* kernel panic when kretprobe all system calls
@ 2005-09-24 18:05 lglyahoo-news
2005-09-24 19:42 ` Frank Ch. Eigler
0 siblings, 1 reply; 7+ messages in thread
From: lglyahoo-news @ 2005-09-24 18:05 UTC (permalink / raw)
To: systemtap
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Hi,
I wrote a very simple stp file:
#! stap -p4
probe begin
{
log("systemtap starting probe")
}
probe kernel.function("sys_*")
{
log("enter")
}
probe kernel.function("sys_*").return
{
log("leave")
}
probe end
{
log("Now end log")
}
After I ran this script, it will print out lots of
"enter" and "leave" as expected. But when I switched
to another console and tried to run any command(such
as ls), the kernel will panic.
I am using RHEL 4 Update 2. kernel is 2.6.9-17.EL
I tried to comment out the probe:
kernel.function("sys_*").return, it worked well, no
kernel panic again in spite of I was running some
commands in another console at the same time.
But if I commented out the probe:
kernel.function("sys_*"), still kernel panic.
So it seems that there is something wrong with
kretprobe.
I will try the latest kernel(2.6.13-2) tomorrow to
see if kretprobe still has this error.
___________________________________________________________
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http://cn.mail.yahoo.com
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kernel panic when kretprobe all system calls
2005-09-24 18:05 kernel panic when kretprobe all system calls lglyahoo-news
@ 2005-09-24 19:42 ` Frank Ch. Eigler
2005-09-26 15:55 ` Hien Nguyen
0 siblings, 1 reply; 7+ messages in thread
From: Frank Ch. Eigler @ 2005-09-24 19:42 UTC (permalink / raw)
To: systemtap; +Cc: lglyahoo-news
Hi -
> [... kretprobes on syscalls ...]
This has been seen before, and is being tracked as bug #1345 in
bugzilla. It has apparently been reproduced by the kretprobes
developers and is being debugged. More RAM seems to trigger the
bug less often.
- FChE
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kernel panic when kretprobe all system calls
2005-09-24 19:42 ` Frank Ch. Eigler
@ 2005-09-26 15:55 ` Hien Nguyen
2005-09-26 16:03 ` Frank Ch. Eigler
2005-11-08 2:31 ` Guang Lei Li
0 siblings, 2 replies; 7+ messages in thread
From: Hien Nguyen @ 2005-09-26 15:55 UTC (permalink / raw)
To: Frank Ch. Eigler; +Cc: systemtap, lglyahoo-news
Frank Ch. Eigler wrote:
>Hi -
>
>
>
>>[... kretprobes on syscalls ...]
>>
>>
>
>This has been seen before, and is being tracked as bug #1345 in
>bugzilla. It has apparently been reproduced by the kretprobes
>developers and is being debugged. More RAM seems to trigger the
>bug less often.
>
>- FChE
>
>
>
It helps if we don't insert return probes in sys_calls such as
sys_execve, sys_exit, sys_groupexit. Frank, can we tempory put an
retprobe embargo policy on those system calls?
Hien.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kernel panic when kretprobe all system calls
2005-09-26 15:55 ` Hien Nguyen
@ 2005-09-26 16:03 ` Frank Ch. Eigler
2005-09-26 16:28 ` Hien Nguyen
2005-11-08 2:31 ` Guang Lei Li
1 sibling, 1 reply; 7+ messages in thread
From: Frank Ch. Eigler @ 2005-09-26 16:03 UTC (permalink / raw)
To: Hien Nguyen; +Cc: systemtap
Hi -
On Mon, Sep 26, 2005 at 08:55:08AM -0700, Hien Nguyen wrote:
> [...]
> It helps if we don't insert return probes in sys_calls such as
> sys_execve, sys_exit, sys_groupexit.
Does that solve the problem completely? We would need to treat
similarly some of their subsidiary "noreturn" functions.
> Frank, can we tempory put an retprobe embargo policy on those system
> calls?
By policy, you mean code that blacklists certain functions from
probing? I was holding off until results from jkenisto's bug #1235
were collected.
- FChE
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kernel panic when kretprobe all system calls
2005-09-26 16:03 ` Frank Ch. Eigler
@ 2005-09-26 16:28 ` Hien Nguyen
0 siblings, 0 replies; 7+ messages in thread
From: Hien Nguyen @ 2005-09-26 16:28 UTC (permalink / raw)
To: Frank Ch. Eigler; +Cc: systemtap
Frank Ch. Eigler wrote:
>Hi -
>
>On Mon, Sep 26, 2005 at 08:55:08AM -0700, Hien Nguyen wrote:
>
>
>>[...]
>>Does that solve the problem completely? We would need to treat
>>similarly some of their subsidiary "noreturn" functions.
>>
>>
>>
It does seem solve a bulk of the problem (particularly excluding
sys_execve). So far those are the "noreturn" system calls (they 're also
tearing down task) that we know of.
>By policy, you mean code that blacklists certain functions from
>probing? I was holding off until results from jkenisto's bug #1235
>were collected.
>
>
>
Yes, put them on the blacklist.
Hien.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kernel panic when kretprobe all system calls
2005-09-26 15:55 ` Hien Nguyen
2005-09-26 16:03 ` Frank Ch. Eigler
@ 2005-11-08 2:31 ` Guang Lei Li
2005-11-10 0:37 ` Jim Keniston
1 sibling, 1 reply; 7+ messages in thread
From: Guang Lei Li @ 2005-11-08 2:31 UTC (permalink / raw)
To: systemtap; +Cc: fche, hien
systemtap-owner@sources.redhat.com wrote on 2005-09-26 23:55:08:
> Frank Ch. Eigler wrote:
>
> >Hi -
> >
> >>[... kretprobes on syscalls ...]
> >
> >This has been seen before, and is being tracked as bug #1345 in
> >bugzilla. It has apparently been reproduced by the kretprobes
> >developers and is being debugged. More RAM seems to trigger the
> >bug less often.
> >
> >- FChE
> >
> It helps if we don't insert return probes in sys_calls such as
> sys_execve, sys_exit, sys_groupexit. Frank, can we tempory put an
> retprobe embargo policy on those system calls?
>
> Hien.
>
Hi, how is the bug #1345 going now? I ran the latest systemTap to probe
all returns of syscalls on my x86, and still got kernel panic. Although
I didn't meet the same problem on my Power5 system, I think it is due to
the large RAM of it(15G)
I looked into the comments in the bugzilla, and found Hien has worked
out a fix for i386. But he abandoned his idea because of not portable.
So at present, will I avoid this problem only by not probing the return
of those syscalls in the blacklist? Is there a better solution now?
Thanks.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kernel panic when kretprobe all system calls
2005-11-08 2:31 ` Guang Lei Li
@ 2005-11-10 0:37 ` Jim Keniston
0 siblings, 0 replies; 7+ messages in thread
From: Jim Keniston @ 2005-11-10 0:37 UTC (permalink / raw)
To: Guang Lei Li; +Cc: SystemTAP, fche, Hien Nguyen
On Mon, 2005-11-07 at 18:30, Guang Lei Li wrote:
> systemtap-owner@sources.redhat.com wrote on 2005-09-26 23:55:08:
>
> > Frank Ch. Eigler wrote:
> >
> > >Hi -
> > >
> > >>[... kretprobes on syscalls ...]
> > >
> > >This has been seen before, and is being tracked as bug #1345 in
> > >bugzilla. It has apparently been reproduced by the kretprobes
> > >developers and is being debugged. More RAM seems to trigger the
> > >bug less often.
> > >
> > >- FChE
> > >
> > It helps if we don't insert return probes in sys_calls such as
> > sys_execve, sys_exit, sys_groupexit. Frank, can we tempory put an
> > retprobe embargo policy on those system calls?
> >
> > Hien.
> >
> Hi, how is the bug #1345 going now? I ran the latest systemTap to probe
> all returns of syscalls on my x86, and still got kernel panic. Although
> I didn't meet the same problem on my Power5 system, I think it is due to
> the large RAM of it(15G)
>
> I looked into the comments in the bugzilla, and found Hien has worked
> out a fix for i386. But he abandoned his idea because of not portable.
> So at present, will I avoid this problem only by not probing the return
> of those syscalls in the blacklist? Is there a better solution now?
>
> Thanks.
Hien and I have discussed an architecture-independent fix to kprobes
that would allow you to set return probes on "problem" functions such as
sys_execve without encountering the problems described in #1345. I've
updated the bugzilla entry.
Jim
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2005-11-10 0:37 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2005-09-24 18:05 kernel panic when kretprobe all system calls lglyahoo-news
2005-09-24 19:42 ` Frank Ch. Eigler
2005-09-26 15:55 ` Hien Nguyen
2005-09-26 16:03 ` Frank Ch. Eigler
2005-09-26 16:28 ` Hien Nguyen
2005-11-08 2:31 ` Guang Lei Li
2005-11-10 0:37 ` Jim Keniston
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