[PATCH v2] export: fix string handling of namespace in EXPORT_SYMBOL_NS

From: Greg Kroah-Hartman
Date: Wed Apr 27 2022 - 05:06:29 EST


Commit c3a6cf19e695 ("export: avoid code duplication in
include/linux/export.h") broke the ability for a defined string to be
used as a namespace value. Fix this up by using stringify to properly
encode the namespace name.

Fixes: c3a6cf19e695 ("export: avoid code duplication in include/linux/export.h")
Cc: Miroslav Benes <mbenes@xxxxxxx>
Cc: Emil Velikov <emil.l.velikov@xxxxxxxxx>
Cc: Jessica Yu <jeyu@xxxxxxxxxx>
Cc: Quentin Perret <qperret@xxxxxxxxxx>
Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Cc: Matthias Maennich <maennich@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
v2: use stringify() instead of 2 step redirection as pointed out by Masahiro

include/linux/export.h | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/include/linux/export.h b/include/linux/export.h
index 27d848712b90..5910ccb66ca2 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -2,6 +2,8 @@
#ifndef _LINUX_EXPORT_H
#define _LINUX_EXPORT_H

+#include <linux/stringify.h>
+
/*
* Export symbols from the kernel to modules. Forked from module.h
* to reduce the amount of pointless cruft we feed to gcc when only
@@ -154,7 +156,6 @@ struct kernel_symbol {
#endif /* CONFIG_MODULES */

#ifdef DEFAULT_SYMBOL_NAMESPACE
-#include <linux/stringify.h>
#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, __stringify(DEFAULT_SYMBOL_NAMESPACE))
#else
#define _EXPORT_SYMBOL(sym, sec) __EXPORT_SYMBOL(sym, sec, "")
@@ -162,8 +163,8 @@ struct kernel_symbol {

#define EXPORT_SYMBOL(sym) _EXPORT_SYMBOL(sym, "")
#define EXPORT_SYMBOL_GPL(sym) _EXPORT_SYMBOL(sym, "_gpl")
-#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", #ns)
-#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", #ns)
+#define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", __stringify(ns))
+#define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "_gpl", __stringify(ns))

#endif /* !__ASSEMBLY__ */

--
2.36.0