Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt
* git://git.kernel.org/pub/scm/linux/kernel/git/tglx/linux-2.6-hrt:
hrtimer: catch expired CLOCK_REALTIME timers early
hrtimer: check relative timeouts for overflow
+40
-22
+2
include/linux/ktime.h
+2
include/linux/ktime.h
···
310
310
return ktime_sub_ns(kt, usec * 1000);
311
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}
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+
extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
314
+
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315
/*
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* The resolution of the clocks. The resolution value is returned in
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317
* the clock_getres() system call to give application programmers an
+1
-1
kernel/futex.c
+1
-1
kernel/futex.c
+1
-1
kernel/futex_compat.c
+1
-1
kernel/futex_compat.c
+31
-17
kernel/hrtimer.c
+31
-17
kernel/hrtimer.c
···
326
326
#endif /* BITS_PER_LONG >= 64 */
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/*
329
+
* Add two ktime values and do a safety check for overflow:
330
+
*/
331
+
ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs)
332
+
{
333
+
ktime_t res = ktime_add(lhs, rhs);
334
+
335
+
/*
336
+
* We use KTIME_SEC_MAX here, the maximum timeout which we can
337
+
* return to user space in a timespec:
338
+
*/
339
+
if (res.tv64 < 0 || res.tv64 < lhs.tv64 || res.tv64 < rhs.tv64)
340
+
res = ktime_set(KTIME_SEC_MAX, 0);
341
+
342
+
return res;
343
+
}
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+
345
+
/*
329
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* Check, whether the timer is on the callback pending list
330
347
*/
331
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static inline int hrtimer_cb_pending(const struct hrtimer *timer)
···
442
425
ktime_t expires = ktime_sub(timer->expires, base->offset);
443
426
int res;
444
427
428
+
WARN_ON_ONCE(timer->expires.tv64 < 0);
429
+
445
430
/*
446
431
* When the callback is running, we do not reprogram the clock event
447
432
* device. The timer callback is either running on a different CPU or
···
453
434
*/
454
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if (hrtimer_callback_running(timer))
455
436
return 0;
437
+
438
+
/*
439
+
* CLOCK_REALTIME timer might be requested with an absolute
440
+
* expiry time which is less than base->offset. Nothing wrong
441
+
* about that, just avoid to call into the tick code, which
442
+
* has now objections against negative expiry values.
443
+
*/
444
+
if (expires.tv64 < 0)
445
+
return -ETIME;
456
446
457
447
if (expires.tv64 >= expires_next->tv64)
458
448
return 0;
···
710
682
*/
711
683
orun++;
712
684
}
713
-
timer->expires = ktime_add(timer->expires, interval);
714
-
/*
715
-
* Make sure, that the result did not wrap with a very large
716
-
* interval.
717
-
*/
718
-
if (timer->expires.tv64 < 0)
719
-
timer->expires = ktime_set(KTIME_SEC_MAX, 0);
685
+
timer->expires = ktime_add_safe(timer->expires, interval);
720
686
721
687
return orun;
722
688
}
···
861
839
new_base = switch_hrtimer_base(timer, base);
862
840
863
841
if (mode == HRTIMER_MODE_REL) {
864
-
tim = ktime_add(tim, new_base->get_time());
842
+
tim = ktime_add_safe(tim, new_base->get_time());
865
843
/*
866
844
* CONFIG_TIME_LOW_RES is a temporary way for architectures
867
845
* to signal that they simply return xtime in
···
870
848
* timeouts. This will go away with the GTOD framework.
871
849
*/
872
850
#ifdef CONFIG_TIME_LOW_RES
873
-
tim = ktime_add(tim, base->resolution);
851
+
tim = ktime_add_safe(tim, base->resolution);
874
852
#endif
875
-
/*
876
-
* Careful here: User space might have asked for a
877
-
* very long sleep, so the add above might result in a
878
-
* negative number, which enqueues the timer in front
879
-
* of the queue.
880
-
*/
881
-
if (tim.tv64 < 0)
882
-
tim.tv64 = KTIME_MAX;
883
853
}
884
854
timer->expires = tim;
885
855
+5
-3
kernel/posix-timers.c
+5
-3
kernel/posix-timers.c
···
767
767
/* SIGEV_NONE timers are not queued ! See common_timer_get */
768
768
if (((timr->it_sigev_notify & ~SIGEV_THREAD_ID) == SIGEV_NONE)) {
769
769
/* Setup correct expiry time for relative timers */
770
-
if (mode == HRTIMER_MODE_REL)
771
-
timer->expires = ktime_add(timer->expires,
772
-
timer->base->get_time());
770
+
if (mode == HRTIMER_MODE_REL) {
771
+
timer->expires =
772
+
ktime_add_safe(timer->expires,
773
+
timer->base->get_time());
774
+
}
773
775
return 0;
774
776
}
775
777