Date: Mon, 21 Jan 2002 17:29:20 +0100 From: Bernd Walter <ticso@cicely8.cicely.de> To: Andrew Gallatin <gallatin@cs.duke.edu> Cc: freebsd-alpha@FreeBSD.ORG Subject: Re: 4.5-RC panic Message-ID: <20020121172920.U58301@cicely8.cicely.de> In-Reply-To: <15436.8686.765933.505738@grasshopper.cs.duke.edu> References: <20020121035556.D58301@cicely8.cicely.de> <15436.8686.765933.505738@grasshopper.cs.duke.edu>
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On Mon, Jan 21, 2002 at 09:13:02AM -0500, Andrew Gallatin wrote:
>
> Bernd Walter writes:
> > (kgdb) bt
> > #0 0xfffffc000037fdc0 in dumpsys () at ../../kern/kern_shutdown.c:472
> > #1 0xfffffc000037f988 in boot (howto=256) at ../../kern/kern_shutdown.c:313
> > #2 0xfffffc00003801d0 in panic (fmt=0xfffffc000051c3dc "trap") at ../../kern/kern_shutdown.c:581
> > #3 0xfffffc00004dba60 in trap (a0=4833124384, a1=4832532772, a2=0, entry=2, framep=0xfffffe00071d3a40)
> > at ../../alpha/alpha/trap.c:551
> > #4 0xfffffc00004cd97c in XentMM ()
> > #5 0xfffffc00004dbcc4 in syscall (code=344, framep=0xfffffe00071d3ee0) at ../../alpha/alpha/trap.c:655
> >
> > dmesg:
>
> <...>
>
> > fatal kernel trap:
> >
> > trap entry = 0x2 (memory management fault)
> > a0 = 0x12013a020
> > a1 = 0x1
> > a2 = 0x0
> > pc = 0xfffffc00004d035c
> > ra = 0xfffffc00004dbcc4
> > curproc = 0xfffffe0005c6efc0
> > pid = 268, comm = tcsh
>
> Truly bizzare. Its trap'ping on what looks like user-space address
> somewhere in the user proc's heap. a2 is 0, so its a load. What
> pointer had this value?
>
> The syscall in question (344) is sigreturn. I haven't been keeping up
> with committers in the last few months. Has anything changed lately
> wrt. signal delivery?
I did not follow the -stable commits regulary so I can't say.
The box has some memory load so I wouldn't be surprised if the complete
tcsh was swapped.
> Can you disassemble this and see if its faulting on the call or the return?
int
sigreturn(struct proc *p,
struct sigreturn_args /* {
ucontext_t *sigcntxp;
} */ *uap)
{
fffffc00004d0354: 09 04 f0 47 mov a0,s0
ucontext_t uc, *ucp;
struct pcb *pcb;
unsigned long val;
if (((struct osigcontext*)uap->sigcntxp)->sc_regs[R_ZERO] == 0xACEDBADE)
fffffc00004d0358: 00 00 31 a4 ldq t0,0(a1)
fffffc00004d035c: 18 01 41 a4 ldq t1,280(t0)
fffffc00004d0360: de ba 3f 20 lda t0,-17698(zero)
fffffc00004d0364: ee ac 21 24 ldah t0,-21266(t0)
fffffc00004d0368: 21 f6 21 48 zapnot t0,0xf,t0
fffffc00004d036c: a2 05 41 40 cmpeq t1,t0,t1
fffffc00004d0370: 03 00 40 e4 beq t1,fffffc00004d0380 <sigreturn+0x40>
return osigreturn(p, (struct osigreturn_args *)uap);
fffffc00004d0374: a4 ff 5f d3 bsr ra,fffffc00004d0208 <osigreturn+0x8>
fffffc00004d0378: 43 00 e0 c3 br fffffc00004d0488 <sigreturn+0x148>
fffffc00004d037c: 00 00 e0 2f unop
ucp = uap->sigcntxp;
pcb = &p->p_addr->u_pcb;
--
B.Walter COSMO-Project http://www.cosmo-project.de
ticso@cicely.de Usergroup info@cosmo-project.de
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