mdev: change subsystem syntax from /subsystem to subsystem/devname

1 files changed, 15 insertions, 13 deletions

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 2451cca05..f965b6069 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -90,21 +90,24 @@ static void make_device(char *path, int delete)
         device_name = bb_basename(path);
         /* http://kernel.org/doc/pending/hotplug.txt says that only
          * "/sys/block/..." is for block devices. "/sys/bus" etc is not.
-         * But since 2.6.25 block devices are also in /sys/class/block.
-         * We use strstr("/block/") to forestall future surprises. */
+         * But since 2.6.25 block devices are also in /sys/class/block,
+         * we use strstr("/block/") to forestall future surprises. */
         type = S_IFCHR;
         if (strstr(path, "/block/"))
                 type = S_IFBLK;
 
+        /* Make path point to subsystem/device_name */
+        path += sizeof("/sys/class/") - 1;
+
 #if !ENABLE_FEATURE_MDEV_CONF
         mode = 0660;
 #else
         /* If we have config file, look up user settings */
         parser = config_open2("/etc/mdev.conf", fopen_for_read);
         while (1) {
-                regmatch_t off[1 + 9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
+                regmatch_t off[1 + 9 * ENABLE_FEATURE_MDEV_RENAME_REGEXP];
                 int keep_matching;
-                char *val;
+                char *val, *name;
                 struct bb_uidgid_t ugid;
                 char *tokens[4];
 # if ENABLE_FEATURE_MDEV_EXEC
@@ -128,6 +131,10 @@ static void make_device(char *path, int delete)
                 keep_matching = ('-' == val[0]);
                 val += keep_matching; /* swallow leading dash */
 
+                /* Match against either subsystem/device_name
+                 * or device_name alone */
+                name = strchr(val, '/') ? path : (char *) device_name;
+
                 /* Fields: regex uid:gid mode [alias] [cmd] */
 
                 /* 1st field: @<numeric maj,min>... */
@@ -149,15 +156,10 @@ static void make_device(char *path, int delete)
                 } else { /* ... or regex to match device name */
                         regex_t match;
                         int result;
-                        const char *dev_name_or_subsystem = device_name;
-                        if ('/' == val[0] && subsystem) {
-                                dev_name_or_subsystem = subsystem;
-                                val++;
-                        }
 
                         /* Is this it? */
                         xregcomp(&match, val, REG_EXTENDED);
-                        result = regexec(&match, dev_name_or_subsystem, ARRAY_SIZE(off), off, 0);
+                        result = regexec(&match, name, ARRAY_SIZE(off), off, 0);
                         regfree(&match);
 
                         //bb_error_msg("matches:");
@@ -171,7 +173,7 @@ static void make_device(char *path, int delete)
                         /* If not this device, skip rest of line */
                         /* (regexec returns whole pattern as "range" 0) */
                         if (result || off[0].rm_so
-                         || ((int)off[0].rm_eo != (int)strlen(dev_name_or_subsystem))
+                         || ((int)off[0].rm_eo != (int)strlen(name))
                         ) {
                                 continue; /* this line doesn't match */
                         }
@@ -214,7 +216,7 @@ static void make_device(char *path, int delete)
                                 if (*s++ == '%')
                                         n++;
 
-                        p = alias = xzalloc(strlen(a) + n * strlen(device_name));
+                        p = alias = xzalloc(strlen(a) + n * strlen(name));
                         s = a + 1;
                         while (*s) {
                                 *p = *s;
@@ -222,7 +224,7 @@ static void make_device(char *path, int delete)
                                         i = (s[1] - '0');
                                         if (i <= 9 && off[i].rm_so >= 0) {
                                                 n = off[i].rm_eo - off[i].rm_so;
-                                                strncpy(p, device_name + off[i].rm_so, n);
+                                                strncpy(p, name + off[i].rm_so, n);
                                                 p += n - 1;
                                                 s++;
                                         }