kernel-ark/include/linux/time.h
Thomas Gleixner c08b8a4910 [PATCH] sys_alarm() unsigned signed conversion fixup
alarm() calls the kernel with an unsigend int timeout in seconds.  The
value is stored in the tv_sec field of a struct timeval to setup the
itimer.  The tv_sec field of struct timeval is of type long, which causes
the tv_sec value to be negative on 32 bit machines if seconds > INT_MAX.

Before the hrtimer merge (pre 2.6.16) such a negative value was converted
to the maximum jiffies timeout by the timeval_to_jiffies conversion.  It's
not clear whether this was intended or just happened to be done by the
timeval_to_jiffies code.

hrtimers expect a timeval in canonical form and treat a negative timeout as
already expired.  This breaks the legitimate usage of alarm() with a
timeout value > INT_MAX seconds.

For 32 bit machines it is therefor necessary to limit the internal seconds
value to avoid API breakage.  Instead of doing this in all implementations
of sys_alarm the duplicated sys_alarm code is moved into a common function
in itimer.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25 08:22:48 -08:00

201 lines
5.1 KiB
C

#ifndef _LINUX_TIME_H
#define _LINUX_TIME_H
#include <linux/types.h>
#ifdef __KERNEL__
# include <linux/seqlock.h>
#endif
#ifndef _STRUCT_TIMESPEC
#define _STRUCT_TIMESPEC
struct timespec {
time_t tv_sec; /* seconds */
long tv_nsec; /* nanoseconds */
};
#endif
struct timeval {
time_t tv_sec; /* seconds */
suseconds_t tv_usec; /* microseconds */
};
struct timezone {
int tz_minuteswest; /* minutes west of Greenwich */
int tz_dsttime; /* type of dst correction */
};
#ifdef __KERNEL__
/* Parameters used to convert the timespec values: */
#define MSEC_PER_SEC 1000L
#define USEC_PER_SEC 1000000L
#define NSEC_PER_SEC 1000000000L
#define NSEC_PER_USEC 1000L
static inline int timespec_equal(struct timespec *a, struct timespec *b)
{
return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
}
/*
* lhs < rhs: return <0
* lhs == rhs: return 0
* lhs > rhs: return >0
*/
static inline int timespec_compare(struct timespec *lhs, struct timespec *rhs)
{
if (lhs->tv_sec < rhs->tv_sec)
return -1;
if (lhs->tv_sec > rhs->tv_sec)
return 1;
return lhs->tv_nsec - rhs->tv_nsec;
}
static inline int timeval_compare(struct timeval *lhs, struct timeval *rhs)
{
if (lhs->tv_sec < rhs->tv_sec)
return -1;
if (lhs->tv_sec > rhs->tv_sec)
return 1;
return lhs->tv_usec - rhs->tv_usec;
}
extern unsigned long mktime(const unsigned int year, const unsigned int mon,
const unsigned int day, const unsigned int hour,
const unsigned int min, const unsigned int sec);
extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
/*
* Returns true if the timespec is norm, false if denorm:
*/
#define timespec_valid(ts) \
(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
/*
* 64-bit nanosec type. Large enough to span 292+ years in nanosecond
* resolution. Ought to be enough for a while.
*/
typedef s64 nsec_t;
extern struct timespec xtime;
extern struct timespec wall_to_monotonic;
extern seqlock_t xtime_lock;
static inline unsigned long get_seconds(void)
{
return xtime.tv_sec;
}
struct timespec current_kernel_time(void);
#define CURRENT_TIME (current_kernel_time())
#define CURRENT_TIME_SEC ((struct timespec) { xtime.tv_sec, 0 })
extern void do_gettimeofday(struct timeval *tv);
extern int do_settimeofday(struct timespec *tv);
extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
extern long do_utimes(int dfd, char __user *filename, struct timeval *times);
struct itimerval;
extern int do_setitimer(int which, struct itimerval *value,
struct itimerval *ovalue);
extern unsigned int alarm_setitimer(unsigned int seconds);
extern int do_getitimer(int which, struct itimerval *value);
extern void getnstimeofday(struct timespec *tv);
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
/**
* timespec_to_ns - Convert timespec to nanoseconds
* @ts: pointer to the timespec variable to be converted
*
* Returns the scalar nanosecond representation of the timespec
* parameter.
*/
static inline nsec_t timespec_to_ns(const struct timespec *ts)
{
return ((nsec_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
}
/**
* timeval_to_ns - Convert timeval to nanoseconds
* @ts: pointer to the timeval variable to be converted
*
* Returns the scalar nanosecond representation of the timeval
* parameter.
*/
static inline nsec_t timeval_to_ns(const struct timeval *tv)
{
return ((nsec_t) tv->tv_sec * NSEC_PER_SEC) +
tv->tv_usec * NSEC_PER_USEC;
}
/**
* ns_to_timespec - Convert nanoseconds to timespec
* @nsec: the nanoseconds value to be converted
*
* Returns the timespec representation of the nsec parameter.
*/
extern struct timespec ns_to_timespec(const nsec_t nsec);
/**
* ns_to_timeval - Convert nanoseconds to timeval
* @nsec: the nanoseconds value to be converted
*
* Returns the timeval representation of the nsec parameter.
*/
extern struct timeval ns_to_timeval(const nsec_t nsec);
#endif /* __KERNEL__ */
#define NFDBITS __NFDBITS
#define FD_SETSIZE __FD_SETSIZE
#define FD_SET(fd,fdsetp) __FD_SET(fd,fdsetp)
#define FD_CLR(fd,fdsetp) __FD_CLR(fd,fdsetp)
#define FD_ISSET(fd,fdsetp) __FD_ISSET(fd,fdsetp)
#define FD_ZERO(fdsetp) __FD_ZERO(fdsetp)
/*
* Names of the interval timers, and structure
* defining a timer setting:
*/
#define ITIMER_REAL 0
#define ITIMER_VIRTUAL 1
#define ITIMER_PROF 2
struct itimerspec {
struct timespec it_interval; /* timer period */
struct timespec it_value; /* timer expiration */
};
struct itimerval {
struct timeval it_interval; /* timer interval */
struct timeval it_value; /* current value */
};
/*
* The IDs of the various system clocks (for POSIX.1b interval timers):
*/
#define CLOCK_REALTIME 0
#define CLOCK_MONOTONIC 1
#define CLOCK_PROCESS_CPUTIME_ID 2
#define CLOCK_THREAD_CPUTIME_ID 3
/*
* The IDs of various hardware clocks:
*/
#define CLOCK_SGI_CYCLE 10
#define MAX_CLOCKS 16
#define CLOCKS_MASK (CLOCK_REALTIME | CLOCK_MONOTONIC)
#define CLOCKS_MONO CLOCK_MONOTONIC
/*
* The various flags for setting POSIX.1b interval timers:
*/
#define TIMER_ABSTIME 0x01
#endif