depmod: simple memory optimization

function                                             old     new   delta
filename2modname                                      67      86     +19
parse_module                                         374     351     -23

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/modutils/depmod.c b/modutils/depmod.c
index a41b3e44097a27a6d88902577d0ebb35c8c0c3b2..37a8482d92c8d43101f2d958d5c2413e34a88947 100644 (file)
--- a/modutils/depmod.c
+++ b/modutils/depmod.c
@@ -33,7 +33,6 @@ typedef struct module_info {
 static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARAM,
                                void *data, int depth UNUSED_PARAM)
 {
-       char modname[MODULE_NAME_LEN];
        module_info **first = (module_info **) data;
        char *image, *ptr;
        module_info *info;
@@ -51,11 +50,10 @@ static int FAST_FUNC parse_module(const char *fname, struct stat *sb UNUSED_PARA
 
        info->dnext = info->dprev = info;
        info->name = xstrdup(fname + 2); /* skip "./" */
-       info->modname = xstrdup(
-               filename2modname(
+       info->modname = filename2modname(
                        bb_get_last_path_component_nostrip(fname),
-                       modname
-       ));
+                       NULL
+       );
        for (ptr = image; ptr < image + len - 10; ptr++) {
                if (strncmp(ptr, "depends=", 8) == 0) {
                        char *u;
@@ -250,11 +248,12 @@ int depmod_main(int argc UNUSED_PARAM, char **argv)
                const char *fname = bb_basename(m->name);
                filename2modname(fname, modname);
                while (m->aliases) {
-                       /* Last word can well be m->modname instead,
-                        * but depmod from module-init-tools 3.4
-                        * uses module basename, i.e., no s/-/_/g.
-                        * (pathname and .ko.* are still stripped)
-                        * Mimicking that... */
+                       /*
+                        * Last word used to be a basename
+                        * (filename with path and .ko.* stripped)
+                        * at the time of module-init-tools 3.4.
+                        * kmod v.12 uses module name, i.e., s/-/_/g.
+                        */
                        printf("alias %s %s\n",
                                (char*)llist_pop(&m->aliases),
                                modname);

diff --git a/modutils/modutils.c b/modutils/modutils.c
index ff79d3fac9c80f17fe9abf8255e37852c651eb63..84300d93158aae58b4ed24903e323d223b687629 100644 (file)
--- a/modutils/modutils.c
+++ b/modutils/modutils.c
@@ -47,13 +47,14 @@ int FAST_FUNC string_to_llist(char *string, llist_t **llist, const char *delim)
 
 char* FAST_FUNC filename2modname(const char *filename, char *modname)
 {
+       char local_modname[MODULE_NAME_LEN];
        int i;
        const char *from;
 
        if (filename == NULL)
                return NULL;
        if (modname == NULL)
-               modname = xmalloc(MODULE_NAME_LEN);
+               modname = local_modname;
        // Disabled since otherwise "modprobe dir/name" would work
        // as if it is "modprobe name". It is unclear why
        // 'basenamization' was here in the first place.
@@ -63,6 +64,9 @@ char* FAST_FUNC filename2modname(const char *filename, char *modname)
                modname[i] = (from[i] == '-') ? '_' : from[i];
        modname[i] = '\0';
 
+       if (modname == local_modname)
+               return xstrdup(modname);
+
        return modname;
 }