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-rw-r--r--kernel/kmod.c40
-rw-r--r--kernel/module.c85
-rw-r--r--scripts/mod/modpost.c1
3 files changed, 73 insertions, 53 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 563f97e2be36..ff68198fe83b 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -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)
diff --git a/kernel/module.c b/kernel/module.c
index b0f92a365140..40f983cbea81 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -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;
}
@@ -1662,31 +1661,36 @@ static inline void remove_notes_attrs(struct module *mod)
}
#endif /* CONFIG_KALLSYMS */
-static void add_usage_links(struct module *mod)
+static void del_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);
- }
+ list_for_each_entry(use, &mod->target_list, target_list)
+ sysfs_remove_link(use->target->holders_dir, mod->name);
mutex_unlock(&module_mutex);
#endif
}
-static void del_usage_links(struct module *mod)
+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)
- sysfs_remove_link(use->target->holders_dir, mod->name);
+ 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)
@@ -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->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;
- info->sechdrs[info->index.vers].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);
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 30d752a4a6a6..48397feb08fb 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -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");
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