Y2038 April 2015

y2038@lists.linaro.org

11 participants
38 discussions

[PATCH v2] Staging: rts5208: Replace timeval with timespec64

by Ksenija Stanojevic

struct timeval tv is used to get current time. 32-bit systems using 'struct timeval' will break in the year 2038, so we have to replace that code with more appropriate types. Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic(a)gmail.com> --- Changes in v2: - use functions that uses real time clock. - do not change interface by removing timeval_buf. drivers/staging/rts5208/rtsx.h | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/staging/rts5208/rtsx.h b/drivers/staging/rts5208/rtsx.h index 9e6ecb7..7d44350 100644 --- a/drivers/staging/rts5208/rtsx.h +++ b/drivers/staging/rts5208/rtsx.h @@ -37,7 +37,7 @@ #include <linux/cdrom.h> #include <linux/workqueue.h> #include <linux/timer.h> -#include <linux/time.h> +#include <linux/time64.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -151,21 +151,21 @@ static inline struct rtsx_dev *host_to_rtsx(struct Scsi_Host *host) static inline void get_current_time(u8 *timeval_buf, int buf_len) { - struct timeval tv; + struct timespec64 ts64; if (!timeval_buf || (buf_len < 8)) return; - do_gettimeofday(&tv); + getnstimeofday64(&ts64); - timeval_buf[0] = (u8)(tv.tv_sec >> 24); - timeval_buf[1] = (u8)(tv.tv_sec >> 16); - timeval_buf[2] = (u8)(tv.tv_sec >> 8); - timeval_buf[3] = (u8)(tv.tv_sec); - timeval_buf[4] = (u8)(tv.tv_usec >> 24); - timeval_buf[5] = (u8)(tv.tv_usec >> 16); - timeval_buf[6] = (u8)(tv.tv_usec >> 8); - timeval_buf[7] = (u8)(tv.tv_usec); + timeval_buf[0] = (u8)(ts64.tv_sec >> 24); + timeval_buf[1] = (u8)(ts64.tv_sec >> 16); + timeval_buf[2] = (u8)(ts64.tv_sec >> 8); + timeval_buf[3] = (u8)(ts64.tv_sec); + timeval_buf[4] = (u8)(ts64.tv_nsec/NSEC_PER_USEC >> 24); + timeval_buf[5] = (u8)(ts64.tv_nsec/NSEC_PER_USEC >> 16); + timeval_buf[6] = (u8)(ts64.tv_nsec/NSEC_PER_USEC >> 8); + timeval_buf[7] = (u8)(ts64.tv_nsec/NSEC_PER_USEC); } /* The scsi_lock() and scsi_unlock() macros protect the sm_state and the -- 1.9.1

9 years, 7 months

[PATCH v1 00/15] Convert the posix_clock_operations and k_clock structure to ready for 2038

by Baolin Wang

This patch series changes the 32-bit time type (timespec/itimerspec) to the 64-bit one (timespec64/itimerspec64), since 32-bit time types will break in the year 2038. This patch series introduces new methods with timespec64/itimerspec64 type, and removes the old ones with timespec/itimerspec type for posix_clock_operations and k_clock structure. Also introduces some new functions with timespec64/itimerspec64 type, like current_kernel_time64(), hrtimer_get_res64(), cputime_to_timespec64() and timespec64_to_cputime(). Changes since V1: -Split some patch into small patch. -Add some default function for new 64bit methods for syscall function. -Move do_sys_settimeofday() function to head file. -Modify the EXPORT_SYMPOL issue. -Add new 64bit methods in cputime_nsecs.h file. Baolin Wang (15): linux/time64.h:Introduce the 'struct itimerspec64' for 64bit timekeeping:Introduce the current_kernel_time64() function with timespec64 type time/hrtimer:Introduce hrtimer_get_res64() with timespec64 type for getting the timer resolution posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure posix-timers:Split out the guts of the syscall and change the implementation posix-timers:Convert to the 64bit methods for the syscall function time:Introduce the do_sys_settimeofday64() function with timespec64 type time/posix-timers:Convert to the 64bit methods for k_clock callback functions char/mmtimer:Convert to the 64bit methods for k_clock callback function time/alarmtimer:Convert to the new methods for k_clock structure time/posix-clock:Convert to the 64bit methods for k_clock and posix_clock_operations structure time/time:Introduce the timespec64_to_jiffies/jiffies_to_timespec64 function cputime:Introduce the cputime_to_timespec64/timespec64_to_cputime function time/posix-cpu-timers:Convert to the 64bit methods for k_clock structure k_clock:Remove the 32bit methods with timespec/itimerspec type arch/powerpc/include/asm/cputime.h | 6 +- arch/s390/include/asm/cputime.h | 8 +- drivers/char/mmtimer.c | 36 +++-- drivers/ptp/ptp_clock.c | 26 +--- include/asm-generic/cputime_jiffies.h | 10 +- include/asm-generic/cputime_nsecs.h | 4 +- include/linux/cputime.h | 15 ++ include/linux/hrtimer.h | 12 +- include/linux/jiffies.h | 21 ++- include/linux/posix-clock.h | 10 +- include/linux/posix-timers.h | 18 +-- include/linux/time64.h | 35 +++++ include/linux/timekeeping.h | 26 +++- kernel/time/alarmtimer.c | 43 +++--- kernel/time/hrtimer.c | 10 +- kernel/time/posix-clock.c | 20 +-- kernel/time/posix-cpu-timers.c | 83 +++++----- kernel/time/posix-timers.c | 269 ++++++++++++++++++++++----------- kernel/time/time.c | 22 +-- kernel/time/timekeeping.c | 6 +- kernel/time/timekeeping.h | 2 +- 21 files changed, 428 insertions(+), 254 deletions(-) -- 1.7.9.5

9 years, 7 months

[PATCH v1 00/14] Convert the posix_clock_operations and k_clock structure to ready for 2038

by Baolin Wang

This patch series changes the 32-bit time type (timespec/itimerspec) to the 64-bit one (timespec64/itimerspec64), since 32-bit time types will break in the year 2038. This patch series introduces new methods with timespec64/itimerspec64 type, and removes the old ones with timespec/itimerspec type for posix_clock_operations and k_clock structure. Also introduces some new functions with timespec64/itimerspec64 type, like current_kernel_time64(), hrtimer_get_res64(), cputime_to_timespec64() and timespec64_to_cputime(). Changes since V0: -Split some patch into small patch. -Modify some patch logs. -Change the methods for converting the syscall function. -Introduce the new function do_sys_settimeofday64(). Baolin Wang (14): linux/time64.h:Introduce the 'struct itimerspec64' for 64bit timekeeping:Introduce the current_kernel_time64() function with timespec64 type time/hrtimer:Introduce hrtimer_get_res64() with timespec64 type for getting the timer resolution posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure posix-timers:Introduce the 64bit methods for posix-timer.c file time:Introduce the do_sys_settimeofday64() function with timespec64 type time/posix-timers:Convert to the 64bit methods for k_clock callback functions char/mmtimer:Convert to the 64bit methods for k_clock callback function time/alarmtimer:Convert to the new methods for k_clock structure time/posix-clock:Convert to the 64bit methods for k_clock and posix_clock_operations structure time/time:Introduce the timespec64_to_jiffies/jiffies_to_timespec64 function cputime:Introduce the cputime_to_timespec64/timespec64_to_cputime function time/posix-cpu-timers:Convert to the 64bit methods for k_clock structure k_clock:Remove the 32bit methods with timespec type arch/powerpc/include/asm/cputime.h | 6 +- arch/s390/include/asm/cputime.h | 8 +- drivers/char/mmtimer.c | 36 +++-- drivers/ptp/ptp_clock.c | 26 +--- include/asm-generic/cputime_jiffies.h | 10 +- include/linux/cputime.h | 15 ++ include/linux/hrtimer.h | 12 +- include/linux/jiffies.h | 3 + include/linux/posix-clock.h | 10 +- include/linux/posix-timers.h | 18 +-- include/linux/time64.h | 25 +++ include/linux/timekeeping.h | 16 +- kernel/time/alarmtimer.c | 43 +++--- kernel/time/hrtimer.c | 10 +- kernel/time/posix-clock.c | 20 +-- kernel/time/posix-cpu-timers.c | 83 +++++----- kernel/time/posix-timers.c | 269 ++++++++++++++++++++++----------- kernel/time/time.c | 41 ++++- kernel/time/timekeeping.c | 6 +- kernel/time/timekeeping.h | 2 +- 20 files changed, 414 insertions(+), 245 deletions(-) -- 1.7.9.5

9 years, 7 months

[PATCH 00/11] Convert the posix_clock_operations and k_clock structure to ready for 2038

by Baolin Wang

This patch series changes the 32-bit time type (timespec/itimerspec) to the 64-bit one (timespec64/itimerspec64), since 32-bit time types will break in the year 2038. This patch series introduces new methods with timespec64/itimerspec64 type, and removes the old ones with timespec/itimerspec type for posix_clock_operations and k_clock structure. Also introduces some new functions with timespec64/itimerspec64 type, like current_kernel_time64(), hrtimer_get_res64(), cputime_to_timespec64() and timespec64_to_cputime(). Baolin Wang (11): linux/time64.h:Introduce the 'struct itimerspec64' for 64bit timekeeping:Introduce the current_kernel_time64() function with timespec64 type time/hrtimer:Introduce hrtimer_get_res64() with timespec64 type for getting the timer resolution posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure time/posix-timers:Convert to the 64bit methods for k_clock callback functions char/mmtimer:Convert to the 64bit methods for k_clock callback function time/alarmtimer:Convert to the new methods for k_clock structure time/posix-clock:Convert to the 64bit methods for k_clock and posix_clock_operations structure cputime:Introduce the cputime_to_timespec64/timespec64_to_cputime function time/posix-cpu-timers:Convert to the 64bit methods for k_clock structure k_clock:Remove the 32bit methods with timespec type arch/powerpc/include/asm/cputime.h | 6 +- arch/s390/include/asm/cputime.h | 8 +- drivers/char/mmtimer.c | 36 ++++---- drivers/ptp/ptp_clock.c | 26 ++---- include/asm-generic/cputime_jiffies.h | 10 +-- include/linux/cputime.h | 15 ++++ include/linux/hrtimer.h | 12 ++- include/linux/jiffies.h | 3 + include/linux/posix-clock.h | 10 +-- include/linux/posix-timers.h | 18 ++-- include/linux/time64.h | 13 +++ include/linux/timekeeping.h | 14 ++- kernel/time/alarmtimer.c | 43 ++++----- kernel/time/hrtimer.c | 10 +-- kernel/time/posix-clock.c | 20 ++--- kernel/time/posix-cpu-timers.c | 83 +++++++++-------- kernel/time/posix-timers.c | 157 +++++++++++++++++++-------------- kernel/time/time.c | 21 +++++ kernel/time/timekeeping.c | 6 +- kernel/time/timekeeping.h | 2 +- 20 files changed, 302 insertions(+), 211 deletions(-) -- 1.7.9.5

9 years, 7 months

Getting started

by Julian Gindi

Howdy, Looking for low-hanging fruit tasks that I can tackle. Any advice? -jhg

9 years, 7 months

[PATCH] Staging: rts5208: Remove timeval

by Ksenija Stanojevic

32-bit systems using struct timeval will break in the year 2038, so we have to replace that code with more appropriate types. ktime_get() is better than using do_gettimeofday(), because it uses the monotonic clock. ktime_to_us() is used to convert ktime to microseconds. Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic(a)gmail.com> --- drivers/staging/rts5208/rtsx.h | 20 ++++++++------------ 1 file changed, 8 insertions(+), 12 deletions(-) diff --git a/drivers/staging/rts5208/rtsx.h b/drivers/staging/rts5208/rtsx.h index 9e6ecb7..5c79d7d 100644 --- a/drivers/staging/rts5208/rtsx.h +++ b/drivers/staging/rts5208/rtsx.h @@ -37,7 +37,7 @@ #include <linux/cdrom.h> #include <linux/workqueue.h> #include <linux/timer.h> -#include <linux/time.h> +#include <linux/ktime.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -151,21 +151,17 @@ static inline struct rtsx_dev *host_to_rtsx(struct Scsi_Host *host) static inline void get_current_time(u8 *timeval_buf, int buf_len) { - struct timeval tv; + u64 us; - if (!timeval_buf || (buf_len < 8)) + if (!timeval_buf || (buf_len < 4)) return; - do_gettimeofday(&tv); + us = ktime_to_us(ktime_get()); - timeval_buf[0] = (u8)(tv.tv_sec >> 24); - timeval_buf[1] = (u8)(tv.tv_sec >> 16); - timeval_buf[2] = (u8)(tv.tv_sec >> 8); - timeval_buf[3] = (u8)(tv.tv_sec); - timeval_buf[4] = (u8)(tv.tv_usec >> 24); - timeval_buf[5] = (u8)(tv.tv_usec >> 16); - timeval_buf[6] = (u8)(tv.tv_usec >> 8); - timeval_buf[7] = (u8)(tv.tv_usec); + timeval_buf[0] = (u8)(us >> 24); + timeval_buf[1] = (u8)(us >> 16); + timeval_buf[2] = (u8)(us >> 8); + timeval_buf[3] = (u8)(us); } /* The scsi_lock() and scsi_unlock() macros protect the sm_state and the -- 1.9.1

9 years, 7 months

[PATCH v5 00/11] Convert the posix clock operation and k_clock structure to ready for 2038

by Baolin Wang

This patch series change the 32-bit time type (timespec/itimerspec) to the 64-bit one (timespec64/itimerspec64), since 32-bit time types will break in the year 2038. This patch series introduce new methods with timespec64/itimerspec64 type, and remove the old ones with timespec/itimerspec type for posix_clock_operations and k_clock structure. Changes since v4: - Modify the conversion between the itimerspec64 and itimerspec for 64bit. - Continue to split up and merge the patch. - Explain more for the patch log. - Re-order the patch of the patch series. Next step will replace the other callback pointers of k_clock structure. Baolin Wang (11): linux/time64.h:Introduce the 'struct itimerspec64' for 64bit timekeeping:Introduce the current_kernel_time64() function with timespec64 type time/hrtimer:Introduce hrtimer_get_res64() with timespec64 type for getting the timer resolution posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure time/posix-timers:Convert to the 64bit methods for k_clock callback functions char/mmtimer:Convert to the 64bit methods for k_clock callback function time/alarmtimer:Convert to the new methods for k_clock structure time/posix-clock:Convert to the 64bit methods for k_clock and posix_clock_operations structure cputime:Introduce the cputime_to_timespec64/timespec64_to_cputime function time/posix-cpu-timers:Convert to the 64bit methods for k_clock structure k_clock:Remove the 32bit methods with timespec type arch/powerpc/include/asm/cputime.h | 24 +++++ arch/s390/include/asm/cputime.h | 26 ++++++ drivers/char/mmtimer.c | 36 ++++---- drivers/ptp/ptp_clock.c | 26 ++---- include/asm-generic/cputime_jiffies.h | 8 ++ include/linux/hrtimer.h | 12 ++- include/linux/jiffies.h | 3 + include/linux/posix-clock.h | 10 +-- include/linux/posix-timers.h | 18 ++-- include/linux/time64.h | 45 ++++++++++ include/linux/timekeeping.h | 14 ++- kernel/time/alarmtimer.c | 43 ++++----- kernel/time/hrtimer.c | 10 +-- kernel/time/posix-clock.c | 20 ++--- kernel/time/posix-cpu-timers.c | 83 +++++++++-------- kernel/time/posix-timers.c | 157 +++++++++++++++++++-------------- kernel/time/time.c | 21 +++++ kernel/time/timekeeping.c | 6 +- kernel/time/timekeeping.h | 2 +- 19 files changed, 365 insertions(+), 199 deletions(-) -- 1.7.9.5

9 years, 7 months

[PATCH v4 00/12] Convert the posix clock operation and k_clock structure to ready for 2038

by Baolin Wang

This patch series change the 32-bit time type (timespec/itimerspec) to the 64-bit one (timespec64/itimerspec64), since 32-bit time types will break in the year 2038. This patch series introduce new methods with timespec64/itimerspec64 type, and remove the old ones with timespec/itimerspec type for posix clock operation and k_clock structure. Changes since v3: - Introduce the new structure 'itimerspec64' for 64bit and the conversion function. - Separate original one patch into two patches. - Remove the 32bit unused code - Re-order the patch of the patch series. Next step will replace the other callback pointers of k_clock structure. Baolin Wang (12): linux/time64.h:Introduce the 'struct itimerspec64' for 64bit posix_clock:Introduce the new methods with explicit 64 bit seconds timekeeping:Introduce the current_kernel_time64() function with timespec64 type time/hrtimer:Introduce hrtimer_get_res64() with timespec64 type for getting the timer resolution posix timers:Introduce the 64bit methods with timespec64 type for k_clock structure time/posix-timers:Convert to the 64bit methods for k_clock callback functions char/mmtimer:Convert to the 64bit methods for k_clock callback function time/alarmtimer:Convert to the new methods for k_clock structure time/posix-clock:Convert to the 64bit methods for k_clock structure time:Introduce the cputime_to_timespec64/timespec64_to_cputime function time/posix-cpu-timers:Convert to the 64bit methods for k_clock structure k_clock:Remove the 32bit methods with timespec type arch/powerpc/include/asm/cputime.h | 24 +++++ arch/s390/include/asm/cputime.h | 26 ++++++ drivers/char/mmtimer.c | 38 ++++---- drivers/ptp/ptp_clock.c | 26 ++---- include/asm-generic/cputime_jiffies.h | 8 ++ include/linux/hrtimer.h | 12 ++- include/linux/jiffies.h | 3 + include/linux/posix-clock.h | 10 +-- include/linux/posix-timers.h | 18 ++-- include/linux/time64.h | 37 ++++++++ include/linux/timekeeping.h | 14 ++- kernel/time/alarmtimer.c | 43 ++++----- kernel/time/hrtimer.c | 10 +-- kernel/time/posix-clock.c | 21 ++--- kernel/time/posix-cpu-timers.c | 83 +++++++++-------- kernel/time/posix-timers.c | 159 +++++++++++++++++++-------------- kernel/time/time.c | 21 +++++ kernel/time/timekeeping.c | 6 +- kernel/time/timekeeping.h | 2 +- 19 files changed, 361 insertions(+), 200 deletions(-) -- 1.7.9.5

9 years, 7 months

Re: [Y2038] [RFC][PATCH] timekeeping: Limit system time to prevent 32-bit time_t overflow

by Arnd Bergmann

On Wednesday 15 April 2015 17:41:28 Miroslav Lichvar wrote: > On systems with 32-bit time_t, it seems there are quite a few problems > that applications may have with time overflowing in year 2038. Beside > getting in an unexpected state by not checking integer operations with > time_t variables, some system calls have unexpected behavior, e.g. the > system time can't be set back to the current time (negative value), > timers with the ABSTIME flag can't be set (negative value) or they > expire immediately (current time is always larger). > > It would be unrealistic to expect all applications to be able to handle > all these problems. Year 2038 is still many years away, but this can be > a problem even now. The clock can be set close to the overflow > accidentally or maliciously, e.g. when the clock is synchronized over > network by NTP or PTP. > > This patch sets a maximum value of the system time to prevent the system > time from getting too close to the overflow. The time can't be set to a > larger value. When the maximum is reached in normal time accumulation, > the clock will be stepped back by one week. > > A new kernel sysctl time_max is added to select the maximum time. It can > be set to 0 for no limit, 1 for one week before 32-bit time_t overflow, > and 2 for one week before ktime_t overflow. The default value is 1 with > 32-bit time_t and 2 with 64-bit time_t. This can be changed later to be > always 2 when 64-bit versions of system calls using 32-bit time_t are > available. > > Signed-off-by: Miroslav Lichvar <mlichvar(a)redhat.com> I have just created a y2038(a)lists.linaro.org mailing list, added to Cc in this reply. The patch looks basically ok to me, though I have no opinion on whether a sysctl is the best API for configuring this. Arnd > --- > Documentation/sysctl/kernel.txt | 19 +++++++++++++ > include/linux/timekeeping.h | 5 ++++ > include/uapi/linux/sysctl.h | 1 + > kernel/sysctl.c | 9 ++++++ > kernel/sysctl_binary.c | 1 + > kernel/time/timekeeping.c | 62 +++++++++++++++++++++++++++++++++++++---- > 6 files changed, 91 insertions(+), 6 deletions(-) > > diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt > index 83ab256..08e4f28 100644 > --- a/Documentation/sysctl/kernel.txt > +++ b/Documentation/sysctl/kernel.txt > @@ -82,6 +82,7 @@ show up in /proc/sys/kernel: > - sysctl_writes_strict > - tainted > - threads-max > +- time_max > - unknown_nmi_panic > - watchdog_thresh > - version > @@ -847,6 +848,24 @@ can be ORed together: > > ============================================================== > > +time_max: > + > +Select the maximum allowed value of the system time. The system clock cannot be > +set to a larger value and when it reaches the maximum on its own, it will be > +stepped back by one week. > + > +0: No limit. > + > +1: One week before 32-bit time_t overflows, i.e. Jan 12 03:14:07 UTC 2038. > + This is currently the default value with 32-bit time_t, but it will likely > + change when 64-bit versions of system calls using time_t are available. > + > +2: One week before time in the internal kernel representation (ktime_t) > + overflows, i.e. Apr 4 23:47:16 UTC 2262. This is the default value with > + 64-bit time_t. > + > +============================================================== > + > unknown_nmi_panic: > > The value in this file affects behavior of handling NMI. When the > diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h > index 99176af..51fc970 100644 > --- a/include/linux/timekeeping.h > +++ b/include/linux/timekeeping.h > @@ -5,6 +5,11 @@ > > void timekeeping_init(void); > extern int timekeeping_suspended; > +extern int sysctl_time_max; > + > +struct ctl_table; > +extern int sysctl_time_max_handler(struct ctl_table *table, int write, > + void __user *buffer, size_t *length, loff_t *ppos); > > /* > * Get and set timeofday > diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h > index 0956373..8fd2aab 100644 > --- a/include/uapi/linux/sysctl.h > +++ b/include/uapi/linux/sysctl.h > @@ -154,6 +154,7 @@ enum > KERN_NMI_WATCHDOG=75, /* int: enable/disable nmi watchdog */ > KERN_PANIC_ON_NMI=76, /* int: whether we will panic on an unrecovered */ > KERN_PANIC_ON_WARN=77, /* int: call panic() in WARN() functions */ > + KERN_TIMEMAX=78, /* int: select maximum allowed system time */ > }; > > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index ce410bb..6713a5b 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -1120,6 +1120,15 @@ static struct ctl_table kern_table[] = { > .extra1 = &zero, > .extra2 = &one, > }, > + { > + .procname = "time_max", > + .data = &sysctl_time_max, > + .maxlen = sizeof(int), > + .mode = 0644, > + .proc_handler = sysctl_time_max_handler, > + .extra1 = &zero, > + .extra2 = &two, > + }, > { } > }; > > diff --git a/kernel/sysctl_binary.c b/kernel/sysctl_binary.c > index 7e7746a..66c0946 100644 > --- a/kernel/sysctl_binary.c > +++ b/kernel/sysctl_binary.c > @@ -138,6 +138,7 @@ static const struct bin_table bin_kern_table[] = { > { CTL_INT, KERN_MAX_LOCK_DEPTH, "max_lock_depth" }, > { CTL_INT, KERN_PANIC_ON_NMI, "panic_on_unrecovered_nmi" }, > { CTL_INT, KERN_PANIC_ON_WARN, "panic_on_warn" }, > + { CTL_INT, KERN_TIMEMAX, "time_max" }, > {} > }; > > diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c > index 946acb7..112932f 100644 > --- a/kernel/time/timekeeping.c > +++ b/kernel/time/timekeeping.c > @@ -32,6 +32,9 @@ > #define TK_MIRROR (1 << 1) > #define TK_CLOCK_WAS_SET (1 << 2) > > +#define SEC_PER_DAY (24 * 3600) > +#define SEC_PER_WEEK (7 * SEC_PER_DAY) > + > /* > * The most important data for readout fits into a single 64 byte > * cache line. > @@ -884,6 +887,37 @@ EXPORT_SYMBOL(getnstime_raw_and_real); > > #endif /* CONFIG_NTP_PPS */ > > +/* Maximum allowed system time as a sysctl setting and in seconds */ > +int sysctl_time_max __read_mostly; > +static u64 time_max_sec __read_mostly; > + > +static void update_time_max_sec(int tm) > +{ > + if (tm > 1) { > + /* One week before ktime_t overflow */ > + time_max_sec = KTIME_SEC_MAX - SEC_PER_WEEK; > + } else if (tm == 1) { > + /* One week before 32-bit time_t overflow */ > + time_max_sec = 0x7fffffff - SEC_PER_WEEK; > + } else { > + /* No limit */ > + time_max_sec = -1; > + } > +} > + > +int sysctl_time_max_handler(struct ctl_table *table, int write, > + void __user *buffer, size_t *length, loff_t *ppos) > +{ > + int rc; > + > + rc = proc_dointvec_minmax(table, write, buffer, length, ppos); > + if (rc) > + return rc; > + > + update_time_max_sec(sysctl_time_max); > + return 0; > +} > + > /** > * do_gettimeofday - Returns the time of day in a timeval > * @tv: pointer to the timeval to be set > @@ -912,7 +946,7 @@ int do_settimeofday64(const struct timespec64 *ts) > struct timespec64 ts_delta, xt; > unsigned long flags; > > - if (!timespec64_valid_strict(ts)) > + if (!timespec64_valid_strict(ts) || ts->tv_sec >= time_max_sec) > return -EINVAL; > > raw_spin_lock_irqsave(&timekeeper_lock, flags); > @@ -965,7 +999,7 @@ int timekeeping_inject_offset(struct timespec *ts) > > /* Make sure the proposed value is valid */ > tmp = timespec64_add(tk_xtime(tk), ts64); > - if (!timespec64_valid_strict(&tmp)) { > + if (!timespec64_valid_strict(&tmp) || tmp.tv_sec >= time_max_sec) { > ret = -EINVAL; > goto error; > } > @@ -1238,6 +1272,10 @@ void __init timekeeping_init(void) > write_seqcount_begin(&tk_core.seq); > ntp_init(); > > + /* For now, prevent 32-bit time_t overflow by default */ > + sysctl_time_max = sizeof(time_t) > 4 ? 2 : 1; > + update_time_max_sec(sysctl_time_max); > + > clock = clocksource_default_clock(); > if (clock->enable) > clock->enable(clock); > @@ -1687,23 +1725,35 @@ static inline unsigned int accumulate_nsecs_to_secs(struct timekeeper *tk) > > while (tk->tkr_mono.xtime_nsec >= nsecps) { > int leap; > + s64 step; > > tk->tkr_mono.xtime_nsec -= nsecps; > tk->xtime_sec++; > > /* Figure out if its a leap sec and apply if needed */ > leap = second_overflow(tk->xtime_sec); > - if (unlikely(leap)) { > + step = leap; > + > + /* If the system time reached the maximum, step it back */ > + if (unlikely(tk->xtime_sec >= time_max_sec)) { > + step = time_max_sec - tk->xtime_sec - SEC_PER_WEEK; > + printk(KERN_NOTICE > + "Clock: maximum time reached, stepping back\n"); > + } > + > + if (unlikely(step)) { > struct timespec64 ts; > > - tk->xtime_sec += leap; > + tk->xtime_sec += step; > > - ts.tv_sec = leap; > + ts.tv_sec = step; > ts.tv_nsec = 0; > tk_set_wall_to_mono(tk, > timespec64_sub(tk->wall_to_monotonic, ts)); > > - __timekeeping_set_tai_offset(tk, tk->tai_offset - leap); > + if (leap) > + __timekeeping_set_tai_offset(tk, > + tk->tai_offset - leap); > > clock_set = TK_CLOCK_WAS_SET; > } >

9 years, 7 months

new mailing list for y2038

by Arnd Bergmann

Hi, I've created a new mailing list on the Linaro mailing list server for discussing the kernel patches for y2038: https://lists.linaro.org/mailman/listinfo/y2038 Please join if you are interested in discussing these or want to send patches. The intention at the moment much to keep this list explicitly open to newbies, so we will get a lot of incorrect patches there along with other patches. Patches can get sent here for an initial review before they get sent to the real maintainers, or you can put the list on Cc when sending a patch that should be applied and you already know what you are doing. We already got a lot of patches last year through the Outreachy (then known as OPW) application process, and John and I also use this work as part of our Linaro job to train new kernel developers. There also a wiki page at http://kernelnewbies.org/y2038 to describe what we are doing, and anybody who wants to help out here is welcome to contribute patches on this list. Arnd

9 years, 7 months

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Y2038 April 2015