From: Prasanna S Panchamukhi <prasanna@in.ibm.com>
To: "Frank Ch. Eigler" <fche@redhat.com>
Cc: systemtap@sources.redhat.com
Subject: Re: kprobe fault handling
Date: Thu, 08 Sep 2005 11:52:00 -0000 [thread overview]
Message-ID: <20050908172206.GC2961@in.ibm.com> (raw)
In-Reply-To: <y0mhdcyi67a.fsf@toenail.toronto.redhat.com>
Hi Frank,
On Tue, Sep 06, 2005 at 11:09:13AM -0400, Frank Ch. Eigler wrote:
>
> prasanna wrote:
>
> > [...] yes, in situtations when fault_handler is executed, users can
> > either correct the faulty instruction and singlestep again or he can
> > just replace back the original instruction, disarm the probe and
> > continue. [...]
>
> Is there a modules-accessible kprobes API for disarming a probe on the
> fly?
There is a arch specific routine to disable the probes as shown below.
void arch_disarm_kprobe(struct kprobe *p)
{
*p->addr = p->opcode;
flush_icache_range((unsigned long) p->addr,
(unsigned long) p->addr + sizeof(kprobe_opcode_t));
}
> For example, if a probe handler does something crazy and branches to
> pc=0, I'd like to unwind/disable the handler, signal the situation,
> and let the kernel run along as if the probe wasn't there in the first
> place. It looks like this may not be all there now, so I will disable
> the new code in the translator code.
Is it enough to export the above routine in all architectures?
Thanks
Prasanna
--
Prasanna S Panchamukhi
Linux Technology Center
India Software Labs, IBM Bangalore
Ph: 91-80-25044636
<prasanna@in.ibm.com>
next prev parent reply other threads:[~2005-09-08 11:52 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-06 12:56 Prasanna S Panchamukhi
2005-09-06 15:09 ` Frank Ch. Eigler
2005-09-08 11:52 ` Prasanna S Panchamukhi [this message]
2005-09-08 17:42 ` Frank Ch. Eigler
-- strict thread matches above, loose matches on Subject: below --
2006-02-09 8:55 Mao, Bibo
2006-02-09 10:22 ` Richard J Moore
2006-02-07 22:19 Keshavamurthy, Anil S
2006-02-07 20:36 Keshavamurthy, Anil S
2006-02-07 20:48 ` Martin Hunt
2006-02-06 19:49 Martin Hunt
2006-02-07 0:51 ` Jim Keniston
2006-02-07 17:31 ` Jim Keniston
2006-02-07 17:50 ` Martin Hunt
2006-02-07 19:49 ` Jim Keniston
2006-02-08 4:38 ` Suparna Bhattacharya
2006-02-08 11:32 ` Richard J Moore
2006-02-09 7:23 ` Prasanna S Panchamukhi
2006-02-09 16:33 ` Keshavamurthy Anil S
2006-02-09 21:35 ` Jim Keniston
2006-02-09 22:06 ` Martin Hunt
2006-02-10 5:39 ` Martin Hunt
2006-02-10 21:46 ` Frank Ch. Eigler
2006-02-10 21:55 ` Martin Hunt
2006-02-10 22:12 ` Frank Ch. Eigler
2006-02-10 22:17 ` Martin Hunt
2006-02-10 22:20 ` Frank Ch. Eigler
2006-02-10 22:41 ` Martin Hunt
2006-02-10 22:47 ` Frank Ch. Eigler
2006-02-10 23:36 ` Martin Hunt
2006-02-11 0:49 ` Frank Ch. Eigler
2006-02-12 1:26 ` Martin Hunt
2006-02-13 13:39 ` Frank Ch. Eigler
2005-09-06 1:06 Frank Ch. Eigler
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