cvs commit: src/sys/alpha/alpha support.s src/sys/i386/i386 swtch.s src/sys/kern kern_shutdown.c src/sys/sys systm.h

[Don Lewis]

On 20 Jan, Nate Lawson wrote:
> On Wed, 21 Jan 2004, Greg 'groggy' Lehey wrote:
>> On Tuesday, 20 January 2004 at 11:31:03 -0800, Nate Lawson wrote:
>> > * GDB over Ethernet
>>
>> We have GDB over firewire.  Ethernet would be nice too, but firewire
>> actually does more.  Take a look at gdb(4) (new man page).
> 
> I'm glad to have this.  More machines have ethernet than firewire ports
> though.
> 
>> > We don't need file/line added to the panic message since panic
>> > messages are unambiguous.
>>
>> You still need to grep for them.
> 
> There are basically two kinds of panics:  assertions and page faults.
> Assertions, whether KASSERT or explicit checks/panic calls, give a unique,
> easily identified message ("foo driver: invalid mbuf length, %d").  If
> this is not obvious enough even without grep, then the panic message
> should be fixed.  There is no difference between "vi +line file.c" and
> "vi file.c /msg", hence phk's commit is not useful in this case.
> 
> Page faults are much harder to track down from the start.  You find
> whether or not it was a NULL pointer, the curproc, and PC.  So the next
> step is to have them recompile with options DDB or preferably -g and type
> "tr" at the DDB prompt.  The changes to panic do not help this case at all
> since you get the file and line of the page fault handler.

I'll put in a request for page faults to report the file and line number
where the trap occurred ;-)