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-rw-r--r--kernel/module.c200
1 files changed, 117 insertions, 83 deletions
diff --git a/kernel/module.c b/kernel/module.c
index c3a9e972d3b2..4bf30e4b3eaa 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1,9 +1,8 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
- Copyright (C) 2002 Richard Henderson
- Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
-
-*/
+ * Copyright (C) 2002 Richard Henderson
+ * Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.
+ */
#define INCLUDE_VERMAGIC
@@ -86,7 +85,8 @@
* 1) List of modules (also safely readable with preempt_disable),
* 2) module_use links,
* 3) module_addr_min/module_addr_max.
- * (delete and add uses RCU list operations). */
+ * (delete and add uses RCU list operations).
+ */
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
@@ -615,8 +615,10 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
return false;
}
-/* Find an exported symbol and return it, along with, (optional) crc and
- * (optional) module which owns it. Needs preempt disabled or module_mutex. */
+/*
+ * Find an exported symbol and return it, along with, (optional) crc and
+ * (optional) module which owns it. Needs preempt disabled or module_mutex.
+ */
static const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const s32 **crc,
@@ -756,13 +758,12 @@ bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
}
/**
- * is_module_percpu_address - test whether address is from module static percpu
+ * is_module_percpu_address() - test whether address is from module static percpu
* @addr: address to test
*
* Test whether @addr belongs to module static percpu area.
*
- * RETURNS:
- * %true if @addr is from module static percpu area
+ * Return: %true if @addr is from module static percpu area
*/
bool is_module_percpu_address(unsigned long addr)
{
@@ -986,11 +987,10 @@ static int try_stop_module(struct module *mod, int flags, int *forced)
}
/**
- * module_refcount - return the refcount or -1 if unloading
- *
+ * module_refcount() - return the refcount or -1 if unloading
* @mod: the module we're checking
*
- * Returns:
+ * Return:
* -1 if the module is in the process of unloading
* otherwise the number of references in the kernel to the module
*/
@@ -1675,8 +1675,10 @@ static void remove_sect_attrs(struct module *mod)
if (mod->sect_attrs) {
sysfs_remove_group(&mod->mkobj.kobj,
&mod->sect_attrs->grp);
- /* We are positive that no one is using any sect attrs
- * at this point. Deallocate immediately. */
+ /*
+ * We are positive that no one is using any sect attrs
+ * at this point. Deallocate immediately.
+ */
free_sect_attrs(mod->sect_attrs);
mod->sect_attrs = NULL;
}
@@ -1924,7 +1926,6 @@ static int mod_sysfs_init(struct module *mod)
if (err)
mod_kobject_put(mod);
- /* delay uevent until full sysfs population */
out:
return err;
}
@@ -1961,7 +1962,6 @@ static int mod_sysfs_setup(struct module *mod,
add_sect_attrs(mod, info);
add_notes_attrs(mod, info);
- kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
return 0;
out_unreg_modinfo_attrs:
@@ -2247,8 +2247,10 @@ static void free_module(struct module *mod)
mod_sysfs_teardown(mod);
- /* We leave it in list to prevent duplicate loads, but make sure
- * that noone uses it while it's being deconstructed. */
+ /*
+ * We leave it in list to prevent duplicate loads, but make sure
+ * that noone uses it while it's being deconstructed.
+ */
mutex_lock(&module_mutex);
mod->state = MODULE_STATE_UNFORMED;
mutex_unlock(&module_mutex);
@@ -2365,8 +2367,10 @@ static int simplify_symbols(struct module *mod, const struct load_info *info)
if (!strncmp(name, "__gnu_lto", 9))
break;
- /* We compiled with -fno-common. These are not
- supposed to happen. */
+ /*
+ * We compiled with -fno-common. These are not
+ * supposed to happen.
+ */
pr_debug("Common symbol: %s\n", name);
pr_warn("%s: please compile with -fno-common\n",
mod->name);
@@ -2469,16 +2473,20 @@ static long get_offset(struct module *mod, unsigned int *size,
return ret;
}
-/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
- might -- code, read-only data, read-write data, small data. Tally
- sizes, and place the offsets into sh_entsize fields: high bit means it
- belongs in init. */
+/*
+ * Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
+ * might -- code, read-only data, read-write data, small data. Tally
+ * sizes, and place the offsets into sh_entsize fields: high bit means it
+ * belongs in init.
+ */
static void layout_sections(struct module *mod, struct load_info *info)
{
static unsigned long const masks[][2] = {
- /* NOTE: all executable code must be the first section
+ /*
+ * NOTE: all executable code must be the first section
* in this array; otherwise modify the text_size
- * finder in the two loops below */
+ * finder in the two loops below
+ */
{ SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL },
{ SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL },
{ SHF_RO_AFTER_INIT | SHF_ALLOC, ARCH_SHF_SMALL },
@@ -2924,40 +2932,43 @@ static int module_sig_check(struct load_info *info, int flags)
/* We truncate the module to discard the signature */
info->len -= markerlen;
err = mod_verify_sig(mod, info);
+ if (!err) {
+ info->sig_ok = true;
+ return 0;
+ }
}
+ /*
+ * We don't permit modules to be loaded into the trusted kernels
+ * without a valid signature on them, but if we're not enforcing,
+ * certain errors are non-fatal.
+ */
switch (err) {
- case 0:
- info->sig_ok = true;
- return 0;
-
- /* We don't permit modules to be loaded into trusted kernels
- * without a valid signature on them, but if we're not
- * enforcing, certain errors are non-fatal.
- */
case -ENODATA:
- reason = "Loading of unsigned module";
- goto decide;
+ reason = "unsigned module";
+ break;
case -ENOPKG:
- reason = "Loading of module with unsupported crypto";
- goto decide;
+ reason = "module with unsupported crypto";
+ break;
case -ENOKEY:
- reason = "Loading of module with unavailable key";
- decide:
- if (is_module_sig_enforced()) {
- pr_notice("%s: %s is rejected\n", info->name, reason);
- return -EKEYREJECTED;
- }
-
- return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
+ reason = "module with unavailable key";
+ break;
- /* All other errors are fatal, including nomem, unparseable
- * signatures and signature check failures - even if signatures
- * aren't required.
- */
default:
+ /*
+ * All other errors are fatal, including lack of memory,
+ * unparseable signatures, and signature check failures --
+ * even if signatures aren't required.
+ */
return err;
}
+
+ if (is_module_sig_enforced()) {
+ pr_notice("%s: loading of %s is rejected\n", info->name, reason);
+ return -EKEYREJECTED;
+ }
+
+ return security_locked_down(LOCKDOWN_MODULE_SIGNATURE);
}
#else /* !CONFIG_MODULE_SIG */
static int module_sig_check(struct load_info *info, int flags)
@@ -3090,8 +3101,10 @@ static int rewrite_section_headers(struct load_info *info, int flags)
return -ENOEXEC;
}
- /* Mark all sections sh_addr with their address in the
- temporary image. */
+ /*
+ * Mark all sections sh_addr with their address in the
+ * temporary image.
+ */
shdr->sh_addr = (size_t)info->hdr + shdr->sh_offset;
#ifndef CONFIG_MODULE_UNLOAD
@@ -3525,9 +3538,11 @@ static struct module *layout_and_allocate(struct load_info *info, int flags)
if (ndx)
info->sechdrs[ndx].sh_flags |= SHF_RO_AFTER_INIT;
- /* 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. */
+ /*
+ * 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(info->mod, info);
layout_symtab(info->mod, info);
@@ -3671,6 +3686,9 @@ static noinline int do_init_module(struct module *mod)
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_LIVE, mod);
+ /* Delay uevent until module has finished its init routine */
+ kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
+
/*
* We need to finish all async code before the module init sequence
* is done. This has potential to deadlock. For example, a newly
@@ -3815,8 +3833,10 @@ static int complete_formation(struct module *mod, struct load_info *info)
module_enable_nx(mod);
module_enable_x(mod);
- /* Mark state as coming so strong_try_module_get() ignores us,
- * but kallsyms etc. can see us. */
+ /*
+ * Mark state as coming so strong_try_module_get() ignores us,
+ * but kallsyms etc. can see us.
+ */
mod->state = MODULE_STATE_COMING;
mutex_unlock(&module_mutex);
@@ -3863,8 +3883,10 @@ static int unknown_module_param_cb(char *param, char *val, const char *modname,
return 0;
}
-/* Allocate and load the module: note that size of section 0 is always
- zero, and we rely on this for optional sections. */
+/*
+ * Allocate and load the module: note that size of section 0 is always
+ * zero, and we rely on this for optional sections.
+ */
static int load_module(struct load_info *info, const char __user *uargs,
int flags)
{
@@ -3938,8 +3960,10 @@ static int load_module(struct load_info *info, const char __user *uargs,
init_param_lock(mod);
- /* Now we've got everything in the final locations, we can
- * find optional sections. */
+ /*
+ * Now we've got everything in the final locations, we can
+ * find optional sections.
+ */
err = find_module_sections(mod, info);
if (err)
goto free_unload;
@@ -4027,6 +4051,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
MODULE_STATE_GOING, mod);
klp_module_going(mod);
bug_cleanup:
+ mod->state = MODULE_STATE_GOING;
/* module_bug_cleanup needs module_mutex protection */
mutex_lock(&module_mutex);
module_bug_cleanup(mod);
@@ -4152,8 +4177,10 @@ static const char *find_kallsyms_symbol(struct module *mod,
bestval = kallsyms_symbol_value(&kallsyms->symtab[best]);
- /* Scan for closest preceding symbol, and next symbol. (ELF
- starts real symbols at 1). */
+ /*
+ * Scan for closest preceding symbol, and next symbol. (ELF
+ * starts real symbols at 1).
+ */
for (i = 1; i < kallsyms->num_symtab; i++) {
const Elf_Sym *sym = &kallsyms->symtab[i];
unsigned long thisval = kallsyms_symbol_value(sym);
@@ -4161,8 +4188,10 @@ static const char *find_kallsyms_symbol(struct module *mod,
if (sym->st_shndx == SHN_UNDEF)
continue;
- /* We ignore unnamed symbols: they're uninformative
- * and inserted at a whim. */
+ /*
+ * We ignore unnamed symbols: they're uninformative
+ * and inserted at a whim.
+ */
if (*kallsyms_symbol_name(kallsyms, i) == '\0'
|| is_arm_mapping_symbol(kallsyms_symbol_name(kallsyms, i)))
continue;
@@ -4192,8 +4221,10 @@ void * __weak dereference_module_function_descriptor(struct module *mod,
return ptr;
}
-/* For kallsyms to ask for address resolution. NULL means not found. Careful
- * not to lock to avoid deadlock on oopses, simply disable preemption. */
+/*
+ * For kallsyms to ask for address resolution. NULL means not found. Careful
+ * not to lock to avoid deadlock on oopses, simply disable preemption.
+ */
const char *module_address_lookup(unsigned long addr,
unsigned long *size,
unsigned long *offset,
@@ -4451,11 +4482,12 @@ static int m_show(struct seq_file *m, void *p)
return 0;
}
-/* Format: modulename size refcount deps address
-
- Where refcount is a number or -, and deps is a comma-separated list
- of depends or -.
-*/
+/*
+ * Format: modulename size refcount deps address
+ *
+ * Where refcount is a number or -, and deps is a comma-separated list
+ * of depends or -.
+ */
static const struct seq_operations modules_op = {
.start = m_start,
.next = m_next,
@@ -4525,8 +4557,8 @@ out:
return e;
}
-/*
- * is_module_address - is this address inside a module?
+/**
+ * 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
@@ -4543,8 +4575,8 @@ bool is_module_address(unsigned long addr)
return ret;
}
-/*
- * __module_address - get the module which contains an address.
+/**
+ * __module_address() - get the module which contains an address.
* @addr: the address.
*
* Must be called with preempt disabled or module mutex held so that
@@ -4568,8 +4600,8 @@ struct module *__module_address(unsigned long addr)
return mod;
}
-/*
- * is_module_text_address - is this address inside module code?
+/**
+ * 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
@@ -4587,8 +4619,8 @@ bool is_module_text_address(unsigned long addr)
return ret;
}
-/*
- * __module_text_address - get the module whose code contains an address.
+/**
+ * __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
@@ -4627,8 +4659,10 @@ void print_modules(void)
}
#ifdef CONFIG_MODVERSIONS
-/* Generate the signature for all relevant module structures here.
- * If these change, we don't want to try to parse the 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,