[PATCH 2/2] Use 64bit type for filesystem timestamp

[Carlos Maiolino <cmaiolino@redhat.com>]

Some filesystems nowadays uses 64bit timestamps for timestamps, so,
update grub_dirhook_info struct to use an int64 type to store mtime.
This also updates grub_unixtime2datetime() to receive a 64-bit timestamp
argument and do 64bit-safe divisions.

Both changes enables grub to support dates beyond y2038.

Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
---
 grub-core/fs/affs.c          |  2 +-
 grub-core/fs/ext2.c          |  2 +-
 grub-core/fs/fat.c           |  4 ++--
 grub-core/fs/hfs.c           |  2 +-
 grub-core/fs/hfsplus.c       |  2 +-
 grub-core/fs/iso9660.c       |  6 +++---
 grub-core/fs/nilfs2.c        |  2 +-
 grub-core/fs/squash4.c       |  2 +-
 grub-core/fs/ufs.c           |  2 +-
 grub-core/fs/zfs/zfs.c       |  2 +-
 grub-core/lib/datetime.c     | 15 ++++++++++++---
 grub-core/net/bootp.c        |  2 +-
 grub-core/normal/misc.c      |  2 +-
 grub-core/tests/sleep_test.c |  4 ++--
 include/grub/datetime.h      |  4 ++--
 include/grub/fs.h            |  4 ++--
 16 files changed, 33 insertions(+), 24 deletions(-)

diff --git a/grub-core/fs/affs.c b/grub-core/fs/affs.c
index 230e26af0..cafcd0fba 100644
--- a/grub-core/fs/affs.c
+++ b/grub-core/fs/affs.c
@@ -641,7 +641,7 @@ grub_affs_label (grub_device_t device, char **label)
 }
 
 static grub_err_t
-grub_affs_mtime (grub_device_t device, grub_int32_t *t)
+grub_affs_mtime (grub_device_t device, grub_int64_t *t)
 {
   struct grub_affs_data *data;
   grub_disk_t disk = device->disk;
diff --git a/grub-core/fs/ext2.c b/grub-core/fs/ext2.c
index 848bf939d..e7dd78e66 100644
--- a/grub-core/fs/ext2.c
+++ b/grub-core/fs/ext2.c
@@ -1055,7 +1055,7 @@ grub_ext2_uuid (grub_device_t device, char **uuid)
 
 /* Get mtime.  */
 static grub_err_t
-grub_ext2_mtime (grub_device_t device, grub_int32_t *tm)
+grub_ext2_mtime (grub_device_t device, grub_int64_t *tm)
 {
   struct grub_ext2_data *data;
   grub_disk_t disk = device->disk;
diff --git a/grub-core/fs/fat.c b/grub-core/fs/fat.c
index 7f775a170..dd82e4ee3 100644
--- a/grub-core/fs/fat.c
+++ b/grub-core/fs/fat.c
@@ -737,7 +737,7 @@ grub_fat_iterate_dir_next (grub_fshelp_node_t node,
  * https://docs.microsoft.com/en-us/windows/win32/fileio/exfat-specification
  */
 static int
-grub_exfat_timestamp (grub_uint32_t field, grub_uint8_t msec, grub_int32_t *nix) {
+grub_exfat_timestamp (grub_uint32_t field, grub_uint8_t msec, grub_int64_t *nix) {
   struct grub_datetime datetime = {
     .year   = (field >> 25) + 1980,
     .month  = (field & 0x01E00000) >> 21,
@@ -891,7 +891,7 @@ grub_fat_iterate_dir_next (grub_fshelp_node_t node,
  * https://www.ecma-international.org/publications/files/ECMA-ST/Ecma-107.pdf
  */
 static int
-grub_fat_timestamp (grub_uint16_t time, grub_uint16_t date, grub_int32_t *nix) {
+grub_fat_timestamp (grub_uint16_t time, grub_uint16_t date, grub_int64_t *nix) {
   struct grub_datetime datetime = {
     .year   = (date >> 9) + 1980,
     .month  = (date & 0x01E0) >> 5,
diff --git a/grub-core/fs/hfs.c b/grub-core/fs/hfs.c
index 9a5b7bbe9..f419965d1 100644
--- a/grub-core/fs/hfs.c
+++ b/grub-core/fs/hfs.c
@@ -1374,7 +1374,7 @@ grub_hfs_label (grub_device_t device, char **label)
 }
 
 static grub_err_t
-grub_hfs_mtime (grub_device_t device, grub_int32_t *tm)
+grub_hfs_mtime (grub_device_t device, grub_int64_t *tm)
 {
   struct grub_hfs_data *data;
 
diff --git a/grub-core/fs/hfsplus.c b/grub-core/fs/hfsplus.c
index 2a69055c7..19c7b3367 100644
--- a/grub-core/fs/hfsplus.c
+++ b/grub-core/fs/hfsplus.c
@@ -1083,7 +1083,7 @@ grub_hfsplus_label (grub_device_t device, char **label)
 
 /* Get mtime.  */
 static grub_err_t
-grub_hfsplus_mtime (grub_device_t device, grub_int32_t *tm)
+grub_hfsplus_mtime (grub_device_t device, grub_int64_t *tm)
 {
   struct grub_hfsplus_data *data;
   grub_disk_t disk = device->disk;
diff --git a/grub-core/fs/iso9660.c b/grub-core/fs/iso9660.c
index 5ec4433b8..ac011950a 100644
--- a/grub-core/fs/iso9660.c
+++ b/grub-core/fs/iso9660.c
@@ -178,7 +178,7 @@ static grub_dl_t my_mod;
 \f
 
 static grub_err_t
-iso9660_to_unixtime (const struct grub_iso9660_date *i, grub_int32_t *nix)
+iso9660_to_unixtime (const struct grub_iso9660_date *i, grub_int64_t *nix)
 {
   struct grub_datetime datetime;
   
@@ -206,7 +206,7 @@ iso9660_to_unixtime (const struct grub_iso9660_date *i, grub_int32_t *nix)
 }
 
 static int
-iso9660_to_unixtime2 (const struct grub_iso9660_date2 *i, grub_int32_t *nix)
+iso9660_to_unixtime2 (const struct grub_iso9660_date2 *i, grub_int64_t *nix)
 {
   struct grub_datetime datetime;
 
@@ -1107,7 +1107,7 @@ grub_iso9660_uuid (grub_device_t device, char **uuid)
 
 /* Get writing time of filesystem. */
 static grub_err_t 
-grub_iso9660_mtime (grub_device_t device, grub_int32_t *timebuf)
+grub_iso9660_mtime (grub_device_t device, grub_int64_t *timebuf)
 {
   struct grub_iso9660_data *data;
   grub_disk_t disk = device->disk;
diff --git a/grub-core/fs/nilfs2.c b/grub-core/fs/nilfs2.c
index 9b76982b3..3c248a910 100644
--- a/grub-core/fs/nilfs2.c
+++ b/grub-core/fs/nilfs2.c
@@ -1186,7 +1186,7 @@ grub_nilfs2_uuid (grub_device_t device, char **uuid)
 
 /* Get mtime.  */
 static grub_err_t
-grub_nilfs2_mtime (grub_device_t device, grub_int32_t * tm)
+grub_nilfs2_mtime (grub_device_t device, grub_int64_t * tm)
 {
   struct grub_nilfs2_data *data;
   grub_disk_t disk = device->disk;
diff --git a/grub-core/fs/squash4.c b/grub-core/fs/squash4.c
index a5f35c10e..6dd731e23 100644
--- a/grub-core/fs/squash4.c
+++ b/grub-core/fs/squash4.c
@@ -1003,7 +1003,7 @@ grub_squash_close (grub_file_t file)
 }
 
 static grub_err_t
-grub_squash_mtime (grub_device_t dev, grub_int32_t *tm)
+grub_squash_mtime (grub_device_t dev, grub_int64_t *tm)
 {
   struct grub_squash_data *data = 0;
 
diff --git a/grub-core/fs/ufs.c b/grub-core/fs/ufs.c
index fca46baa1..34a698b71 100644
--- a/grub-core/fs/ufs.c
+++ b/grub-core/fs/ufs.c
@@ -837,7 +837,7 @@ grub_ufs_uuid (grub_device_t device, char **uuid)
 
 /* Get mtime.  */
 static grub_err_t
-grub_ufs_mtime (grub_device_t device, grub_int32_t *tm)
+grub_ufs_mtime (grub_device_t device, grub_int64_t *tm)
 {
   struct grub_ufs_data *data = 0;
 
diff --git a/grub-core/fs/zfs/zfs.c b/grub-core/fs/zfs/zfs.c
index f9e755197..cf4d2ab18 100644
--- a/grub-core/fs/zfs/zfs.c
+++ b/grub-core/fs/zfs/zfs.c
@@ -3771,7 +3771,7 @@ zfs_uuid (grub_device_t device, char **uuid)
 }
 
 static grub_err_t 
-zfs_mtime (grub_device_t device, grub_int32_t *mt)
+zfs_mtime (grub_device_t device, grub_int64_t *mt)
 {
   struct grub_zfs_data *data;
   grub_zfs_endian_t ub_endian = GRUB_ZFS_UNKNOWN_ENDIAN;
diff --git a/grub-core/lib/datetime.c b/grub-core/lib/datetime.c
index 95b8c9ff5..3e84fa1db 100644
--- a/grub-core/lib/datetime.c
+++ b/grub-core/lib/datetime.c
@@ -19,6 +19,7 @@
 
 #include <grub/datetime.h>
 #include <grub/i18n.h>
+#include <grub/misc.h>
 
 static const char *const grub_weekday_names[] =
 {
@@ -60,9 +61,10 @@ grub_get_weekday_name (struct grub_datetime *datetime)
 
 
 void
-grub_unixtime2datetime (grub_int32_t nix, struct grub_datetime *datetime)
+grub_unixtime2datetime (grub_int64_t nix, struct grub_datetime *datetime)
 {
   int i;
+  grub_uint64_t rem;
   grub_uint8_t months[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
   /* In the period of validity of unixtime all years divisible by 4
      are bissextile*/
@@ -75,9 +77,16 @@ grub_unixtime2datetime (grub_int32_t nix, struct grub_datetime *datetime)
   unsigned secs_in_day;
   /* Transform C divisions and modulos to mathematical ones */
   if (nix < 0)
-    days_epoch = -(((unsigned) (SECPERDAY-nix-1)) / SECPERDAY);
+    /*
+     * the division here shouldn't be larger than INT_MAX,
+     * so, it's safe to store the result back in an int
+     */
+    days_epoch = -(grub_divmod64(((grub_int64_t)(SECPERDAY) - nix - 1),
+			        SECPERDAY,
+				&rem));
   else
-    days_epoch = ((unsigned) nix) / SECPERDAY;
+    days_epoch = grub_divmod64(nix, SECPERDAY, &rem);
+
   secs_in_day = nix - days_epoch * SECPERDAY;
   days = days_epoch + 69 * DAYSPERYEAR + 17;
 
diff --git a/grub-core/net/bootp.c b/grub-core/net/bootp.c
index e33be51f8..6fb562702 100644
--- a/grub-core/net/bootp.c
+++ b/grub-core/net/bootp.c
@@ -468,7 +468,7 @@ send_dhcp_packet (struct grub_net_network_level_interface *iface)
   grub_err_t err;
   struct grub_net_bootp_packet *pack;
   struct grub_datetime date;
-  grub_int32_t t = 0;
+  grub_int64_t t = 0;
   struct grub_net_buff *nb;
   struct udphdr *udph;
   grub_net_network_level_address_t target;
diff --git a/grub-core/normal/misc.c b/grub-core/normal/misc.c
index 8bb6da31f..f7e9e3ac4 100644
--- a/grub-core/normal/misc.c
+++ b/grub-core/normal/misc.c
@@ -136,7 +136,7 @@ grub_normal_print_device_info (const char *name)
 	    }
 	  if (fs->fs_mtime)
 	    {
-	      grub_int32_t tm;
+	      grub_int64_t tm;
 	      struct grub_datetime datetime;
 	      (fs->fs_mtime) (dev, &tm);
 	      if (grub_errno == GRUB_ERR_NONE)
diff --git a/grub-core/tests/sleep_test.c b/grub-core/tests/sleep_test.c
index 3d11c717c..63f671316 100644
--- a/grub-core/tests/sleep_test.c
+++ b/grub-core/tests/sleep_test.c
@@ -32,7 +32,7 @@ static void
 sleep_test (void)
 {
   struct grub_datetime st, en;
-  grub_int32_t stu = 0, enu = 0;
+  grub_int64_t stu = 0, enu = 0;
   int is_delayok;
   grub_test_assert (!grub_get_datetime (&st), "Couldn't retrieve start time");
   grub_millisleep (10000);
@@ -45,7 +45,7 @@ sleep_test (void)
   if (enu - stu >= 15 && enu - stu <= 17)
     is_delayok = 1;
 #endif
-  grub_test_assert (is_delayok, "Interval out of range: %d", enu-stu);
+  grub_test_assert (is_delayok, "Interval out of range: %lld", enu-stu);
 
 }
 
diff --git a/include/grub/datetime.h b/include/grub/datetime.h
index fef281404..23ae0791c 100644
--- a/include/grub/datetime.h
+++ b/include/grub/datetime.h
@@ -48,11 +48,11 @@ grub_err_t grub_set_datetime (struct grub_datetime *datetime);
 int grub_get_weekday (struct grub_datetime *datetime);
 const char *grub_get_weekday_name (struct grub_datetime *datetime);
 
-void grub_unixtime2datetime (grub_int32_t nix,
+void grub_unixtime2datetime (grub_int64_t nix,
 			     struct grub_datetime *datetime);
 
 static inline int
-grub_datetime2unixtime (const struct grub_datetime *datetime, grub_int32_t *nix)
+grub_datetime2unixtime (const struct grub_datetime *datetime, grub_int64_t *nix)
 {
   grub_int32_t ret;
   int y4, ay;
diff --git a/include/grub/fs.h b/include/grub/fs.h
index 302e48d4b..026bc3bb8 100644
--- a/include/grub/fs.h
+++ b/include/grub/fs.h
@@ -39,7 +39,7 @@ struct grub_dirhook_info
   unsigned mtimeset:1;
   unsigned case_insensitive:1;
   unsigned inodeset:1;
-  grub_int32_t mtime;
+  grub_int64_t mtime;
   grub_uint64_t inode;
 };
 
@@ -81,7 +81,7 @@ struct grub_fs
   grub_err_t (*fs_uuid) (grub_device_t device, char **uuid);
 
   /* Get writing time of filesystem. */
-  grub_err_t (*fs_mtime) (grub_device_t device, grub_int32_t *timebuf);
+  grub_err_t (*fs_mtime) (grub_device_t device, grub_int64_t *timebuf);
 
 #ifdef GRUB_UTIL
   /* Determine sectors available for embedding.  */
-- 
2.29.2