mirror of
https://github.com/torvalds/linux.git
synced 2024-11-10 14:11:52 +00:00
Modules updates for v4.13
Summary of modules changes for the 4.13 merge window:
- Minor code cleanups
- Avoid accessing mod struct prior to checking module struct version, from Kees
- Fix racy atomic inc/dec logic of kmod_concurrent_max in kmod, from Luis
Signed-off-by: Jessica Yu <jeyu@kernel.org>
-----BEGIN PGP SIGNATURE-----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=tYuD
-----END PGP SIGNATURE-----
Merge tag 'modules-for-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull modules updates from Jessica Yu:
"Summary of modules changes for the 4.13 merge window:
- Minor code cleanups
- Avoid accessing mod struct prior to checking module struct version,
from Kees
- Fix racy atomic inc/dec logic of kmod_concurrent_max in kmod, from
Luis"
* tag 'modules-for-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
module: make the modinfo name const
kmod: reduce atomic operations on kmod_concurrent and simplify
module: use list_for_each_entry_rcu() on find_module_all()
kernel/module.c: suppress warning about unused nowarn variable
module: Add module name to modinfo
module: Pass struct load_info into symbol checks
This commit is contained in:
Linus Torvalds
commit
3a75ad1457
@ -45,8 +45,6 @@
|
||||
|
||||
#include <trace/events/module.h>
|
||||
|
||||
extern int max_threads;
|
||||
|
||||
#define CAP_BSET (void *)1
|
||||
#define CAP_PI (void *)2
|
||||
|
||||
@ -56,6 +54,20 @@ static DEFINE_SPINLOCK(umh_sysctl_lock);
|
||||
static DECLARE_RWSEM(umhelper_sem);
|
||||
|
||||
#ifdef CONFIG_MODULES
|
||||
/*
|
||||
* Assuming:
|
||||
*
|
||||
* threads = div64_u64((u64) totalram_pages * (u64) PAGE_SIZE,
|
||||
* (u64) THREAD_SIZE * 8UL);
|
||||
*
|
||||
* If you need less than 50 threads would mean we're dealing with systems
|
||||
* smaller than 3200 pages. This assuems you are capable of having ~13M memory,
|
||||
* and this would only be an be an upper limit, after which the OOM killer
|
||||
* would take effect. Systems like these are very unlikely if modules are
|
||||
* enabled.
|
||||
*/
|
||||
#define MAX_KMOD_CONCURRENT 50
|
||||
static atomic_t kmod_concurrent_max = ATOMIC_INIT(MAX_KMOD_CONCURRENT);
|
||||
|
||||
/*
|
||||
modprobe_path is set via /proc/sys.
|
||||
@ -127,10 +139,7 @@ int __request_module(bool wait, const char *fmt, ...)
|
||||
{
|
||||
va_list args;
|
||||
char module_name[MODULE_NAME_LEN];
|
||||
unsigned int max_modprobes;
|
||||
int ret;
|
||||
static atomic_t kmod_concurrent = ATOMIC_INIT(0);
|
||||
#define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
|
||||
static int kmod_loop_msg;
|
||||
|
||||
/*
|
||||
@ -154,21 +163,7 @@ int __request_module(bool wait, const char *fmt, ...)
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
/* If modprobe needs a service that is in a module, we get a recursive
|
||||
* loop. Limit the number of running kmod threads to max_threads/2 or
|
||||
* MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method
|
||||
* would be to run the parents of this process, counting how many times
|
||||
* kmod was invoked. That would mean accessing the internals of the
|
||||
* process tables to get the command line, proc_pid_cmdline is static
|
||||
* and it is not worth changing the proc code just to handle this case.
|
||||
* KAO.
|
||||
*
|
||||
* "trace the ppid" is simple, but will fail if someone's
|
||||
* parent exits. I think this is as good as it gets. --RR
|
||||
*/
|
||||
max_modprobes = min(max_threads/2, MAX_KMOD_CONCURRENT);
|
||||
atomic_inc(&kmod_concurrent);
|
||||
if (atomic_read(&kmod_concurrent) > max_modprobes) {
|
||||
if (atomic_dec_if_positive(&kmod_concurrent_max) < 0) {
|
||||
/* We may be blaming an innocent here, but unlikely */
|
||||
if (kmod_loop_msg < 5) {
|
||||
printk(KERN_ERR
|
||||
@ -176,7 +171,6 @@ int __request_module(bool wait, const char *fmt, ...)
|
||||
module_name);
|
||||
kmod_loop_msg++;
|
||||
}
|
||||
atomic_dec(&kmod_concurrent);
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
@ -184,10 +178,12 @@ int __request_module(bool wait, const char *fmt, ...)
|
||||
|
||||
ret = call_modprobe(module_name, wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
|
||||
|
||||
atomic_dec(&kmod_concurrent);
|
||||
atomic_inc(&kmod_concurrent_max);
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL(__request_module);
|
||||
|
||||
#endif /* CONFIG_MODULES */
|
||||
|
||||
static void call_usermodehelper_freeinfo(struct subprocess_info *info)
|
||||
|
||||
@ -300,6 +300,7 @@ int unregister_module_notifier(struct notifier_block *nb)
|
||||
EXPORT_SYMBOL(unregister_module_notifier);
|
||||
|
||||
struct load_info {
|
||||
const char *name;
|
||||
Elf_Ehdr *hdr;
|
||||
unsigned long len;
|
||||
Elf_Shdr *sechdrs;
|
||||
@ -600,7 +601,7 @@ static struct module *find_module_all(const char *name, size_t len,
|
||||
|
||||
module_assert_mutex_or_preempt();
|
||||
|
||||
list_for_each_entry(mod, &modules, list) {
|
||||
list_for_each_entry_rcu(mod, &modules, list) {
|
||||
if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
|
||||
continue;
|
||||
if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
|
||||
@ -1273,12 +1274,13 @@ static u32 resolve_rel_crc(const s32 *crc)
|
||||
return *(u32 *)((void *)crc + *crc);
|
||||
}
|
||||
|
||||
static int check_version(Elf_Shdr *sechdrs,
|
||||
unsigned int versindex,
|
||||
static int check_version(const struct load_info *info,
|
||||
const char *symname,
|
||||
struct module *mod,
|
||||
const s32 *crc)
|
||||
{
|
||||
Elf_Shdr *sechdrs = info->sechdrs;
|
||||
unsigned int versindex = info->index.vers;
|
||||
unsigned int i, num_versions;
|
||||
struct modversion_info *versions;
|
||||
|
||||
@ -1312,17 +1314,16 @@ static int check_version(Elf_Shdr *sechdrs,
|
||||
}
|
||||
|
||||
/* Broken toolchain. Warn once, then let it go.. */
|
||||
pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
|
||||
pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
|
||||
return 1;
|
||||
|
||||
bad_version:
|
||||
pr_warn("%s: disagrees about version of symbol %s\n",
|
||||
mod->name, symname);
|
||||
info->name, symname);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
|
||||
unsigned int versindex,
|
||||
static inline int check_modstruct_version(const struct load_info *info,
|
||||
struct module *mod)
|
||||
{
|
||||
const s32 *crc;
|
||||
@ -1338,8 +1339,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
|
||||
BUG();
|
||||
}
|
||||
preempt_enable();
|
||||
return check_version(sechdrs, versindex,
|
||||
VMLINUX_SYMBOL_STR(module_layout), mod, crc);
|
||||
return check_version(info, VMLINUX_SYMBOL_STR(module_layout),
|
||||
mod, crc);
|
||||
}
|
||||
|
||||
/* First part is kernel version, which we ignore if module has crcs. */
|
||||
@ -1353,8 +1354,7 @@ static inline int same_magic(const char *amagic, const char *bmagic,
|
||||
return strcmp(amagic, bmagic) == 0;
|
||||
}
|
||||
#else
|
||||
static inline int check_version(Elf_Shdr *sechdrs,
|
||||
unsigned int versindex,
|
||||
static inline int check_version(const struct load_info *info,
|
||||
const char *symname,
|
||||
struct module *mod,
|
||||
const s32 *crc)
|
||||
@ -1362,8 +1362,7 @@ static inline int check_version(Elf_Shdr *sechdrs,
|
||||
return 1;
|
||||
}
|
||||
|
||||
static inline int check_modstruct_version(Elf_Shdr *sechdrs,
|
||||
unsigned int versindex,
|
||||
static inline int check_modstruct_version(const struct load_info *info,
|
||||
struct module *mod)
|
||||
{
|
||||
return 1;
|
||||
@ -1399,7 +1398,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
|
||||
if (!sym)
|
||||
goto unlock;
|
||||
|
||||
if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
|
||||
if (!check_version(info, name, mod, crc)) {
|
||||
sym = ERR_PTR(-EINVAL);
|
||||
goto getname;
|
||||
}
|
||||
@ -1662,21 +1661,6 @@ static inline void remove_notes_attrs(struct module *mod)
|
||||
}
|
||||
#endif /* CONFIG_KALLSYMS */
|
||||
|
||||
static void add_usage_links(struct module *mod)
|
||||
{
|
||||
#ifdef CONFIG_MODULE_UNLOAD
|
||||
struct module_use *use;
|
||||
int nowarn;
|
||||
|
||||
mutex_lock(&module_mutex);
|
||||
list_for_each_entry(use, &mod->target_list, target_list) {
|
||||
nowarn = sysfs_create_link(use->target->holders_dir,
|
||||
&mod->mkobj.kobj, mod->name);
|
||||
}
|
||||
mutex_unlock(&module_mutex);
|
||||
#endif
|
||||
}
|
||||
|
||||
static void del_usage_links(struct module *mod)
|
||||
{
|
||||
#ifdef CONFIG_MODULE_UNLOAD
|
||||
@ -1689,6 +1673,26 @@ static void del_usage_links(struct module *mod)
|
||||
#endif
|
||||
}
|
||||
|
||||
static int add_usage_links(struct module *mod)
|
||||
{
|
||||
int ret = 0;
|
||||
#ifdef CONFIG_MODULE_UNLOAD
|
||||
struct module_use *use;
|
||||
|
||||
mutex_lock(&module_mutex);
|
||||
list_for_each_entry(use, &mod->target_list, target_list) {
|
||||
ret = sysfs_create_link(use->target->holders_dir,
|
||||
&mod->mkobj.kobj, mod->name);
|
||||
if (ret)
|
||||
break;
|
||||
}
|
||||
mutex_unlock(&module_mutex);
|
||||
if (ret)
|
||||
del_usage_links(mod);
|
||||
#endif
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int module_add_modinfo_attrs(struct module *mod)
|
||||
{
|
||||
struct module_attribute *attr;
|
||||
@ -1797,13 +1801,18 @@ static int mod_sysfs_setup(struct module *mod,
|
||||
if (err)
|
||||
goto out_unreg_param;
|
||||
|
||||
add_usage_links(mod);
|
||||
err = add_usage_links(mod);
|
||||
if (err)
|
||||
goto out_unreg_modinfo_attrs;
|
||||
|
||||
add_sect_attrs(mod, info);
|
||||
add_notes_attrs(mod, info);
|
||||
|
||||
kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
|
||||
return 0;
|
||||
|
||||
out_unreg_modinfo_attrs:
|
||||
module_remove_modinfo_attrs(mod);
|
||||
out_unreg_param:
|
||||
module_param_sysfs_remove(mod);
|
||||
out_unreg_holders:
|
||||
@ -2910,9 +2919,15 @@ static int rewrite_section_headers(struct load_info *info, int flags)
|
||||
info->index.vers = 0; /* Pretend no __versions section! */
|
||||
else
|
||||
info->index.vers = find_sec(info, "__versions");
|
||||
info->index.info = find_sec(info, ".modinfo");
|
||||
info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
|
||||
info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
|
||||
|
||||
info->index.info = find_sec(info, ".modinfo");
|
||||
if (!info->index.info)
|
||||
info->name = "(missing .modinfo section)";
|
||||
else
|
||||
info->name = get_modinfo(info, "name");
|
||||
info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -2952,21 +2967,29 @@ static struct module *setup_load_info(struct load_info *info, int flags)
|
||||
|
||||
info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
|
||||
if (!info->index.mod) {
|
||||
pr_warn("No module found in object\n");
|
||||
pr_warn("%s: No module found in object\n",
|
||||
info->name ?: "(missing .modinfo name field)");
|
||||
return ERR_PTR(-ENOEXEC);
|
||||
}
|
||||
/* This is temporary: point mod into copy of data. */
|
||||
mod = (void *)info->sechdrs[info->index.mod].sh_addr;
|
||||
|
||||
/*
|
||||
* If we didn't load the .modinfo 'name' field, fall back to
|
||||
* on-disk struct mod 'name' field.
|
||||
*/
|
||||
if (!info->name)
|
||||
info->name = mod->name;
|
||||
|
||||
if (info->index.sym == 0) {
|
||||
pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
|
||||
pr_warn("%s: module has no symbols (stripped?)\n", info->name);
|
||||
return ERR_PTR(-ENOEXEC);
|
||||
}
|
||||
|
||||
info->index.pcpu = find_pcpusec(info);
|
||||
|
||||
/* Check module struct version now, before we try to use module. */
|
||||
if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
|
||||
if (!check_modstruct_version(info, mod))
|
||||
return ERR_PTR(-ENOEXEC);
|
||||
|
||||
return mod;
|
||||
@ -2987,7 +3010,7 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
|
||||
return err;
|
||||
} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
|
||||
pr_err("%s: version magic '%s' should be '%s'\n",
|
||||
mod->name, modmagic, vermagic);
|
||||
info->name, modmagic, vermagic);
|
||||
return -ENOEXEC;
|
||||
}
|
||||
|
||||
@ -3237,7 +3260,7 @@ int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
|
||||
|
||||
/* module_blacklist is a comma-separated list of module names */
|
||||
static char *module_blacklist;
|
||||
static bool blacklisted(char *module_name)
|
||||
static bool blacklisted(const char *module_name)
|
||||
{
|
||||
const char *p;
|
||||
size_t len;
|
||||
@ -3267,7 +3290,7 @@ static struct module *layout_and_allocate(struct load_info *info, int flags)
|
||||
if (IS_ERR(mod))
|
||||
return mod;
|
||||
|
||||
if (blacklisted(mod->name))
|
||||
if (blacklisted(info->name))
|
||||
return ERR_PTR(-EPERM);
|
||||
|
||||
err = check_modinfo(mod, info, flags);
|
||||
|
||||
@ -2126,6 +2126,7 @@ static void add_header(struct buffer *b, struct module *mod)
|
||||
buf_printf(b, "#include <linux/compiler.h>\n");
|
||||
buf_printf(b, "\n");
|
||||
buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
|
||||
buf_printf(b, "MODULE_INFO(name, KBUILD_MODNAME);\n");
|
||||
buf_printf(b, "\n");
|
||||
buf_printf(b, "__visible struct module __this_module\n");
|
||||
buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
|
||||
|
||||
Loading…
Reference in New Issue
Block a user