X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmdev.c;h=73a82314c3cf3ef572ffcdf7b697898c83c2c06f;hb=1449a2014a4e715a7a52b27caec528a9c802fa5f;hp=f6d4d8df00c103ef4ec7af8bf699b75a9f6352c6;hpb=271aa40a15be3d111f2016e24832a86657661cca;p=oweals%2Fbusybox.git

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index f6d4d8df0..73a82314c 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -16,6 +16,7 @@
 #include <string.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <unistd.h>
 #include <stdlib.h>
@@ -27,6 +28,13 @@
 
 #include <busybox.h>
 
+struct mdev_globals
+{
+	int root_major, root_minor;
+} mdev_globals;
+
+#define bbg mdev_globals
+
 /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
 static void make_device(char *path)
 {
@@ -35,23 +43,25 @@ static void make_device(char *path)
 	int mode = 0660;
 	uid_t uid = 0;
 	gid_t gid = 0;
+	char *temp = path + strlen(path);
 
-	RESERVE_CONFIG_BUFFER(temp, PATH_MAX);
+	/* Try to read major/minor string.  Note that the kernel puts \n after
+	 * the data, so we don't need to worry about null terminating the string
+	 * because sscanf() will stop at the first nondigit, which \n is.  We
+	 * also depend on path having writeable space after it. */
 
-	/* Try to read major/minor string */
-
-	snprintf(temp, PATH_MAX, "%s/dev", path);
-	fd = open(temp, O_RDONLY);
-	len = read(fd, temp, PATH_MAX-1);
+	strcat(path, "/dev");
+	fd = open(path, O_RDONLY);
+	len = read(fd, temp + 1, 64);
+	*temp++ = 0;
 	close(fd);
-	if (len < 1) goto end;
+	if (len < 1) return;
 
 	/* Determine device name, type, major and minor */
 
 	device_name = strrchr(path, '/') + 1;
-	type = strncmp(path+5, "block/", 6) ? S_IFCHR : S_IFBLK;
-	if (sscanf(temp, "%d:%d", &major, &minor) != 2)
-		goto end;
+	type = path[5]=='c' ? S_IFCHR : S_IFBLK;
+	if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
 
 	/* If we have a config file, look up permissions for this device */
 
@@ -164,15 +174,14 @@ found_device:
 		}
 	}
 
-	sprintf(temp, "%s/%s", DEV_PATH, device_name);
 	umask(0);
-	if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
-		bb_perror_msg_and_die("mknod %s failed", temp);
-
-	if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid);
+	if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+		bb_perror_msg_and_die("mknod %s failed", device_name);
 
-end:
-	RELEASE_CONFIG_BUFFER(temp);
+	if (major==bbg.root_major && minor==bbg.root_minor)
+		symlink(device_name, "root");
+	
+	if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
 }
 
 /* Recursive search of /sys/block or /sys/class.  path must be a writeable
@@ -188,17 +197,18 @@ static void find_dev(char *path)
 		return;
 
 	while ((entry = readdir(dir)) != NULL) {
+		struct stat st;
 
 		/* Skip "." and ".." (also skips hidden files, which is ok) */
 
 		if (entry->d_name[0] == '.')
 			continue;
 
-		if (entry->d_type == DT_DIR) {
-			snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
-			find_dev(path);
-			path[len] = 0;
-		}
+		// uClibc doesn't fill out entry->d_type reliably. so we use lstat().
+
+		snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
+		if (!lstat(path, &st) && S_ISDIR(st.st_mode)) find_dev(path);
+		path[len] = 0;
 
 		/* If there's a dev entry, mknod it */
 
@@ -214,9 +224,16 @@ int mdev_main(int argc, char *argv[])
 	char *env_path;
 	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
 
+	bb_xchdir(DEV_PATH);
+
 	/* Scan */
 
 	if (argc == 2 && !strcmp(argv[1],"-s")) {
+		struct stat st;
+
+		stat("/", &st);  // If this fails, we have bigger problems.
+		bbg.root_major=major(st.st_dev);
+		bbg.root_minor=minor(st.st_dev);
 		strcpy(temp,"/sys/block");
 		find_dev(temp);
 		strcpy(temp,"/sys/class");
@@ -234,8 +251,7 @@ int mdev_main(int argc, char *argv[])
 			sprintf(temp, "/sys%s", env_path);
 			make_device(temp);
 		} else if (!strcmp(action, "remove")) {
-			sprintf(temp, "%s/%s", DEV_PATH, strrchr(env_path, '/') + 1);
-			unlink(temp);
+			unlink(strrchr(env_path, '/') + 1);
 		}
 	}