hdr);
         return ERR_PTR(err);
-
- truncated:
-        printk(KERN_ERR "Module len %lu truncated\n", len);
-        err = -ENOEXEC;
-        goto free_hdr;
 }
 
 /* Call module constructors. */