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>
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index ae0117a..12178d2 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -31,6 +31,7 @@
 extern void __print_symbol(const char *fmt, unsigned long address);
 
 int lookup_symbol_name(unsigned long addr, char *symname);
+int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name);
 
 #else /* !CONFIG_KALLSYMS */
 
@@ -65,6 +66,11 @@
 	return -ERANGE;
 }
 
+static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name)
+{
+	return -ERANGE;
+}
+
 /* Stupid that this does nothing, but I didn't create this mess. */
 #define __print_symbol(fmt, addr)
 #endif /*CONFIG_KALLSYMS*/