Commit Graph

1296 Commits

Author SHA1 Message Date
Thomas Gleixner
c5780e976e [PATCH] Use the correct restart option for futex_lock_pi
The current implementation of futex_lock_pi returns -ERESTART_RESTARTBLOCK
in case that the lock operation has been interrupted by a signal.  This
results in a return of -EINTR to userspace in case there is an handler for
the signal.  This is wrong, because userspace expects that the lock
function does not return in any case of signal delivery.

This was not caught by my insufficient test case, but triggered a nasty
userspace problem in an high load application scenario.  Unfortunately also
glibc does not check for this invalid return value.

Using -ERSTARTNOINTR makes sure, that the interrupted syscall is restarted.
 The restart block related code can be safely removed, as the possible
timeout argument is an absolute time value.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-08 10:22:50 -07:00
Ingo Molnar
068c4579fe [PATCH] lockdep: do not touch console state when tainting the kernel
Remove an unintended console_verbose() side-effect from add_taint().

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-06 11:00:02 -07:00
Pavel Machek
471b40d0df [PATCH] prevent swsusp with PAE
PAE + swsusp results in hard-to-debug crash about 50% of time during
resume.  Cause is known, fix needs to be ported from x86-64 (but we can't
make it to 2.6.18, and I'd like this to be worked around in 2.6.18).

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-06 11:00:02 -07:00
Jarek Poplawski
fc47e7b592 [PATCH] lockdep ifdef fix
With

	CONFIG_SMP=y
	CONFIG_PREEMPT=y
	CONFIG_LOCKDEP=y
	CONFIG_DEBUG_LOCK_ALLOC=y
	# CONFIG_PROVE_LOCKING is not set

spin_unlock_irqrestore() goes through lockdep but spin_lock_irqsave() doesn't.
Apparently, bad things happen.

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-06 11:00:01 -07:00
Oleg Nesterov
3b6362b833 [PATCH] eligible_child: remove an obsolete ->tgid check
It is not possible to find a sub-thread in ->children/->ptrace_children
lists, ptrace_attach() does not allow to attach to sub-threads.

Even if it was possible to ptrace the task from the same thread group,
we can't allow to release ->group_leader while there are others (ptracer)
threads in the same group.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-02 14:51:27 -07:00
Henrik Kretzschmar
43a1dd502f [PATCH] kerneldoc for handle_bad_irq()
Adds the description of the parameters from handle_bad_irq().

Signed-off-by: Henrik Kretzschmar <henne@nachtwindheim.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-01 11:39:09 -07:00
Shailabh Nagar
35df17c57c [PATCH] task delay accounting fixes
Cleanup allocation and freeing of tsk->delays used by delay accounting.
This solves two problems reported for delay accounting:

1. oops in __delayacct_blkio_ticks
http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1844.html

Currently tsk->delays is getting freed too early in task exit which can
cause a NULL tsk->delays to get accessed via reading of /proc/<tgid>/stats.
 The patch fixes this problem by freeing tsk->delays closer to when
task_struct itself is freed up.  As a result, it also eliminates the use of
tsk->delays_lock which was only being used (inadequately) to safeguard
access to tsk->delays while a task was exiting.

2. Possible memory leak in kernel/delayacct.c
http://www.uwsg.indiana.edu/hypermail/linux/kernel/0608.2/1389.html

The patch cleans up tsk->delays allocations after a bad fork which was
missing earlier.

The patch has been tested to fix the problems listed above and stress
tested with rapid calls to delay accounting's taskstats command interface
(which is the other path that can access the same data, besides the /proc
interface causing the oops above).

Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-01 11:39:08 -07:00
Nick Piggin
0d673a5a47 [PATCH] cpuset: oom panic fix
cpuset_excl_nodes_overlap always returns 0 if current is exiting.  This caused
customer's systems to panic in the OOM killer when processes were having
trouble getting memory for the final put_user in mm_release.  Even though
there were lots of processes to kill.

Change to returning 1 in this case.  This achieves parity with !CONFIG_CPUSETS
case, and was observed to fix the problem.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:32 -07:00
Paul Jackson
4c4d50f7b3 [PATCH] cpuset: top_cpuset tracks hotplug changes to cpu_online_map
Change the list of cpus allowed to tasks in the top (root) cpuset to
dynamically track what cpus are online, using a CPU hotplug notifier.  Make
this top cpus file read-only.

On systems that have cpusets configured in their kernel, but that aren't
actively using cpusets (for some distros, this covers the majority of
systems) all tasks end up in the top cpuset.

If that system does support CPU hotplug, then these tasks cannot make use
of CPUs that are added after system boot, because the CPUs are not allowed
in the top cpuset.  This is a surprising regression over earlier kernels
that didn't have cpusets enabled.

In order to keep the behaviour of cpusets consistent between systems
actively making use of them and systems not using them, this patch changes
the behaviour of the 'cpus' file in the top (root) cpuset, making it read
only, and making it automatically track the value of cpu_online_map.  Thus
tasks in the top cpuset will have automatic use of hot plugged CPUs allowed
by their cpuset.

Thanks to Anton Blanchard and Nathan Lynch for reporting this problem,
driving the fix, and earlier versions of this patch.

Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Nathan Lynch <ntl@pobox.com>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:32 -07:00
Yingchao Zhou
4edb9a143e [PATCH] Remove redundant up() in stop_machine()
An up() is called in kernel/stop_machine.c on failure, and also in the
caller (unconditionally).

Signed-off-by: Zhou Yingchao <yingchao.zhou@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:31 -07:00
Oleg Nesterov
d015baebba [PATCH] futex_find_get_task(): remove an obscure EXIT_ZOMBIE check
futex_find_get_task:

	if (p->state == EXIT_ZOMBIE || p->exit_state == EXIT_ZOMBIE)
		return NULL;

I can't understand this.  First, p->state can't be EXIT_ZOMBIE.  The
->exit_state check looks strange too.  Sub-threads or tasks whose ->parent
ignores SIGCHLD go directly to EXIT_DEAD state (I am ignoring a ptrace
case).  Why EXIT_DEAD tasks should be ok?  Yes, EXIT_ZOMBIE is more
important (a task may stay zombie for a long time), but this doesn't mean
we should explicitely ignore other EXIT_XXX states.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:30 -07:00
Oleg Nesterov
f8986c241d [PATCH] revert "Drop tasklist lock in do_sched_setscheduler"
sched_setscheduler() looks at ->signal->rlim[].  It is unsafe do
dereference ->signal unless tasklist_lock or ->siglock is held (or p ==
current).  We pin the task structure, but this can't prevent from
release_task()->__exit_signal() which sets ->signal = NULL.

Restore tasklist_lock across the setscheduler call.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-27 11:01:29 -07:00
Andrew Morton
9b41ea7289 [PATCH] workqueue: remove lock_cpu_hotplug()
Use a private lock instead.  It protects all per-cpu data structures in
workqueue.c, including the workqueues list.

Fix a bug in schedule_on_each_cpu(): it was forgetting to lock down the
per-cpu resources.

Unfixed long-standing bug: if someone unplugs the CPU identified by
`singlethread_cpu' the kernel will get very sick.

Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:29 -07:00
john stultz
e579dcbf23 [PATCH] futex_handle_fault always fails
We found this issue last week w/ the -RT kernel, but it seems the same
issue is in mainline as well.

Basically it is possible for futex_unlock_pi to return without actually
freeing the lock.  This is due to buggy logic in the use of
futex_handle_fault() and its attempt argument in a failure case.

Looking at futex.c the logic is as follows:

1) In futex_unlock_pi() we start w/ ret=0 and we go down to the first
   futex_atomic_cmpxchg_inatomic(), where we find uval==-EFAULT.  We then
   jump to the pi_faulted label.

2) From pi_faulted: We increment attempt, unlock the sem and hit the
   retry label.

3) From the retry label, with ret still zero, we again hit EFAULT on the
   first futex_atomic_cmpxchg_inatomic(), and again goto the pi_faulted
   label.

4) Again from pi_faulted: we increment attempt and enter the
   conditional, where we call futex_handle_fault.

5) futex_handle_fault fails, and we goto the out_unlock_release_sem
   label.

6) From out_unlock_release_sem we return, and since ret is still zero,
   we return without error, while never actually unlocking the lock.

Issue #1: at the first futex_atomic_cmpxchg_inatomic() we should probably
be setting ret=-EFAULT before jumping to pi_faulted: However in our case
this doesn't really affect anything, as the glibc we're using ignores the
error value from futex_unlock_pi().

Issue #2: Look at futex_handle_fault(), its first conditional will return
-EFAULT if attempt is >= 2.  However, from the "if(attempt++)
futex_handle_fault(attempt)" logic above, we'll *never* call
futex_handle_fault when attempt is less then two.  So we never get a chance
to even try to fault the page in.

The following patch addresses these two issues by 1) Always setting ret to
-EFAULT if futex_handle_fault fails, and 2) Removing the = in
futex_handle_fault's (attempt >= 2) check.

I'm really not sure this is the right fix, but wanted to bring it up so
folks knew the issue is alive and well in the current -git tree.  From
looking at the git logs the logic was first introduced (then later copied
to other places) in the following commit almost a year ago:

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=4732efbeb997189d9f9b04708dc26bf8613ed721;hp=5b039e681b8c5f30aac9cc04385cc94be45d0823

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:29 -07:00
Kirill Korotaev
6997a6faaa [PATCH] sys_getppid oopses on debug kernel
sys_getppid() optimization can access a freed memory.  On kernels with
DEBUG_SLAB turned ON, this results in Oops.  As Dave Hansen noted, this
optimization is also unsafe for memory hotplug.

So this patch always takes the lock to be safe.

[oleg@tv-sign.ru: simplifications]
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Cc: <stable@kernel.org>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:29 -07:00
Andrew Morton
657b3010d8 [PATCH] panic.c build fix
kernel/panic.c: In function 'add_taint':
kernel/panic.c:176: warning: implicit declaration of function 'debug_locks_off'

Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:28 -07:00
Jan Blunck
3773dc9205 [PATCH] fix hrtimer percpu usage typo
The percpu variable is used incorrectly in switch_hrtimer_base().

Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-08-14 12:54:28 -07:00
Thomas Gleixner
ce2c6b5384 [PATCH] futex: Apply recent futex fixes to futex_compat
The recent fixups in futex.c need to be applied to futex_compat.c too.  Fixes
a hang reported by Olaf.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Olaf Hering <olh@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:49 -07:00
KAMEZAWA Hiroyuki
58c1b5b079 [PATCH] memory hotadd fixes: find_next_system_ram catch range fix
find_next_system_ram() is used to find available memory resource at onlining
newly added memory.  This patch fixes following problem.

find_next_system_ram() cannot catch this case.

Resource:      (start)-------------(end)
Section :                (start)-------------(end)

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Keith Mannthey <kmannth@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:48 -07:00
KAMEZAWA Hiroyuki
0f04ab5efb [PATCH] memory hotadd fixes: change find_next_system_ram's return value manner
find_next_system_ram() returns valid memory range which meets requested area,
only used by memory-hot-add.

This function always rewrite requested resource even if returned area is not
fully fit in requested one.  And sometimes the returnd resource is larger than
requested area.  This annoyes the caller.  This patch changes the returned
value to fit in requested area.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Keith Mannthey <kmannth@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:48 -07:00
Antonino A. Daplas
78944e549d [PATCH] vt: printk: Fix framebuffer console triggering might_sleep assertion
Reported by: Dave Jones

Whilst printk'ing to both console and serial console, I got this...
(2.6.18rc1)

BUG: sleeping function called from invalid context at kernel/sched.c:4438
in_atomic():0, irqs_disabled():1

Call Trace:
 [<ffffffff80271db8>] show_trace+0xaa/0x23d
 [<ffffffff80271f60>] dump_stack+0x15/0x17
 [<ffffffff8020b9f8>] __might_sleep+0xb2/0xb4
 [<ffffffff8029232e>] __cond_resched+0x15/0x55
 [<ffffffff80267eb8>] cond_resched+0x3b/0x42
 [<ffffffff80268c64>] console_conditional_schedule+0x12/0x14
 [<ffffffff80368159>] fbcon_redraw+0xf6/0x160
 [<ffffffff80369c58>] fbcon_scroll+0x5d9/0xb52
 [<ffffffff803a43c4>] scrup+0x6b/0xd6
 [<ffffffff803a4453>] lf+0x24/0x44
 [<ffffffff803a7ff8>] vt_console_print+0x166/0x23d
 [<ffffffff80295528>] __call_console_drivers+0x65/0x76
 [<ffffffff80295597>] _call_console_drivers+0x5e/0x62
 [<ffffffff80217e3f>] release_console_sem+0x14b/0x232
 [<ffffffff8036acd6>] fb_flashcursor+0x279/0x2a6
 [<ffffffff80251e3f>] run_workqueue+0xa8/0xfb
 [<ffffffff8024e5e0>] worker_thread+0xef/0x122
 [<ffffffff8023660f>] kthread+0x100/0x136
 [<ffffffff8026419e>] child_rip+0x8/0x12

This can occur when release_console_sem() is called but the log
buffer still has contents that need to be flushed. The console drivers
are called while the console_may_schedule flag is still true. The
might_sleep() is triggered when fbcon calls console_conditional_schedule().

Fix by setting console_may_schedule to zero earlier, before the call to the
console drivers.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:47 -07:00
Chuck Ebbert
9f59ce5d0e [PATCH] ptrace: make pid of child process available for PTRACE_EVENT_VFORK_DONE
When delivering PTRACE_EVENT_VFORK_DONE, provide pid of the child process
when tracer calls ptrace(PTRACE_GETEVENTMSG).  This is already
(accidentally) available when the tracer is tracing VFORK in addition to
VFORK_DONE.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Cc: Daniel Jacobowitz <dan@debian.org>
Cc: Albert Cahalan <acahalan@gmail.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:46 -07:00
Christian Borntraeger
e91467ecd1 [PATCH] bug in futex unqueue_me
This patch adds a barrier() in futex unqueue_me to avoid aliasing of two
pointers.

On my s390x system I saw the following oops:

Unable to handle kernel pointer dereference at virtual kernel address
0000000000000000
Oops: 0004 [#1]
CPU:    0    Not tainted
Process mytool (pid: 13613, task: 000000003ecb6ac0, ksp: 00000000366bdbd8)
Krnl PSW : 0704d00180000000 00000000003c9ac2 (_spin_lock+0xe/0x30)
Krnl GPRS: 00000000ffffffff 000000003ecb6ac0 0000000000000000 0700000000000000
           0000000000000000 0000000000000000 000001fe00002028 00000000000c091f
           000001fe00002054 000001fe00002054 0000000000000000 00000000366bddc0
           00000000005ef8c0 00000000003d00e8 0000000000144f91 00000000366bdcb8
Krnl Code: ba 4e 20 00 12 44 b9 16 00 3e a7 84 00 08 e3 e0 f0 88 00 04
Call Trace:
([<0000000000144f90>] unqueue_me+0x40/0xe4)
 [<0000000000145a0c>] do_futex+0x33c/0xc40
 [<000000000014643e>] sys_futex+0x12e/0x144
 [<000000000010bb00>] sysc_noemu+0x10/0x16
 [<000002000003741c>] 0x2000003741c

The code in question is:

static int unqueue_me(struct futex_q *q)
{
        int ret = 0;
        spinlock_t *lock_ptr;

        /* In the common case we don't take the spinlock, which is nice. */
 retry:
        lock_ptr = q->lock_ptr;
        if (lock_ptr != 0) {
                spin_lock(lock_ptr);
		/*
                 * q->lock_ptr can change between reading it and
                 * spin_lock(), causing us to take the wrong lock.  This
                 * corrects the race condition.
[...]

and my compiler (gcc 4.1.0) makes the following out of it:

00000000000003c8 <unqueue_me>:
     3c8:       eb bf f0 70 00 24       stmg    %r11,%r15,112(%r15)
     3ce:       c0 d0 00 00 00 00       larl    %r13,3ce <unqueue_me+0x6>
                        3d0: R_390_PC32DBL      .rodata+0x2a
     3d4:       a7 f1 1e 00             tml     %r15,7680
     3d8:       a7 84 00 01             je      3da <unqueue_me+0x12>
     3dc:       b9 04 00 ef             lgr     %r14,%r15
     3e0:       a7 fb ff d0             aghi    %r15,-48
     3e4:       b9 04 00 b2             lgr     %r11,%r2
     3e8:       e3 e0 f0 98 00 24       stg     %r14,152(%r15)
     3ee:       e3 c0 b0 28 00 04       lg      %r12,40(%r11)
		/* write q->lock_ptr in r12 */
     3f4:       b9 02 00 cc             ltgr    %r12,%r12
     3f8:       a7 84 00 4b             je      48e <unqueue_me+0xc6>
		/* if r12 is zero then jump over the code.... */
     3fc:       e3 20 b0 28 00 04       lg      %r2,40(%r11)
		/* write q->lock_ptr in r2 */
     402:       c0 e5 00 00 00 00       brasl   %r14,402 <unqueue_me+0x3a>
                        404: R_390_PC32DBL      _spin_lock+0x2
		/* use r2 as parameter for spin_lock */

So the code becomes more or less:
if (q->lock_ptr != 0) spin_lock(q->lock_ptr)
instead of
if (lock_ptr != 0) spin_lock(lock_ptr)

Which caused the oops from above.
After adding a barrier gcc creates code without this problem:
[...] (the same)
     3ee:       e3 c0 b0 28 00 04       lg      %r12,40(%r11)
     3f4:       b9 02 00 cc             ltgr    %r12,%r12
     3f8:       b9 04 00 2c             lgr     %r2,%r12
     3fc:       a7 84 00 48             je      48c <unqueue_me+0xc4>
     400:       c0 e5 00 00 00 00       brasl   %r14,400 <unqueue_me+0x38>
                        402: R_390_PC32DBL      _spin_lock+0x2

As a general note, this code of unqueue_me seems a bit fishy. The retry logic
of unqueue_me only works if we can guarantee, that the original value of
q->lock_ptr is always a spinlock (Otherwise we overwrite kernel memory). We
know that q->lock_ptr can change. I dont know what happens with the original
spinlock, as I am not an expert with the futex code.

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@timesys.com>
Signed-off-by: Christian Borntraeger <borntrae@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:46 -07:00
Rafael J. Wysocki
a7ef7878ea [PATCH] Make suspend possible with a traced process at a breakpoint
It should be possible to suspend, either to RAM or to disk, if there's a
traced process that has just reached a breakpoint.  However, this is a
special case, because its parent process might have been frozen already and
then we are unable to deliver the "freeze" signal to the traced process.
If this happens, it's better to cancel the freezing of the traced process.

Ref. http://bugzilla.kernel.org/show_bug.cgi?id=6787

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-06 08:57:45 -07:00
Al Viro
3f2792ffbd [PATCH] take filling ->pid, etc. out of audit_get_context()
move that stuff downstream and into the only branch where it'll be
used.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:59:51 -04:00
Al Viro
5ac3a9c26c [PATCH] don't bother with aux entires for dummy context
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:59:42 -04:00
Al Viro
d51374adf5 [PATCH] mark context of syscall entered with no rules as dummy
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:59:26 -04:00
Al Viro
471a5c7c83 [PATCH] introduce audit rules counter
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:55:18 -04:00
Amy Griffis
5422e01ac1 [PATCH] fix audit oops with invalid operator
Michael C Thompson wrote:  [Tue Aug 01 2006, 02:36:36PM EDT]
> The trigger for this oops is:
> # auditctl -a exit,always -S pread64 -F 'inode<1'

Setting the err value will fix it.

Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:54:43 -04:00
Amy Griffis
6988434ee5 [PATCH] fix oops with CONFIG_AUDIT and !CONFIG_AUDITSYSCALL
Always initialize the audit_inode_hash[] so we don't oops on list rules.

Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:50:39 -04:00
Amy Griffis
73d3ec5aba [PATCH] fix missed create event for directory audit
When an object is created via a symlink into an audited directory, audit misses
the event due to not having collected the inode data for the directory.  Modify
__audit_inode_child() to copy the parent inode data if a parent wasn't found in
audit_names[].

Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:50:30 -04:00
Amy Griffis
3e2efce067 [PATCH] fix faulty inode data collection for open() with O_CREAT
When the specified path is an existing file or when it is a symlink, audit
collects the wrong inode number, which causes it to miss the open() event.
Adding a second hook to the open() path fixes this.

Also add audit_copy_inode() to consolidate some code.

Signed-off-by: Amy Griffis <amy.griffis@hp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-08-03 10:50:21 -04:00
Linus Torvalds
ae74c3b69a Fix force_sig_info() semantics after cleanups
Suresh points out that commit b0423a0d9c
broke the semantics of a synchronous signal like SIGSEGV occurring
recursively inside its own handler handler (or, indeed, any other
context when the signal was blocked).

That was unintentional, and this fixes things up by reinstating the old
semantics, but without reverting the cleanups.

Cc: Paul E. McKenney <paulmck@us.ibm.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-08-02 20:17:49 -07:00
Josh Triplett
51d8c5edd3 [PATCH] timer: Fix tvec_bases initializer
kernel/timer.c defines a (per-cpu) pointer to tvec_base_t, but initializes
it using { &a_tvec_base_t }, which sparse warns about; change this to just
&a_tvec_base_t.

Signed-off-by: Josh Triplett <josh@freedesktop.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:44 -07:00
Steven Rostedt
d07fe82c24 [PATCH] reference rt-mutex-design in rtmutex.c
In order to prevent Doc Rot, this patch adds a reference to the design
document for rtmutex.c in rtmutex.c.  So when someone needs to update or
change the design of that file they will know that a document actually
exists that explains the design (helping them change it), and hopefully
that they will update the document if they too change the design.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:43 -07:00
Tim Chen
3c829c367a [PATCH] Reducing local_bh_enable/disable overhead in irqtrace
The recent changes from irqtrace feature has added overheads to
local_bh_disable and local_bh_enable that reduces UDP performance across
x86_64 and IA64, even though IA64 does not support the irqtrace feature.
Patch in question is

[PATCH]lockdep: irqtrace subsystem, core
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=c
ommit;h=de30a2b355ea85350ca2f58f3b9bf4e5bc007986

Prior to this patch, local_bh_disable was a short macro.  Now it is a
function which calls __local_bh_disable with added irq flags save and
restore.  The irq flags save and restore were also added to
local_bh_enable, probably for injecting the trace irqs code.

This overhead is on the generic code path across all architectures.  On a
IA_64 test machine (Itanium-2 1.6 GHz) running a benchmark like netperf's
UDP streaming test, the added overhead results in a drop of 3% in
throughput, as udp_sendmsg calls the local_bh_enable/disable several times.

Other workloads that have heavy usages of local_bh_enable/disable could
also be affected.  The patch ideally should not have affected IA-64
performance as it does not have IRQ tracing support.  A significant portion
of the overhead is in the added irq flags save and restore, which I think
is not needed if IRQ tracing is unused.  A suggested patch is attached
below that recovers the lost performance.  However, the "ifdef"s in the
patch are a bit ugly.

Signed-off-by: Tim Chen <tim.c.chen@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:42 -07:00
Heiko Carstens
b50f60ceee [PATCH] pi-futex: missing pi_waiters plist initialization
Initialize init task's pi_waiters plist.  Otherwise cpu hotplug of cpu 0
might crash, since rt_mutex_getprio() accesses an uninitialized list head.

call chain which led to crash:

take_cpu_down
sched_idle_next
__setscheduler
rt_mutex_getprio

Using PLIST_HEAD_INIT in the INIT_TASK macro doesn't work unfortunately,
since the pi_waiters member is only conditionally present.

Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:41 -07:00
Rolf Eike Beer
0fcb78c22f [PATCH] Add DocBook documentation for workqueue functions
kernel/workqueue.c was omitted from generating kernel documentation.  This
adds a new section "Workqueues and Kevents" and adds documentation for some
of the functions.

Some functions in this file already had DocBook-style comments, now they
finally become visible.

Signed-off-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:40 -07:00
Jim Houston
2d7d253548 [PATCH] fix cond_resched() fix
In cond_resched_lock() it calls __resched_legal() before dropping the spin
lock.  __resched_legal() will always finds the preempt_count non-zero and
will prevent the call to __cond_resched().

The attached patch adds a parameter to __resched_legal() with the expected
preempt_count value.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:40 -07:00
Steven Rostedt
6ea24f9ad1 [PATCH] fix bad macro param in timer.c
We have

#define INDEX(N) (base->timer_jiffies >> (TVR_BITS + N * TVN_BITS)) & TVN_MASK

and it's used via

	list = varray[i + 1]->vec + (INDEX(i + 1));

So, due to underparenthesisation, this INDEX(i+1) is now a ...  (TVR_BITS + i
+ 1 * TVN_BITS)) ...

So this bugfix changes behaviour.  It worked before by sheer luck:

  "If i was anything but 0, it was broken.  But this was only used by
   s390 and arm.  Since it was for the next interrupt, could that next
   interrupt be a problem (going into the second cascade)? But it was
   probably seldom wrong.  That is, this would fail if the next
   interrupt was in the second cascade, and was wrapped.  Which may
   never of happened.  Also if it did happen, it would have just missed
   the interrupt.

   If an interrupt was missed, and no one was there to miss it, was it
   really missed :-)"

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:40 -07:00
Chandra Seetharaman
8c78f3075d [PATCH] cpu hotplug: replace __devinit* with __cpuinit* for cpu notifications
Few of the callback functions and notifier blocks that are associated with cpu
notifications incorrectly have __devinit and __devinitdata.  They should be
__cpuinit and __cpuinitdata instead.

It makes no functional difference but wastes text area when CONFIG_HOTPLUG is
enabled and CONFIG_HOTPLUG_CPU is not.

This patch fixes all those instances.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:39 -07:00
bibo, mao
a9ad965ea9 [PATCH] IA64: kprobe invalidate icache of jump buffer
Kprobe inserts breakpoint instruction in probepoint and then jumps to
instruction slot when breakpoint is hit, the instruction slot icache must
be consistent with dcache.  Here is the patch which invalidates instruction
slot icache area.

Without this patch, in some machines there will be fault when executing
instruction slot where icache content is inconsistent with dcache.

Signed-off-by: bibo,mao <bibo.mao@intel.com>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Keshavamurthy Anil S <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:38 -07:00
Shailabh Nagar
163ecdff06 [PATCH] delay accounting: temporarily enable by default
Enable delay accounting by default so that feature gets coverage testing
without requiring special measures.

Earlier, it was off by default and had to be enabled via a boot time param.
 This patch reverses the default behaviour to improve coverage testing.  It
can be removed late in the kernel development cycle if its believed users
shouldn't have to incur any cost if they don't want delay accounting.  Or
it can be retained forever if the utility of the stats is deemed common
enough to warrant keeping the feature on.

Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:37 -07:00
Shailabh Nagar
d94a041519 [PATCH] taskstats: free skb, avoid returns in send_cpu_listeners
Add a missing freeing of skb in the case there are no listeners at all.
Also remove the returning of error values by the function as it is unused
by the sole caller.

Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:37 -07:00
Shailabh Nagar
7d94dddd43 [PATCH] make taskstats sending completely independent of delay accounting on/off status
Complete the separation of delay accounting and taskstats by ignoring the
return value of delay accounting functions that fill in parts of taskstats
before it is sent out (either in response to a command or as part of a task
exit).

Also make delayacct_add_tsk return silently when delay accounting is turned
off rather than treat it as an error.

Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:37 -07:00
David Brownell
15a647eba9 [PATCH] genirq: {en,dis}able_irq_wake() need refcounting too
IRQs need refcounting and a state flag to track whether the the IRQ should
be enabled or disabled as a "normal IRQ" source after a series of calls to
{en,dis}able_irq().  For shared IRQs, the IRQ must be enabled so long as at
least one driver needs it active.

Likewise, IRQs need the same support to track whether the IRQ should be
enabled or disabled as a "wakeup event" source after a series of calls to
{en,dis}able_irq_wake().  For shared IRQs, the IRQ must be enabled as a
wakeup source during sleep so long as at least one driver needs it.  But
right now they _don't have_ that refcounting ...  which means sharing a
wakeup-capable IRQ can't work correctly in some configurations.

This patch adds the refcount and flag mechanisms to set_irq_wake() -- which
is what {en,dis}able_irq_wake() call -- and minimal documentation of what
the irq wake mechanism does.

Drivers relying on the older (broken) "toggle" semantics will trigger a
warning; that'll be a handful of drivers on ARM systems.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:36 -07:00
Siddha, Suresh B
f712c0c7e1 [PATCH] sched: build_sched_domains() fix
Use the correct groups while initializing sched groups power for
allnodes_domain.  This fixes the crash observed while creating exclusive
cpusets.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Reported-and-tested-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-31 13:28:36 -07:00
Ingo Molnar
e3f2ddeac7 [PATCH] pi-futex: robust-futex exit
Fix robust PI-futexes to be properly unlocked on unexpected exit.

For this to work the kernel has to know whether a futex is a PI or a
non-PI one, because the semantics are different.  Since the space in
relevant glibc data structures is extremely scarce, the best solution is
to encode the 'PI' information in bit 0 of the robust list pointer.
Existing (non-PI) glibc robust futexes have this bit always zero, so the
ABI is kept.  New glibc with PI-robust-futexes will set this bit.

Further fixes from Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-28 21:02:00 -07:00
Ingo Molnar
627371d73c [PATCH] pi-futex: robust-futex exit crash fix
Fix pi_state->list handling bugs: list handling mishap, locking error.
Plus add more debug checks and fix a few style issues i noticed while
debugging this.

(reported by Ulrich Drepper and Jakub Jelinek.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-28 21:02:00 -07:00
Paul Jackson
abb5a5cc6b [PATCH] Cpuset: fix ABBA deadlock with cpu hotplug lock
Fix ABBA deadlock between lock_cpu_hotplug() and the cpuset
callback_mutex lock.

It only happens on cpu_exclusive cpusets, due to the dynamic
sched domain code trying to take the cpu hotplug lock inside
the cpuset callback_mutex lock.

This bug has apparently been here for several months, but didn't
get hit until the right customer load on a large system.

This fix appears right from inspection, but it will take a few
more days running it on that customers workload to be confident
we nailed it.  We don't have any other reproducible test case.

The cpu_hotplug_lock() tends to cover large runs of code.
The other places that hold both that lock and the cpuset callback
mutex lock always nest the cpuset lock inside the hotplug lock.
This place tries to do the reverse, risking an ABBA deadlock.

This is in the cpuset_rmdir() code, where we:
  * take the callback_mutex lock
  * mark the cpuset CS_REMOVED
  * call update_cpu_domains for cpu_exclusive cpusets
  * in that call, take the cpu_hotplug lock if the
    cpuset is marked for removal.

Thanks to Jack Steiner for identifying this deadlock.

The fix is to tear down the dynamic sched domain before we grab
the cpuset callback_mutex lock.  This way, the two locks are
serialized, with the hotplug lock taken and released before
trying for the cpuset lock.

I suspect that this bug was introduced when I changed the
cpuset locking from one lock to two.  The dynamic sched domain
dependency on cpu_exclusive cpusets and its hotplug hooks were
added to this code earlier, when cpusets had only a single lock.
It may well have been fine then.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-23 13:03:05 -07:00