From d19f05d8a8fa221e5d5f4eaca0f3ca5874c990d3 Mon Sep 17 00:00:00 2001 From: "Luis R. Rodriguez" Date: Wed, 27 May 2015 11:09:38 +0930 Subject: [PATCH] kernel/params.c: generalize bool_enable_only This takes out the bool_enable_only implementation from the module loading code and generalizes it so that others can make use of it. Cc: Rusty Russell Cc: Jani Nikula Cc: Andrew Morton Cc: Kees Cook Cc: Tejun Heo Cc: Ingo Molnar Cc: linux-kernel@vger.kernel.org Cc: cocci@systeme.lip6.fr Signed-off-by: Luis R. Rodriguez Signed-off-by: Rusty Russell --- include/linux/moduleparam.h | 6 ++++++ kernel/module.c | 31 ------------------------------- kernel/params.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 36 insertions(+), 31 deletions(-) diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 5d0f4d97997f..7e0079936396 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -427,6 +427,12 @@ extern int param_set_bool(const char *val, const struct kernel_param *kp); extern int param_get_bool(char *buffer, const struct kernel_param *kp); #define param_check_bool(name, p) __param_check(name, p, bool) +extern const struct kernel_param_ops param_ops_bool_enable_only; +extern int param_set_bool_enable_only(const char *val, + const struct kernel_param *kp); +/* getter is the same as for the regular bool */ +#define param_check_bool_enable_only param_check_bool + extern const struct kernel_param_ops param_ops_invbool; extern int param_set_invbool(const char *val, const struct kernel_param *kp); extern int param_get_invbool(char *buffer, const struct kernel_param *kp); diff --git a/kernel/module.c b/kernel/module.c index 9e8c9305bba9..9b0e36145474 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -298,37 +298,6 @@ static bool sig_enforce = true; #else static bool sig_enforce = false; -static int param_set_bool_enable_only(const char *val, - const struct kernel_param *kp) -{ - int err = 0; - bool new_value; - bool orig_value = *(bool *)kp->arg; - struct kernel_param dummy_kp = *kp; - - dummy_kp.arg = &new_value; - - err = param_set_bool(val, &dummy_kp); - if (err) - return err; - - /* Don't let them unset it once it's set! */ - if (!new_value && orig_value) - return -EROFS; - - if (new_value) - err = param_set_bool(val, kp); - - return err; -} - -static const struct kernel_param_ops param_ops_bool_enable_only = { - .flags = KERNEL_PARAM_OPS_FL_NOARG, - .set = param_set_bool_enable_only, - .get = param_get_bool, -}; -#define param_check_bool_enable_only param_check_bool - module_param(sig_enforce, bool_enable_only, 0644); #endif /* !CONFIG_MODULE_SIG_FORCE */ #endif /* CONFIG_MODULE_SIG */ diff --git a/kernel/params.c b/kernel/params.c index b7635c025e9b..324624ed620f 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -335,6 +335,36 @@ const struct kernel_param_ops param_ops_bool = { }; EXPORT_SYMBOL(param_ops_bool); +int param_set_bool_enable_only(const char *val, const struct kernel_param *kp) +{ + int err = 0; + bool new_value; + bool orig_value = *(bool *)kp->arg; + struct kernel_param dummy_kp = *kp; + + dummy_kp.arg = &new_value; + + err = param_set_bool(val, &dummy_kp); + if (err) + return err; + + /* Don't let them unset it once it's set! */ + if (!new_value && orig_value) + return -EROFS; + + if (new_value) + err = param_set_bool(val, kp); + + return err; +} +EXPORT_SYMBOL_GPL(param_set_bool_enable_only); + +const struct kernel_param_ops param_ops_bool_enable_only = { + .flags = KERNEL_PARAM_OPS_FL_NOARG, + .set = param_set_bool_enable_only, + .get = param_get_bool, +}; + /* This one must be bool. */ int param_set_invbool(const char *val, const struct kernel_param *kp) {