[v2,7/8] kernel/module.c: avoid ifdefs for sig_enforce declaration

Commit Message

Luis R. Rodriguez April 22, 2015, 9:55 p.m. UTC

From: "Luis R. Rodriguez" <[e-mail]>

There's no need to require an ifdef over the declaration
of sig_enforce as IS_ENABLED() can be used. While at it,
there's no harm in exposing this kernel parameter outside of
CONFIG_MODULE_SIG as it'd be a no-op on non module sig
kernels.

Now, technically we should in theory be able to remove
the #ifdef'ery over the declaration of the module parameter
as we are also trusting the bool_enable_only code for
CONFIG_MODULE_SIG kernels but for now remain paranoid
and keep it.

With time if no one can put a bullet through bool_enable_only
and if there are no technical requirements over not exposing
CONFIG_MODULE_SIG_FORCE with the measures in place by
bool_enable_only we could remove this last ifdef.

Cc: Rusty Russell <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Kees Cook <[e-mail]>
Cc: Tejun Heo <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Luis R. Rodriguez <[e-mail]>
---
 kernel/module.c | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

Patch

diff --git a/kernel/module.c b/kernel/module.c
index 43a1ef3..9e51b37 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -105,15 +105,10 @@  static LIST_HEAD(modules);
 struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
 #endif /* CONFIG_KGDB_KDB */
 
-#ifdef CONFIG_MODULE_SIG
-#ifdef CONFIG_MODULE_SIG_FORCE
-static bool sig_enforce = true;
-#else
-static bool sig_enforce = false;
-
+static bool sig_enforce = IS_ENABLED(CONFIG_MODULE_SIG_FORCE);
+#ifndef CONFIG_MODULE_SIG_FORCE
 module_param(sig_enforce, bool_enable_only, 0644);
 #endif /* !CONFIG_MODULE_SIG_FORCE */
-#endif /* CONFIG_MODULE_SIG */
 
 /* Block module loading/unloading? */
 int modules_disabled = 0;