[PATCH] lib/smokey: Handle built-in modules properly

[Jan Kiszka via Xenomai]

From: Jan Kiszka <jan.kis...@siemens.com>

Check again after loading a module if it was actually added. If not but
modprobe returned no error, the module is built-in and must not be
removed on exit - which only fails.

Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
 lib/smokey/helpers.c | 41 ++++++++++++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 13 deletions(-)

diff --git a/lib/smokey/helpers.c b/lib/smokey/helpers.c
index 9fc4236ff1..0fc450ff65 100644
--- a/lib/smokey/helpers.c
+++ b/lib/smokey/helpers.c
@@ -293,35 +293,48 @@ int smokey_fork_exec(const char *path, const char *arg)
 
 }
 
-#define SMOKEY_MOD_NUM       32
-static char *smokey_modules[SMOKEY_MOD_NUM];
-
-int smokey_modprobe(const char *name, bool silent)
+static bool module_loaded(const char *name)
 {
+       bool result = false;
        char buffer[128];
-       int err, len, i, midx = -1;
+       int len;
        FILE *fp;
 
-       if (!name)
-               return -EINVAL;
-
        fp = fopen("/proc/modules", "r");
        if (fp == NULL)
-               return -errno;
+               return false;
 
        len = strlen(name);
 
        while (fgets(buffer, sizeof(buffer), fp)) {
                if (strncmp(buffer, name, len) == 0 &&
                    len < sizeof(buffer) && buffer[len] == ' ') {
-                       smokey_trace("%s module already loaded", name);
-                       fclose(fp);
-                       return 0;
+                       result = true;
+                       break;
                }
        }
 
        fclose(fp);
 
+       return result;
+}
+
+#define SMOKEY_MOD_NUM       32
+static char *smokey_modules[SMOKEY_MOD_NUM];
+
+int smokey_modprobe(const char *name, bool silent)
+{
+       char buffer[128];
+       int err, i, midx = -1;
+
+       if (!name)
+               return -EINVAL;
+
+       if (module_loaded(name)) {
+               smokey_trace("%s module already loaded", name);
+               return 0;
+       }
+
        for (i = 0; i < SMOKEY_MOD_NUM; i++) {
                if (!smokey_modules[i]) {
                        midx = i;
@@ -350,7 +363,9 @@ int smokey_modprobe(const char *name, bool silent)
                return -EINVAL;
        }
 
-       smokey_modules[midx] = strdup(name);
+       if (!err && module_loaded(name))
+               smokey_modules[midx] = strdup(name);
+
        return err;
 }
 
-- 
2.31.1