From dc49cd769b5fa6b7e0114b051c34a849828a7603 Mon Sep 17 00:00:00 2001 From: "Shawn O. Pearce" Date: Tue, 6 Mar 2007 20:44:37 -0500 Subject: Cast 64 bit off_t to 32 bit size_t Some systems have sizeof(off_t) == 8 while sizeof(size_t) == 4. This implies that we are able to access and work on files whose maximum length is around 2^63-1 bytes, but we can only malloc or mmap somewhat less than 2^32-1 bytes of memory. On such a system an implicit conversion of off_t to size_t can cause the size_t to wrap, resulting in unexpected and exciting behavior. Right now we are working around all gcc warnings generated by the -Wshorten-64-to-32 option by passing the off_t through xsize_t(). In the future we should make xsize_t on such problematic platforms detect the wrapping and die if such a file is accessed. Signed-off-by: Shawn O. Pearce Signed-off-by: Junio C Hamano --- dir.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'dir.c') diff --git a/dir.c b/dir.c index 32b57f012..b48e19dc0 100644 --- a/dir.c +++ b/dir.c @@ -130,13 +130,13 @@ static int add_excludes_from_file_1(const char *fname, { struct stat st; int fd, i; - long size; + size_t size; char *buf, *entry; fd = open(fname, O_RDONLY); if (fd < 0 || fstat(fd, &st) < 0) goto err; - size = st.st_size; + size = xsize_t(st.st_size); if (size == 0) { close(fd); return 0; -- cgit v1.2.1