From 190f4939222b8c07cd62a20e1ce0c7a97fffde99 Mon Sep 17 00:00:00 2001 From: Jeff Dike Date: Fri, 30 Jun 2006 01:55:55 -0700 Subject: [PATCH] uml: fix off-by-one bug in VM file creation Fix an off-by-one bug in temp file creation. Seeking to the desired length and writing a byte resulted in the file being one byte longer than expected. Signed-off-by: Jeff Dike Cc: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/um/os-Linux/mem.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c index d24d1a96052..560c8063c77 100644 --- a/arch/um/os-Linux/mem.c +++ b/arch/um/os-Linux/mem.c @@ -210,8 +210,11 @@ int create_tmp_file(unsigned long long len) exit(1); } - if (lseek64(fd, len, SEEK_SET) < 0) { - perror("os_seek_file"); + /* Seek to len - 1 because writing a character there will + * increase the file size by one byte, to the desired length. + */ + if (lseek64(fd, len - 1, SEEK_SET) < 0) { + perror("os_seek_file"); exit(1); } -- cgit v1.2.3