210918 - Unaligned accesses in morkWriter::PutRowDict

Status: RESOLVED WORKSFORME

(SeaMonkey :: General, defect)

Description

[Jim Brown]

User-Agent:       Mozilla/5.0 (X11; U; OSF1 alpha; en-US; rv:1.5a) Gecko/20030627
Build Identifier: Mozilla/5.0 (X11; U; OSF1 alpha; en-US; rv:1.5a) Gecko/20030627

Many unaligned accesses since updating from 030625 trunk to 030627 trunk.

In morkWriter::PutRowDict, the pointer 'cells' in not well-aligned.
The 'cells' pointer increments by one on each loop iteration.
This is in mozilla/db/mork/src which makes libmork.so.

Loading pages like QA/CVS Checkins Today and QA/Tree Status
causes hundreds of 'unaligned access' messages to be displayed.

morkWriter.cpp:
>  1866       morkAtom* atom = cells->GetAtom();

(ladebug) p cells
0x1410610cc

(ladebug) where 5
>0  0x3000b863780 in ((morkWriter*)0x14112a800)->morkWriter::PutRowDict(ev=0x140
fd9140, ioRow=0x141061084) "morkWriter.cpp":1867
#1  0x3000b861900 in ((morkWriter*)0x14112a800)->morkWriter::WriteAllStoreTables
(ev=0x140fd9140) "morkWriter.cpp":1134
#2  0x3000b861aa8 in ((morkWriter*)0x14112a800)->morkWriter::OnStoreRowSpacesTab
les(ev=0x140fd9140) "morkWriter.cpp":1180
#3  0x3000b86007c in ((morkWriter*)0x14112a800)->morkWriter::WriteMore(ev=0x140f
d9140) "morkWriter.cpp":378
#4  0x3000b85e680 in ((morkThumb*)0x141148c40)->morkThumb::DoMore_Commit(ev=0x14
0fd9140) "morkThumb.cpp":515


Reproducible: Always

Steps to Reproduce:
1. start mozilla
2. select QA/CVS Checkins Today
3.

Comment 1

[Jim Brown]

Happens all over, here is another one.

>0  0x3000b868e4c in ((morkZone*)0x140fca990)->morkZone::ZoneNewRun(ev=0x140fd91
40, inSize=16) "morkZone.cpp":390
#1  0x3000b846fa8 in ((morkPool*)0x140fcb208)->morkPool::NewCells(ev=0x140fd9140
, inSize=1, ioZone=0x140fca990) "morkPool.cpp":276
#2  0x3000b8470c4 in ((morkPool*)0x140fcb208)->morkPool::AddRowCells(ev=0x140fd9
140, ioRow=0x141093710, inNewSize=1, ioZone=0x140fca990) "morkPool.cpp":322

>   390       *bucket = hit->RunNext();

(ladebug) p hit
0x141091ce4

Comment 2

[Jim Brown]

Unaligned accesses also happen at morkRow::AcquireRowObject
("morkNode.cpp":497), morkRowObject::CloseRowObject ("morkRowObject.cpp":607),
and morkNode::SlotWeakNode ("morkRow.cpp":267).

Comment 3

[Jim Brown]

Attachment: Full traceback for one unaligned access

nsParser::BuildModel() is involved (entry #88).

Comment 4

[Jim Brown]

After updating to 
Mozilla/5.0 (X11; U; OSF1 alpha; en-US; rv:1.5a) Gecko/20030628
I can no longer reproduce this behavior.