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		81f1962393
		
	
	
	
	
		
			
			Some filesystems nowadays use 64-bit types for timestamps. So, update grub_dirhook_info struct to use an grub_int64_t type to store mtime. This also updates the grub_unixtime2datetime() function to receive a 64-bit timestamp argument and do 64-bit-safe divisions. All the remaining conversion from 32-bit to 64-bit should be safe, as 32-bit to 64-bit attributions will be implicitly casted. The most critical part in the 32-bit to 64-bit conversion is in the function grub_unixtime2datetime() where it needs to deal with the 64-bit type. So, for that, the grub_divmod64() helper has been used. These changes enables the GRUB to support dates beyond y2038. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
		
			
				
	
	
		
			118 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			118 lines
		
	
	
		
			3.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* datetime.c - Module for common datetime function.  */
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| /*
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|  *  GRUB  --  GRand Unified Bootloader
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|  *  Copyright (C) 2008  Free Software Foundation, Inc.
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|  *
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|  *  GRUB is free software: you can redistribute it and/or modify
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|  *  it under the terms of the GNU General Public License as published by
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|  *  the Free Software Foundation, either version 3 of the License, or
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|  *  (at your option) any later version.
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|  *
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|  *  GRUB is distributed in the hope that it will be useful,
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|  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  *  GNU General Public License for more details.
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|  *
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|  *  You should have received a copy of the GNU General Public License
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|  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
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|  */
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| 
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| #include <grub/datetime.h>
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| #include <grub/i18n.h>
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| #include <grub/misc.h>
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| #include <grub/mm.h>
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| 
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| static const char *const grub_weekday_names[] =
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| {
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|   N_("Sunday"),
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|   N_("Monday"),
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|   N_("Tuesday"),
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|   N_("Wednesday"),
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|   N_("Thursday"),
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|   N_("Friday"),
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|   N_("Saturday"),
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| };
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| 
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| int
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| grub_get_weekday (struct grub_datetime *datetime)
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| {
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|   unsigned a, y, m;
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| 
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|   if (datetime->month <= 2)
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|     a = 1;
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|   else
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|     a = 0;
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|   y = datetime->year - a;
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|   m = datetime->month + 12 * a - 2;
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| 
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|   return (datetime->day + y + y / 4 - y / 100 + y / 400 + (31 * m / 12)) % 7;
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| }
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| 
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| const char *
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| grub_get_weekday_name (struct grub_datetime *datetime)
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| {
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|   return _ (grub_weekday_names[grub_get_weekday (datetime)]);
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| }
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| 
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| #define SECPERMIN 60
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| #define SECPERHOUR (60*SECPERMIN)
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| #define SECPERDAY (24*SECPERHOUR)
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| #define DAYSPERYEAR 365
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| #define DAYSPER4YEARS (4*DAYSPERYEAR+1)
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| 
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| 
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| void
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| grub_unixtime2datetime (grub_int64_t nix, struct grub_datetime *datetime)
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| {
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|   int i;
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|   grub_uint8_t months[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
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|   /* In the period of validity of unixtime all years divisible by 4
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|      are bissextile*/
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|   /* Convenience: let's have 3 consecutive non-bissextile years
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|      at the beginning of the counting date. So count from 1901. */
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|   int days_epoch;
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|   /* Number of days since 1st Januar, 1901.  */
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|   unsigned days;
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|   /* Seconds into current day.  */
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|   unsigned secs_in_day;
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| 
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|   /* Transform C divisions and modulos to mathematical ones */
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|   if (nix < 0)
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|     /*
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|      * The result of division here shouldn't be larger than GRUB_INT_MAX.
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|      * So, it's safe to store the result back in an int.
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|      */
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|     days_epoch = -(grub_divmod64 (((grub_int64_t) (SECPERDAY) - nix - 1), SECPERDAY, NULL));
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|   else
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|     days_epoch = grub_divmod64 (nix, SECPERDAY, NULL);
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| 
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|   secs_in_day = nix - days_epoch * SECPERDAY;
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|   days = days_epoch + 69 * DAYSPERYEAR + 17;
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| 
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|   datetime->year = 1901 + 4 * (days / DAYSPER4YEARS);
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|   days %= DAYSPER4YEARS;
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|   /* On 31st December of bissextile years 365 days from the beginning
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|      of the year elapsed but year isn't finished yet */
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|   if (days / DAYSPERYEAR == 4)
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|     {
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|       datetime->year += 3;
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|       days -= 3*DAYSPERYEAR;
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|     }
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|   else
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|     {
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|       datetime->year += days / DAYSPERYEAR;
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|       days %= DAYSPERYEAR;
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|     }
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|   for (i = 0; i < 12
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| 	 && days >= (i==1 && datetime->year % 4 == 0
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| 		      ? 29 : months[i]); i++)
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|     days -= (i==1 && datetime->year % 4 == 0
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| 			    ? 29 : months[i]);
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|   datetime->month = i + 1;
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|   datetime->day = 1 + days;
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|   datetime->hour = (secs_in_day / SECPERHOUR);
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|   secs_in_day %= SECPERHOUR;
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|   datetime->minute = secs_in_day / SECPERMIN;
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|   datetime->second = secs_in_day % SECPERMIN;
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| }
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