Re: [PATCH v4 12/34] lsm: rework the LSM enable/disable setter/getter functions

[Mimi Zohar <zohar@linux.ibm.com>]

On Tue, 2025-09-16 at 18:03 -0400, Paul Moore wrote:
> In addition to style changes, rename set_enabled() to lsm_enabled_set()
> and is_enabled() to lsm_is_enabled() to better fit within the LSM
> initialization code.
> 
> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
> Reviewed-by: John Johansen <john.johhansen@canonical.com>
> Signed-off-by: Paul Moore <paul@paul-moore.com>

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>

> ---
>  security/lsm_init.c | 62 ++++++++++++++++++++++-----------------------
>  1 file changed, 31 insertions(+), 31 deletions(-)
> 
> diff --git a/security/lsm_init.c b/security/lsm_init.c
> index 87e2147016b3..2cfd72ade6fb 100644
> --- a/security/lsm_init.c
> +++ b/security/lsm_init.c
> @@ -10,6 +10,10 @@
>  
>  #include "lsm.h"
>  
> +/* LSM enabled constants. */
> +static __initdata int lsm_enabled_true = 1;
> +static __initdata int lsm_enabled_false = 0;
> +
>  /* Pointers to LSM sections defined in include/asm-generic/vmlinux.lds.h */
>  extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
>  extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[];
> @@ -75,37 +79,33 @@ static int __init lsm_debug_enable(char *str)
>  }
>  __setup("lsm.debug", lsm_debug_enable);
>  
> -/* Mark an LSM's enabled flag. */
> -static int lsm_enabled_true __initdata = 1;
> -static int lsm_enabled_false __initdata = 0;
> -static void __init set_enabled(struct lsm_info *lsm, bool enabled)
> +/**
> + * lsm_enabled_set - Mark a LSM as enabled
> + * @lsm: LSM definition
> + * @enabled: enabled flag
> + */
> +static void __init lsm_enabled_set(struct lsm_info *lsm, bool enabled)
>  {
>  	/*
>  	 * When an LSM hasn't configured an enable variable, we can use
>  	 * a hard-coded location for storing the default enabled state.
>  	 */
> -	if (!lsm->enabled) {
> -		if (enabled)
> -			lsm->enabled = &lsm_enabled_true;
> -		else
> -			lsm->enabled = &lsm_enabled_false;
> -	} else if (lsm->enabled == &lsm_enabled_true) {
> -		if (!enabled)
> -			lsm->enabled = &lsm_enabled_false;
> -	} else if (lsm->enabled == &lsm_enabled_false) {
> -		if (enabled)
> -			lsm->enabled = &lsm_enabled_true;
> +	if (!lsm->enabled ||
> +	    lsm->enabled == &lsm_enabled_true ||
> +	    lsm->enabled == &lsm_enabled_false) {
> +		lsm->enabled = enabled ? &lsm_enabled_true : &lsm_enabled_false;
>  	} else {
>  		*lsm->enabled = enabled;
>  	}
>  }
>  
> -static inline bool is_enabled(struct lsm_info *lsm)
> +/**
> + * lsm_is_enabled - Determine if a LSM is enabled
> + * @lsm: LSM definition
> + */
> +static inline bool lsm_is_enabled(struct lsm_info *lsm)
>  {
> -	if (!lsm->enabled)
> -		return false;
> -
> -	return *lsm->enabled;
> +	return (lsm->enabled ? *lsm->enabled : false);
>  }
>  
>  /* Is an LSM already listed in the ordered LSMs list? */
> @@ -139,7 +139,7 @@ static void __init append_ordered_lsm(struct lsm_info *lsm, const char *from)
>  	lsm_idlist[last_lsm++] = lsm->id;
>  
>  	init_debug("%s ordered: %s (%s)\n", from, lsm->id->name,
> -		   is_enabled(lsm) ? "enabled" : "disabled");
> +		   lsm_is_enabled(lsm) ? "enabled" : "disabled");
>  }
>  
>  static void __init lsm_set_blob_size(int *need, int *lbs)
> @@ -162,17 +162,17 @@ static void __init lsm_prepare(struct lsm_info *lsm)
>  {
>  	struct lsm_blob_sizes *blobs;
>  
> -	if (!is_enabled(lsm)) {
> -		set_enabled(lsm, false);
> +	if (!lsm_is_enabled(lsm)) {
> +		lsm_enabled_set(lsm, false);
>  		return;
>  	} else if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && lsm_exclusive) {
>  		init_debug("exclusive disabled: %s\n", lsm->id->name);
> -		set_enabled(lsm, false);
> +		lsm_enabled_set(lsm, false);
>  		return;
>  	}
>  
>  	/* Mark the LSM as enabled. */
> -	set_enabled(lsm, true);
> +	lsm_enabled_set(lsm, true);
>  	if ((lsm->flags & LSM_FLAG_EXCLUSIVE) && !lsm_exclusive) {
>  		init_debug("exclusive chosen:   %s\n", lsm->id->name);
>  		lsm_exclusive = lsm;
> @@ -206,7 +206,7 @@ static void __init lsm_prepare(struct lsm_info *lsm)
>  /* Initialize a given LSM, if it is enabled. */
>  static void __init initialize_lsm(struct lsm_info *lsm)
>  {
> -	if (is_enabled(lsm)) {
> +	if (lsm_is_enabled(lsm)) {
>  		int ret;
>  
>  		init_debug("initializing %s\n", lsm->id->name);
> @@ -240,7 +240,7 @@ 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, lsm_order_legacy) != 0) {
> -				set_enabled(major, false);
> +				lsm_enabled_set(major, false);
>  				init_debug("security=%s disabled: %s (only one legacy major LSM)\n",
>  					   lsm_order_legacy, major->id->name);
>  			}
> @@ -286,7 +286,7 @@ static void __init ordered_lsm_parse(const char *order, const char *origin)
>  	lsm_for_each_raw(lsm) {
>  		if (exists_ordered_lsm(lsm))
>  			continue;
> -		set_enabled(lsm, false);
> +		lsm_enabled_set(lsm, false);
>  		init_debug("%s skipped: %s (not in requested order)\n",
>  			   origin, lsm->id->name);
>  	}
> @@ -319,12 +319,12 @@ static void __init lsm_init_ordered(void)
>  
>  	pr_info("initializing lsm=");
>  	lsm_early_for_each_raw(early) {
> -		if (is_enabled(early))
> +		if (lsm_is_enabled(early))
>  			pr_cont("%s%s",
>  				first++ == 0 ? "" : ",", early->id->name);
>  	}
>  	lsm_order_for_each(lsm) {
> -		if (is_enabled(*lsm))
> +		if (lsm_is_enabled(*lsm))
>  			pr_cont("%s%s",
>  				first++ == 0 ? "" : ",", (*lsm)->id->name);
>  	}
> @@ -440,7 +440,7 @@ int __init security_init(void)
>  	 */
>  	lsm_early_for_each_raw(lsm) {
>  		init_debug("  early started: %s (%s)\n", lsm->id->name,
> -			   is_enabled(lsm) ? "enabled" : "disabled");
> +			   lsm_is_enabled(lsm) ? "enabled" : "disabled");
>  	}
>  
>  	/* Load LSMs in specified order. */