struct timeval uses a 32-bit seconds representation which will overflow in the year 2038 and beyond. This patch replaces the usage of struct timeval with ktime_t which is a 64-bit timestamp and is year 2038 safe. This patch is part of a larger attempt to remove all instances of 32-bit timekeeping variables (timeval, timespec, time_t) which are not year 2038 safe, from the kernel.
Signed-off-by: Tina Ruchandani ruchandani.tina@gmail.com Suggested-by: Arnd Bergmann arndb@arndb.de
-- Changes in v3: - Clean up commit message. - Use ktime_us_delta which is more concise than the combination of ktime_sub and ktime_to_us Changes in v2: - Use the more concise ktime_us_delta - Preserve the waketime argument in dvb_frontend_sleep_until as a pointer, fixes bug introduced in v1 of the patch where the caller doesn't get its timestamp modified.
Signed-off-by: Tina Ruchandani ruchandani.tina@gmail.com --- drivers/media/dvb-core/dvb_frontend.c | 41 ++++++++++------------------------- drivers/media/dvb-core/dvb_frontend.h | 3 +-- drivers/media/dvb-frontends/stv0299.c | 12 +++++----- 3 files changed, 19 insertions(+), 37 deletions(-)
diff --git a/drivers/media/dvb-core/dvb_frontend.c b/drivers/media/dvb-core/dvb_frontend.c index 882ca41..69be73c 100644 --- a/drivers/media/dvb-core/dvb_frontend.c +++ b/drivers/media/dvb-core/dvb_frontend.c @@ -40,6 +40,7 @@ #include <linux/freezer.h> #include <linux/jiffies.h> #include <linux/kthread.h> +#include <linux/ktime.h> #include <asm/processor.h>
#include "dvb_frontend.h" @@ -889,42 +890,21 @@ static void dvb_frontend_stop(struct dvb_frontend *fe) fepriv->thread); }
-s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime) -{ - return ((curtime.tv_usec < lasttime.tv_usec) ? - 1000000 - lasttime.tv_usec + curtime.tv_usec : - curtime.tv_usec - lasttime.tv_usec); -} -EXPORT_SYMBOL(timeval_usec_diff); - -static inline void timeval_usec_add(struct timeval *curtime, u32 add_usec) -{ - curtime->tv_usec += add_usec; - if (curtime->tv_usec >= 1000000) { - curtime->tv_usec -= 1000000; - curtime->tv_sec++; - } -} - /* * Sleep until gettimeofday() > waketime + add_usec * This needs to be as precise as possible, but as the delay is * usually between 2ms and 32ms, it is done using a scheduled msleep * followed by usleep (normally a busy-wait loop) for the remainder */ -void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec) +void dvb_frontend_sleep_until(ktime_t *waketime, u32 add_usec) { - struct timeval lasttime; s32 delta, newdelta;
- timeval_usec_add(waketime, add_usec); - - do_gettimeofday(&lasttime); - delta = timeval_usec_diff(lasttime, *waketime); + ktime_add_us(*waketime, add_usec); + delta = ktime_us_delta(ktime_get_real(), *waketime); if (delta > 2500) { msleep((delta - 1500) / 1000); - do_gettimeofday(&lasttime); - newdelta = timeval_usec_diff(lasttime, *waketime); + newdelta = ktime_us_delta(ktime_get_real(), *waketime); delta = (newdelta > delta) ? 0 : newdelta; } if (delta > 0) @@ -2458,13 +2438,13 @@ static int dvb_frontend_ioctl_legacy(struct file *file, * include the initialization or start bit */ unsigned long swcmd = ((unsigned long) parg) << 1; - struct timeval nexttime; - struct timeval tv[10]; + ktime_t nexttime; + ktime_t tv[10]; int i; u8 last = 1; if (dvb_frontend_debug) printk("%s switch command: 0x%04lx\n", __func__, swcmd); - do_gettimeofday(&nexttime); + nexttime = ktime_get_real(); if (dvb_frontend_debug) tv[0] = nexttime; /* before sending a command, initialize by sending @@ -2475,7 +2455,7 @@ static int dvb_frontend_ioctl_legacy(struct file *file,
for (i = 0; i < 9; i++) { if (dvb_frontend_debug) - do_gettimeofday(&tv[i + 1]); + tv[i+1] = ktime_get_real(); if ((swcmd & 0x01) != last) { /* set voltage to (last ? 13V : 18V) */ fe->ops.set_voltage(fe, (last) ? SEC_VOLTAGE_13 : SEC_VOLTAGE_18); @@ -2489,7 +2469,8 @@ static int dvb_frontend_ioctl_legacy(struct file *file, printk("%s(%d): switch delay (should be 32k followed by all 8k\n", __func__, fe->dvb->num); for (i = 1; i < 10; i++) - printk("%d: %d\n", i, timeval_usec_diff(tv[i-1] , tv[i])); + printk("%d: %d\n", i, + (int) ktime_us_delta(tv[i], tv[i-1]); } err = 0; fepriv->state = FESTATE_DISEQC; diff --git a/drivers/media/dvb-core/dvb_frontend.h b/drivers/media/dvb-core/dvb_frontend.h index 816269e..5b64686 100644 --- a/drivers/media/dvb-core/dvb_frontend.h +++ b/drivers/media/dvb-core/dvb_frontend.h @@ -439,7 +439,6 @@ extern void dvb_frontend_reinitialise(struct dvb_frontend *fe); extern int dvb_frontend_suspend(struct dvb_frontend *fe); extern int dvb_frontend_resume(struct dvb_frontend *fe);
-extern void dvb_frontend_sleep_until(struct timeval *waketime, u32 add_usec); -extern s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime); +extern void dvb_frontend_sleep_until(ktime_t *waketime, u32 add_usec);
#endif diff --git a/drivers/media/dvb-frontends/stv0299.c b/drivers/media/dvb-frontends/stv0299.c index b57ecf4..347c2bc 100644 --- a/drivers/media/dvb-frontends/stv0299.c +++ b/drivers/media/dvb-frontends/stv0299.c @@ -44,6 +44,7 @@
#include <linux/init.h> #include <linux/kernel.h> +#include <linux/ktime.h> #include <linux/module.h> #include <linux/string.h> #include <linux/slab.h> @@ -404,8 +405,8 @@ static int stv0299_send_legacy_dish_cmd (struct dvb_frontend* fe, unsigned long u8 lv_mask = 0x40; u8 last = 1; int i; - struct timeval nexttime; - struct timeval tv[10]; + ktime_t nexttime; + ktime_t tv[10];
reg0x08 = stv0299_readreg (state, 0x08); reg0x0c = stv0299_readreg (state, 0x0c); @@ -418,7 +419,7 @@ static int stv0299_send_legacy_dish_cmd (struct dvb_frontend* fe, unsigned long if (debug_legacy_dish_switch) printk ("%s switch command: 0x%04lx\n",__func__, cmd);
- do_gettimeofday (&nexttime); + nexttime = ktime_get_real(); if (debug_legacy_dish_switch) tv[0] = nexttime; stv0299_writeregI (state, 0x0c, reg0x0c | 0x50); /* set LNB to 18V */ @@ -427,7 +428,7 @@ static int stv0299_send_legacy_dish_cmd (struct dvb_frontend* fe, unsigned long
for (i=0; i<9; i++) { if (debug_legacy_dish_switch) - do_gettimeofday (&tv[i+1]); + tv[i+1] = ktime_get_real(); if((cmd & 0x01) != last) { /* set voltage to (last ? 13V : 18V) */ stv0299_writeregI (state, 0x0c, reg0x0c | (last ? lv_mask : 0x50)); @@ -443,7 +444,8 @@ static int stv0299_send_legacy_dish_cmd (struct dvb_frontend* fe, unsigned long printk ("%s(%d): switch delay (should be 32k followed by all 8k\n", __func__, fe->dvb->num); for (i = 1; i < 10; i++) - printk ("%d: %d\n", i, timeval_usec_diff(tv[i-1] , tv[i])); + printk("%d: %d\n", i, + (int) ktime_us_delta(tv[i], tv[i-1])); }
return 0;
On Sunday 31 May 2015 12:47:06 Tina Ruchandani wrote:
struct timeval uses a 32-bit seconds representation which will overflow in the year 2038 and beyond. This patch replaces the usage of struct timeval with ktime_t which is a 64-bit timestamp and is year 2038 safe. This patch is part of a larger attempt to remove all instances of 32-bit timekeeping variables (timeval, timespec, time_t) which are not year 2038 safe, from the kernel.
Signed-off-by: Tina Ruchandani ruchandani.tina@gmail.com Suggested-by: Arnd Bergmann arndb@arndb.de
Reviewed-by: Arnd Bergmann arnd@arndb.de