linux-stable.git/kernel/hrtimer.c, branch linux-2.6.24.y

hrtimer: catch expired CLOCK_REALTIME timers early

2008-02-26T00:18:57+00:00

commit 63070a79ba482c274bad10ac8c4b587a3e011f2c

A CLOCK_REALTIME timer, which has an absolute expiry time less than
the clock realtime offset calls with a negative delta into the clock
events code and triggers the WARN_ON() there.

This is a false positive and needs to be prevented. Check the result
of timer->expires - timer->base->offset right away and return -ETIME
right away.

Thanks to Frans Pop, who reported the problem and tested the fixes.

Signed-off-by: Thomas Gleixner 
Tested-by: Frans Pop 
Signed-off-by: Greg Kroah-Hartman

hrtimer: check relative timeouts for overflow

2008-02-26T00:18:57+00:00

commit: 5a7780e725d1bb4c3094fcc12f1c5c5faea1e988

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 
Signed-off-by: Greg Kroah-Hartman

hrtimer: fix *rmtp handling in hrtimer_nanosleep()

2008-02-26T00:18:56+00:00

commit 080344b98805553f9b01de0f59a41b1533036d8d

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 easier

Change 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 Gleixner 
Signed-off-by: Greg Kroah-Hartman

hrtimer: fix section mismatch

2008-01-22T03:39:41+00:00

Fix section mismatch in hrtimer.c:

WARNING: vmlinux.o(.text+0x50c61): Section mismatch: reference to .init.text: (between 'hrtimer_cpu_notify' and 'down_read_trylock')

Noticed by Johannes Berg and confirmed by Sam Ravnborg.

Signed-off-by: Randy Dunlap 
Cc: Sam Ravnborg 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

hrtimers: avoid overflow for large relative timeouts

2007-12-07T18:16:17+00:00

Relative hrtimers with a large timeout value might end up as negative
timer values, when the current time is added in hrtimer_start().

This in turn is causing the clockevents_set_next() function to set an
huge timeout and sleep for quite a long time when we have a clock
source which is capable of long sleeps like HPET. With PIT this almost
goes unnoticed as the maximum delta is ~27ms. The non-hrt/nohz code
sorts this out in the next timer interrupt, so we never noticed that
problem which has been there since the first day of hrtimers.

This bug became more apparent in 2.6.24 which activates HPET on more
hardware.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

Quieten hrtimer printk: "Switched to high resolution mode .."

2007-10-29T08:39:38+00:00

Change the hrtimer printk "Switched to high resolution mode .." to
be KERN_DEBUG, rather than KERN_INFO. If users need to see this they
can pass "loglevel" or "debug" on the command line, or check dmesg.

Signed-off-by: Michael Ellerman 
Signed-off-by: Thomas Gleixner 

 kernel/hrtimer.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

fix comment: unlock_hrtimer_base is the counterpart of lock_hrtimer_base

2007-10-19T23:56:53+00:00

Signed-off-by: Uwe Kleine-König 
Signed-off-by: Adrian Bunk

Fix misspellings of "system", "controller", "interrupt" and "necessary".

2007-10-19T21:10:43+00:00

Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day 
Signed-off-by: Adrian Bunk

hrtimer: Rework hrtimer_nanosleep to make sys_compat_nanosleep easier

2007-10-18T20:54:18+00:00

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

[KTIME]: Introduce ktime_sub_ns and ktime_sub_us

2007-10-10T23:48:12+00:00

First user will be the DCCP transport networking protocol.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller