kmodloader: cleanup duplicated mmap() code

Refactor code from get_module_info() and print_modinfo() to locate modinfo
data, call mmap() and handle errors, into new mmap_modinfo(). This drops
~30 source lines and shrinks the compressed binary ~100 bytes.

Signed-off-by: Tony Ambardar <itugrok@yahoo.com>

diff --git a/kmodloader.c b/kmodloader.c
index 49327a9d0a4f03ae81fdb53be0cf625d9e39c1d5..b4ef52a519ea01cafbf37a53f42dc583c76e5113 100644 (file)
--- a/kmodloader.c
+++ b/kmodloader.c
@@ -364,23 +364,18 @@ out:
        return rv;
 }
 
-static struct module* get_module_info(const char *module, const char *name)
+static char *mmap_modinfo(const char *module, const char *name, struct stat *s, unsigned int *offset, unsigned int *size)
 {
        const bool is_builtin = (module == NULL);
-       unsigned int offset, size;
-       char *map = MAP_FAILED, *strings, *dep = NULL;
-       const char **aliases = NULL;
-       const char **aliasesr;
        const char *mpath = NULL;
+       char *map = MAP_FAILED;
        char path[350], **f;
-       int fd = -1, naliases = 0;
-       struct module *m = NULL;
-       struct stat s;
+       int fd = -1;
 
        if (is_builtin)
                for (f = module_folders; *f; f++) {
                        snprintf(path, sizeof(path), "%s%s", *f, MOD_BUILTIN_MODINFO);
-                       if (!stat(path, &s) && S_ISREG(s.st_mode)) {
+                       if (!stat(path, s) && S_ISREG(s->st_mode)) {
                                mpath = path;
                                break;
                        }
@@ -399,25 +394,47 @@ static struct module* get_module_info(const char *module, const char *name)
                goto out;
        }
 
-       if (fstat(fd, &s) == -1) {
+       if (fstat(fd, s) == -1) {
                ULOG_ERR("failed to stat %s\n", mpath);
                goto out;
        }
 
-       map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+       map = mmap(NULL, s->st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        if (map == MAP_FAILED) {
                ULOG_ERR("failed to mmap %s\n", mpath);
                goto out;
        }
 
        if (is_builtin) {
-               offset = 0;
-               size = s.st_size;
-       } else if (elf_find_section(map, ".modinfo", &offset, &size)) {
+               *offset = 0;
+               *size = s->st_size;
+       } else if (elf_find_section(map, ".modinfo", offset, size)) {
                ULOG_ERR("failed to load the .modinfo section from %s\n", mpath);
-               goto out;
+               munmap(map, s->st_size);
+               map = MAP_FAILED;
        }
 
+out:
+       if (fd >= 0)
+               close(fd);
+       return map;
+}
+
+static struct module* get_module_info(const char *module, const char *name)
+{
+       const bool is_builtin = (module == NULL);
+       unsigned int offset, size;
+       char *map, *strings, *dep = NULL;
+       const char **aliases = NULL;
+       const char **aliasesr;
+       int naliases = 0;
+       struct module *m = NULL;
+       struct stat s;
+
+       map = mmap_modinfo(module, name, &s, &offset, &size);
+       if (map == MAP_FAILED)
+               goto out;
+
        strings = map + offset;
        while (true) {
                char *sep;
@@ -467,9 +484,6 @@ out:
        if (map != MAP_FAILED)
                munmap(map, s.st_size);
 
-       if (fd >= 0)
-               close(fd);
-
        free(aliases);
 
        return m;
@@ -590,52 +604,15 @@ static int print_modinfo(const struct module *m)
        unsigned int offset, size;
        struct param *p;
        struct stat s;
-       char *map = MAP_FAILED, *strings, **f;
-       char path[350], *mpath = NULL;
-       int fd, rv = -1;
+       char *map, *strings, *mpath;
+       int rv = -1;
 
        LIST_HEAD(params);
 
-       if (is_builtin)
-               for (f = module_folders; *f; f++) {
-                       snprintf(path, sizeof(path), "%s%s", *f, MOD_BUILTIN_MODINFO);
-                       if (!stat(path, &s) && S_ISREG(s.st_mode)) {
-                               mpath = path;
-                               break;
-                       }
-               }
-       else
-               mpath = get_module_path(m->name);
-
-       if (!mpath) {
-               ULOG_ERR("cannot find modinfo path of module - %s\n", m->name);
-               return -1;
-       }
-
-       fd = open(mpath, O_RDONLY);
-       if (fd < 0) {
-               ULOG_ERR("failed to open %s\n", mpath);
-               goto out;
-       }
-
-       if (fstat(fd, &s) == -1) {
-               ULOG_ERR("failed to stat %s\n", mpath);
-               goto out;
-       }
-
-       map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
-       if (map == MAP_FAILED) {
-               ULOG_ERR("failed to mmap %s\n", mpath);
+       mpath = get_module_path(m->name);
+       map = mmap_modinfo(mpath, m->name, &s, &offset, &size);
+       if (map == MAP_FAILED)
                goto out;
-       }
-
-       if (is_builtin) {
-               offset = 0;
-               size = s.st_size;
-       } else if (elf_find_section(map, ".modinfo", &offset, &size)) {
-               ULOG_ERR("failed to load the .modinfo section from %s\n", mpath);
-               goto out;
-       }
 
        strings = map + offset;
        if (is_builtin)
@@ -720,9 +697,6 @@ out:
        if (map != MAP_FAILED)
                munmap(map, s.st_size);
 
-       if (fd >= 0)
-               close(fd);
-
        return rv;
 }