modules: Fix build error in the !CONFIG_KALLSYMS case

> James Bottomley (1):
>       module: workaround duplicate section names

-tip testing found that this patch breaks the build on x86 if
CONFIG_KALLSYMS is disabled:

 kernel/module.c: In function ‘load_module’:
 kernel/module.c:2367: error: ‘struct module’ has no member named ‘sect_attrs’
 distcc[8269] ERROR: compile kernel/module.c on ph/32 failed
 make[1]: *** [kernel/module.o] Error 1
 make: *** [kernel] Error 2
 make: *** Waiting for unfinished jobs....

Commit 1b364bf4 misses the fact that section attributes are only
built and dealt with if kallsyms is enabled. The patch below fixes
this.

( note, technically speaking this should depend on CONFIG_SYSFS as
  well but this patch is correct too and keeps the #ifdef less
  intrusive - in the KALLSYMS && !SYSFS case the code is a NOP. )
Signed-off-by: NIngo Molnar <mingo@elte.hu>
[ Replaced patch with a slightly cleaner variation by James Bottomley ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel/module.c

@@ -1274,6 +1274,10 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
 	struct module_notes_attrs *notes_attrs;
 	struct bin_attribute *nattr;
 
+	/* failed to create section attributes, so can't create notes */
+	if (!mod->sect_attrs)
+		return;
+
 	/* Count notes sections and allocate structures.  */
 	notes = 0;
 	for (i = 0; i < nsect; i++)
@@ -2355,8 +2359,7 @@ static noinline struct module *load_module(void __user *umod,
 	if (err < 0)
 		goto unlink;
 	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
-	if (mod->sect_attrs)
-		add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
+	add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
 
 	/* Get rid of temporary copy */
 	vfree(hdr);