Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"Mostly small fixes for the fallout of the timekeeping overhaul in 3.6
along with stable fixes to address an accumulation problem and missing
sanity checks for RTC readouts and user space provided values."
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Avoid making adjustments if we haven't accumulated anything
time: Avoid potential shift overflow with large shift values
time: Fix casting issue in timekeeping_forward_now
time: Ensure we normalize the timekeeper in tk_xtime_add
time: Improve sanity checking of timekeeping inputs
+52
-14
-7
include/linux/ktime.h
-7
include/linux/ktime.h
···
58
58
59
59
typedef union ktime ktime_t; /* Kill this */
60
60
61
-
#define KTIME_MAX ((s64)~((u64)1 << 63))
62
-
#if (BITS_PER_LONG == 64)
63
-
# define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
64
-
#else
65
-
# define KTIME_SEC_MAX LONG_MAX
66
-
#endif
67
-
68
61
/*
69
62
* ktime_t definitions when using the 64-bit scalar representation:
70
63
*/
+20
-2
include/linux/time.h
+20
-2
include/linux/time.h
···
107
107
return ts_delta;
108
108
}
109
109
110
+
#define KTIME_MAX ((s64)~((u64)1 << 63))
111
+
#if (BITS_PER_LONG == 64)
112
+
# define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
113
+
#else
114
+
# define KTIME_SEC_MAX LONG_MAX
115
+
#endif
116
+
110
117
/*
111
118
* Returns true if the timespec is norm, false if denorm:
112
119
*/
113
-
#define timespec_valid(ts) \
114
-
(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
120
+
static inline bool timespec_valid(const struct timespec *ts)
121
+
{
122
+
/* Dates before 1970 are bogus */
123
+
if (ts->tv_sec < 0)
124
+
return false;
125
+
/* Can't have more nanoseconds then a second */
126
+
if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
127
+
return false;
128
+
/* Disallow values that could overflow ktime_t */
129
+
if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
130
+
return false;
131
+
return true;
132
+
}
115
133
116
134
extern void read_persistent_clock(struct timespec *ts);
117
135
extern void read_boot_clock(struct timespec *ts);
+32
-5
kernel/time/timekeeping.c
+32
-5
kernel/time/timekeeping.c
···
115
115
{
116
116
tk->xtime_sec += ts->tv_sec;
117
117
tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
118
+
tk_normalize_xtime(tk);
118
119
}
119
120
120
121
static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
···
277
276
tk->xtime_nsec += cycle_delta * tk->mult;
278
277
279
278
/* If arch requires, add in gettimeoffset() */
280
-
tk->xtime_nsec += arch_gettimeoffset() << tk->shift;
279
+
tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
281
280
282
281
tk_normalize_xtime(tk);
283
282
···
428
427
struct timespec ts_delta, xt;
429
428
unsigned long flags;
430
429
431
-
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
430
+
if (!timespec_valid(tv))
432
431
return -EINVAL;
433
432
434
433
write_seqlock_irqsave(&tk->lock, flags);
···
464
463
{
465
464
struct timekeeper *tk = &timekeeper;
466
465
unsigned long flags;
466
+
struct timespec tmp;
467
+
int ret = 0;
467
468
468
469
if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
469
470
return -EINVAL;
···
474
471
475
472
timekeeping_forward_now(tk);
476
473
474
+
/* Make sure the proposed value is valid */
475
+
tmp = timespec_add(tk_xtime(tk), *ts);
476
+
if (!timespec_valid(&tmp)) {
477
+
ret = -EINVAL;
478
+
goto error;
479
+
}
477
480
478
481
tk_xtime_add(tk, ts);
479
482
tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
480
483
484
+
error: /* even if we error out, we forwarded the time, so call update */
481
485
timekeeping_update(tk, true);
482
486
483
487
write_sequnlock_irqrestore(&tk->lock, flags);
···
492
482
/* signal hrtimers about time change */
493
483
clock_was_set();
494
484
495
-
return 0;
485
+
return ret;
496
486
}
497
487
EXPORT_SYMBOL(timekeeping_inject_offset);
498
488
···
659
649
struct timespec now, boot, tmp;
660
650
661
651
read_persistent_clock(&now);
652
+
if (!timespec_valid(&now)) {
653
+
pr_warn("WARNING: Persistent clock returned invalid value!\n"
654
+
" Check your CMOS/BIOS settings.\n");
655
+
now.tv_sec = 0;
656
+
now.tv_nsec = 0;
657
+
}
658
+
662
659
read_boot_clock(&boot);
660
+
if (!timespec_valid(&boot)) {
661
+
pr_warn("WARNING: Boot clock returned invalid value!\n"
662
+
" Check your CMOS/BIOS settings.\n");
663
+
boot.tv_sec = 0;
664
+
boot.tv_nsec = 0;
665
+
}
663
666
664
667
seqlock_init(&tk->lock);
665
668
···
1152
1129
offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
1153
1130
#endif
1154
1131
1132
+
/* Check if there's really nothing to do */
1133
+
if (offset < tk->cycle_interval)
1134
+
goto out;
1135
+
1155
1136
/*
1156
1137
* With NO_HZ we may have to accumulate many cycle_intervals
1157
1138
* (think "ticks") worth of time at once. To do this efficiently,
···
1188
1161
* the vsyscall implementations are converted to use xtime_nsec
1189
1162
* (shifted nanoseconds), this can be killed.
1190
1163
*/
1191
-
remainder = tk->xtime_nsec & ((1 << tk->shift) - 1);
1164
+
remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
1192
1165
tk->xtime_nsec -= remainder;
1193
-
tk->xtime_nsec += 1 << tk->shift;
1166
+
tk->xtime_nsec += 1ULL << tk->shift;
1194
1167
tk->ntp_error += remainder << tk->ntp_error_shift;
1195
1168
1196
1169
/*