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2007-02-16[PATCH] hrtimers: prevent possible itimer DoSThomas Gleixner
Fix potential setitimer DoS with high-res timers by pushing itimer rearm processing to process context. [Fixes from: Ingo Molnar <mingo@elte.hu>] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] hrtimers: add high resolution timer supportThomas Gleixner
Implement high resolution timers on top of the hrtimers infrastructure and the clockevents / tick-management framework. This provides accurate timers for all hrtimer subsystem users. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] hrtimers: namespace and enum cleanupThomas Gleixner
- hrtimers did not use the hrtimer_restart enum and relied on the implict int representation. Fix the prototypes and the functions using the enums. - Use seperate name spaces for the enumerations - Convert hrtimer_restart macro to inline function - Add comments No functional changes. [akpm@osdl.org: fix input driver] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-03-26[PATCH] hrtimers: remove data fieldRoman Zippel
The nanosleep cleanup allows to remove the data field of hrtimer. The callback function can use container_of() to get it's own data. Since the hrtimer structure is anyway embedded in other structures, this adds no overhead. Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-26[PATCH] hrtimers: pass current time to hrtimer_forward()Roman Zippel
Pass current time to hrtimer_forward(). This allows to use the softirq time in the timer base when the forward function is called from the timer callback. Other places pass current time with a call to timer->base->get_time(). Signed-off-by: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25[PATCH] Validate and sanitze itimer timeval from userspaceThomas Gleixner
According to the specification the timevals must be validated and an errorcode -EINVAL returned in case the timevals are not in canonical form. This check was never done in Linux. The pre 2.6.16 code converted invalid timevals silently. Negative timeouts were converted by the timeval_to_jiffies conversion to the maximum timeout. hrtimers and the ktime_t operations expect timevals in canonical form. Otherwise random results might happen on 32 bits machines due to the optimized ktime_add/sub operations. Negative timeouts are treated as already expired. This might break applications which work on pre 2.6.16. To prevent random behaviour and API breakage the timevals are checked and invalid timevals sanitized in a simliar way as the pre 2.6.16 code did. Invalid timevals are reported with a per boot limited number of kernel messages so applications which use this misfeature can be corrected. After a grace period of one year the sanitizing should be replaced by a correct validation check. This is also documented in Documentation/feature-removal-schedule.txt The validation and sanitizing is done inside do_setitimer so all callers (sys_setitimer, compat_sys_setitimer, osf_setitimer) are catched. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-25[PATCH] sys_alarm() unsigned signed conversion fixupThomas Gleixner
alarm() calls the kernel with an unsigend int timeout in seconds. The value is stored in the tv_sec field of a struct timeval to setup the itimer. The tv_sec field of struct timeval is of type long, which causes the tv_sec value to be negative on 32 bit machines if seconds > INT_MAX. Before the hrtimer merge (pre 2.6.16) such a negative value was converted to the maximum jiffies timeout by the timeval_to_jiffies conversion. It's not clear whether this was intended or just happened to be done by the timeval_to_jiffies code. hrtimers expect a timeval in canonical form and treat a negative timeout as already expired. This breaks the legitimate usage of alarm() with a timeout value > INT_MAX seconds. For 32 bit machines it is therefor necessary to limit the internal seconds value to avoid API breakage. Instead of doing this in all implementations of sys_alarm the duplicated sys_alarm code is moved into a common function in itimer.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] hrtimers: fix oldvalue return in setitimerThomas Gleixner
This resolves bugzilla bug#5617. The oldvalue of the timer was read after the timer was cancelled, so the remaining time was always zero. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01[PATCH] hrtimers: fixup itimer conversionThomas Gleixner
The itimer conversion removed the locking which protects the timer and variables in the shared signal structure. Steven Rostedt found the problem in the latest -rt patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10[PATCH] hrtimer: switch itimers to hrtimerThomas Gleixner
switch itimers to a hrtimers-based implementation Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27[PATCH] itimer fixesGeorge Anzinger
Fix the recent off-by-one fix in the itimer code: 1. The repeating timer is figured using the requested time (not +1 as we know where we are in the jiffie). 2. The tests for interval too large are left to the time_val to jiffie code. Signed-off-by: George Anzinger <george@mvista.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-29[PATCH] ITIMER_REAL: fix possible deadlock and raceOleg Nesterov
As Steven Rostedt pointed out, there are 2 problems with ITIMER_REAL timers. 1. do_setitimer() does not call del_timer_sync() in case when the timer is not pending (it_real_value() returns 0). This is wrong, the timer may still be running, and it can rearm itself. 2. It calls del_timer_sync() with tsk->sighand->siglock held. This is deadlockable, because timer's handler needs this lock too. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05[PATCH] setitimer timer expires too earlyPaulo Marques
It seems that the code responsible for this is in kernel/itimer.c:126: p->signal->real_timer.expires = jiffies + interval; add_timer(&p->signal->real_timer); If you request an interval of, lets say 900 usecs, the interval given by timeval_to_jiffies will be 1. If you request this when we are half-way between two timer ticks, the interval will only give 400 usecs. If we want to guarantee that we never ever give intervals less than requested, the simple solution would be to change that to: p->signal->real_timer.expires = jiffies + interval + 1; This however will produce pathological cases, like having a idle system being requested 1 ms timeouts will give systematically 2 ms timeouts, whereas currently it simply gives a few usecs less than 1 ms. The complex (and more computationally expensive) solution would be to check the gettimeofday time, and compute the correct number of jiffies. This way, if we request a 300 usecs timer 200 usecs inside the timer tick, we can wait just one tick, but not if we are 800 usecs inside the tick. This would also mean that we would have to lock preemption during these computations to avoid races, etc. I've searched the archives but couldn't find this particular issue being discussed before. Attached is a patch to do the simple solution, in case anybody thinks that it should be used. Signed-Off-By: Paulo Marques <pmarques@grupopie.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!