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 --- combine-diff.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'combine-diff.c') diff --git a/combine-diff.c b/combine-diff.c index 6d928f282a..3a9b32f6b8 100644 --- a/combine-diff.c +++ b/combine-diff.c @@ -684,7 +684,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, goto deleted_file; if (S_ISLNK(st.st_mode)) { - size_t len = st.st_size; + size_t len = xsize_t(st.st_size); result_size = len; result = xmalloc(len + 1); if (result_size != readlink(elem->path, result, len)) { @@ -697,7 +697,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent, } else if (0 <= (fd = open(elem->path, O_RDONLY)) && !fstat(fd, &st)) { - size_t len = st.st_size; + size_t len = xsize_t(st.st_size); size_t sz = 0; int is_file, i; -- cgit v1.2.1