u-boot/common/cmd_date.c
Wolfgang Denk 54841ab50c Make sure that argv[] argument pointers are not modified.
The hush shell dynamically allocates (and re-allocates) memory for the
argument strings in the "char *argv[]" argument vector passed to
commands.  Any code that modifies these pointers will cause serious
corruption of the malloc data structures and crash U-Boot, so make
sure the compiler can check that no such modifications are being done
by changing the code into "char * const argv[]".

This modification is the result of debugging a strange crash caused
after adding a new command, which used the following argument
processing code which has been working perfectly fine in all Unix
systems since version 6 - but not so in U-Boot:

int main (int argc, char **argv)
{
	while (--argc > 0 && **++argv == '-') {
/* ====> */	while (*++*argv) {
			switch (**argv) {
			case 'd':
				debug++;
				break;
			...
			default:
				usage ();
			}
		}
	}
	...
}

The line marked "====>" will corrupt the malloc data structures and
usually cause U-Boot to crash when the next command gets executed by
the shell.  With the modification, the compiler will prevent this with
an
	error: increment of read-only location '*argv'

N.B.: The code above can be trivially rewritten like this:

	while (--argc > 0 && **++argv == '-') {
		char *arg = *argv;
		while (*++arg) {
			switch (*arg) {
			...

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-by: Mike Frysinger <vapier@gentoo.org>
2010-07-04 23:55:42 +02:00

227 lines
4.6 KiB
C

/*
* (C) Copyright 2001
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/*
* RTC, Date & Time support: get and set date & time
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
DECLARE_GLOBAL_DATA_PTR;
const char *weekdays[] = {
"Sun", "Mon", "Tues", "Wednes", "Thurs", "Fri", "Satur",
};
#ifdef CONFIG_RELOC_FIXUP_WORKS
#define RELOC(a) a
#else
#define RELOC(a) ((typeof(a))((unsigned long)(a) + gd->reloc_off))
#endif
int mk_date (char *, struct rtc_time *);
int do_date (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
struct rtc_time tm;
int rcode = 0;
int old_bus;
/* switch to correct I2C bus */
old_bus = I2C_GET_BUS();
I2C_SET_BUS(CONFIG_SYS_RTC_BUS_NUM);
switch (argc) {
case 2: /* set date & time */
if (strcmp(argv[1],"reset") == 0) {
puts ("Reset RTC...\n");
rtc_reset ();
} else {
/* initialize tm with current time */
rcode = rtc_get (&tm);
if(!rcode) {
/* insert new date & time */
if (mk_date (argv[1], &tm) != 0) {
puts ("## Bad date format\n");
break;
}
/* and write to RTC */
rcode = rtc_set (&tm);
if(rcode)
puts("## Set date failed\n");
} else {
puts("## Get date failed\n");
}
}
/* FALL TROUGH */
case 1: /* get date & time */
rcode = rtc_get (&tm);
if (rcode) {
puts("## Get date failed\n");
break;
}
printf ("Date: %4d-%02d-%02d (%sday) Time: %2d:%02d:%02d\n",
tm.tm_year, tm.tm_mon, tm.tm_mday,
(tm.tm_wday<0 || tm.tm_wday>6) ?
"unknown " : RELOC(weekdays[tm.tm_wday]),
tm.tm_hour, tm.tm_min, tm.tm_sec);
break;
default:
cmd_usage(cmdtp);
rcode = 1;
}
/* switch back to original I2C bus */
I2C_SET_BUS(old_bus);
return rcode;
}
/*
* simple conversion of two-digit string with error checking
*/
static int cnvrt2 (char *str, int *valp)
{
int val;
if ((*str < '0') || (*str > '9'))
return (-1);
val = *str - '0';
++str;
if ((*str < '0') || (*str > '9'))
return (-1);
*valp = 10 * val + (*str - '0');
return (0);
}
/*
* Convert date string: MMDDhhmm[[CC]YY][.ss]
*
* Some basic checking for valid values is done, but this will not catch
* all possible error conditions.
*/
int mk_date (char *datestr, struct rtc_time *tmp)
{
int len, val;
char *ptr;
ptr = strchr (datestr,'.');
len = strlen (datestr);
/* Set seconds */
if (ptr) {
int sec;
*ptr++ = '\0';
if ((len - (ptr - datestr)) != 2)
return (-1);
len = strlen (datestr);
if (cnvrt2 (ptr, &sec))
return (-1);
tmp->tm_sec = sec;
} else {
tmp->tm_sec = 0;
}
if (len == 12) { /* MMDDhhmmCCYY */
int year, century;
if (cnvrt2 (datestr+ 8, &century) ||
cnvrt2 (datestr+10, &year) ) {
return (-1);
}
tmp->tm_year = 100 * century + year;
} else if (len == 10) { /* MMDDhhmmYY */
int year, century;
century = tmp->tm_year / 100;
if (cnvrt2 (datestr+ 8, &year))
return (-1);
tmp->tm_year = 100 * century + year;
}
switch (len) {
case 8: /* MMDDhhmm */
/* fall thru */
case 10: /* MMDDhhmmYY */
/* fall thru */
case 12: /* MMDDhhmmCCYY */
if (cnvrt2 (datestr+0, &val) ||
val > 12) {
break;
}
tmp->tm_mon = val;
if (cnvrt2 (datestr+2, &val) ||
val > ((tmp->tm_mon==2) ? 29 : 31)) {
break;
}
tmp->tm_mday = val;
if (cnvrt2 (datestr+4, &val) ||
val > 23) {
break;
}
tmp->tm_hour = val;
if (cnvrt2 (datestr+6, &val) ||
val > 59) {
break;
}
tmp->tm_min = val;
/* calculate day of week */
GregorianDay (tmp);
return (0);
default:
break;
}
return (-1);
}
/***************************************************/
U_BOOT_CMD(
date, 2, 1, do_date,
"get/set/reset date & time",
"[MMDDhhmm[[CC]YY][.ss]]\ndate reset\n"
" - without arguments: print date & time\n"
" - with numeric argument: set the system date & time\n"
" - with 'reset' argument: reset the RTC"
);