dd: silence warning on 64-bit systems

On 64-bit systems size_t may be larger than unsigned long, resulting in
a warning when -1L is cast to size_t.

There's little to be gained from allowing obs and ibs take values
larger than will fit in a signed long as the subsequent malloc will
probably fail.  Limit their range to ULONG_MAX/2.

Signed-off-by: Ron Yorston <rmy@pobox.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/coreutils/dd.c b/coreutils/dd.c
index 9ea4897d5..14d270a1e 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -347,11 +347,11 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
 #if ENABLE_FEATURE_DD_IBS_OBS
                 if (what == OP_ibs) {
                         /* Must fit into positive ssize_t */
-                        ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
+                        ibs = xatoul_range_sfx(val, 1, ULONG_MAX/2, cwbkMG_suffixes);
                         /*continue;*/
                 }
                 if (what == OP_obs) {
-                        obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
+                        obs = xatoul_range_sfx(val, 1, ULONG_MAX/2, cwbkMG_suffixes);
                         /*continue;*/
                 }
                 if (what == OP_conv) {
@@ -364,7 +364,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                 }
 #endif
                 if (what == OP_bs) {
-                        ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
+                        ibs = xatoul_range_sfx(val, 1, ULONG_MAX/2, cwbkMG_suffixes);
                         obs = ibs;
                         /*continue;*/
                 }