syslinux: Correctly handle the case of installing into the root

When installing into the root directory, we should logically search
the root directory first.  Thus, we need to make sure the current path
is "/" not "".

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/linux/syslinux.c b/linux/syslinux.c
index d8b31491..d6a5d834 100644
--- a/linux/syslinux.c
+++ b/linux/syslinux.c
@@ -276,7 +276,7 @@ int main(int argc, char *argv[])
     char mntname[128];
     char *ldlinux_name;
     char *ldlinux_path;
-    const char *subdir;
+    char *subdir;
     uint32_t *sectors = NULL;
     int ldlinux_sectors = (boot_image_len + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
     const char *errmsg;
@@ -288,7 +288,12 @@ int main(int argc, char *argv[])
     umask(077);
     parse_options(argc, argv, MODE_SYSLINUX);
 
-    subdir = opt.directory;
+    asprintf(&subdir, "%s%s",
+	     opt.directory[0] == '/' ? "" : "/", opt.directory);
+    if (!subdir) {
+	perror(program);
+	exit(1);
+    }
 
     if (!opt.device)
 	usage(EX_USAGE, MODE_SYSLINUX);