Re: module: Remove const attribute from alias for MODULE_DEVICE_TABLE

From: Jessica Yu
Date: Sat Jul 29 2017 - 17:49:12 EST


+++ Matthias Kaehlcke [24/07/17 18:27 -0700]:
MODULE_DEVICE_TABLE(type, name) creates an alias of type 'extern const
typeof(name)'. If 'name' is already constant the 'const' attribute is
specified twice, which is not allowed in C89 (see discussion at
https://lkml.org/lkml/2017/5/23/1440). Since the kernel is built with
-std=gnu89 clang generates warnings like this:

drivers/thermal/x86_pkg_temp_thermal.c:509:1: warning: duplicate 'const'
declaration specifier
[-Wduplicate-decl-specifier]
MODULE_DEVICE_TABLE(x86cpu, pkg_temp_thermal_ids);
^
./include/linux/module.h:212:8: note: expanded from macro 'MODULE_DEVICE_TABLE'
extern const typeof(name) __mod_##type##__##name##_device_table

Remove the const attribute from the alias to avoid the duplicate
specifier. After all it is only an alias and the attribute shouldn't
have any effect.

Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx>

Applied, thanks!

Jessica

include/linux/module.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index e7bdd549e527..fe5aa3736707 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -209,7 +209,7 @@ extern void cleanup_module(void);
#ifdef MODULE
/* Creates an alias so file2alias.c can find device table. */
#define MODULE_DEVICE_TABLE(type, name) \
-extern const typeof(name) __mod_##type##__##name##_device_table \
+extern typeof(name) __mod_##type##__##name##_device_table \
__attribute__ ((unused, alias(__stringify(name))))
#else /* !MODULE */
#define MODULE_DEVICE_TABLE(type, name)
--
2.14.0.rc0.284.gd933b75aa4-goog