X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftime.c;h=c6324d96009ec20214ce0be3c7e468b5c7679bb1;hb=e6c8fba7771563b2f3dfb96a78f36ec17e15bdf0;hp=cbe0d5a222ff8727286701b90099528a533cfc73;hpb=f8bd2258e2d520dff28c855658bd24bdafb5102d;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/time.c b/kernel/time.c index cbe0d5a..c6324d9 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include @@ -59,14 +60,15 @@ EXPORT_SYMBOL(sys_tz); * why not move it into the appropriate arch directory (for those * architectures that need it). */ -asmlinkage long sys_time(time_t __user * tloc) +SYSCALL_DEFINE1(time, time_t __user *, tloc) { time_t i = get_seconds(); if (tloc) { if (put_user(i,tloc)) - i = -EFAULT; + return -EFAULT; } + force_successful_syscall_return(); return i; } @@ -77,7 +79,7 @@ asmlinkage long sys_time(time_t __user * tloc) * architectures that need it). */ -asmlinkage long sys_stime(time_t __user *tptr) +SYSCALL_DEFINE1(stime, time_t __user *, tptr) { struct timespec tv; int err; @@ -97,8 +99,8 @@ asmlinkage long sys_stime(time_t __user *tptr) #endif /* __ARCH_WANT_SYS_TIME */ -asmlinkage long sys_gettimeofday(struct timeval __user *tv, - struct timezone __user *tz) +SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv, + struct timezone __user *, tz) { if (likely(tv != NULL)) { struct timeval ktv; @@ -134,7 +136,6 @@ static inline void warp_clock(void) write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; - update_xtime_cache(0); write_sequnlock_irq(&xtime_lock); clock_was_set(); } @@ -182,8 +183,8 @@ int do_sys_settimeofday(struct timespec *tv, struct timezone *tz) return 0; } -asmlinkage long sys_settimeofday(struct timeval __user *tv, - struct timezone __user *tz) +SYSCALL_DEFINE2(settimeofday, struct timeval __user *, tv, + struct timezone __user *, tz) { struct timeval user_tv; struct timespec new_ts; @@ -203,7 +204,7 @@ asmlinkage long sys_settimeofday(struct timeval __user *tv, return do_sys_settimeofday(tv ? &new_ts : NULL, tz ? &new_tz : NULL); } -asmlinkage long sys_adjtimex(struct timex __user *txc_p) +SYSCALL_DEFINE1(adjtimex, struct timex __user *, txc_p) { struct timex txc; /* Local copy of parameter */ int ret; @@ -246,7 +247,7 @@ unsigned int inline jiffies_to_msecs(const unsigned long j) return (j + (HZ / MSEC_PER_SEC) - 1)/(HZ / MSEC_PER_SEC); #else # if BITS_PER_LONG == 32 - return ((u64)HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32; + return (HZ_TO_MSEC_MUL32 * j) >> HZ_TO_MSEC_SHR32; # else return (j * HZ_TO_MSEC_NUM) / HZ_TO_MSEC_DEN; # endif @@ -262,7 +263,7 @@ unsigned int inline jiffies_to_usecs(const unsigned long j) return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC); #else # if BITS_PER_LONG == 32 - return ((u64)HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; + return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; # else return (j * HZ_TO_USEC_NUM) / HZ_TO_USEC_DEN; # endif @@ -368,13 +369,20 @@ EXPORT_SYMBOL(mktime); * 0 <= tv_nsec < NSEC_PER_SEC * For negative values only the tv_sec field is negative ! */ -void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec) +void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec) { while (nsec >= NSEC_PER_SEC) { + /* + * The following asm() prevents the compiler from + * optimising this loop into a modulo operation. See + * also __iter_div_u64_rem() in include/linux/time.h + */ + asm("" : "+rm"(nsec)); nsec -= NSEC_PER_SEC; ++sec; } while (nsec < 0) { + asm("" : "+rm"(nsec)); nsec += NSEC_PER_SEC; --sec; } @@ -476,7 +484,7 @@ unsigned long msecs_to_jiffies(const unsigned int m) if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) return MAX_JIFFY_OFFSET; - return ((u64)MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) + return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32; #endif } @@ -491,7 +499,7 @@ unsigned long usecs_to_jiffies(const unsigned int u) #elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) return u * (HZ / USEC_PER_SEC); #else - return ((u64)USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) + return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) >> USEC_TO_HZ_SHR32; #endif } @@ -653,6 +661,36 @@ u64 nsec_to_clock_t(u64 x) #endif } +/** + * nsecs_to_jiffies - Convert nsecs in u64 to jiffies + * + * @n: nsecs in u64 + * + * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64. + * And this doesn't return MAX_JIFFY_OFFSET since this function is designed + * for scheduler, not for use in device drivers to calculate timeout value. + * + * note: + * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512) + * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years + */ +unsigned long nsecs_to_jiffies(u64 n) +{ +#if (NSEC_PER_SEC % HZ) == 0 + /* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */ + return div_u64(n, NSEC_PER_SEC / HZ); +#elif (HZ % 512) == 0 + /* overflow after 292 years if HZ = 1024 */ + return div_u64(n * HZ / 512, NSEC_PER_SEC / 512); +#else + /* + * Generic case - optimized for cases where HZ is a multiple of 3. + * overflow after 64.99 years, exact for HZ = 60, 72, 90, 120 etc. + */ + return div_u64(n * 9, (9ull * NSEC_PER_SEC + HZ / 2) / HZ); +#endif +} + #if (BITS_PER_LONG < 64) u64 get_jiffies_64(void) { @@ -669,3 +707,21 @@ EXPORT_SYMBOL(get_jiffies_64); #endif EXPORT_SYMBOL(jiffies); + +/* + * Add two timespec values and do a safety check for overflow. + * It's assumed that both values are valid (>= 0) + */ +struct timespec timespec_add_safe(const struct timespec lhs, + const struct timespec rhs) +{ + struct timespec res; + + set_normalized_timespec(&res, lhs.tv_sec + rhs.tv_sec, + lhs.tv_nsec + rhs.tv_nsec); + + if (res.tv_sec < lhs.tv_sec || res.tv_sec < rhs.tv_sec) + res.tv_sec = TIME_T_MAX; + + return res; +}