Raspberry Pi prefetch aborts

[George Mitchell]

Am I the only one seeing these?

Fatal kernel mode prefetch abort at 0x4278f502
trapframe: 0xdd2eafa0, spsr=200000f3
r0 =00000001, r1 =00000001, r2 =00000001, r3 =c058dbd0
r4 =c2400000, r5 =00000004, r6 =c05826a0, r7 =c2400308
r8 =c058d8c8, r9 =c25fd300, r10=c29aa9e4, r11=0004240c
r12=00000000, ssp=dd2eaff0, slr=c046079c, pc =4278f502

[ thread pid 27951 tid 100090 ]
Stopped at      0x4278f502:     address 0x4278f502 is invalid
*** error reading from address 4278f502 ***
db> t
Tracing pid 27951 tid 100090 td 0xc2799c80
db_trace_self() at db_trace_self
           pc = 0xc045d3b0  lr = 0xc012c5e8 (db_stack_trace+0xf4)
           sp = 0xdd2eacc8  fp = 0xdd2eace0
          r10 = 0xc0542420
db_stack_trace() at db_stack_trace+0xf4
           pc = 0xc012c5e8  lr = 0xc012bf54 (db_command+0x264)
           sp = 0xdd2eace8  fp = 0xdd2ead88
           r4 = 0x00000000  r5 = 0x00000000
           r6 = 0xc04b9e26
db_command() at db_command+0x264
           pc = 0xc012bf54  lr = 0xc012bcc4 (db_command_loop+0x60)
           sp = 0xdd2ead90  fp = 0xdd2eada0
           r4 = 0xc0493b6b  r5 = 0xc04ab7ec
           r6 = 0xc058bf7c  r7 = 0xdd2eafa0
           r8 = 0xdd2eafa0  r9 = 0xc0582b24
          r10 = 0xc0542690
db_command_loop() at db_command_loop+0x60
           pc = 0xc012bcc4  lr = 0xc012e6c4 (db_trap+0xdc)
           sp = 0xdd2eada8  fp = 0xdd2eaec8
           r4 = 0x00000000  r5 = 0xdd2eadb0
           r6 = 0xc0582b50
db_trap() at db_trap+0xdc
           pc = 0xc012e6c4  lr = 0xc0267be0 (kdb_trap+0xd4)
           sp = 0xdd2eaed0  fp = 0xdd2eaef0
           r4 = 0x00000000  r5 = 0x00000000
           r6 = 0xc0582b50  r7 = 0xdd2eafa0
kdb_trap() at kdb_trap+0xd4
           pc = 0xc0267be0  lr = 0xc046e824 (dab_fatal+0x174)
           sp = 0xdd2eaef8  fp = 0xdd2eaf10
           r4 = 0xdd2eafa0  r5 = 0x200001d3
           r6 = 0x4278f502  r7 = 0x00000000
           r8 = 0xdd2eafa0  r9 = 0xc25fd300
          r10 = 0xc2981960
dab_fatal() at dab_fatal+0x174
           pc = 0xc046e824  lr = 0xc046eb10 ($d)
           sp = 0xdd2eaf18  fp = 0xdd2eaf98
           r4 = 0xc2400000  r5 = 0xc2799c80
           r6 = 0xc05826a0  r7 = 0xc2400308
$d() at $d
           pc = 0xc046eb10  lr = 0xc045eb60 (exception_exit)
           sp = 0xdd2eafa0  fp = 0x0004240c
           r4 = 0xc2400000  r5 = 0x00000004
           r6 = 0xc05826a0  r7 = 0xc2400308
           r8 = 0xc058d8c8  r9 = 0xc25fd300
          r10 = 0xc29aa9e4
exception_exit() at exception_exit
           pc = 0xc045eb60  lr = 0xc046079c (spinlock_exit+0x18)
           sp = 0xdd2eaff8  fp = 0x0004240c
           r0 = 0x00000001  r1 = 0x00000001
           r2 = 0x00000001  r3 = 0xc058dbd0
           r4 = 0xc2400000  r5 = 0x00000004
           r6 = 0xc05826a0  r7 = 0xc2400308
           r8 = 0xc058d8c8  r9 = 0xc25fd300
          r10 = 0xc29aa9e4 r12 = 0x00000000
Unable to unwind into user mode
db>

The numbers vary, but the list of addresses is always the same.  I do a
portmaster run, and sometimes it goes all the way through, and sometimes
I get crashes every five minutes.  The crashes seem somewhat more likely
to happen during portmaster's dependency checking than at other times,
and they almost never happen while configuring, compiling, linking,
or installing is in progress.

SVN revision r256073M (RPI-B config file modified for serial console).

Suggestions, please?                                        -- George