Date: Mon, 10 Jun 2013 21:20:36 -0700 From: Justin Hibbits <jhibbits@freebsd.org> To: Nathan Whitehorn <nwhitehorn@freebsd.org> Cc: FreeBSD PowerPC ML <freebsd-ppc@freebsd.org> Subject: Re: Strange panic on ppc64 Message-ID: <CAHSQbTCposTE1AwHS0Ov=FT4w8gNkgpE4x_7-cHhyzMDfZr5UA@mail.gmail.com> In-Reply-To: <51B5D539.8050102@freebsd.org> References: <CAHSQbTAZTc9puGaH0rbhyY11s0%2BL0xGjSabK1kj65UMm1t7j3w@mail.gmail.com> <51AF6661.3060007@freebsd.org> <CAHSQbTBjza0u7nZf4z%2BxpTCcWj-TW-ZigV2-CZexuBOYQX5=3A@mail.gmail.com> <CAHSQbTCvFXDZPsOnmogc0FkZeMXwOP6h40F2kFUu2s6UmffyPw@mail.gmail.com> <51B345BE.5030905@freebsd.org> <CAHSQbTDnwne3KJWN7xjcUw4PhF-uiD4B-4y1Lf90Bfou-2Ppvw@mail.gmail.com> <51B4A389.4020607@freebsd.org> <CAHSQbTACtejaRKiG4qScSV_EdTC8y_k5Qghx_FYebWzstBP61g@mail.gmail.com> <51B5D28C.505@freebsd.org> <51B5D539.8050102@freebsd.org>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jun 10, 2013 at 6:31 AM, Nathan Whitehorn <nwhitehorn@freebsd.org>wrote:
> On 06/10/13 08:20, Nathan Whitehorn wrote:
> > This is now getting interesting. Reading the tea leaves, what has
> > happened is that the kernel has called into Open Firmware. Open Firmware
> > has then crashed early on, before setting up its own trap handlers,
> > which has then flung you back into FreeBSD's handlers with a totally
> > bogus environment, causing a second panic, which then causes a *third*
> > panic when trying to acquire a lock. It would be interesting to know
> > what the OF environment looked like and what commands it was trying to
> > execute (in r3), but that may be tricky to get...
> > -Nathan
> > _______________________________________________
>
> One other point: you can trace this pretty easily by just putting
> something like:
>
> if (pmap_bootstrapped) printf("Open Firmware call %p\n", args);
>
> in the top of openfirmware(). If I understood the debugger output
> correctly, something should be making a firmware call immediately before
> the crash.
>
> As a random guess about what is happening, it is possible OF is trying
> to allocate memory for itself. We just ignore the possibility that it
> might want to do that at present, but that is not necessarily a good
> assumption.
> -Nathan
>
I added that, both on entry and exit. I also have it printing out the name
of the ofw call, since the first item is always a pointer to the name.
I'll be able to report more tomorrow.
- Justin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAHSQbTCposTE1AwHS0Ov=FT4w8gNkgpE4x_7-cHhyzMDfZr5UA>