From d7b4202e0581683f1a14fe598633da0067f5241e Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 4 Sep 2012 15:12:07 -0400 Subject: time: Move timekeeper structure to timekeeper_internal.h for vsyscall changes We're going to need to access the timekeeper in update_vsyscall, so make the structure available for those who need it. Cc: Tony Luck Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Andy Lutomirski Cc: Martin Schwidefsky Cc: Paul Turner Cc: Steven Rostedt Cc: Richard Cochran Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 56 +---------------------------------------------- 1 file changed, 1 insertion(+), 55 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index d3b91e75cecd..02c19d3d8e0d 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -8,6 +8,7 @@ * */ +#include #include #include #include @@ -21,61 +22,6 @@ #include #include -/* Structure holding internal timekeeping values. */ -struct timekeeper { - /* Current clocksource used for timekeeping. */ - struct clocksource *clock; - /* NTP adjusted clock multiplier */ - u32 mult; - /* The shift value of the current clocksource. */ - u32 shift; - /* Number of clock cycles in one NTP interval. */ - cycle_t cycle_interval; - /* Number of clock shifted nano seconds in one NTP interval. */ - u64 xtime_interval; - /* shifted nano seconds left over when rounding cycle_interval */ - s64 xtime_remainder; - /* Raw nano seconds accumulated per NTP interval. */ - u32 raw_interval; - - /* Current CLOCK_REALTIME time in seconds */ - u64 xtime_sec; - /* Clock shifted nano seconds */ - u64 xtime_nsec; - - /* Difference between accumulated time and NTP time in ntp - * shifted nano seconds. */ - s64 ntp_error; - /* Shift conversion between clock shifted nano seconds and - * ntp shifted nano seconds. */ - u32 ntp_error_shift; - - /* - * wall_to_monotonic is what we need to add to xtime (or xtime corrected - * for sub jiffie times) to get to monotonic time. Monotonic is pegged - * at zero at system boot time, so wall_to_monotonic will be negative, - * however, we will ALWAYS keep the tv_nsec part positive so we can use - * the usual normalization. - * - * wall_to_monotonic is moved after resume from suspend for the - * monotonic time not to jump. We need to add total_sleep_time to - * wall_to_monotonic to get the real boot based time offset. - * - * - wall_to_monotonic is no longer the boot time, getboottime must be - * used instead. - */ - struct timespec wall_to_monotonic; - /* Offset clock monotonic -> clock realtime */ - ktime_t offs_real; - /* time spent in suspend */ - struct timespec total_sleep_time; - /* Offset clock monotonic -> clock boottime */ - ktime_t offs_boot; - /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */ - struct timespec raw_time; - /* Seqlock for all timekeeper values */ - seqlock_t lock; -}; static struct timekeeper timekeeper; -- cgit v1.2.3 From 706394211648117762edfaeffd6fc04bf3b1a75d Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 4 Sep 2012 15:34:21 -0400 Subject: time: Convert CONFIG_GENERIC_TIME_VSYSCALL to CONFIG_GENERIC_TIME_VSYSCALL_OLD To help migrate archtectures over to the new update_vsyscall method, redfine CONFIG_GENERIC_TIME_VSYSCALL as CONFIG_GENERIC_TIME_VSYSCALL_OLD Cc: Tony Luck Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Andy Lutomirski Cc: Martin Schwidefsky Cc: Paul Turner Cc: Steven Rostedt Cc: Richard Cochran Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 02c19d3d8e0d..7c2851384c46 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -199,7 +199,7 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp) ntp_clear(); } xt = tk_xtime(tk); - update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult); + update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult); } /** -- cgit v1.2.3 From 576094b7f0aaf41aadab9b7d4e5bd85faa432711 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 11 Sep 2012 19:58:13 -0400 Subject: time: Introduce new GENERIC_TIME_VSYSCALL Now that we moved everyone over to GENERIC_TIME_VSYSCALL_OLD, introduce the new declaration and config option for the new update_vsyscall method. Cc: Tony Luck Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Andy Lutomirski Cc: Martin Schwidefsky Cc: Paul Turner Cc: Steven Rostedt Cc: Richard Cochran Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 7c2851384c46..ce618010c373 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -42,15 +42,6 @@ static inline void tk_normalize_xtime(struct timekeeper *tk) } } -static struct timespec tk_xtime(struct timekeeper *tk) -{ - struct timespec ts; - - ts.tv_sec = tk->xtime_sec; - ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift); - return ts; -} - static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts) { tk->xtime_sec = ts->tv_sec; @@ -192,14 +183,11 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk) /* must hold write on timekeeper.lock */ static void timekeeping_update(struct timekeeper *tk, bool clearntp) { - struct timespec xt; - if (clearntp) { tk->ntp_error = 0; ntp_clear(); } - xt = tk_xtime(tk); - update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult); + update_vsyscall(tk); } /** -- cgit v1.2.3 From 92bb1fcf57a0c2e45f7e67fbf0a8ed475a749236 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 4 Sep 2012 15:38:12 -0400 Subject: time: Only do nanosecond rounding on GENERIC_TIME_VSYSCALL_OLD systems We only do rounding to the next nanosecond so we don't see minor 1ns inconsistencies in the vsyscall implementations. Since we're changing the vsyscall implementations to avoid this, conditionalize the rounding only to the GENERIC_TIME_VSYSCALL_OLD architectures. Cc: Tony Luck Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: Andy Lutomirski Cc: Martin Schwidefsky Cc: Paul Turner Cc: Steven Rostedt Cc: Richard Cochran Cc: Prarit Bhargava Cc: Thomas Gleixner Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 45 +++++++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 14 deletions(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index ce618010c373..16280ff3cf82 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1062,6 +1062,33 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, return offset; } +#ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD +static inline void old_vsyscall_fixup(struct timekeeper *tk) +{ + s64 remainder; + + /* + * Store only full nanoseconds into xtime_nsec after rounding + * it up and add the remainder to the error difference. + * XXX - This is necessary to avoid small 1ns inconsistnecies caused + * by truncating the remainder in vsyscalls. However, it causes + * additional work to be done in timekeeping_adjust(). Once + * the vsyscall implementations are converted to use xtime_nsec + * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD + * users are removed, this can be killed. + */ + remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); + tk->xtime_nsec -= remainder; + tk->xtime_nsec += 1ULL << tk->shift; + tk->ntp_error += remainder << tk->ntp_error_shift; + +} +#else +#define old_vsyscall_fixup(tk) +#endif + + + /** * update_wall_time - Uses the current clocksource to increment the wall time * @@ -1073,7 +1100,6 @@ static void update_wall_time(void) cycle_t offset; int shift = 0, maxshift; unsigned long flags; - s64 remainder; write_seqlock_irqsave(&tk->lock, flags); @@ -1115,20 +1141,11 @@ static void update_wall_time(void) /* correct the clock when NTP error is too big */ timekeeping_adjust(tk, offset); - /* - * Store only full nanoseconds into xtime_nsec after rounding - * it up and add the remainder to the error difference. - * XXX - This is necessary to avoid small 1ns inconsistnecies caused - * by truncating the remainder in vsyscalls. However, it causes - * additional work to be done in timekeeping_adjust(). Once - * the vsyscall implementations are converted to use xtime_nsec - * (shifted nanoseconds), this can be killed. - */ - remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1); - tk->xtime_nsec -= remainder; - tk->xtime_nsec += 1ULL << tk->shift; - tk->ntp_error += remainder << tk->ntp_error_shift; + * XXX This can be killed once everyone converts + * to the new update_vsyscall. + */ + old_vsyscall_fixup(tk); /* * Finally, make sure that after the rounding -- cgit v1.2.3 From 5b3900cd409466c0070b234d941650685ad0c791 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 9 Oct 2012 10:18:23 +0300 Subject: timekeeping: Cast raw_interval to u64 to avoid shift overflow We fixed a bunch of integer overflows in timekeeping code during the 3.6 cycle. I did an audit based on that and found this potential overflow. Signed-off-by: Dan Carpenter Acked-by: John Stultz Link: http://lkml.kernel.org/r/20121009071823.GA19159@elgon.mountain Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org --- kernel/time/timekeeping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/time/timekeeping.c') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 16280ff3cf82..3eb3fc7c1600 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -1045,7 +1045,7 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset, accumulate_nsecs_to_secs(tk); /* Accumulate raw time */ - raw_nsecs = tk->raw_interval << shift; + raw_nsecs = (u64)tk->raw_interval << shift; raw_nsecs += tk->raw_time.tv_nsec; if (raw_nsecs >= NSEC_PER_SEC) { u64 raw_secs = raw_nsecs; -- cgit v1.2.3