android-mainline/NOUPSTREAM-ANDROID-modpost-Forbid-double-exports.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Quentin Perret <qperret@google.com>
Date: Tue, 24 Nov 2020 14:40:13 +0000
Subject: NOUPSTREAM: ANDROID: modpost: Forbid double exports

In the context of GKI we are exporting quite a few internal kernel
symbols, some of which may be static functions (yes this is bad, but
technically it works). As such, we need to be careful about conflicts
and we really should not allow a symbol to be exported more than once.

To ensure this is the case, turn the modpost check 'fatal' to bail out
immediately when such a situation is detected.

[CPNOTE: 03/06/21] Lee: Fatal only makes sense for GKI based builds

Bug: 174214891
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: I674c9c9c327849503e94d79654e6288411a830af
---
 scripts/mod/modpost.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -418,10 +418,9 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod,
 		s = new_symbol(name, mod, export);
 	} else if (!external_module || s->module->is_vmlinux ||
 		   s->module == mod) {
-		warn("%s: '%s' exported twice. Previous export was in %s%s\n",
-		     mod->name, name, s->module->name,
-		     s->module->is_vmlinux ? "" : ".ko");
-		return s;
+		fatal("%s: '%s' exported twice. Previous export was in %s%s\n",
+		      mod->name, name, s->module->name,
+		      s->module->is_vmlinux ? "" : ".ko");
 	}
 
 	s->module = mod;