On 4/9/25 11:49, Paul Moore wrote:
One part of a larger effort to cleanup the LSM framework initialization
code.

Signed-off-by: Paul Moore <p...@paul-moore.com>

with the commit message updates already brought up, code looks good

Reviewed-by: John Johansen <john.johan...@canonical.com>

---
  security/lsm_init.c | 88 +++++++++++++++++++++++++--------------------
  1 file changed, 49 insertions(+), 39 deletions(-)

diff --git a/security/lsm_init.c b/security/lsm_init.c
index d458a365b0d5..edf2f4140eaa 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(...)                                                       
\
@@ -33,36 +33,46 @@ 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_early_for_each_raw(iter)                                  \
        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;
@@ -124,7 +134,7 @@ 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,
@@ -154,7 +164,7 @@ static void __init lsm_prep_single(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;
@@ -162,9 +172,9 @@ static void __init lsm_prep_single(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. */
@@ -220,7 +230,7 @@ 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;
/*
@@ -232,10 +242,10 @@ static void __init ordered_lsm_parse(const char *order, 
const char *origin)
                for (major = __start_lsm_info; major < __end_lsm_info;
                     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);
                        }
                }
        }
@@ -260,11 +270,11 @@ static void __init ordered_lsm_parse(const char *order, 
const char *origin)
        }
/* Process "security=", if given. */
-       if (chosen_major_lsm) {
+       if (lsm_order_legacy) {
                for (lsm = __start_lsm_info; lsm < __end_lsm_info; 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=");
                }
        }
@@ -295,15 +305,15 @@ 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_prep_single(*lsm);
@@ -319,7 +329,7 @@ static void __init lsm_init_ordered(void)
        lsm_order_for_each(lsm) {
                if (is_enabled(*lsm))
                        pr_cont("%s%s",
-                               lsm == ordered_lsms ? "" : ",", 
(*lsm)->id->name);
+                               lsm == lsm_order ? "" : ",", (*lsm)->id->name);
        }
        pr_cont("\n");
@@ -465,9 +475,9 @@ 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


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