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 --- diff.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'diff.c') diff --git a/diff.c b/diff.c index e225de2305..8f7a7d1108 100644 --- a/diff.c +++ b/diff.c @@ -1399,7 +1399,7 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only) return err; } } - s->size = st.st_size; + s->size = xsize_t(st.st_size); if (!s->size) goto empty; if (size_only) @@ -1515,12 +1515,13 @@ static void prepare_temp_file(const char *name, if (S_ISLNK(st.st_mode)) { int ret; char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */ + size_t sz = xsize_t(st.st_size); if (sizeof(buf) <= st.st_size) die("symlink too long: %s", name); - ret = readlink(name, buf, st.st_size); + ret = readlink(name, buf, sz); if (ret < 0) die("readlink(%s)", name); - prep_temp_blob(temp, buf, st.st_size, + prep_temp_blob(temp, buf, sz, (one->sha1_valid ? one->sha1 : null_sha1), (one->sha1_valid ? @@ -2138,7 +2139,7 @@ static int parse_num(const char **cp_p) /* user says num divided by scale and we say internally that * is MAX_SCORE * num / scale. */ - return (num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale); + return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale)); } int diff_scoreopt_parse(const char *opt) -- cgit v1.2.3