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timekeeping: Consolidate timekeeping_inject_offset code

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The code to check the adjtimex() or clock_adjtime() arguments is spread
out across multiple files for presumably only historic reasons. As a
preparatation for a rework to get rid of the use of 'struct timeval'
and 'struct timespec' in there, this moves all the portions into
kernel/time/timekeeping.c and marks them as 'static'.

The warp_clock() function here is not as closely related as the others,
but I feel it still makes sense to move it here in order to consolidate
all callers of timekeeping_inject_offset().

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[jstultz: Whitespace fixup]
Signed-off-by: John Stultz <john.stultz@linaro.org>
This commit is contained in:
Arnd Bergmann 2017-10-19 13:14:44 +02:00 committed by John Stultz
parent 0f295b0650
commit e0956dcc4b
6 changed files with 123 additions and 126 deletions
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26
include/linux/time.h
View file

@ -134,32 +134,6 @@ static inline bool timeval_valid(const struct timeval *tv)
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
/*
* Validates if a timespec/timeval used to inject a time offset is valid.
* Offsets can be postive or negative. The value of the timeval/timespec
* is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
* always be non-negative.
*/
static inline bool timeval_inject_offset_valid(const struct timeval *tv)
{
/* We don't check the tv_sec as it can be positive or negative */
/* Can't have more microseconds then a second */
if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
return false;
return true;
}
static inline bool timespec_inject_offset_valid(const struct timespec *ts)
{
/* We don't check the tv_sec as it can be positive or negative */
/* Can't have more nanoseconds then a second */
if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
return false;
return true;
}
/* Some architectures do not supply their own clocksource.
* This is mainly the case in architectures that get their
* inter-tick times by reading the counter on their interval

61
kernel/time/ntp.c
View file

@ -713,67 +713,6 @@ static inline void process_adjtimex_modes(struct timex *txc,
}
/**
* ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex
*/
int ntp_validate_timex(struct timex *txc)
{
if (txc->modes & ADJ_ADJTIME) {
/* singleshot must not be used with any other mode bits */
if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
return -EINVAL;
if (!(txc->modes & ADJ_OFFSET_READONLY) &&
!capable(CAP_SYS_TIME))
return -EPERM;
} else {
/* In order to modify anything, you gotta be super-user! */
if (txc->modes && !capable(CAP_SYS_TIME))
return -EPERM;
/*
* if the quartz is off by more than 10% then
* something is VERY wrong!
*/
if (txc->modes & ADJ_TICK &&
(txc->tick < 900000/USER_HZ ||
txc->tick > 1100000/USER_HZ))
return -EINVAL;
}
if (txc->modes & ADJ_SETOFFSET) {
/* In order to inject time, you gotta be super-user! */
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (txc->modes & ADJ_NANO) {
struct timespec ts;
ts.tv_sec = txc->time.tv_sec;
ts.tv_nsec = txc->time.tv_usec;
if (!timespec_inject_offset_valid(&ts))
return -EINVAL;
} else {
if (!timeval_inject_offset_valid(&txc->time))
return -EINVAL;
}
}
/*
* Check for potential multiplication overflows that can
* only happen on 64-bit systems:
*/
if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {
if (LLONG_MIN / PPM_SCALE > txc->freq)
return -EINVAL;
if (LLONG_MAX / PPM_SCALE < txc->freq)
return -EINVAL;
}
return 0;
}
/*
* adjtimex mainly allows reading (and writing, if superuser) of
* kernel time-keeping variables. used by xntpd.

1
kernel/time/ntp_internal.h
View file

@ -7,7 +7,6 @@ extern void ntp_clear(void);
extern u64 ntp_tick_length(void);
extern ktime_t ntp_get_next_leap(void);
extern int second_overflow(time64_t secs);
extern int ntp_validate_timex(struct timex *);
extern int __do_adjtimex(struct timex *, struct timespec64 *, s32 *);
extern void __hardpps(const struct timespec64 *, const struct timespec64 *);
#endif /* _LINUX_NTP_INTERNAL_H */

36
kernel/time/time.c
View file

@ -157,40 +157,6 @@ SYSCALL_DEFINE2(gettimeofday, struct timeval __user *, tv,
return 0;
}
/*
* Indicates if there is an offset between the system clock and the hardware
* clock/persistent clock/rtc.
*/
int persistent_clock_is_local;
/*
* Adjust the time obtained from the CMOS to be UTC time instead of
* local time.
*
* This is ugly, but preferable to the alternatives. Otherwise we
* would either need to write a program to do it in /etc/rc (and risk
* confusion if the program gets run more than once; it would also be
* hard to make the program warp the clock precisely n hours) or
* compile in the timezone information into the kernel. Bad, bad....
*
* - TYT, 1992-01-01
*
* The best thing to do is to keep the CMOS clock in universal time (UTC)
* as real UNIX machines always do it. This avoids all headaches about
* daylight saving times and warping kernel clocks.
*/
static inline void warp_clock(void)
{
if (sys_tz.tz_minuteswest != 0) {
struct timespec adjust;
persistent_clock_is_local = 1;
adjust.tv_sec = sys_tz.tz_minuteswest * 60;
adjust.tv_nsec = 0;
timekeeping_inject_offset(&adjust);
}
}
/*
* In case for some reason the CMOS clock has not already been running
* in UTC, but in some local time: The first time we set the timezone,
@ -224,7 +190,7 @@ int do_sys_settimeofday64(const struct timespec64 *tv, const struct timezone *tz
if (firsttime) {
firsttime = 0;
if (!tv)
warp_clock();
timekeeping_warp_clock();
}
}
if (tv)

123
kernel/time/timekeeping.c
View file

@ -1258,13 +1258,39 @@ out:
}
EXPORT_SYMBOL(do_settimeofday64);
/*
* Validates if a timespec/timeval used to inject a time offset is valid.
* Offsets can be postive or negative. The value of the timeval/timespec
* is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
* always be non-negative.
*/
static inline bool timeval_inject_offset_valid(const struct timeval *tv)
{
/* We don't check the tv_sec as it can be positive or negative */
/* Can't have more microseconds then a second */
if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
return false;
return true;
}
static inline bool timespec_inject_offset_valid(const struct timespec *ts)
{
/* We don't check the tv_sec as it can be positive or negative */
/* Can't have more nanoseconds then a second */
if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
return false;
return true;
}
/**
* timekeeping_inject_offset - Adds or subtracts from the current time.
* @tv: pointer to the timespec variable containing the offset
*
* Adds or subtracts an offset value from the current time.
*/
int timekeeping_inject_offset(struct timespec *ts)
static int timekeeping_inject_offset(struct timespec *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned long flags;
@ -1303,7 +1329,40 @@ error: /* even if we error out, we forwarded the time, so call update */
return ret;
}
EXPORT_SYMBOL(timekeeping_inject_offset);
/*
* Indicates if there is an offset between the system clock and the hardware
* clock/persistent clock/rtc.
*/
int persistent_clock_is_local;
/*
* Adjust the time obtained from the CMOS to be UTC time instead of
* local time.
*
* This is ugly, but preferable to the alternatives. Otherwise we
* would either need to write a program to do it in /etc/rc (and risk
* confusion if the program gets run more than once; it would also be
* hard to make the program warp the clock precisely n hours) or
* compile in the timezone information into the kernel. Bad, bad....
*
* - TYT, 1992-01-01
*
* The best thing to do is to keep the CMOS clock in universal time (UTC)
* as real UNIX machines always do it. This avoids all headaches about
* daylight saving times and warping kernel clocks.
*/
void timekeeping_warp_clock(void)
{
if (sys_tz.tz_minuteswest != 0) {
struct timespec adjust;
persistent_clock_is_local = 1;
adjust.tv_sec = sys_tz.tz_minuteswest * 60;
adjust.tv_nsec = 0;
timekeeping_inject_offset(&adjust);
}
}
/**
* __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic
@ -2247,6 +2306,66 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
return base;
}
/**
* ntp_validate_timex - Ensures the timex is ok for use in do_adjtimex
*/
static int ntp_validate_timex(struct timex *txc)
{
if (txc->modes & ADJ_ADJTIME) {
/* singleshot must not be used with any other mode bits */
if (!(txc->modes & ADJ_OFFSET_SINGLESHOT))
return -EINVAL;
if (!(txc->modes & ADJ_OFFSET_READONLY) &&
!capable(CAP_SYS_TIME))
return -EPERM;
} else {
/* In order to modify anything, you gotta be super-user! */
if (txc->modes && !capable(CAP_SYS_TIME))
return -EPERM;
/*
* if the quartz is off by more than 10% then
* something is VERY wrong!
*/
if (txc->modes & ADJ_TICK &&
(txc->tick < 900000/USER_HZ ||
txc->tick > 1100000/USER_HZ))
return -EINVAL;
}
if (txc->modes & ADJ_SETOFFSET) {
/* In order to inject time, you gotta be super-user! */
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (txc->modes & ADJ_NANO) {
struct timespec ts;
ts.tv_sec = txc->time.tv_sec;
ts.tv_nsec = txc->time.tv_usec;
if (!timespec_inject_offset_valid(&ts))
return -EINVAL;
} else {
if (!timeval_inject_offset_valid(&txc->time))
return -EINVAL;
}
}
/*
* Check for potential multiplication overflows that can
* only happen on 64-bit systems:
*/
if ((txc->modes & ADJ_FREQUENCY) && (BITS_PER_LONG == 64)) {
if (LLONG_MIN / PPM_SCALE > txc->freq)
return -EINVAL;
if (LLONG_MAX / PPM_SCALE < txc->freq)
return -EINVAL;
}
return 0;
}
/**
* do_adjtimex() - Accessor function to NTP __do_adjtimex function
*/

2
kernel/time/timekeeping.h
View file

@ -10,7 +10,7 @@ extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq,
extern int timekeeping_valid_for_hres(void);
extern u64 timekeeping_max_deferment(void);
extern int timekeeping_inject_offset(struct timespec *ts);
extern void timekeeping_warp_clock(void);
extern int timekeeping_suspend(void);
extern void timekeeping_resume(void);