Fix coverity false positives introduced by the post-2038 changes

Commit ca8bc9240a00 ("Add post-2038 timestamp support...") did things
like casting a 64-bit unsigned integer into a signed 32-bit integer
deliberately; but Coverity thinks this is a bug.  So mask off the bits
to make it clear this was deliberate.

Addresses-Coverity-Bug: 1596519
Addresses-Coverity-Bug: 1596515
Addresses-Coverity-Bug: 1596514
Addresses-Coverity-Bug: 1596513
Addresses-Coverity-Bug: 1596511
Addresses-Coverity-Bug: 1596509
Addresses-Coverity-Bug: 1596508
Addresses-Coverity-Bug: 1596504
Addresses-Coverity-Bug: 1596502
Addresses-Coverity-Bug: 1596501
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 9ecbb50..a325913 100644 (file)
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -584,7 +584,8 @@ static inline __u32 __encode_extra_time(time_t seconds, __u32 nsec)
        __u32 extra = 0;
 
 #if (SIZEOF_TIME_T > 4)
-       extra = ((seconds - (__s32)seconds) >> 32) & EXT4_EPOCH_MASK;
+       extra = ((seconds - (__s32)(seconds & 0xffffffff)) >> 32) &
+               EXT4_EPOCH_MASK;
 #endif
        return extra | (nsec << EXT4_EPOCH_BITS);
 }
@@ -610,7 +611,7 @@ static inline __u32 __decode_extra_nsec(__u32 extra)
 do {                                                                         \
        if (ext2fs_inode_includes(ext2fs_inode_actual_size(inode),            \
                                  field ## _extra)) {                         \
-               (inode)->field = (__s32)sec;                                  \
+               (inode)->field = (__s32)(sec & 0xfffffff);                    \
                ((struct ext2_inode_large *)(inode))->field ## _extra =       \
                        __encode_extra_time(sec, 0);                          \
        } else {                                                              \
@@ -627,7 +628,7 @@ static inline void __sb_set_tstamp(__u32 *lo, __u8 *hi, time_t seconds)
 {
        *lo = seconds & 0xffffffff;
 #if (SIZEOF_TIME_T > 4)
-       *hi = seconds >> 32;
+       *hi = (seconds >> 32) & EXT4_EPOCH_MASK;
 #else
        *hi = 0;
 #endif