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authorLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 06:03:39 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-06 06:03:39 +0300
commit0bbb2753584231db364b624bf8cf82551b94da7d (patch)
tree559c49330037fa4e2f5d231e06576f80dc49caaf /kernel
parent0578c3b4d44c34e499e1fd5916ed6c63635b25cf (diff)
parent9e01892c4234070bbcf3a9f582514c8b91464375 (diff)
downloadlinux-0bbb2753584231db364b624bf8cf82551b94da7d.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: module: convert to stop_machine_create/destroy. stop_machine: introduce stop_machine_create/destroy. parisc: fix module loading failure of large kernel modules module: fix module loading failure of large kernel modules for parisc module: fix warning of unused function when !CONFIG_PROC_FS kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms. remove CONFIG_KMOD
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c6
-rw-r--r--kernel/module.c59
-rw-r--r--kernel/stop_machine.c55
3 files changed, 94 insertions, 26 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 47fff3b63cbf..30e74dd6d01b 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -269,8 +269,11 @@ out_release:
int __ref cpu_down(unsigned int cpu)
{
- int err = 0;
+ int err;
+ err = stop_machine_create();
+ if (err)
+ return err;
cpu_maps_update_begin();
if (cpu_hotplug_disabled) {
@@ -297,6 +300,7 @@ int __ref cpu_down(unsigned int cpu)
out:
cpu_maps_update_done();
+ stop_machine_destroy();
return err;
}
EXPORT_SYMBOL(cpu_down);
diff --git a/kernel/module.c b/kernel/module.c
index dd2a54155b54..f47cce910f25 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -757,8 +757,16 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
- if (mutex_lock_interruptible(&module_mutex) != 0)
- return -EINTR;
+ /* Create stop_machine threads since free_module relies on
+ * a non-failing stop_machine call. */
+ ret = stop_machine_create();
+ if (ret)
+ return ret;
+
+ if (mutex_lock_interruptible(&module_mutex) != 0) {
+ ret = -EINTR;
+ goto out_stop;
+ }
mod = find_module(name);
if (!mod) {
@@ -817,10 +825,12 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
out:
mutex_unlock(&module_mutex);
+out_stop:
+ stop_machine_destroy();
return ret;
}
-static void print_unload_info(struct seq_file *m, struct module *mod)
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
struct module_use *use;
int printed_something = 0;
@@ -893,7 +903,7 @@ void module_put(struct module *module)
EXPORT_SYMBOL(module_put);
#else /* !CONFIG_MODULE_UNLOAD */
-static void print_unload_info(struct seq_file *m, struct module *mod)
+static inline void print_unload_info(struct seq_file *m, struct module *mod)
{
/* We don't know the usage count, or what modules are using. */
seq_printf(m, " - -");
@@ -1578,11 +1588,21 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
return ret;
}
+/* Additional bytes needed by arch in front of individual sections */
+unsigned int __weak arch_mod_section_prepend(struct module *mod,
+ unsigned int section)
+{
+ /* default implementation just returns zero */
+ return 0;
+}
+
/* Update size with this section: return offset. */
-static long get_offset(unsigned int *size, Elf_Shdr *sechdr)
+static long get_offset(struct module *mod, unsigned int *size,
+ Elf_Shdr *sechdr, unsigned int section)
{
long ret;
+ *size += arch_mod_section_prepend(mod, section);
ret = ALIGN(*size, sechdr->sh_addralign ?: 1);
*size = ret + sechdr->sh_size;
return ret;
@@ -1622,7 +1642,7 @@ static void layout_sections(struct module *mod,
|| strncmp(secstrings + s->sh_name,
".init", 5) == 0)
continue;
- s->sh_entsize = get_offset(&mod->core_size, s);
+ s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
if (m == 0)
@@ -1640,7 +1660,7 @@ static void layout_sections(struct module *mod,
|| strncmp(secstrings + s->sh_name,
".init", 5) != 0)
continue;
- s->sh_entsize = (get_offset(&mod->init_size, s)
+ s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
| INIT_OFFSET_MASK);
DEBUGP("\t%s\n", secstrings + s->sh_name);
}
@@ -1725,15 +1745,15 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
return NULL;
}
-static int is_exported(const char *name, const struct module *mod)
+static int is_exported(const char *name, unsigned long value,
+ const struct module *mod)
{
- if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab))
- return 1;
+ const struct kernel_symbol *ks;
+ if (!mod)
+ ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
else
- if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms))
- return 1;
- else
- return 0;
+ ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
+ return ks != NULL && ks->value == value;
}
/* As per nm */
@@ -1865,6 +1885,13 @@ static noinline struct module *load_module(void __user *umod,
/* vmalloc barfs on "unusual" numbers. Check here */
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;
@@ -2248,6 +2275,7 @@ static noinline struct module *load_module(void __user *umod,
/* Get rid of temporary copy */
vfree(hdr);
+ stop_machine_destroy();
/* Done! */
return mod;
@@ -2270,6 +2298,7 @@ static noinline struct module *load_module(void __user *umod,
kfree(args);
free_hdr:
vfree(hdr);
+ stop_machine_destroy();
return ERR_PTR(err);
truncated:
@@ -2504,7 +2533,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
- *exported = is_exported(name, mod);
+ *exported = is_exported(name, *value, mod);
preempt_enable();
return 0;
}
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 286c41722e8c..0cd415ee62a2 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -38,7 +38,10 @@ struct stop_machine_data {
static unsigned int num_threads;
static atomic_t thread_ack;
static DEFINE_MUTEX(lock);
-
+/* setup_lock protects refcount, stop_machine_wq and stop_machine_work. */
+static DEFINE_MUTEX(setup_lock);
+/* Users of stop_machine. */
+static int refcount;
static struct workqueue_struct *stop_machine_wq;
static struct stop_machine_data active, idle;
static const cpumask_t *active_cpus;
@@ -109,6 +112,43 @@ static int chill(void *unused)
return 0;
}
+int stop_machine_create(void)
+{
+ mutex_lock(&setup_lock);
+ if (refcount)
+ goto done;
+ stop_machine_wq = create_rt_workqueue("kstop");
+ if (!stop_machine_wq)
+ goto err_out;
+ stop_machine_work = alloc_percpu(struct work_struct);
+ if (!stop_machine_work)
+ goto err_out;
+done:
+ refcount++;
+ mutex_unlock(&setup_lock);
+ return 0;
+
+err_out:
+ if (stop_machine_wq)
+ destroy_workqueue(stop_machine_wq);
+ mutex_unlock(&setup_lock);
+ return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(stop_machine_create);
+
+void stop_machine_destroy(void)
+{
+ mutex_lock(&setup_lock);
+ refcount--;
+ if (refcount)
+ goto done;
+ destroy_workqueue(stop_machine_wq);
+ free_percpu(stop_machine_work);
+done:
+ mutex_unlock(&setup_lock);
+}
+EXPORT_SYMBOL_GPL(stop_machine_destroy);
+
int __stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
struct work_struct *sm_work;
@@ -146,19 +186,14 @@ int stop_machine(int (*fn)(void *), void *data, const struct cpumask *cpus)
{
int ret;
+ ret = stop_machine_create();
+ if (ret)
+ return ret;
/* No CPUs can come up or down during this. */
get_online_cpus();
ret = __stop_machine(fn, data, cpus);
put_online_cpus();
-
+ stop_machine_destroy();
return ret;
}
EXPORT_SYMBOL_GPL(stop_machine);
-
-static int __init stop_machine_init(void)
-{
- stop_machine_wq = create_rt_workqueue("kstop");
- stop_machine_work = alloc_percpu(struct work_struct);
- return 0;
-}
-core_initcall(stop_machine_init);