Re: [RFC PATCH v2 09/34] lsm: rename the lsm order variables for consistency

[Casey Schaufler <casey@schaufler-ca.com>]

On 7/21/2025 4:21 PM, Paul Moore wrote:
> Rename the builtin_lsm_order variable to lsm_order_builtin,
> chosen_lsm_order to lsm_order_cmdline, chosen_major_lsm to
> lsm_order_legacy, ordered_lsms[] to lsm_order[], and exclusive
> to lsm_exclusive.
>
> This patch also renames the associated kernel command line parsing
> functions and adds some basic function comment blocks.  The parsing
> function choose_major_lsm() was renamed to lsm_choose_security(),
> choose_lsm_order() to lsm_choose_lsm(), and enable_debug() to
> lsm_debug_enable().
>
> Reviewed-by: Kees Cook <kees@kernel.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Paul Moore <paul@paul-moore.com>

Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>


> ---
>  security/lsm_init.c | 86 +++++++++++++++++++++++++--------------------
>  1 file changed, 48 insertions(+), 38 deletions(-)
>
> diff --git a/security/lsm_init.c b/security/lsm_init.c
> index 96d51e4d625b..cbdfac31ede4 100644
> --- a/security/lsm_init.c
> +++ b/security/lsm_init.c
> @@ -16,14 +16,14 @@ char *lsm_names;
>  extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
>  extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[];
>  
> -/* Boot-time LSM user choice */
> -static __initconst const char *const builtin_lsm_order = CONFIG_LSM;
> -static __initdata const char *chosen_lsm_order;
> -static __initdata const char *chosen_major_lsm;
> +/* Build and boot-time LSM ordering. */
> +static __initconst const char *const lsm_order_builtin = CONFIG_LSM;
> +static __initdata const char *lsm_order_cmdline;
> +static __initdata const char *lsm_order_legacy;
>  
>  /* Ordered list of LSMs to initialize. */
> -static __initdata struct lsm_info *ordered_lsms[MAX_LSM_COUNT + 1];
> -static __initdata struct lsm_info *exclusive;
> +static __initdata struct lsm_info *lsm_order[MAX_LSM_COUNT + 1];
> +static __initdata struct lsm_info *lsm_exclusive;
>  
>  static __initdata bool debug;
>  #define init_debug(...)							\
> @@ -33,7 +33,7 @@ static __initdata bool debug;
>  	} while (0)
>  
>  #define lsm_order_for_each(iter)					\
> -	for ((iter) = ordered_lsms; *(iter); (iter)++)
> +	for ((iter) = lsm_order; *(iter); (iter)++)
>  #define lsm_for_each_raw(iter)						\
>  	for ((iter) = __start_lsm_info;					\
>  	     (iter) < __end_lsm_info; (iter)++)
> @@ -41,31 +41,41 @@ static __initdata bool debug;
>  	for ((iter) = __start_early_lsm_info;				\
>  	     (iter) < __end_early_lsm_info; (iter)++)
>  
> -static int lsm_append(const char *new, char **result);
> -
> -/* Save user chosen LSM */
> -static int __init choose_major_lsm(char *str)
> +/**
> + * lsm_choose_security - Legacy "major" LSM selection
> + * @str: kernel command line parameter
> + */
> +static int __init lsm_choose_security(char *str)
>  {
> -	chosen_major_lsm = str;
> +	lsm_order_legacy = str;
>  	return 1;
>  }
> -__setup("security=", choose_major_lsm);
> +__setup("security=", lsm_choose_security);
>  
> -/* Explicitly choose LSM initialization order. */
> -static int __init choose_lsm_order(char *str)
> +/**
> + * lsm_choose_lsm - Modern LSM selection
> + * @str: kernel command line parameter
> + */
> +static int __init lsm_choose_lsm(char *str)
>  {
> -	chosen_lsm_order = str;
> +	lsm_order_cmdline = str;
>  	return 1;
>  }
> -__setup("lsm=", choose_lsm_order);
> +__setup("lsm=", lsm_choose_lsm);
>  
> -/* Enable LSM order debugging. */
> -static int __init enable_debug(char *str)
> +/**
> + * lsm_debug_enable - Enable LSM framework debugging
> + * @str: kernel command line parameter
> + *
> + * Currently we only provide debug info during LSM initialization, but we may
> + * want to expand this in the future.
> + */
> +static int __init lsm_debug_enable(char *str)
>  {
>  	debug = true;
>  	return 1;
>  }
> -__setup("lsm.debug", enable_debug);
> +__setup("lsm.debug", lsm_debug_enable);
>  
>  /* Mark an LSM's enabled flag. */
>  static int lsm_enabled_true __initdata = 1;
> @@ -127,7 +137,7 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from)
>  	/* Enable this LSM, if it is not already set. */
>  	if (!lsm->enabled)
>  		lsm->enabled = &lsm_enabled_true;
> -	ordered_lsms[last_lsm] = lsm;
> +	lsm_order[last_lsm] = lsm;
>  	lsm_idlist[last_lsm++] = lsm->id;
>  
>  	init_debug("%s ordered: %s (%s)\n", from, lsm->id->name,
> @@ -157,7 +167,7 @@ static void __init lsm_prepare(struct lsm_info *lsm)
>  	if (!is_enabled(lsm)) {
>  		set_enabled(lsm, false);
>  		return;
> -	} else if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && exclusive) {
> +	} else if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && lsm_exclusive) {
>  		init_debug("exclusive disabled: %s\n", lsm->id->name);
>  		set_enabled(lsm, false);
>  		return;
> @@ -165,9 +175,9 @@ static void __init lsm_prepare(struct lsm_info *lsm)
>  
>  	/* Mark the LSM as enabled. */
>  	set_enabled(lsm, true);
> -	if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !exclusive) {
> +	if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !lsm_exclusive) {
>  		init_debug("exclusive chosen:   %s\n", lsm->id->name);
> -		exclusive = lsm;
> +		lsm_exclusive = lsm;
>  	}
>  
>  	/* Register the LSM blob sizes. */
> @@ -223,7 +233,7 @@ static void __init ordered_lsm_parse(const char *order, const char *origin)
>  	}
>  
>  	/* Process "security=", if given. */
> -	if (chosen_major_lsm) {
> +	if (lsm_order_legacy) {
>  		struct lsm_info *major;
>  
>  		/*
> @@ -234,10 +244,10 @@ static void __init ordered_lsm_parse(const char *order, const char *origin)
>  		 */
>  		lsm_for_each_raw(major) {
>  			if ((major->flags & LSM_FLAG_LEGACY_MAJOR) &&
> -			    strcmp(major->id->name, chosen_major_lsm) != 0) {
> +			    strcmp(major->id->name, lsm_order_legacy) != 0) {
>  				set_enabled(major, false);
>  				init_debug("security=%s disabled: %s (only one legacy major LSM)\n",
> -					   chosen_major_lsm, major->id->name);
> +					   lsm_order_legacy, major->id->name);
>  			}
>  		}
>  	}
> @@ -262,11 +272,11 @@ static void __init ordered_lsm_parse(const char *order, const char *origin)
>  	}
>  
>  	/* Process "security=", if given. */
> -	if (chosen_major_lsm) {
> +	if (lsm_order_legacy) {
>  		lsm_for_each_raw(lsm) {
>  			if (exists_ordered_lsm(lsm))
>  				continue;
> -			if (strcmp(lsm->id->name, chosen_major_lsm) == 0)
> +			if (strcmp(lsm->id->name, lsm_order_legacy) == 0)
>  				append_ordered_lsm(lsm, "security=");
>  		}
>  	}
> @@ -298,15 +308,15 @@ static void __init lsm_init_ordered(void)
>  	struct lsm_info **lsm;
>  	struct lsm_info *early;
>  
> -	if (chosen_lsm_order) {
> -		if (chosen_major_lsm) {
> +	if (lsm_order_cmdline) {
> +		if (lsm_order_legacy) {
>  			pr_warn("security=%s is ignored because it is superseded by lsm=%s\n",
> -				chosen_major_lsm, chosen_lsm_order);
> -			chosen_major_lsm = NULL;
> +				lsm_order_legacy, lsm_order_cmdline);
> +			lsm_order_legacy = NULL;
>  		}
> -		ordered_lsm_parse(chosen_lsm_order, "cmdline");
> +		ordered_lsm_parse(lsm_order_cmdline, "cmdline");
>  	} else
> -		ordered_lsm_parse(builtin_lsm_order, "builtin");
> +		ordered_lsm_parse(lsm_order_builtin, "builtin");
>  
>  	lsm_order_for_each(lsm) {
>  		lsm_prepare(*lsm);
> @@ -467,9 +477,9 @@ int __init security_init(void)
>  {
>  	struct lsm_info *lsm;
>  
> -	init_debug("legacy security=%s\n", chosen_major_lsm ? : " *unspecified*");
> -	init_debug("  CONFIG_LSM=%s\n", builtin_lsm_order);
> -	init_debug("boot arg lsm=%s\n", chosen_lsm_order ? : " *unspecified*");
> +	init_debug("legacy security=%s\n", lsm_order_legacy ? : " *unspecified*");
> +	init_debug("  CONFIG_LSM=%s\n", lsm_order_builtin);
> +	init_debug("boot arg lsm=%s\n", lsm_order_cmdline ? : " *unspecified*");
>  
>  	/*
>  	 * Append the names of the early LSM modules now that kmalloc() is