modprobe: pick up module options from /proc/cmdline too

Based on patch by Ozan Çağlayan (ozan AT pardus.org.tr)

function                                             old     new   delta
parse_and_add_kcmdline_module_options                  -     149    +149
do_modprobe                                          357     365      +8

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

1 files changed, 34 insertions, 0 deletions

diff --git a/modutils/modprobe.c b/modutils/modprobe.c
index 292f2df22..0cfb365b6 100644
--- a/modutils/modprobe.c
+++ b/modutils/modprobe.c
@@ -228,6 +228,39 @@ static const char *humanly_readable_name(struct module_entry *m)
         return m->probed_name ? m->probed_name : m->modname;
 }
 
+static char *parse_and_add_kcmdline_module_options(char *options, const char *modulename)
+{
+        /* defined in arch/<architecture>/include/asm/setup.h
+         * (maximum is 2048 for IA64 and SPARC) */
+        char kcmdline_buf[2048];
+        char *kcmdline;
+        char *kptr;
+        int len;
+
+        len = open_read_close("/proc/cmdline", kcmdline_buf, 2047);
+        if (len <= 0)
+                return options;
+        kcmdline_buf[len] = '\0';
+
+        len = strlen(modulename);
+        kcmdline = kcmdline_buf;
+        while ((kptr = strsep(&kcmdline, "\n\t ")) != NULL) {
+                if (strncmp(modulename, kptr, len) != 0)
+                        continue;
+                kptr += len;
+                if (*kptr != '.')
+                        continue;
+                /* It is "modulename.xxxx" */
+                kptr++;
+                if (strchr(kptr, '=') != NULL) {
+                        /* It is "modulename.opt=[val]" */
+                        options = gather_options_str(options, kptr);
+                }
+        }
+
+        return options;
+}
+
 /* Return: similar to bb_init_module:
  * 0 on success,
  * -errno on open/read error,
@@ -288,6 +321,7 @@ static int do_modprobe(struct module_entry *m)
 
                 options = m2->options;
                 m2->options = NULL;
+                options = parse_and_add_kcmdline_module_options(options, m2->modname);
                 if (m == m2)
                         options = gather_options_str(options, G.cmdline_mopts);
                 rc = bb_init_module(fn, options);