Date: Fri, 24 Aug 2001 10:21:27 +0930 From: Greg Lehey <grog@FreeBSD.org> To: John Baldwin <jhb@FreeBSD.org> Cc: cvs-all@FreeBSD.org, cvs-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/conf options src/sys/i386/conf NOTES src Message-ID: <20010824102127.A21776@wantadilla.lemis.com> In-Reply-To: <XFMail.010823172710.jhb@FreeBSD.org>; from jhb@FreeBSD.org on Thu, Aug 23, 2001 at 05:27:10PM -0700 References: <20010824095113.E9221@wantadilla.lemis.com> <XFMail.010823172710.jhb@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thursday, 23 August 2001 at 17:27:10 -0700, John Baldwin wrote:
>
> On 24-Aug-01 Greg Lehey wrote:
>> On Thursday, 23 August 2001 at 13:32:21 -0700, John Baldwin wrote:
>>> jhb 2001/08/23 13:32:21 PDT
>>>
>>> Modified files:
>>> sys/conf options
>>> sys/i386/conf NOTES
>>> sys/kern kern_shutdown.c
>>> sys/sys param.h
>>> Log:
>>> Add a new kernel option RESTARTABLE_PANICS. If this option is present,
>>> then one can restart from a panic by resetting the panicstr variable to
>>> NULL. This commit conditionalizes the previously committed functionality
>>> on this variable. It also removes the __dead2 attribute from the panic()
>>> function so that when one continues from a panic() the behavior will
>>> be predictable.
>>
>> The only way I can see to restart from a panic is to enter the
>> debugger and then return, and your code seems to bear this out. Am I
>> missing something? I would think that we can always return from the
>> debugger if we want to continue, and that the RESTARTABLE_PANICS and
>> check for null format string are not necessary. Are you concerned
>> about people who will return from the debugger when they don't mean
>> to? There are plenty of other ways to shoot down the system from the
>> debugger.
>
> Err. If you continue from the debugger, the panic() function calls boot() which
> reboots the system. If you chagne panicstr to NULL, then we don't call boot()
> but return from panic(), thus effectively turning the panic() into a
> Debugger().
So reset the panic string.
#if defined(DDB)
if (debugger_on_panic) {
Debugger ("panic");
panicstr = NULL;
#ifdef SMP
atomic_store_rel_int(&panic_cpu, NOCPU);
#endif
return;
}
#endif
boot(bootopt);
Greg
--
See complete headers for address and phone numbers
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010824102127.A21776>