[OpenBIOS] [PATCH] grubfs: don't try to read a file beyond its end

[Aurelien Jarno]

Yaboot relies on the read function from openbios to stop reading at the
end of a file. This patch makes sure to not read beyond the end of the
file. This fixes the boot of debian-installer using a CD-ROM.

Signed-off-by: Aurelien Jarno

diff --git a/fs/grubfs/grubfs_fs.c b/fs/grubfs/grubfs_fs.c
index f172b75..588d677 100644
--- a/fs/grubfs/grubfs_fs.c
+++ b/fs/grubfs/grubfs_fs.c
@@ -161,6 +161,9 @@ grubfs_file_read( file_desc_t *fd, void *buf, size_t count )
    filepos=file->pos;
    filemax=file->len;

+	if (count > filemax - filepos)
+		count = filemax - filepos;
+
    ret=curfs->fsys->read_func(buf, count);

file->pos=filepos;