22 Oct, 2008
1 commit
-
Conflicts:
kernel/time/tick-sched.c
Signed-off-by: Thomas Gleixner
20 Oct, 2008
1 commit
-
…tp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus
18 Oct, 2008
1 commit
-
Conflicts:
arch/x86/kvm/i8254.c
03 Oct, 2008
1 commit
-
Found by static checker (http://repo.or.cz/w/smatch.git).
Signed-off-by: Dan Carpenter
Acked-by: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Sep, 2008
9 commits
-
Cleanup. Imho makes the code much more understandable. At least this
patch lessens both the source and compiled code.Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
lock_timer() checks that the timer found by idr_find(timer_id) has ->it_id
== timer_id. This buys nothing. This check can fail only if
sys_timer_create() unlocked idr_lock after idr_get_new(), but didn't set
->it_id = new_timer_id yet. But in that case ->it_process == NULL so
lock_timer() can't succeed anyway.Also remove a couple of unneeded typecasts.
Note that with or without this patch we have a small problem.
sys_timer_create() doesn't ensure that the result of setting (say)
->it_sigev_notify must be visible if lock_timer() succeeds.Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
With the recent changes ->it_sigev_signo and ->it_sigev_value are only
used in sys_timer_create(), kill them.Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
Cleanup.
- sys_timer_create() is big and complicated. The code above the "out:"
label relies on the fact that "error" must be == 0. This is not very
robust, make the code more explicit. Remove the unneeded initialization
of error.- If idr_get_new() succeeds (as it normally should), we check the returned
value twice. Move the "-EAGAIN" check under "if (error)".Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
posix_timer_event() always populates timer->sigq with the same numbers,
move this code into sys_timer_create().Note that with this patch we can kill it_sigev_signo and it_sigev_value.
Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
- Change the code to do rcu_read_lock() instead of taking tasklist_lock,
it is safe to get_task_struct(p) if p was found under RCU.However, now we must not use process's sighand/signal, they may be NULL.
We can use current->sighand/signal instead, this "process" must belong
to the current's thread-group.- Factor out the common code for 2 "if (timer_event_spec)" branches, the
!timer_event_spec case can use current too.- use spin_lock_irq() instead of _irqsave(), kill "flags".
Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
sys_timer_create() return -EINVAL if the target thread has PF_EXITING.
This doesn't really make sense, the sub-thread can die right after unlock.
And in fact, this is just wrong. Without SIGEV_THREAD_ID good_sigevent()
returns ->group_leader, and it is very possible that the leader is already
dead. This is OK, we shouldn't return the error in this case.Remove this check and the comment. Note that the "process" was found
under tasklist_lock, it must have ->sighand != NULL.Also, remove a couple of unneeded initializations.
Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
Change the code to get/put timer->it_process regardless of
SIGEV_THREAD_ID. This streamlines the create/destroy paths and allows us
to simplify the usage of exit_itimers() in de_thread().Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner -
posix_timer_event() drops SIGEV_THREAD_ID and switches to ->group_leader
if send_sigqueue() fails.This is not very useful and doesn't work reliably. send_sigqueue() can
only fail if ->it_process is dead. But it can die before it dequeues the
SI_TIMER signal, in that case the timer stops anyway.Remove this code. I guess it was needed a long ago to ensure that the
timer is not destroyed when when its creator thread dies.Q: perhaps it makes sense to change sys_timer_settime() to return an error
if ->it_process is dead?Signed-off-by: Oleg Nesterov
Cc: mingo@elte.hu
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Thomas Gleixner
06 Sep, 2008
1 commit
-
In order to be able to do range hrtimers we need to use accessor functions
to the "expire" member of the hrtimer struct.
This patch converts kernel/* to these accessors.Signed-off-by: Arjan van de Ven
21 Aug, 2008
1 commit
-
In talking with Josip Loncaric, and his work on clock synchronization (see
btime.sf.net), he mentioned that for really close synchronization, it is
useful to have access to "hardware time", that is a notion of time that is
not in any way adjusted by the clock slewing done to keep close time sync.Part of the issue is if we are using the kernel's ntp adjusted
representation of time in order to measure how we should correct time, we
can run into what Paul McKenney aptly described as "Painting a road using
the lines we're painting as the guide".I had been thinking of a similar problem, and was trying to come up with a
way to give users access to a purely hardware based time representation
that avoided users having to know the underlying frequency and mask values
needed to deal with the wide variety of possible underlying hardware
counters.My solution is to introduce CLOCK_MONOTONIC_RAW. This exposes a
nanosecond based time value, that increments starting at bootup and has no
frequency adjustments made to it what so ever.The time is accessed from userspace via the posix_clock_gettime() syscall,
passing CLOCK_MONOTONIC_RAW as the clock_id.Signed-off-by: John Stultz
Signed-off-by: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Ingo Molnar
12 Aug, 2008
1 commit
-
…el/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
posix-timers: fix posix_timer_event() vs dequeue_signal() race
posix-timers: do_schedule_next_timer: fix the setting of ->si_overrun
26 Jul, 2008
2 commits
-
release_posix_timer() can't be called with ->it_process != NULL. Once
sys_timer_create() sets ->it_process it must not call
release_posix_timer(), otherwise we can race with another thread doing
sys_timer_delete(), this timer is visible to idr_find() and unlocked.The same is true for two other callers (actually, for any possible
caller), sys_timer_delete() and itimer_delete(). They must clear
->it_process before unlock_timer() + release_posix_timer().Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Cc: john stultz
Cc: Thomas Gleixner
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
sys_timer_delete() and itimer_delete() check "timer->it_process != NULL",
this looks completely bogus. ->it_process == NULL means that this timer
is already under destruction or it is not fully initialized, this must not
happen.sys_timer_delete: the timer is locked, and lock_timer() can't succeed
if ->it_process == NULL.itimer_delete: it is called by exit_itimers() when there are no other
threads which can play with signal_struct->posix_timers.Signed-off-by: Oleg Nesterov
Acked-by: Roland McGrath
Cc: john stultz
Cc: Thomas Gleixner
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Jul, 2008
2 commits
-
The bug was reported and analysed by Mark McLoughlin ,
the patch is based on his and Roland's suggestions.posix_timer_event() always rewrites the pre-allocated siginfo before sending
the signal. Most of the written info is the same all the time, but memset(0)
is very wrong. If ->sigq is queued we can race with collect_signal() which
can fail to find this siginfo looking at .si_signo, or copy_siginfo() can
copy the wrong .si_code/si_tid/etc.In short, sys_timer_settime() can in fact stop the active timer, or the user
can receive the siginfo with the wrong .si_xxx values.Move "memset(->info, 0)" from posix_timer_event() to alloc_posix_timer(),
change send_sigqueue() to set .si_overrun = 0 when ->sigq is not queued.
It would be nice to move the whole sigq->info initialization from send to
create path, but this is not easy to do without uglifying timer_create()
further.As Roland rightly pointed out, we need more cleanups/fixes here, see the
"FIXME" comment in the patch. Hopefully this patch makes sense anyway, and
it can mask the most bad implications.Reported-by: Mark McLoughlin
Signed-off-by: Oleg Nesterov
Cc: Mark McLoughlin
Cc: Oliver Pinter
Cc: Roland McGrath
Cc: stable@kernel.org
Cc: Andrew Morton
Signed-off-by: Thomas Gleixnerkernel/posix-timers.c | 17 +++++++++++++----
kernel/signal.c | 1 +
2 files changed, 14 insertions(+), 4 deletions(-) -
do_schedule_next_timer() sets info->si_overrun = timr->it_overrun_last,
this discards the already accumulated overruns.Signed-off-by: Oleg Nesterov
Cc: Mark McLoughlin
Cc: Oliver Pinter
Cc: Roland McGrath
Cc: stable@kernel.org
Cc: Andrew Morton
Signed-off-by: Thomas Gleixner
30 Apr, 2008
1 commit
-
We export send_sigqueue() and send_group_sigqueue() for the only user,
posix_timer_event(). This is a bit silly, because both are just trivial
helpers on top of do_send_sigqueue() and because the we pass the unused
.si_signo parameter.Kill them both, rename do_send_sigqueue() to send_sigqueue(), and export it.
Signed-off-by: Oleg Nesterov
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Apr, 2008
1 commit
-
None of these files use any of the functionality promised by
asm/semaphore.h.Signed-off-by: Matthew Wilcox
15 Feb, 2008
1 commit
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Various user space callers ask for relative timeouts. While we fixed
that overflow issue in hrtimer_start(), the sites which convert
relative user space values to absolute timeouts themself were uncovered.Instead of putting overflow checks into each place add a function
which does the sanity checking and convert all affected callers to use
it.Thanks to Frans Pop, who reported the problem and tested the fixes.
Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Tested-by: Frans Pop
10 Feb, 2008
1 commit
-
Spotted by Pavel Emelyanov and Alexey Dobriyan.
hrtimer_nanosleep() sets restart_block->arg1 = rmtp, but this rmtp points to
the local variable which lives in the caller's stack frame. This means that
if sys_restart_syscall() actually happens and it is interrupted as well, we
don't update the user-space variable, but write into the already dead stack
frame.Introduced by commit 04c227140fed77587432667a574b14736a06dd7f
hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easierChange the callers to pass "__user *rmtp" to hrtimer_nanosleep(), and change
hrtimer_nanosleep() to use copy_to_user() to actually update *rmtp.Small problem remains. man 2 nanosleep states that *rtmp should be written if
nanosleep() was interrupted (it says nothing whether it is OK to update *rmtp
if nanosleep returns 0), but (with or without this patch) we can dirty *rem
even if nanosleep() returns 0.NOTE: this patch doesn't change compat_sys_nanosleep(), because it has other
bugs. Fixed by the next patch.Signed-off-by: Oleg Nesterov
Cc: Alexey Dobriyan
Cc: Michael Kerrisk
Cc: Pavel Emelyanov
Cc: Peter Zijlstra
Cc: Toyo Abe
Cc: Andrew Morton
Signed-off-by: Thomas Gleixnerinclude/linux/hrtimer.h | 2 -
kernel/hrtimer.c | 51 +++++++++++++++++++++++++-----------------------
kernel/posix-timers.c | 14 +------------
3 files changed, 30 insertions(+), 37 deletions(-)
09 Feb, 2008
1 commit
-
All the functions that need to lookup a task by pid in posix timers obtain
this pid from a user space, and thus this value refers to a task in the same
namespace, as the current task lives in.So the proper behavior is to call find_task_by_vpid() here.
Signed-off-by: Pavel Emelyanov
Cc: "Eric W. Biederman"
Cc: Thomas Gleixner
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Feb, 2008
1 commit
-
This is the new timerfd API as it is implemented by the following patch:
int timerfd_create(int clockid, int flags);
int timerfd_settime(int ufd, int flags,
const struct itimerspec *utmr,
struct itimerspec *otmr);
int timerfd_gettime(int ufd, struct itimerspec *otmr);The timerfd_create() API creates an un-programmed timerfd fd. The "clockid"
parameter can be either CLOCK_MONOTONIC or CLOCK_REALTIME.The timerfd_settime() API give new settings by the timerfd fd, by optionally
retrieving the previous expiration time (in case the "otmr" parameter is not
NULL).The time value specified in "utmr" is absolute, if the TFD_TIMER_ABSTIME bit
is set in the "flags" parameter. Otherwise it's a relative time.The timerfd_gettime() API returns the next expiration time of the timer, or
{0, 0} if the timerfd has not been set yet.Like the previous timerfd API implementation, read(2) and poll(2) are
supported (with the same interface). Here's a simple test program I used to
exercise the new timerfd APIs:http://www.xmailserver.org/timerfd-test2.c
[akpm@linux-foundation.org: coding-style cleanups]
[akpm@linux-foundation.org: fix ia64 build]
[akpm@linux-foundation.org: fix m68k build]
[akpm@linux-foundation.org: fix mips build]
[akpm@linux-foundation.org: fix alpha, arm, blackfin, cris, m68k, s390, sparc and sparc64 builds]
[heiko.carstens@de.ibm.com: fix s390]
[akpm@linux-foundation.org: fix powerpc build]
[akpm@linux-foundation.org: fix sparc64 more]
Signed-off-by: Davide Libenzi
Cc: Michael Kerrisk
Cc: Thomas Gleixner
Cc: Davide Libenzi
Cc: Michael Kerrisk
Cc: Martin Schwidefsky
Signed-off-by: Heiko Carstens
Cc: Michael Kerrisk
Cc: Davide Libenzi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Feb, 2008
1 commit
-
Signed-off-by: Joe Perches
Signed-off-by: Adrian Bunk
20 Oct, 2007
1 commit
-
With pid namespaces this field is now dangerous to use explicitly, so hide
it behind the helpers.Also the pid and pgrp fields o task_struct and signal_struct are to be
deprecated. Unfortunately this patch cannot be sent right now as this
leads to tons of warnings, so start isolating them, and deprecate later.Actually the p->tgid == pid has to be changed to has_group_leader_pid(),
but Oleg pointed out that in case of posix cpu timers this is the same, and
thread_group_leader() is more preferable.Signed-off-by: Pavel Emelyanov
Acked-by: Oleg Nesterov
Cc: Sukadev Bhattiprolu
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Oct, 2007
1 commit
-
Pull the copy_to_user out of hrtimer_nanosleep and into the callers
(common_nsleep, sys_nanosleep) in preparation for converting
compat_sys_nanosleep to use hrtimers.Signed-off-by: Anton Blanchard
Acked-by: Arnd Bergmann
Signed-off-by: Thomas Gleixner
17 Oct, 2007
1 commit
-
These aren't modular, so SLAB_PANIC is OK.
Signed-off-by: Alexey Dobriyan
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Oct, 2007
1 commit
-
Signed-off-by: Al Viro
Signed-off-by: Linus Torvalds
23 Aug, 2007
2 commits
-
sys_timer_create() sets ->it_process and unlocks ->siglock, then checks
tmr->it_sigev_notify to define if get_task_struct() is needed.We already passed ->it_id to the caller, another thread can delete this timer
and free its memory in between.As a minimal fix, move this code under ->siglock, sys_timer_delete() takes it
too before calling release_posix_timer(). A proper serialization would be to
take ->it_lock, we add a partly initialized timer on posix_timers_id, not
good.Signed-off-by: Oleg Nesterov
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
timer_delete does:
lock_timer();
timer->it_process = NULL;
unlock_timer();
release_posix_timer();timer->it_process is checked in lock_timer() to prevent access to a
timer, which is on the way to be deleted, but the check happens after
idr_lock is dropped. This allows release_posix_timer() to delete the
timer before the lock code can check the timer:CPU 0 CPU 1
lock_timer();
timer->it_process = NULL;
unlock_timer();
lock_timer()
spin_lock(idr_lock);
timer = idr_find();
spin_lock(timer->lock);
spin_unlock(idr_lock);
release_posix_timer();
spin_lock(idr_lock);
idr_remove(timer);
spin_unlock(idr_lock);
free_timer(timer);
if (timer->......)Change the locking to prevent this.
Signed-off-by: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Jul, 2007
1 commit
-
Slab destructors were no longer supported after Christoph's
c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been
BUGs for both slab and slub, and slob never supported them
either.This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).Signed-off-by: Paul Mundt
22 Jun, 2007
1 commit
-
posix-timers which deliver an ignored signal are currently rearmed in
the timer softirq: This is necessary because the timer needs to be
delivered again when SIG_IGN is removed. This is not a problem, when
the interval is reasonable.With high resolution timers enabled one might arm a posix timer with a
very small interval and ignore the signal. This might lead to a
softirq starvation when the interval is so small that the timer is
requeued onto the softirq pending list right away.This problem was pointed out by Jan Kiszka. Thanks Jan !
The correct solution would be to stop the timer, when the signal is
ignored and rearm it when SIG_IGN is removed. Unfortunately this
requires modification in sigaction and involves non trivial sighand
locking. It's too late in the release cycle for such a change.For now we just keep the timer running and enforce that the timer only
fires every jiffie. This does not break anything as we keep the
overrun counter correct. It adds a little inaccuracy to the
timer_gettime() interface, but...The more complex change is necessary anyway to fix another short
coming of the current implementation, which I discovered while looking
at this problem: A pending signal is discarded when SIG_IGN is set. In
case that a posixtimer signal is pending then it is discarded as well,
but when SIG_IGN is removed later nothing rearms the timer. This is
not new, it's that way since posix timers have been merged. So nothing
to worry about right now.I have a working solution to fix all of this, but the impact is too
large for both stable and 2.6.22. I'm going to send it out for review
in the next days.This should go into 2.6.21.stable as well.
Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Cc: Jan Kiszka
Cc: Ulrich Drepper
Cc: Stable Team
Signed-off-by: Linus Torvalds
09 May, 2007
1 commit
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Remove includes of where it is not used/needed.
Suggested by Al Viro.Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).Signed-off-by: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Feb, 2007
2 commits
-
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
Signed-off-by: Ingo Molnar
Cc: john stultz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- 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 commentsNo functional changes.
[akpm@osdl.org: fix input driver]
Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
Cc: john stultz
Cc: Roman Zippel
Cc: Dmitry Torokhov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Feb, 2007
1 commit
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Replace appropriate pairs of "kmem_cache_alloc()" + "memset(0)" with the
corresponding "kmem_cache_zalloc()" call.Signed-off-by: Robert P. J. Day
Cc: "Luck, Tony"
Cc: Andi Kleen
Cc: Roland McGrath
Cc: James Bottomley
Cc: Greg KH
Acked-by: Joel Becker
Cc: Steven Whitehouse
Cc: Jan Kara
Cc: Michael Halcrow
Cc: "David S. Miller"
Cc: Stephen Smalley
Cc: James Morris
Cc: Chris Wright
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Dec, 2006
1 commit
-
Replace all uses of kmem_cache_t with struct kmem_cache.
The patch was generated using the following script:
#!/bin/sh
#
# Replace one string by another in all the kernel sources.
#set -e
for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
quilt add $file
sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
mv /tmp/$$ $file
quilt refresh
doneThe script was run like this
sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
