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-rw-r--r--kernel/module.c228
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. */