This happens on a filesystem with a lot of files when a lot of files are 
overwritten. I'm not clear on exactly what causes this. Note the deep 
recursion of yaffs_GarbageCollectBlock. What might be the cause, and is there 
a way to fix this?

----8<-----------
Here is kernel backtrace (MIPS):

Kernel unaligned instruction access in unaligned.c::do_ade, line 574:
$0 : 00000000 1010a800 802f63c0 00000000 0000423f 81402078 0000003e 00000000
$8 : 802f0000 802f6860 802f0000 00000000 00000065 000000cb 8140220d 814021ed
$16: 80314a28 00000001 80314a28 00000800 ffffffff 814021f7 8035d000 802e92d0
$24: 00000002 801206d8                   81402000 81402100 803148a8 8026ce8d
Hi : 29022d9e
Lo : 385cc932
epc   : 8026ce8d    Tainted: P 
Status: 1010a802
Cause : 10800010
PrId  : 0001800a
Process  (pid: -2126503816, stackpage=81402000)
Stack:    0000000c 00003d9e 0000001a 0000056c 0000002e 0000005b 00000000
 1010a800 1010a801 80310000 803148a8 ffffffff 00000000 00000000 00000000
 0000000c fffffff3 00000000 00000065 000000cb 8140220d 814021ed 80314a28
 00000001 80314a28 00000800 ffffffff 814021f8 8035d000 802e92d0 00000002
 000000a5 00000000 802ad038 81402000 814021b0 803148a8 801e30cc 1010a803
 4bee4000 ...
Call Trace:   [<801e30cc>] [<801e9774>] [<801e4ce8>] [<8019506c>] [<8018b1c8>]
 [<8018b610>] [<8018c4fc>] [<80189714>] [<801896c0>] [<8018df84>] [<8018b49c>]
 [<8018b610>] [<8018c4fc>] [<80189714>] [<801896c0>] [<8018df84>] [<8018b49c>]
 [<8018b610>] [<8018c4fc>] [<80189714>] [<801896c0>] [<8018df84>] [<8018b49c>]
 [<8018b610>] [<8018c4fc>] [<80189714>] [<801896c0>] [<8018df84>] [<8018b49c>]
 [<8018b610>] [<8018c4fc>]

Code:<4>unaligned data access at 0x80108ad0
 7c000000 <4>unaligned data access at 0x80108ad0
 070c0430 <4>unaligned data access at 0x80108ad0
 e0240400 <4>unaligned data access at 0x80108ad0
<0008041d><4>unaligned data access at 0x80108ad0
 2a000000 <4>unaligned data access at 0x80108ad0
 210c09b3 <4>unaligned data access at 0x80108ad0
 e0010020 <4>unaligned data access at 0x80108ad0
 0008041d <4>unaligned data access at 0x80108ad0
 00000000 

----8<-----------
And here is debug info from gdb:

0x8018b1c8 is in yaffs_GarbageCollectBlock (yaffs_guts.c:111).
0x8018b610 is in yaffs_CheckGarbageCollection (yaffs_guts.c:2360).
0x8018c4fc is in yaffs_UpdateObjectHeader (yaffs_guts.c:2820).
0x80189714 is in yaffs_ChangeObjectName (yaffs_guts.c:1741).
0x801896c0 is in yaffs_ChangeObjectName (yaffs_guts.c:1734).
0x8018df84 is in yaffs_DoGenericObjectDeletion (yaffs_guts.c:3705).
0x8018b49c is in yaffs_GarbageCollectBlock (yaffs_guts.c:2290).