Fix race between cat /proc/slab_allocators and rmmod

Same story as with cat /proc/*/wchan race vs rmmod race, only
/proc/slab_allocators want more info than just symbol name.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 0 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 3da76ad32d78..d36e45477fac 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2149,6 +2149,33 @@ out:
         return -ERANGE;
 }
 
+int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
+                        unsigned long *offset, char *modname, char *name)
+{
+        struct module *mod;
+
+        mutex_lock(&module_mutex);
+        list_for_each_entry(mod, &modules, list) {
+                if (within(addr, mod->module_init, mod->init_size) ||
+                    within(addr, mod->module_core, mod->core_size)) {
+                        const char *sym;
+
+                        sym = get_ksymbol(mod, addr, size, offset);
+                        if (!sym)
+                                goto out;
+                        if (modname)
+                                strlcpy(modname, mod->name, MODULE_NAME_LEN + 1);
+                        if (name)
+                                strlcpy(name, sym, KSYM_NAME_LEN + 1);
+                        mutex_unlock(&module_mutex);
+                        return 0;
+                }
+        }
+out:
+        mutex_unlock(&module_mutex);
+        return -ERANGE;
+}
+
 int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
                         char *name, char *module_name, int *exported)
 {