aboutsummaryrefslogtreecommitdiff
path: root/kernel/module.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c274
1 files changed, 161 insertions, 113 deletions
diff --git a/kernel/module.c b/kernel/module.c
index f77ac320d0b..f6e08b7cff7 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -68,7 +68,8 @@
/* List of modules, protected by module_mutex or preempt_disable
* (delete uses stop_machine/add uses RCU list operations). */
-static DEFINE_MUTEX(module_mutex);
+DEFINE_MUTEX(module_mutex);
+EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
/* Waiting for a module to finish initializing? */
@@ -76,7 +77,7 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq);
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
-/* Bounds of module allocation, for speeding __module_text_address */
+/* Bounds of module allocation, for speeding __module_address */
static unsigned long module_addr_min = -1UL, module_addr_max = 0;
int register_module_notifier(struct notifier_block * nb)
@@ -186,17 +187,6 @@ extern const unsigned long __start___kcrctab_unused_gpl[];
#define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
#endif
-struct symsearch {
- const struct kernel_symbol *start, *stop;
- const unsigned long *crcs;
- enum {
- NOT_GPL_ONLY,
- GPL_ONLY,
- WILL_BE_GPL_ONLY,
- } licence;
- bool unused;
-};
-
static bool each_symbol_in_section(const struct symsearch *arr,
unsigned int arrsize,
struct module *owner,
@@ -217,10 +207,8 @@ static bool each_symbol_in_section(const struct symsearch *arr,
}
/* Returns true as soon as fn returns true, otherwise false. */
-static bool each_symbol(bool (*fn)(const struct symsearch *arr,
- struct module *owner,
- unsigned int symnum, void *data),
- void *data)
+bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
+ unsigned int symnum, void *data), void *data)
{
struct module *mod;
const struct symsearch arr[] = {
@@ -273,6 +261,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr,
}
return false;
}
+EXPORT_SYMBOL_GPL(each_symbol);
struct find_symbol_arg {
/* Input */
@@ -283,7 +272,7 @@ struct find_symbol_arg {
/* Output */
struct module *owner;
const unsigned long *crc;
- unsigned long value;
+ const struct kernel_symbol *sym;
};
static bool find_symbol_in_section(const struct symsearch *syms,
@@ -324,17 +313,17 @@ static bool find_symbol_in_section(const struct symsearch *syms,
fsa->owner = owner;
fsa->crc = symversion(syms->crcs, symnum);
- fsa->value = syms->start[symnum].value;
+ fsa->sym = &syms->start[symnum];
return true;
}
-/* Find a symbol, return value, (optional) crc and (optional) module
- * which owns it */
-static unsigned long find_symbol(const char *name,
- struct module **owner,
- const unsigned long **crc,
- bool gplok,
- bool warn)
+/* Find a symbol and return it, along with, (optional) crc and
+ * (optional) module which owns it */
+const struct kernel_symbol *find_symbol(const char *name,
+ struct module **owner,
+ const unsigned long **crc,
+ bool gplok,
+ bool warn)
{
struct find_symbol_arg fsa;
@@ -347,15 +336,16 @@ static unsigned long find_symbol(const char *name,
*owner = fsa.owner;
if (crc)
*crc = fsa.crc;
- return fsa.value;
+ return fsa.sym;
}
DEBUGP("Failed to find symbol %s\n", name);
- return -ENOENT;
+ return NULL;
}
+EXPORT_SYMBOL_GPL(find_symbol);
/* Search for module by name: must hold module_mutex. */
-static struct module *find_module(const char *name)
+struct module *find_module(const char *name)
{
struct module *mod;
@@ -365,6 +355,7 @@ static struct module *find_module(const char *name)
}
return NULL;
}
+EXPORT_SYMBOL_GPL(find_module);
#ifdef CONFIG_SMP
@@ -641,7 +632,7 @@ static int already_uses(struct module *a, struct module *b)
}
/* Module a uses b */
-static int use_module(struct module *a, struct module *b)
+int use_module(struct module *a, struct module *b)
{
struct module_use *use;
int no_warn, err;
@@ -674,6 +665,7 @@ static int use_module(struct module *a, struct module *b)
no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
return 1;
}
+EXPORT_SYMBOL_GPL(use_module);
/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
@@ -894,7 +886,7 @@ void __symbol_put(const char *symbol)
struct module *owner;
preempt_disable();
- if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
+ if (!find_symbol(symbol, &owner, NULL, true, false))
BUG();
module_put(owner);
preempt_enable();
@@ -908,8 +900,10 @@ void symbol_put_addr(void *addr)
if (core_kernel_text((unsigned long)addr))
return;
- if (!(modaddr = module_text_address((unsigned long)addr)))
- BUG();
+ /* module_text_address is safe here: we're supposed to have reference
+ * to module from symbol_get, so it can't go away. */
+ modaddr = __module_text_address((unsigned long)addr);
+ BUG_ON(!modaddr);
module_put(modaddr);
}
EXPORT_SYMBOL_GPL(symbol_put_addr);
@@ -949,10 +943,11 @@ static inline void module_unload_free(struct module *mod)
{
}
-static inline int use_module(struct module *a, struct module *b)
+int use_module(struct module *a, struct module *b)
{
return strong_try_module_get(b) == 0;
}
+EXPORT_SYMBOL_GPL(use_module);
static inline void module_unload_init(struct module *mod)
{
@@ -995,12 +990,12 @@ static struct module_attribute *modinfo_attrs[] = {
static const char vermagic[] = VERMAGIC_STRING;
-static int try_to_force_load(struct module *mod, const char *symname)
+static int try_to_force_load(struct module *mod, const char *reason)
{
#ifdef CONFIG_MODULE_FORCE_LOAD
if (!test_taint(TAINT_FORCED_MODULE))
- printk("%s: no version for \"%s\" found: kernel tainted.\n",
- mod->name, symname);
+ printk(KERN_WARNING "%s: %s: kernel tainted.\n",
+ mod->name, reason);
add_taint_module(mod, TAINT_FORCED_MODULE);
return 0;
#else
@@ -1057,9 +1052,9 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
{
const unsigned long *crc;
- if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
+ if (!find_symbol("module_layout", NULL, &crc, true, false))
BUG();
- return check_version(sechdrs, versindex, "struct_module", mod, crc);
+ return check_version(sechdrs, versindex, "module_layout", mod, crc);
}
/* First part is kernel version, which we ignore if module has crcs. */
@@ -1098,25 +1093,25 @@ static inline int same_magic(const char *amagic, const char *bmagic,
/* Resolve a symbol for this module. I.e. if we find one, record usage.
Must be holding module_mutex. */
-static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
- unsigned int versindex,
- const char *name,
- struct module *mod)
+static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
+ unsigned int versindex,
+ const char *name,
+ struct module *mod)
{
struct module *owner;
- unsigned long ret;
+ const struct kernel_symbol *sym;
const unsigned long *crc;
- ret = find_symbol(name, &owner, &crc,
+ sym = find_symbol(name, &owner, &crc,
!(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
- if (!IS_ERR_VALUE(ret)) {
- /* use_module can fail due to OOM,
- or module initialization or unloading */
+ /* use_module can fail due to OOM,
+ or module initialization or unloading */
+ if (sym) {
if (!check_version(sechdrs, versindex, name, mod, crc) ||
!use_module(mod, owner))
- ret = -EINVAL;
+ sym = NULL;
}
- return ret;
+ return sym;
}
/*
@@ -1491,6 +1486,9 @@ static void free_module(struct module *mod)
/* Module unload stuff */
module_unload_free(mod);
+ /* Free any allocated parameters. */
+ destroy_params(mod->kp, mod->num_kp);
+
/* release any pointers to mcount in this module */
ftrace_release(mod->module_core, mod->core_size);
@@ -1513,17 +1511,15 @@ static void free_module(struct module *mod)
void *__symbol_get(const char *symbol)
{
struct module *owner;
- unsigned long value;
+ const struct kernel_symbol *sym;
preempt_disable();
- value = find_symbol(symbol, &owner, NULL, true, true);
- if (IS_ERR_VALUE(value))
- value = 0;
- else if (strong_try_module_get(owner))
- value = 0;
+ sym = find_symbol(symbol, &owner, NULL, true, true);
+ if (sym && strong_try_module_get(owner))
+ sym = NULL;
preempt_enable();
- return (void *)value;
+ return sym ? (void *)sym->value : NULL;
}
EXPORT_SYMBOL_GPL(__symbol_get);
@@ -1551,8 +1547,7 @@ static int verify_export_symbols(struct module *mod)
for (i = 0; i < ARRAY_SIZE(arr); i++) {
for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
- if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
- NULL, true, false))) {
+ if (find_symbol(s->name, &owner, NULL, true, false)) {
printk(KERN_ERR
"%s: exports duplicate symbol %s"
" (owned by %s)\n",
@@ -1576,6 +1571,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
unsigned long secbase;
unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
int ret = 0;
+ const struct kernel_symbol *ksym;
for (i = 1; i < n; i++) {
switch (sym[i].st_shndx) {
@@ -1595,13 +1591,14 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
break;
case SHN_UNDEF:
- sym[i].st_value
- = resolve_symbol(sechdrs, versindex,
- strtab + sym[i].st_name, mod);
-
+ ksym = resolve_symbol(sechdrs, versindex,
+ strtab + sym[i].st_name, mod);
/* Ok if resolved. */
- if (!IS_ERR_VALUE(sym[i].st_value))
+ if (ksym) {
+ sym[i].st_value = ksym->value;
break;
+ }
+
/* Ok if weak. */
if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
break;
@@ -1676,8 +1673,7 @@ static void layout_sections(struct module *mod,
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
- || strncmp(secstrings + s->sh_name,
- ".init", 5) == 0)
+ || strstarts(secstrings + s->sh_name, ".init"))
continue;
s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
DEBUGP("\t%s\n", secstrings + s->sh_name);
@@ -1694,8 +1690,7 @@ static void layout_sections(struct module *mod,
if ((s->sh_flags & masks[m][0]) != masks[m][0]
|| (s->sh_flags & masks[m][1])
|| s->sh_entsize != ~0UL
- || strncmp(secstrings + s->sh_name,
- ".init", 5) != 0)
+ || !strstarts(secstrings + s->sh_name, ".init"))
continue;
s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
| INIT_OFFSET_MASK);
@@ -1828,8 +1823,7 @@ static char elf_type(const Elf_Sym *sym,
else
return 'b';
}
- if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
- ".debug", strlen(".debug")) == 0)
+ if (strstarts(secstrings + sechdrs[sym->st_shndx].sh_name, ".debug"))
return 'n';
return '?';
}
@@ -1898,8 +1892,7 @@ static noinline struct module *load_module(void __user *umod,
unsigned int symindex = 0;
unsigned int strindex = 0;
unsigned int modindex, versindex, infoindex, pcpuindex;
- unsigned int num_kp, num_mcount;
- struct kernel_param *kp;
+ unsigned int num_mcount;
struct module *mod;
long err = 0;
void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
@@ -1916,12 +1909,6 @@ static noinline struct module *load_module(void __user *umod,
if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
return ERR_PTR(-ENOMEM);
- /* Create stop_machine threads since the error path relies on
- * a non-failing stop_machine call. */
- err = stop_machine_create();
- if (err)
- goto free_hdr;
-
if (copy_from_user(hdr, umod, len) != 0) {
err = -EFAULT;
goto free_hdr;
@@ -1962,9 +1949,12 @@ static noinline struct module *load_module(void __user *umod,
}
#ifndef CONFIG_MODULE_UNLOAD
/* Don't load .exit sections */
- if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
+ if (strstarts(secstrings+sechdrs[i].sh_name, ".exit"))
sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
#endif
+ /* Don't keep __versions around; it's just for loading. */
+ if (strcmp(secstrings + sechdrs[i].sh_name, "__versions") == 0)
+ sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
}
modindex = find_sec(hdr, sechdrs, secstrings,
@@ -2006,7 +1996,7 @@ static noinline struct module *load_module(void __user *umod,
modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
/* This is allowed: modprobe --force will invalidate it. */
if (!modmagic) {
- err = try_to_force_load(mod, "magic");
+ err = try_to_force_load(mod, "bad vermagic");
if (err)
goto free_hdr;
} else if (!same_magic(modmagic, vermagic, versindex)) {
@@ -2144,8 +2134,8 @@ static noinline struct module *load_module(void __user *umod,
/* Now we've got everything in the final locations, we can
* find optional sections. */
- kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp),
- &num_kp);
+ mod->kp = section_objs(hdr, sechdrs, secstrings, "__param",
+ sizeof(*mod->kp), &mod->num_kp);
mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
sizeof(*mod->syms), &mod->num_syms);
mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
@@ -2195,8 +2185,8 @@ static noinline struct module *load_module(void __user *umod,
|| (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
#endif
) {
- printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
- err = try_to_force_load(mod, "nocrc");
+ err = try_to_force_load(mod,
+ "no versions for exported symbols");
if (err)
goto cleanup;
}
@@ -2291,11 +2281,11 @@ static noinline struct module *load_module(void __user *umod,
*/
list_add_rcu(&mod->list, &modules);
- err = parse_args(mod->name, mod->args, kp, num_kp, NULL);
+ err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
if (err < 0)
goto unlink;
- err = mod_sysfs_setup(mod, kp, num_kp);
+ err = mod_sysfs_setup(mod, mod->kp, mod->num_kp);
if (err < 0)
goto unlink;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
@@ -2304,12 +2294,13 @@ static noinline struct module *load_module(void __user *umod,
/* Get rid of temporary copy */
vfree(hdr);
- stop_machine_destroy();
/* Done! */
return mod;
unlink:
- stop_machine(__unlink_module, mod, NULL);
+ /* Unlink carefully: kallsyms could be walking list. */
+ list_del_rcu(&mod->list);
+ synchronize_sched();
module_arch_cleanup(mod);
cleanup:
kobject_del(&mod->mkobj.kobj);
@@ -2317,8 +2308,8 @@ static noinline struct module *load_module(void __user *umod,
ftrace_release(mod->module_core, mod->core_size);
free_unload:
module_unload_free(mod);
- free_init:
#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+ free_init:
percpu_modfree(mod->refptr);
#endif
module_free(mod, mod->module_init);
@@ -2332,7 +2323,6 @@ static noinline struct module *load_module(void __user *umod,
kfree(args);
free_hdr:
vfree(hdr);
- stop_machine_destroy();
return ERR_PTR(err);
truncated:
@@ -2609,6 +2599,25 @@ unsigned long module_kallsyms_lookup_name(const char *name)
preempt_enable();
return ret;
}
+
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+ struct module *, unsigned long),
+ void *data)
+{
+ struct module *mod;
+ unsigned int i;
+ int ret;
+
+ list_for_each_entry(mod, &modules, list) {
+ for (i = 0; i < mod->num_symtab; i++) {
+ ret = fn(data, mod->strtab + mod->symtab[i].st_name,
+ mod, mod->symtab[i].st_value);
+ if (ret != 0)
+ return ret;
+ }
+ }
+ return 0;
+}
#endif /* CONFIG_KALLSYMS */
static char *module_flags(struct module *mod, char *buf)
@@ -2744,29 +2753,31 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
}
/*
- * Is this a valid module address?
+ * is_module_address - is this address inside a module?
+ * @addr: the address to check.
+ *
+ * See is_module_text_address() if you simply want to see if the address
+ * is code (not data).
*/
-int is_module_address(unsigned long addr)
+bool is_module_address(unsigned long addr)
{
- struct module *mod;
+ bool ret;
preempt_disable();
-
- list_for_each_entry_rcu(mod, &modules, list) {
- if (within_module_core(addr, mod)) {
- preempt_enable();
- return 1;
- }
- }
-
+ ret = __module_address(addr) != NULL;
preempt_enable();
- return 0;
+ return ret;
}
-
-/* Is this a valid kernel address? */
-__notrace_funcgraph struct module *__module_text_address(unsigned long addr)
+/*
+ * __module_address - get the module which contains an address.
+ * @addr: the address.
+ *
+ * Must be called with preempt disabled or module mutex held so that
+ * module doesn't get freed during this.
+ */
+__notrace_funcgraph struct module *__module_address(unsigned long addr)
{
struct module *mod;
@@ -2774,22 +2785,51 @@ __notrace_funcgraph struct module *__module_text_address(unsigned long addr)
return NULL;
list_for_each_entry_rcu(mod, &modules, list)
- if (within(addr, mod->module_init, mod->init_text_size)
- || within(addr, mod->module_core, mod->core_text_size))
+ if (within_module_core(addr, mod)
+ || within_module_init(addr, mod))
return mod;
return NULL;
}
+EXPORT_SYMBOL_GPL(__module_address);
-struct module *module_text_address(unsigned long addr)
+/*
+ * is_module_text_address - is this address inside module code?
+ * @addr: the address to check.
+ *
+ * See is_module_address() if you simply want to see if the address is
+ * anywhere in a module. See kernel_text_address() for testing if an
+ * address corresponds to kernel or module code.
+ */
+bool is_module_text_address(unsigned long addr)
{
- struct module *mod;
+ bool ret;
preempt_disable();
- mod = __module_text_address(addr);
+ ret = __module_text_address(addr) != NULL;
preempt_enable();
+ return ret;
+}
+
+/*
+ * __module_text_address - get the module whose code contains an address.
+ * @addr: the address.
+ *
+ * Must be called with preempt disabled or module mutex held so that
+ * module doesn't get freed during this.
+ */
+struct module *__module_text_address(unsigned long addr)
+{
+ struct module *mod = __module_address(addr);
+ if (mod) {
+ /* Make sure it's within the text section. */
+ if (!within(addr, mod->module_init, mod->init_text_size)
+ && !within(addr, mod->module_core, mod->core_text_size))
+ mod = NULL;
+ }
return mod;
}
+EXPORT_SYMBOL_GPL(__module_text_address);
/* Don't grab lock, we're oopsing. */
void print_modules(void)
@@ -2809,9 +2849,17 @@ void print_modules(void)
}
#ifdef CONFIG_MODVERSIONS
-/* Generate the signature for struct module here, too, for modversions. */
-void struct_module(struct module *mod) { return; }
-EXPORT_SYMBOL(struct_module);
+/* Generate the signature for all relevant module structures here.
+ * If these change, we don't want to try to parse the module. */
+void module_layout(struct module *mod,
+ struct modversion_info *ver,
+ struct kernel_param *kp,
+ struct kernel_symbol *ks,
+ struct marker *marker,
+ struct tracepoint *tp)
+{
+}
+EXPORT_SYMBOL(module_layout);
#endif
#ifdef CONFIG_MARKERS
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 13:47:13 +0000